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Sample records for reliability intra-class correlation

  1. Estimating a graphical intra-class correlation coefficient (GICC) using multivariate probit-linear mixed models.

    Science.gov (United States)

    Yue, Chen; Chen, Shaojie; Sair, Haris I; Airan, Raag; Caffo, Brian S

    2015-09-01

    Data reproducibility is a critical issue in all scientific experiments. In this manuscript, the problem of quantifying the reproducibility of graphical measurements is considered. The image intra-class correlation coefficient (I2C2) is generalized and the graphical intra-class correlation coefficient (GICC) is proposed for such purpose. The concept for GICC is based on multivariate probit-linear mixed effect models. A Markov Chain Monte Carlo EM (mcm-cEM) algorithm is used for estimating the GICC. Simulation results with varied settings are demonstrated and our method is applied to the KIRBY21 test-retest dataset.

  2. Intra-class correlation estimates for assessment of vitamin A intake in children.

    Science.gov (United States)

    Agarwal, Girdhar G; Awasthi, Shally; Walter, Stephen D

    2005-03-01

    In many community-based surveys, multi-level sampling is inherent in the design. In the design of these studies, especially to calculate the appropriate sample size, investigators need good estimates of intra-class correlation coefficient (ICC), along with the cluster size, to adjust for variation inflation due to clustering at each level. The present study used data on the assessment of clinical vitamin A deficiency and intake of vitamin A-rich food in children in a district in India. For the survey, 16 households were sampled from 200 villages nested within eight randomly-selected blocks of the district. ICCs and components of variances were estimated from a three-level hierarchical random effects analysis of variance model. Estimates of ICCs and variance components were obtained at village and block levels. Between-cluster variation was evident at each level of clustering. In these estimates, ICCs were inversely related to cluster size, but the design effect could be substantial for large clusters. At the block level, most ICC estimates were below 0.07. At the village level, many ICC estimates ranged from 0.014 to 0.45. These estimates may provide useful information for the design of epidemiological studies in which the sampled (or allocated) units range in size from households to large administrative zones.

  3. The coefficient of determination R2 and intra-class correlation coefficient from generalized linear mixed-effects models revisited and expanded.

    Science.gov (United States)

    Nakagawa, Shinichi; Johnson, Paul C D; Schielzeth, Holger

    2017-09-01

    The coefficient of determination R 2 quantifies the proportion of variance explained by a statistical model and is an important summary statistic of biological interest. However, estimating R 2 for generalized linear mixed models (GLMMs) remains challenging. We have previously introduced a version of R 2 that we called [Formula: see text] for Poisson and binomial GLMMs, but not for other distributional families. Similarly, we earlier discussed how to estimate intra-class correlation coefficients (ICCs) using Poisson and binomial GLMMs. In this paper, we generalize our methods to all other non-Gaussian distributions, in particular to negative binomial and gamma distributions that are commonly used for modelling biological data. While expanding our approach, we highlight two useful concepts for biologists, Jensen's inequality and the delta method, both of which help us in understanding the properties of GLMMs. Jensen's inequality has important implications for biologically meaningful interpretation of GLMMs, whereas the delta method allows a general derivation of variance associated with non-Gaussian distributions. We also discuss some special considerations for binomial GLMMs with binary or proportion data. We illustrate the implementation of our extension by worked examples from the field of ecology and evolution in the R environment. However, our method can be used across disciplines and regardless of statistical environments. © 2017 The Author(s).

  4. Context-sensitive intra-class clustering

    KAUST Repository

    Yu, Yingwei; Gutierrez-Osuna, Ricardo; Choe, Yoonsuck

    2014-01-01

    This paper describes a new semi-supervised learning algorithm for intra-class clustering (ICC). ICC partitions each class into sub-classes in order to minimize overlap across clusters from different classes. This is achieved by allowing partitioning

  5. Understanding Intra-Class Knowledge Inside CNN

    OpenAIRE

    Wei, Donglai; Zhou, Bolei; Torrabla, Antonio; Freeman, William

    2015-01-01

    Convolutional Neural Network (CNN) has been successful in image recognition tasks, and recent works shed lights on how CNN separates different classes with the learned inter-class knowledge through visualization. In this work, we instead visualize the intra-class knowledge inside CNN to better understand how an object class is represented in the fully-connected layers. To invert the intra-class knowledge into more interpretable images, we propose a non-parametric patch prior upon previous CNN...

  6. Context-sensitive intra-class clustering

    KAUST Repository

    Yu, Yingwei

    2014-02-01

    This paper describes a new semi-supervised learning algorithm for intra-class clustering (ICC). ICC partitions each class into sub-classes in order to minimize overlap across clusters from different classes. This is achieved by allowing partitioning of a certain class to be assisted by data points from other classes in a context-dependent fashion. The result is that overlap across sub-classes (both within- and across class) is greatly reduced. ICC is particularly useful when combined with algorithms that assume that each class has a unimodal Gaussian distribution (e.g., Linear Discriminant Analysis (LDA), quadratic classifiers), an assumption that is not always true in many real-world situations. ICC can help partition non-Gaussian, multimodal distributions to overcome such a problem. In this sense, ICC works as a preprocessor. Experiments with our ICC algorithm on synthetic data sets and real-world data sets indicated that it can significantly improve the performance of LDA and quadratic classifiers. We expect our approach to be applicable to a broader class of pattern recognition problems where class-conditional densities are significantly non-Gaussian or multi-modal. © 2013 Elsevier Ltd. All rights reserved.

  7. Reliable computation from contextual correlations

    Science.gov (United States)

    Oestereich, André L.; Galvão, Ernesto F.

    2017-12-01

    An operational approach to the study of computation based on correlations considers black boxes with one-bit inputs and outputs, controlled by a limited classical computer capable only of performing sums modulo-two. In this setting, it was shown that noncontextual correlations do not provide any extra computational power, while contextual correlations were found to be necessary for the deterministic evaluation of nonlinear Boolean functions. Here we investigate the requirements for reliable computation in this setting; that is, the evaluation of any Boolean function with success probability bounded away from 1 /2 . We show that bipartite CHSH quantum correlations suffice for reliable computation. We also prove that an arbitrarily small violation of a multipartite Greenberger-Horne-Zeilinger noncontextuality inequality also suffices for reliable computation.

  8. Performance of intraclass correlation coefficient (ICC) as a reliability index under various distributions in scale reliability studies.

    Science.gov (United States)

    Mehta, Shraddha; Bastero-Caballero, Rowena F; Sun, Yijun; Zhu, Ray; Murphy, Diane K; Hardas, Bhushan; Koch, Gary

    2018-04-29

    Many published scale validation studies determine inter-rater reliability using the intra-class correlation coefficient (ICC). However, the use of this statistic must consider its advantages, limitations, and applicability. This paper evaluates how interaction of subject distribution, sample size, and levels of rater disagreement affects ICC and provides an approach for obtaining relevant ICC estimates under suboptimal conditions. Simulation results suggest that for a fixed number of subjects, ICC from the convex distribution is smaller than ICC for the uniform distribution, which in turn is smaller than ICC for the concave distribution. The variance component estimates also show that the dissimilarity of ICC among distributions is attributed to the study design (ie, distribution of subjects) component of subject variability and not the scale quality component of rater error variability. The dependency of ICC on the distribution of subjects makes it difficult to compare results across reliability studies. Hence, it is proposed that reliability studies should be designed using a uniform distribution of subjects because of the standardization it provides for representing objective disagreement. In the absence of uniform distribution, a sampling method is proposed to reduce the non-uniformity. In addition, as expected, high levels of disagreement result in low ICC, and when the type of distribution is fixed, any increase in the number of subjects beyond a moderately large specification such as n = 80 does not have a major impact on ICC. Copyright © 2018 John Wiley & Sons, Ltd.

  9. System Reliability Analysis Considering Correlation of Performances

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Saekyeol; Lee, Tae Hee [Hanyang Univ., Seoul (Korea, Republic of); Lim, Woochul [Mando Corporation, Seongnam (Korea, Republic of)

    2017-04-15

    Reliability analysis of a mechanical system has been developed in order to consider the uncertainties in the product design that may occur from the tolerance of design variables, uncertainties of noise, environmental factors, and material properties. In most of the previous studies, the reliability was calculated independently for each performance of the system. However, the conventional methods cannot consider the correlation between the performances of the system that may lead to a difference between the reliability of the entire system and the reliability of the individual performance. In this paper, the joint probability density function (PDF) of the performances is modeled using a copula which takes into account the correlation between performances of the system. The system reliability is proposed as the integral of joint PDF of performances and is compared with the individual reliability of each performance by mathematical examples and two-bar truss example.

  10. System Reliability Analysis Considering Correlation of Performances

    International Nuclear Information System (INIS)

    Kim, Saekyeol; Lee, Tae Hee; Lim, Woochul

    2017-01-01

    Reliability analysis of a mechanical system has been developed in order to consider the uncertainties in the product design that may occur from the tolerance of design variables, uncertainties of noise, environmental factors, and material properties. In most of the previous studies, the reliability was calculated independently for each performance of the system. However, the conventional methods cannot consider the correlation between the performances of the system that may lead to a difference between the reliability of the entire system and the reliability of the individual performance. In this paper, the joint probability density function (PDF) of the performances is modeled using a copula which takes into account the correlation between performances of the system. The system reliability is proposed as the integral of joint PDF of performances and is compared with the individual reliability of each performance by mathematical examples and two-bar truss example.

  11. Pitfalls and important issues in testing reliability using intraclass correlation coefficients in orthopaedic research.

    Science.gov (United States)

    Lee, Kyoung Min; Lee, Jaebong; Chung, Chin Youb; Ahn, Soyeon; Sung, Ki Hyuk; Kim, Tae Won; Lee, Hui Jong; Park, Moon Seok

    2012-06-01

    Intra-class correlation coefficients (ICCs) provide a statistical means of testing the reliability. However, their interpretation is not well documented in the orthopedic field. The purpose of this study was to investigate the use of ICCs in the orthopedic literature and to demonstrate pitfalls regarding their use. First, orthopedic articles that used ICCs were retrieved from the Pubmed database, and journal demography, ICC models and concurrent statistics used were evaluated. Second, reliability test was performed on three common physical examinations in cerebral palsy, namely, the Thomas test, the Staheli test, and popliteal angle measurement. Thirty patients were assessed by three orthopedic surgeons to explore the statistical methods testing reliability. Third, the factors affecting the ICC values were examined by simulating the data sets based on the physical examination data where the ranges, slopes, and interobserver variability were modified. Of the 92 orthopedic articles identified, 58 articles (63%) did not clarify the ICC model used, and only 5 articles (5%) described all models, types, and measures. In reliability testing, although the popliteal angle showed a larger mean absolute difference than the Thomas test and the Staheli test, the ICC of popliteal angle was higher, which was believed to be contrary to the context of measurement. In addition, the ICC values were affected by the model, type, and measures used. In simulated data sets, the ICC showed higher values when the range of data sets were larger, the slopes of the data sets were parallel, and the interobserver variability was smaller. Care should be taken when interpreting the absolute ICC values, i.e., a higher ICC does not necessarily mean less variability because the ICC values can also be affected by various factors. The authors recommend that researchers clarify ICC models used and ICC values are interpreted in the context of measurement.

  12. Reliability of Structural Systems with Correlated Elements

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Sørensen, John Dalsgaard

    1982-01-01

    Calculation of the probability of failure of a system with correlation members is usually a difficult and time-consuming numerical problem. However, for some types of systems with equally correlated elements this calculation can be performed in a simple way. This has suggested two new methods bas...... on so-called average and equivalent correlation coefficients. By using these methods approximate values for the probability of failure can easily be calculated. The accuracy of these methods is illustrated with examples....

  13. Reliability of the Wii Balance Board in kayak.

    Science.gov (United States)

    Vando, Stefano; Laffaye, Guillaume; Masala, Daniele; Falese, Lavinia; Padulo, Johnny

    2015-01-01

    the seat of the kayaker represent the principal contact point to express mechanical Energy. therefore we investigated the reliability of the Wii Balance Board measures in the kayak vs. on the ground. Bland-Altman test showed a low systematic bias on the ground (2.85%) and in kayak (-2.13%) respectively; while 0.996 for Intra-class correlation coefficient. the Wii Balance Board is useful to assess postural sway in kayak.

  14. Reliability of one-repetition maximum performance in people with chronic heart failure.

    Science.gov (United States)

    Ellis, Rachel; Holland, Anne E; Dodd, Karen; Shields, Nora

    2018-02-24

    Evaluate intra-rater and inter-rater reliability of the one-repetition maximum strength test in people with chronic heart failure. Intra-rater and inter-rater reliability study. A public tertiary hospital in northern metropolitan Melbourne. Twenty-four participants (nine female, mean age 71.8 ± 13.1 years) with mild to moderate heart failure of any aetiology. Lower limb strength was assessed by determining the maximum weight that could be lifted using a leg press. Intra-rater reliability was tested by one assessor on two separate occasions . Inter-rater reliability was tested by two assessors in random order. Intra-class correlation coefficients and 95% confidence intervals were calculated. Bland and Altman analyses were also conducted, including calculation of mean differences between measures ([Formula: see text]) and limits of agreement . Ten intra-rater and 21 inter-rater assessments were completed. Excellent intra-rater (intra-class correlation coefficient 2,1 0.96) and inter-rater (intra-class correlation coefficient 2,1 0.93) reliability was found. Intra-rater assessment showed less variability (mean difference 4.5 kg, limits of agreement -8.11 to 17.11 kg) than inter-rater agreement (mean difference -3.81 kg, limits of agreement -23.39 to 15.77 kg). One-repetition maximum determined using a leg press is a reliable measure in people with heart failure. Given its smaller limits of agreement, intra-rater testing is recommended. Implications for Rehabilitation Using a leg press to determine a one-repetition maximum we were able to demonstrate excellent inter-rater and intra-rater reliability using an intra-class correlation coefficient. The Bland and Altman levels of agreement were wide for inter-rater reliability and so we recommend using one assessor if measuring change in strength within an individual over time.

  15. Reliability-guided digital image correlation for image deformation measurement

    International Nuclear Information System (INIS)

    Pan Bing

    2009-01-01

    A universally applicable reliability-guided digital image correlation (DIC) method is proposed for reliable image deformation measurement. The zero-mean normalized cross correlation (ZNCC) coefficient is used to identify the reliability of the point computed. The correlation calculation begins with a seed point and is then guided by the ZNCC coefficient. That means the neighbors of the point with the highest ZNCC coefficient in a queue for computed points will be processed first. Thus the calculation path is always along the most reliable direction, and possible error propagation of the conventional DIC method can be avoided. The proposed novel DIC method is universally applicable to the images with shadows, discontinuous areas, and deformation discontinuity. Two image pairs were used to evaluate the performance of the proposed technique, and the successful results clearly demonstrate its robustness and effectiveness

  16. How to assess and compare inter-rater reliability, agreement and correlation of ratings: an exemplary analysis of mother-father and parent-teacher expressive vocabulary rating pairs

    Science.gov (United States)

    Stolarova, Margarita; Wolf, Corinna; Rinker, Tanja; Brielmann, Aenne

    2014-01-01

    This report has two main purposes. First, we combine well-known analytical approaches to conduct a comprehensive assessment of agreement and correlation of rating-pairs and to dis-entangle these often confused concepts, providing a best-practice example on concrete data and a tutorial for future reference. Second, we explore whether a screening questionnaire developed for use with parents can be reliably employed with daycare teachers when assessing early expressive vocabulary. A total of 53 vocabulary rating pairs (34 parent–teacher and 19 mother–father pairs) collected for two-year-old children (12 bilingual) are evaluated. First, inter-rater reliability both within and across subgroups is assessed using the intra-class correlation coefficient (ICC). Next, based on this analysis of reliability and on the test-retest reliability of the employed tool, inter-rater agreement is analyzed, magnitude and direction of rating differences are considered. Finally, Pearson correlation coefficients of standardized vocabulary scores are calculated and compared across subgroups. The results underline the necessity to distinguish between reliability measures, agreement and correlation. They also demonstrate the impact of the employed reliability on agreement evaluations. This study provides evidence that parent–teacher ratings of children's early vocabulary can achieve agreement and correlation comparable to those of mother–father ratings on the assessed vocabulary scale. Bilingualism of the evaluated child decreased the likelihood of raters' agreement. We conclude that future reports of agreement, correlation and reliability of ratings will benefit from better definition of terms and stricter methodological approaches. The methodological tutorial provided here holds the potential to increase comparability across empirical reports and can help improve research practices and knowledge transfer to educational and therapeutic settings. PMID:24994985

  17. How to assess and compare inter-rater reliability, agreement and correlation of ratings: an exemplary analysis of mother-father and parent-teacher expressive vocabulary rating pairs

    Directory of Open Access Journals (Sweden)

    Margarita eStolarova

    2014-06-01

    Full Text Available This report has two main purposes. First, we combine well-known analytical approaches to conduct a comprehensive assessment of agreement and correlation of rating-pairs and to dis-entangle these often confused concepts, providing a best-practice example on concrete data and a tutorial for future reference. Second, we explore whether a screening questionnaire deve-loped for use with parents can be reliably employed with daycare teachers when assessing early expressive vocabulary. A total of 53 vocabulary rating pairs (34 parent-teacher and 19 mother-father pairs collected for two-year-old children (12 bilingual are evaluated. First, inter-rater reliability both within and across subgroups is assessed using the intra-class correlation coefficient (ICC. Next, based on this analysis of reliability and on the test-retest reliability of the employed tool, inter-rater agreement is analyzed, magnitude and direction of rating differences are considered. Finally, Pearson correlation coefficients of standardized vocabulary scores are calculated and compared across subgroups. The results underline the necessity to distinguish between reliability measures, agreement and correlation. They also demonstrate the impact of the employed reliability on agreement evaluations. This study provides evidence that parent-teacher ratings of children’s early vocabulary can achieve agreement and correlation comparable to those of mother-father ratings on the assessed vocabulary scale. Bilingualism of the evaluated child decreased the likelihood of raters’ agreement. We conclude that future reports of agree-ment, correlation and reliability of ratings will benefit from better definition of terms and stricter methodological approaches. The methodological tutorial provided here holds the potential to increase comparability across empirical reports and can help improve research practices and knowledge transfer to educational and therapeutic settings.

  18. How to assess and compare inter-rater reliability, agreement and correlation of ratings: an exemplary analysis of mother-father and parent-teacher expressive vocabulary rating pairs.

    Science.gov (United States)

    Stolarova, Margarita; Wolf, Corinna; Rinker, Tanja; Brielmann, Aenne

    2014-01-01

    This report has two main purposes. First, we combine well-known analytical approaches to conduct a comprehensive assessment of agreement and correlation of rating-pairs and to dis-entangle these often confused concepts, providing a best-practice example on concrete data and a tutorial for future reference. Second, we explore whether a screening questionnaire developed for use with parents can be reliably employed with daycare teachers when assessing early expressive vocabulary. A total of 53 vocabulary rating pairs (34 parent-teacher and 19 mother-father pairs) collected for two-year-old children (12 bilingual) are evaluated. First, inter-rater reliability both within and across subgroups is assessed using the intra-class correlation coefficient (ICC). Next, based on this analysis of reliability and on the test-retest reliability of the employed tool, inter-rater agreement is analyzed, magnitude and direction of rating differences are considered. Finally, Pearson correlation coefficients of standardized vocabulary scores are calculated and compared across subgroups. The results underline the necessity to distinguish between reliability measures, agreement and correlation. They also demonstrate the impact of the employed reliability on agreement evaluations. This study provides evidence that parent-teacher ratings of children's early vocabulary can achieve agreement and correlation comparable to those of mother-father ratings on the assessed vocabulary scale. Bilingualism of the evaluated child decreased the likelihood of raters' agreement. We conclude that future reports of agreement, correlation and reliability of ratings will benefit from better definition of terms and stricter methodological approaches. The methodological tutorial provided here holds the potential to increase comparability across empirical reports and can help improve research practices and knowledge transfer to educational and therapeutic settings.

  19. Face validity and reliability of a pictorial instrument for assessing fundamental movement skill perceived competence in young children.

    Science.gov (United States)

    Barnett, Lisa M; Ridgers, Nicola D; Zask, Avigdor; Salmon, Jo

    2015-01-01

    To determine reliability and face validity of an instrument to assess young children's perceived fundamental movement skill competence. Validation and reliability study. A pictorial instrument based on the Test Gross Motor Development-2 assessed perceived locomotor (six skills) and object control (six skills) competence using the format and item structure from the physical competence subscale of the Pictorial Scale of Perceived Competence and Acceptance for Young Children. Sample 1 completed object control items in May (n=32) and locomotor items in October 2012 (n=23) at two time points seven days apart. Children were asked at the end of the test-retest their understanding of what was happening in each picture to determine face validity. Sample 2 (n=58) completed 12 items in November 2012 on a single occasion to test internal reliability only. Sample 1 children were aged 5-7 years (M=6.0, SD=0.8) at object control assessment and 5-8 years at locomotor assessment (M=6.5, SD=0.9). Sample 2 children were aged 6-8 years (M=7.2, SD=0.73). Intra-class correlations assessed in Sample 1 children were excellent for object control (intra-class correlation=0.78), locomotor (intra-class correlation=0.82) and all 12 skills (intra-class correlations=0.83). Face validity was acceptable. Internal consistency was adequate in both samples for each subscale and all 12 skills (alpha range 0.60-0.81). This study has provided preliminary evidence for instrument reliability and face validity. This enables future alignment between the measurement of perceived and actual fundamental movement skill competence in young children. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  20. Foundations for a time reliability correlation system to quantify human reliability

    International Nuclear Information System (INIS)

    Dougherty, E.M. Jr.; Fragola, J.R.

    1988-01-01

    Time reliability correlations (TRCs) have been used in human reliability analysis (HRA) in conjunction with probabilistic risk assessment (PRA) to quantify post-initiator human failure events. The first TRCs were judgmental but recent data taken from simulators have provided evidence for development of a system of TRCs. This system has the equational form: t = tau R X tau U , where the first factor is the lognormally distributed random variable of successful response time, derived from the simulator data, and the second factor is a unitary lognormal random variable to account for uncertainty in the model. The first random variable is further factored into a median response time and a factor to account for the dominant type of behavior assumed to be involved in the response and a second factor to account for other influences on the reliability of the response

  1. Development and reliability testing of a food store observation form.

    Science.gov (United States)

    Rimkus, Leah; Powell, Lisa M; Zenk, Shannon N; Han, Euna; Ohri-Vachaspati, Punam; Pugach, Oksana; Barker, Dianne C; Resnick, Elissa A; Quinn, Christopher M; Myllyluoma, Jaana; Chaloupka, Frank J

    2013-01-01

    To develop a reliable food store observational data collection instrument to be used for measuring product availability, pricing, and promotion. Observational data collection. A total of 120 food stores (26 supermarkets, 34 grocery stores, 54 gas/convenience stores, and 6 mass merchandise stores) in the Chicago metropolitan statistical area. Inter-rater reliability for product availability, pricing, and promotion measures on a food store observational data collection instrument. Cohen's kappa coefficient and proportion of overall agreement for dichotomous variables and intra-class correlation coefficient for continuous variables. Inter-rater reliability, as measured by average kappa coefficient, was 0.84 for food and beverage product availability measures, 0.80 for interior store characteristics, and 0.70 for exterior store characteristics. For continuous measures, average intra-class correlation coefficient was 0.82 for product pricing measures; 0.90 for counts of fresh, frozen, and canned fruit and vegetable options; and 0.85 for counts of advertisements on the store exterior and property. The vast majority of measures demonstrated substantial or almost perfect agreement. Although some items may require revision, results suggest that the instrument may be used to reliably measure the food store environment. Copyright © 2013 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  2. [The reliability of a questionnaire regarding Colombian children's physical activity].

    Science.gov (United States)

    Herazo-Beltrán, Aliz Y; Domínguez-Anaya, Regina

    2012-10-01

    Reporting the Physical Activity Questionnaire for school children's (PAQ-C) test-retest reliability and internal consistency. This was a descriptive study of 100 school-aged children aged 9 to 11 years old attending a school in Cartagena, Colombia. The sample was randomly selected. The PAQ-C was given twice, one week apart, after the informed consent forms had been signing by the children's parents and school officials. Cronbach's alpha coefficient of reliability was used for assessing internal consistency and an intra-class correlation coefficient for test-retest reliability SPSS (version 17.0) was used for statistical analysis. The questionnaire scored 0.73 internal consistencies during the first measurement and 0.78 on the second; intra-class correlation coefficient was 0.60. There were differences between boys and girls regarding both measurements. The PAQ-C had acceptable internal consistency and test-retest reliability, thereby making it useful for measuring children's self-reported physical activity and a valuable tool for population studies in Colombia.

  3. Intra-rater reliability of cervical sensory motor function and cervical reconstruction test in healthy subjects

    Directory of Open Access Journals (Sweden)

    Hatamvand S

    2016-07-01

    Full Text Available Impairment of cervicocephalic and head joint position sense has an important role in the recurrent and chronic of cervicocephalic pain. The various tools are suggested for evaluating the cervicocephalic joint position sense. Although reconstruction of cervical angle is a clinical criterion for measuring the cervicocephalic proprioception, the reliability of this method has not been completely accepted. The purpose of this study was to evaluate intra-rater reliability of cervical sensory motor function and cervical reconstruction test in healthy subjects. twenty four healthy subjects (25.70±6.08 y through simple non-probability sampling participated in this single-group repeatedmeasures reliability study. Participants were asked to relocate the neck, as accurately as possible, after full active cervical flexion, extension and rotation to the left and right sides. Five trials were performed for each movement. Laser pointer was used in head of patient. The distance between zero spot and joint position which patient had been reconstructed, was measured by centimeter. Intra-class correlation Coefficient (ICCs and Pearson's correlation coefficient test was used to determine intra-rater reliability of variables. The results showed that intra-class correlation Coefficient (ICCs values with 95% confidence interval (CI and the standard error of the measurement (SEM were good to excellent agreement for a single investigator between measurement occasions. Intra-class correlation Coefficient (ICCs values were obtained for flexion movement (ICCs:0.75, good, extension movement (ICCs:0.81, very good, right rotation (ICCs:0.64, good and left rotation (ICCs:0.64, good. The cervicocephalic relocation test to neutral head position by laser pointer is a reliable method to measure cervical sensory motor function. Therefore, it can be used for evaluating cervicocephalic proprioception of patient with cervicocephalic pain.

  4. A Systematic Review of Statistical Methods Used to Test for Reliability of Medical Instruments Measuring Continuous Variables

    Directory of Open Access Journals (Sweden)

    Rafdzah Zaki

    2013-06-01

    Full Text Available   Objective(s: Reliability measures precision or the extent to which test results can be replicated. This is the first ever systematic review to identify statistical methods used to measure reliability of equipment measuring continuous variables. This studyalso aims to highlight the inappropriate statistical method used in the reliability analysis and its implication in the medical practice.   Materials and Methods: In 2010, five electronic databases were searched between 2007 and 2009 to look for reliability studies. A total of 5,795 titles were initially identified. Only 282 titles were potentially related, and finally 42 fitted the inclusion criteria. Results: The Intra-class Correlation Coefficient (ICC is the most popular method with 25 (60% studies having used this method followed by the comparing means (8 or 19%. Out of 25 studies using the ICC, only 7 (28% reported the confidence intervals and types of ICC used. Most studies (71% also tested the agreement of instruments. Conclusion: This study finds that the Intra-class Correlation Coefficient is the most popular method used to assess the reliability of medical instruments measuring continuous outcomes. There are also inappropriate applications and interpretations of statistical methods in some studies. It is important for medical researchers to be aware of this issue, and be able to correctly perform analysis in reliability studies.

  5. Reliable Recognition of Partially Occluded Objects with Correlation Filters

    Directory of Open Access Journals (Sweden)

    Alexey Ruchay

    2018-01-01

    Full Text Available Design of conventional correlation filters requires explicit knowledge of the appearance and shape of a target object, so the performance of correlation filters is significantly affected by changes in the appearance of the object in the input scene. In particular, the performance of correlation filters worsens when objects to be recognized are partially occluded by other objects, and the input scene contains a cluttered background and noise. In this paper, we propose a new algorithm for the design of a system consisting of a set of adaptive correlation filters for recognition of partially occluded objects in noisy scenes. Since the input scene may contain different fragments of the target, false objects, and background to be rejected, the system is designed in such a manner to guarantee equally high correlation peaks corresponding to parts of the target in the scenes. The key points of the system are as follows: (i it consists of a bank of composite optimum filters, which yield the best performance for different parts of the target; (ii it includes a fragmentation of the target into a given number of parts in the training stage to provide equal intensity responses of the system for each part of the target. With the help of computer simulation, the performance of the proposed algorithm for recognition partially occluded objects is compared with that of common algorithms in terms of objective metrics.

  6. Test-retest reliability of the Progressive Isoinertial Lifting Evaluation (PILE).

    Science.gov (United States)

    Lygren, Hildegunn; Dragesund, Tove; Joensen, Jón; Ask, Tove; Moe-Nilssen, Rolf

    2005-05-01

    A repeated measures single group design. To investigate test-retest reliability of Progressive Isoinertial Lifting Evaluation on patients with long lasting musculoskeletal problems related to the lumbar spine. Test-retest reliability has been satisfactory in healthy men. Test-retest reliability for clinical populations has not been reported. A total of 31 patients (17 women and 14 men) with long lasting low back pain participated in the study. The patients were tested twice at an interval of 2 days and at the same time of the day. The heaviest load that the patient could lift 4 times was used as outcome measure. The error of measurement indicates that the true result in 95% of cases will be within +/-4.5 kg from the measured value, while the difference between 2 measurements in 95% of cases will be less than 6.4 kg. Intra-class correlation (1,1) was 0.91. Relative test-retest reliability was high assessed by intra-class correlation, but absolute measurement variability reported as the smallest detectable difference has relevance for the interpretation of clinical test results and should also be considered.

  7. Reliability measures in item response theory: manifest versus latent correlation functions.

    Science.gov (United States)

    Milanzi, Elasma; Molenberghs, Geert; Alonso, Ariel; Verbeke, Geert; De Boeck, Paul

    2015-02-01

    For item response theory (IRT) models, which belong to the class of generalized linear or non-linear mixed models, reliability at the scale of observed scores (i.e., manifest correlation) is more difficult to calculate than latent correlation based reliability, but usually of greater scientific interest. This is not least because it cannot be calculated explicitly when the logit link is used in conjunction with normal random effects. As such, approximations such as Fisher's information coefficient, Cronbach's α, or the latent correlation are calculated, allegedly because it is easy to do so. Cronbach's α has well-known and serious drawbacks, Fisher's information is not meaningful under certain circumstances, and there is an important but often overlooked difference between latent and manifest correlations. Here, manifest correlation refers to correlation between observed scores, while latent correlation refers to correlation between scores at the latent (e.g., logit or probit) scale. Thus, using one in place of the other can lead to erroneous conclusions. Taylor series based reliability measures, which are based on manifest correlation functions, are derived and a careful comparison of reliability measures based on latent correlations, Fisher's information, and exact reliability is carried out. The latent correlations are virtually always considerably higher than their manifest counterparts, Fisher's information measure shows no coherent behaviour (it is even negative in some cases), while the newly introduced Taylor series based approximations reflect the exact reliability very closely. Comparisons among the various types of correlations, for various IRT models, are made using algebraic expressions, Monte Carlo simulations, and data analysis. Given the light computational burden and the performance of Taylor series based reliability measures, their use is recommended. © 2014 The British Psychological Society.

  8. Intra-observer and interobserver reliability ofOne Leg Stand Test as a measure of posturalbalance in low back pain patients

    DEFF Research Database (Denmark)

    Maribo, Thomas; Iversen, Elena; Andersen, Niels Trolle

    2009-01-01

    Objective: To determine the absolute and relative reliability of intra-observer and interobserver To determine the absolute and relative reliability of intra-observer and interobserver measurements of postural balance using the One Leg Stand Test in patients with low back pain. Patients and methods...... to stand for the maximum time, and no further analysis was done. Eyes closed: intra-observer reliability was tested in 21 patients; absolute reliability showed a standard error of the measurement (SEM) of 2.48 s and a minimal detectable change (MDC) of 6.88. The relative reliability was acceptable...... with an intra class correlation coefficient (ICC) of 0.86. Interobserver reliability was tested in 27 patients; absolute reliability showed a SEM of 1.42 s and a MDC of 3.95. The relative reliability was acceptable with an ICC of 0.91. Conclusions: The One Leg Stand Test can be used to test postural balance...

  9. Learning Low-Rank Class-Specific Dictionary and Sparse Intra-Class Variant Dictionary for Face Recognition.

    Science.gov (United States)

    Tang, Xin; Feng, Guo-Can; Li, Xiao-Xin; Cai, Jia-Xin

    2015-01-01

    Face recognition is challenging especially when the images from different persons are similar to each other due to variations in illumination, expression, and occlusion. If we have sufficient training images of each person which can span the facial variations of that person under testing conditions, sparse representation based classification (SRC) achieves very promising results. However, in many applications, face recognition often encounters the small sample size problem arising from the small number of available training images for each person. In this paper, we present a novel face recognition framework by utilizing low-rank and sparse error matrix decomposition, and sparse coding techniques (LRSE+SC). Firstly, the low-rank matrix recovery technique is applied to decompose the face images per class into a low-rank matrix and a sparse error matrix. The low-rank matrix of each individual is a class-specific dictionary and it captures the discriminative feature of this individual. The sparse error matrix represents the intra-class variations, such as illumination, expression changes. Secondly, we combine the low-rank part (representative basis) of each person into a supervised dictionary and integrate all the sparse error matrix of each individual into a within-individual variant dictionary which can be applied to represent the possible variations between the testing and training images. Then these two dictionaries are used to code the query image. The within-individual variant dictionary can be shared by all the subjects and only contribute to explain the lighting conditions, expressions, and occlusions of the query image rather than discrimination. At last, a reconstruction-based scheme is adopted for face recognition. Since the within-individual dictionary is introduced, LRSE+SC can handle the problem of the corrupted training data and the situation that not all subjects have enough samples for training. Experimental results show that our method achieves the

  10. Learning Low-Rank Class-Specific Dictionary and Sparse Intra-Class Variant Dictionary for Face Recognition.

    Directory of Open Access Journals (Sweden)

    Xin Tang

    Full Text Available Face recognition is challenging especially when the images from different persons are similar to each other due to variations in illumination, expression, and occlusion. If we have sufficient training images of each person which can span the facial variations of that person under testing conditions, sparse representation based classification (SRC achieves very promising results. However, in many applications, face recognition often encounters the small sample size problem arising from the small number of available training images for each person. In this paper, we present a novel face recognition framework by utilizing low-rank and sparse error matrix decomposition, and sparse coding techniques (LRSE+SC. Firstly, the low-rank matrix recovery technique is applied to decompose the face images per class into a low-rank matrix and a sparse error matrix. The low-rank matrix of each individual is a class-specific dictionary and it captures the discriminative feature of this individual. The sparse error matrix represents the intra-class variations, such as illumination, expression changes. Secondly, we combine the low-rank part (representative basis of each person into a supervised dictionary and integrate all the sparse error matrix of each individual into a within-individual variant dictionary which can be applied to represent the possible variations between the testing and training images. Then these two dictionaries are used to code the query image. The within-individual variant dictionary can be shared by all the subjects and only contribute to explain the lighting conditions, expressions, and occlusions of the query image rather than discrimination. At last, a reconstruction-based scheme is adopted for face recognition. Since the within-individual dictionary is introduced, LRSE+SC can handle the problem of the corrupted training data and the situation that not all subjects have enough samples for training. Experimental results show that our

  11. Learning Low-Rank Class-Specific Dictionary and Sparse Intra-Class Variant Dictionary for Face Recognition

    Science.gov (United States)

    Tang, Xin; Feng, Guo-can; Li, Xiao-xin; Cai, Jia-xin

    2015-01-01

    Face recognition is challenging especially when the images from different persons are similar to each other due to variations in illumination, expression, and occlusion. If we have sufficient training images of each person which can span the facial variations of that person under testing conditions, sparse representation based classification (SRC) achieves very promising results. However, in many applications, face recognition often encounters the small sample size problem arising from the small number of available training images for each person. In this paper, we present a novel face recognition framework by utilizing low-rank and sparse error matrix decomposition, and sparse coding techniques (LRSE+SC). Firstly, the low-rank matrix recovery technique is applied to decompose the face images per class into a low-rank matrix and a sparse error matrix. The low-rank matrix of each individual is a class-specific dictionary and it captures the discriminative feature of this individual. The sparse error matrix represents the intra-class variations, such as illumination, expression changes. Secondly, we combine the low-rank part (representative basis) of each person into a supervised dictionary and integrate all the sparse error matrix of each individual into a within-individual variant dictionary which can be applied to represent the possible variations between the testing and training images. Then these two dictionaries are used to code the query image. The within-individual variant dictionary can be shared by all the subjects and only contribute to explain the lighting conditions, expressions, and occlusions of the query image rather than discrimination. At last, a reconstruction-based scheme is adopted for face recognition. Since the within-individual dictionary is introduced, LRSE+SC can handle the problem of the corrupted training data and the situation that not all subjects have enough samples for training. Experimental results show that our method achieves the

  12. System reliability with correlated components: Accuracy of the Equivalent Planes method

    NARCIS (Netherlands)

    Roscoe, K.; Diermanse, F.; Vrouwenvelder, A.C.W.M.

    2015-01-01

    Computing system reliability when system components are correlated presents a challenge because it usually requires solving multi-fold integrals numerically, which is generally infeasible due to the computational cost. In Dutch flood defense reliability modeling, an efficient method for computing

  13. System reliability with correlated components : Accuracy of the Equivalent Planes method

    NARCIS (Netherlands)

    Roscoe, K.; Diermanse, F.; Vrouwenvelder, T.

    2015-01-01

    Computing system reliability when system components are correlated presents a challenge because it usually requires solving multi-fold integrals numerically, which is generally infeasible due to the computational cost. In Dutch flood defense reliability modeling, an efficient method for computing

  14. The Comprehensive Snack Parenting Questionnaire (CSPQ: Development and Test-Retest Reliability

    Directory of Open Access Journals (Sweden)

    Dorus W. M. Gevers

    2018-04-01

    Full Text Available The narrow focus of existing food parenting instruments led us to develop a food parenting practices instrument measuring the full range of food practices constructs with a focus on snacking behavior. We present the development of the questionnaire and our research on the test-retest reliability. The developed Comprehensive Snack Parenting Questionnaire (CSPQ covers 21 constructs. Test-retest reliability was assessed by calculating intra class correlation coefficients and percentage agreement after two administrations of the CSPQ among a sample of 66 Dutch parents. Test-retest reliability analysis revealed acceptable intra class correlation coefficients (≥0.41 or agreement scores (≥0.60 for all items. These results, together with earlier work, suggest sufficient psychometric characteristics. The comprehensive, but brief CSPQ opens up chances for highly essential but unstudied research questions to understand and predict children’s snack intake. Example applications include studying the interactional nature of food parenting practices or interactions of food parenting with general parenting or child characteristics.

  15. Reliability Worth Analysis of Distribution Systems Using Cascade Correlation Neural Networks

    DEFF Research Database (Denmark)

    Heidari, Alireza; Agelidis, Vassilios; Pou, Josep

    2018-01-01

    Reliability worth analysis is of great importance in the area of distribution network planning and operation. The reliability worth's precision can be affected greatly by the customer interruption cost model used. The choice of the cost models can change system and load point reliability indices....... In this study, a cascade correlation neural network is adopted to further develop two cost models comprising a probabilistic distribution model and an average or aggregate model. A contingency-based analytical technique is adopted to conduct the reliability worth analysis. Furthermore, the possible effects...

  16. Attenuation of the Squared Canonical Correlation Coefficient under Varying Estimates of Score Reliability

    Science.gov (United States)

    Wilson, Celia M.

    2010-01-01

    Research pertaining to the distortion of the squared canonical correlation coefficient has traditionally been limited to the effects of sampling error and associated correction formulas. The purpose of this study was to compare the degree of attenuation of the squared canonical correlation coefficient under varying conditions of score reliability.…

  17. Reliability of the AMA Guides to the Evaluation of Permanent Impairment.

    Science.gov (United States)

    Forst, Linda; Friedman, Lee; Chukwu, Abraham

    2010-12-01

    AMA's Guides to the Evaluation of Permanent Impairment is used to rate loss of function and determine compensation and ability to work after injury or illness; however, there are few studies that evaluate reliability or construct validity. To evaluate the reliability of the fifth and sixth editions for back injury; to determine best methods for further study. Intra-class correlation coefficients within and between raters were relatively high. There was wider variability for individual cases. Impairment ratings were lower and correlated less well for the sixth edition, though confidence intervals overlapped. The sixth edition may not be an improvement over the fifth. A research agenda should include investigations of reliability and construct validity for different body sites and organ systems along the entire rating scale and among different categories of raters.

  18. Validity and reliability of the novel thyroid-specific quality of life questionnaire, ThyPRO

    DEFF Research Database (Denmark)

    Watt, Torquil; Hegedüs, Laszlo; Groenvold, Mogens

    2010-01-01

    Background Appropriate scale validity and internal consistency reliability have recently been documented for the new thyroid-specific quality of life (QoL) patient-reported outcome (PRO) measure for benign thyroid disorders, the ThyPRO. However, before clinical use, clinical validity and test......-retest reliability should be evaluated. Aim To investigate clinical ('known-groups') validity and test-retest reliability of the Danish version of the ThyPRO. Methods For each of the 13 ThyPRO scales, we defined groups expected to have high versus low scores ('known-groups'). The clinical validity (known......-groups validity) was evaluated by whether the ThyPRO scales could detect expected differences in a cross-sectional study of 907 thyroid patients. Test-retest reliability was evaluated by intra-class correlations of two responses to the ThyPRO 2 weeks apart in a subsample of 87 stable patients. Results On all 13...

  19. Reliability of short form-36 in an Internet- and a pen-and-paper version

    DEFF Research Database (Denmark)

    Basnov, Maja; Kongsved, Sissel Marie; Bech, Per

    2009-01-01

    Use of Internet versions of questionnaires may have several advantages in clinical and epidemiological research, but we know little about if Internet versions differ with respect to validity and reliability. We aimed to compare Internet- and pen-and-paper versions of short form-36 (SF-36......) with respect to test-retest reliability and internal consistency. Women referred to mammography (n = 782) were randomised to receive either a paper version with a prepaid return envelope or a guideline on how to fill in the Internet version. A subgroup was asked to answer the questionnaire once again...... in the alternative version. Test-retest reliability was assessed by the intra-class correlation coefficient. Internal consistency was calculated as Cronbach's alpha. The between-version test-retest reliability for the eight subscales were between 0.63 and 0.92. Cronbach's alpha for the two versions were all between...

  20. Reliability

    OpenAIRE

    Condon, David; Revelle, William

    2017-01-01

    Separating the signal in a test from the irrelevant noise is a challenge for all measurement. Low test reliability limits test validity, attenuates important relationships, and can lead to regression artifacts. Multiple approaches to the assessment and improvement of reliability are discussed. The advantages and disadvantages of several different approaches to reliability are considered. Practical advice on how to assess reliability using open source software is provided.

  1. Analytic tools for investigating the structure of network reliability measures with regard to observation correlations

    Science.gov (United States)

    Prószyński, W.; Kwaśniak, M.

    2018-03-01

    A global measure of observation correlations in a network is proposed, together with the auxiliary indices related to non-diagonal elements of the correlation matrix. Based on the above global measure, a specific representation of the correlation matrix is presented, being the result of rigorously proven theorem formulated within the present research. According to the theorem, each positive definite correlation matrix can be expressed by a scale factor and a so-called internal weight matrix. Such a representation made it possible to investigate the structure of the basic reliability measures with regard to observation correlations. Numerical examples carried out for two test networks illustrate the structure of those measures that proved to be dependent on global correlation index. Also, the levels of global correlation are proposed. It is shown that one can readily find an approximate value of the global correlation index, and hence the correlation level, for the expected values of auxiliary indices being the only knowledge about a correlation matrix of interest. The paper is an extended continuation of the previous study of authors that was confined to the elementary case termed uniform correlation. The extension covers arbitrary correlation matrices and a structure of correlation effect.

  2. The bridge crane mechanism shaft reliability calculating in case of the fatigue fracture parameters correlation

    Directory of Open Access Journals (Sweden)

    Krutitskiy M.N.

    2016-03-01

    Full Text Available The method of statistical tests examines the impact of the correlation of the parameters of fatigue-such as the durability of the shaft mechanism of an overhead traveling crane for General use is under consideration in this article. It is be-lieved that the normal and shear stresses together affect the overall durability of the shaft. There may be a correlation between endurance limits and coefficients of block similarity of loading. To calculate resource used corrected linear theory of fatigue damage accumulation. Parameters on the reliability are computed after building the function, the reli-ability function directly or through private functions the reliability function for each type of stress.

  3. Inter-arch digital model vs. manual cast measurements: Accuracy and reliability.

    Science.gov (United States)

    Kiviahde, Heikki; Bukovac, Lea; Jussila, Päivi; Pesonen, Paula; Sipilä, Kirsi; Raustia, Aune; Pirttiniemi, Pertti

    2017-06-28

    The purpose of this study was to evaluate the accuracy and reliability of inter-arch measurements using digital dental models and conventional dental casts. Thirty sets of dental casts with permanent dentition were examined. Manual measurements were done with a digital caliper directly on the dental casts, and digital measurements were made on 3D models by two independent examiners. Intra-class correlation coefficients (ICC), a paired sample t-test or Wilcoxon signed-rank test, and Bland-Altman plots were used to evaluate intra- and inter-examiner error and to determine the accuracy and reliability of the measurements. The ICC values were generally good for manual and excellent for digital measurements. The Bland-Altman plots of all the measurements showed good agreement between the manual and digital methods and excellent inter-examiner agreement using the digital method. Inter-arch occlusal measurements on digital models are accurate and reliable and are superior to manual measurements.

  4. Reliability Assessment of IGBT Modules Modeled as Systems with Correlated Components

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard

    2013-01-01

    configuration. The estimated system reliability by the proposed method is a conservative estimate. Application of the suggested method could be extended for reliability estimation of systems composing of welding joints, bolts, bearings, etc. The reliability model incorporates the correlation between...... was applied for the systems failure functions estimation. It is desired to compare the results with the true system failure function, which is possible to estimate using simulation techniques. Theoretical model development should be applied for the further research. One of the directions for it might...... be modeling the system based on the Sequential Order Statistics, by considering the failure of the minimum (weakest component) at each loading level. The proposed idea to represent the system by the independent components could also be used for modeling reliability by Sequential Order Statistics....

  5. The relative and absolute reliability of the Functional Independence and Difficulty Scale in community-dwelling frail elderly Japanese people using long-term care insurance services.

    Science.gov (United States)

    Saito, Takashi; Izawa, Kazuhiro P; Watanabe, Shuichiro

    2017-06-01

    The newly developed Functional Independence and Difficulty Scale is a tool for assessing the performance of basic activities of daily living in terms of both independence and difficulty. The reliability of this new scale has not been assessed. The aim of this study was to examine the relative reliability and absolute reliability of the newly developed scale in community-dwelling frail elderly people in Japan. Participants were 47 community-dwelling elderly subjects (22 for assessing test-retest reliability and 25 for assessing inter-rater reliability). As relative reliability indices, intra-class correlation coefficients were used. From an absolute reliability perspective, we conducted Bland-Altman analysis and calculated the limit of agreement or minimal detectable change to determine the acceptable range of error. Intra-class correlation coefficients for test-retest and inter-rater reliability were 0.90 (P reliability was -5.2 to 1.8, representing an increase of over six points for improvement and a decrease of over two points for decline of basic activities of daily living ability. The minimal detectable change for inter-rater reliability was 3.7, indicating that a three-point difference might be existed between difference raters. The results of this study demonstrated that the FIDS appeared to be a reliable instrument for use in Japanese community-dwelling frail elderly people. While further research using a large and more diverse sample of participants is needed, our findings support the use of FIDS in clinical practice or clinical research targeting frail elderly Japanese people.

  6. The reliability of four widely used patellar height ratios.

    Science.gov (United States)

    van Duijvenbode, Dennis; Stavenuiter, Michel; Burger, Bart; van Dijke, Cees; Spermon, Jacco; Hoozemans, Marco

    2016-03-01

    The objective of this study was to evaluate the inter-observer reliability and the intra-observer reliability of four patellar height ratios: Insall-Salvati (IS), modified Insall-Salvati (MIS), Blackburne-Peel (BP) and Caton-Deschamps (CD). The patellar height ratios were assessed by four independent examiners using weight-bearing lateral knee radiographs in 30° flexion. Intra-class correlation coefficients and Fleiss' kappa's were determined. The inter-observer reliability was excellent for the IS and moderate for the other ratios. When the ratio values were categorized, the inter-observer reliability was strong for the IS, moderate for the MIS and BP, and poor for the CD. The intra-observer reliability was excellent for the IS, MIS and CD, and strong for the BP. When the ratio values were categorized, the intra-observer reliability was strong for the IS and MIS, and moderate for the other ratios. Although the IS showed best reliability, we advise to use the MIS as it showed the second best reliability but is, according to the literature, associated with better validity.

  7. Improved estimation of subject-level functional connectivity using full and partial correlation with empirical Bayes shrinkage.

    Science.gov (United States)

    Mejia, Amanda F; Nebel, Mary Beth; Barber, Anita D; Choe, Ann S; Pekar, James J; Caffo, Brian S; Lindquist, Martin A

    2018-05-15

    Reliability of subject-level resting-state functional connectivity (FC) is determined in part by the statistical techniques employed in its estimation. Methods that pool information across subjects to inform estimation of subject-level effects (e.g., Bayesian approaches) have been shown to enhance reliability of subject-level FC. However, fully Bayesian approaches are computationally demanding, while empirical Bayesian approaches typically rely on using repeated measures to estimate the variance components in the model. Here, we avoid the need for repeated measures by proposing a novel measurement error model for FC describing the different sources of variance and error, which we use to perform empirical Bayes shrinkage of subject-level FC towards the group average. In addition, since the traditional intra-class correlation coefficient (ICC) is inappropriate for biased estimates, we propose a new reliability measure denoted the mean squared error intra-class correlation coefficient (ICC MSE ) to properly assess the reliability of the resulting (biased) estimates. We apply the proposed techniques to test-retest resting-state fMRI data on 461 subjects from the Human Connectome Project to estimate connectivity between 100 regions identified through independent components analysis (ICA). We consider both correlation and partial correlation as the measure of FC and assess the benefit of shrinkage for each measure, as well as the effects of scan duration. We find that shrinkage estimates of subject-level FC exhibit substantially greater reliability than traditional estimates across various scan durations, even for the most reliable connections and regardless of connectivity measure. Additionally, we find partial correlation reliability to be highly sensitive to the choice of penalty term, and to be generally worse than that of full correlations except for certain connections and a narrow range of penalty values. This suggests that the penalty needs to be chosen carefully

  8. Reliability of externally fixed dynamometry hamstring strength testing in elite youth football players.

    Science.gov (United States)

    Wollin, Martin; Purdam, Craig; Drew, Michael K

    2016-01-01

    To investigate inter and intra-tester reliability of an externally fixed dynamometry unilateral hamstring strength test, in the elite sports setting. Reliability study. Sixteen, injury-free, elite male youth football players (age=16.81±0.54 years, height=180.22±5.29cm, weight 73.88±6.54kg, BMI=22.57±1.42) gave written informed consent. Unilateral maximum isometric peak hamstring force was evaluated by externally fixed dynamometry for inter-tester, intra-day and intra-tester, inter-week reliability. The test position was standardised to correlate with the terminal swing phase of the gait running cycle. Inter and intra-tester values demonstrated good to high levels of reliability. The intra-class coefficient (ICC) for inter-tester, intra-day reliability was 0.87 (95% CI=0.75-0.93) with standard error of measure percentage (SEM%) 4.7 and minimal detectable change percentage (MDC%) 12.9. Intra-tester, inter-week reliability results were ICC 0.86 (95% CI, 0.74-0.93), SEM% 5.0 and MDC% 14.0. This study demonstrates good to high inter and intra-tester reliability of isometric externally fixed dynamometry unilateral hamstring strength testing in the regular elite sport setting involving elite male youth football players. The intra-class coefficient in association with the low standard error of measure and minimal detectable change percentages suggest that this procedure is appropriate for clinical and academic use as well as monitoring hamstring strength in the elite sport setting. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  9. A Combined Reliability Model of VSC-HVDC Connected Offshore Wind Farms Considering Wind Speed Correlation

    DEFF Research Database (Denmark)

    Guo, Yifei; Gao, Houlei; Wu, Qiuwei

    2017-01-01

    and WTGs outage. The wind speed correlation between different WFs is included in the two-dimensional multistate WF model by using an improved k-means clustering method. Then, the entire system with two WFs and a threeterminal VSC-HVDC system is modeled as a multi-state generation unit. The proposed model...... is applied to the Roy Billinton test system (RBTS) for adequacy studies. Both the probability and frequency indices are calculated. The effectiveness and accuracy of the combined model is validated by comparing results with the sequential Monte Carlo simulation (MCS) method. The effects of the outage of VSC-HVDC...... system and wind speed correlation on the system reliability were analyzed. Sensitivity analyses were conducted to investigate the impact of repair time of the offshore VSC-HVDC system on system reliability....

  10. Reliability assessment and correlation analysis of evaluating orthodontic treatment outcome in Chinese patients

    OpenAIRE

    Song, Guang-Ying; Zhao, Zhi-He; Ding, Yin; Bai, Yu-Xing; Wang, Lin; He, Hong; Shen, Gang; Li, Wei-Ran; Baumrind, Sheldon; Geng, Zhi; Xu, Tian-Min

    2013-01-01

    This study aimed to assess the reliability of experienced Chinese orthodontists in evaluating treatment outcome and to determine the correlations between three diagnostic information sources. Sixty-nine experienced Chinese orthodontic specialists each evaluated the outcome of orthodontic treatment of 108 Chinese patients. Three different information sources: study casts (SC), lateral cephalometric X-ray images (LX) and facial photographs (PH) were generated at the end of treatment for 108 pat...

  11. Population coding in mouse visual cortex: response reliability and dissociability of stimulus tuning and noise correlation

    Directory of Open Access Journals (Sweden)

    Jorrit S. Montijn

    2014-06-01

    Full Text Available The primary visual cortex is an excellent model system for investigating how neuronal populations encode information, because of well-documented relationships between stimulus characteristics and neuronal activation patterns. We used two-photon calcium imaging data to relate the performance of different methods for studying population coding (population vectors, template matching, and Bayesian decoding algorithms to their underlying assumptions. We show that the variability of neuronal responses may hamper the decoding of population activity, and that a normalization to correct for this variability may be of critical importance for correct decoding of population activity. Second, by comparing noise correlations and stimulus tuning we find that these properties have dissociated anatomical correlates, even though noise correlations have been previously hypothesized to reflect common synaptic input. We hypothesize that noise correlations arise from large non-specific increases in spiking activity acting on many weak synapses simultaneously, while neuronal stimulus response properties are dependent on more reliable connections. Finally, this paper provides practical guidelines for further research on population coding and shows that population coding cannot be approximated by a simple summation of inputs, but is heavily influenced by factors such as input reliability and noise correlation structure.

  12. Inter-rater reliability of kinesthetic measurements with the KINARM robotic exoskeleton.

    Science.gov (United States)

    Semrau, Jennifer A; Herter, Troy M; Scott, Stephen H; Dukelow, Sean P

    2017-05-22

    Kinesthesia (sense of limb movement) has been extremely difficult to measure objectively, especially in individuals who have survived a stroke. The development of valid and reliable measurements for proprioception is important to developing a better understanding of proprioceptive impairments after stroke and their impact on the ability to perform daily activities. We recently developed a robotic task to evaluate kinesthetic deficits after stroke and found that the majority (~60%) of stroke survivors exhibit significant deficits in kinesthesia within the first 10 days post-stroke. Here we aim to determine the inter-rater reliability of this robotic kinesthetic matching task. Twenty-five neurologically intact control subjects and 15 individuals with first-time stroke were evaluated on a robotic kinesthetic matching task (KIN). Subjects sat in a robotic exoskeleton with their arms supported against gravity. In the KIN task, the robot moved the subjects' stroke-affected arm at a preset speed, direction and distance. As soon as subjects felt the robot begin to move their affected arm, they matched the robot movement with the unaffected arm. Subjects were tested in two sessions on the KIN task: initial session and then a second session (within an average of 18.2 ± 13.8 h of the initial session for stroke subjects), which were supervised by different technicians. The task was performed both with and without the use of vision in both sessions. We evaluated intra-class correlations of spatial and temporal parameters derived from the KIN task to determine the reliability of the robotic task. We evaluated 8 spatial and temporal parameters that quantify kinesthetic behavior. We found that the parameters exhibited moderate to high intra-class correlations between the initial and retest conditions (Range, r-value = [0.53-0.97]). The robotic KIN task exhibited good inter-rater reliability. This validates the KIN task as a reliable, objective method for quantifying

  13. Reliability of pulse waveform separation analysis: effects of posture and fasting.

    Science.gov (United States)

    Stoner, Lee; Credeur, Daniel; Fryer, Simon; Faulkner, James; Lambrick, Danielle; Gibbs, Bethany Barone

    2017-03-01

    Oscillometric pulse wave analysis devices enable, with relative simplicity and objectivity, the measurement of central hemodynamic parameters. The important parameters are central blood pressures and indices of arterial wave reflection, including wave separation analysis (backward pressure component Pb and reflection magnitude). This study sought to determine whether the measurement precision (between-day reliability) of Pb and reflection magnitude: exceeds the criterion for acceptable reliability; and is affected by posture (supine, seated) and fasting state. Twenty healthy adults (50% female, 27.9 years, 24.2 kg/m) were tested on six different mornings: 3 days fasted, 3 days nonfasted condition. On each occasion, participants were tested in supine and seated postures. Oscillometric pressure waveforms were recorded on the left upper arm. The criterion intra-class correlation coefficient value of 0.75 was exceeded for Pb (0.76) and reflection magnitude (0.77) when participants were assessed under the combined supine-fasted condition. The intra-class correlation coefficient was lowest for Pb in seated-nonfasted condition (0.57), and lowest for reflection magnitude in the seated-fasted condition (0.56). For Pb, the smallest detectible change that must be exceeded in order for a significant change to occur in an individual was 2.5 mmHg, and for reflection magnitude, the smallest detectable change was 8.5%. Assessments of Pb and reflection magnitude are as follows: exceed the criterion for acceptable reliability; and are most reliable when participants are fasted in a supine position. The demonstrated reliability suggests sufficient precision to detect clinically meaningful changes in reflection magnitude and Pb.

  14. A Guideline of Selecting and Reporting Intraclass Correlation Coefficients for Reliability Research.

    Science.gov (United States)

    Koo, Terry K; Li, Mae Y

    2016-06-01

    Intraclass correlation coefficient (ICC) is a widely used reliability index in test-retest, intrarater, and interrater reliability analyses. This article introduces the basic concept of ICC in the content of reliability analysis. There are 10 forms of ICCs. Because each form involves distinct assumptions in their calculation and will lead to different interpretations, researchers should explicitly specify the ICC form they used in their calculation. A thorough review of the research design is needed in selecting the appropriate form of ICC to evaluate reliability. The best practice of reporting ICC should include software information, "model," "type," and "definition" selections. When coming across an article that includes ICC, readers should first check whether information about the ICC form has been reported and if an appropriate ICC form was used. Based on the 95% confident interval of the ICC estimate, values less than 0.5, between 0.5 and 0.75, between 0.75 and 0.9, and greater than 0.90 are indicative of poor, moderate, good, and excellent reliability, respectively. This article provides a practical guideline for clinical researchers to choose the correct form of ICC and suggests the best practice of reporting ICC parameters in scientific publications. This article also gives readers an appreciation for what to look for when coming across ICC while reading an article.

  15. Reliability analysis based on a novel density estimation method for structures with correlations

    Directory of Open Access Journals (Sweden)

    Baoyu LI

    2017-06-01

    Full Text Available Estimating the Probability Density Function (PDF of the performance function is a direct way for structural reliability analysis, and the failure probability can be easily obtained by integration in the failure domain. However, efficiently estimating the PDF is still an urgent problem to be solved. The existing fractional moment based maximum entropy has provided a very advanced method for the PDF estimation, whereas the main shortcoming is that it limits the application of the reliability analysis method only to structures with independent inputs. While in fact, structures with correlated inputs always exist in engineering, thus this paper improves the maximum entropy method, and applies the Unscented Transformation (UT technique to compute the fractional moments of the performance function for structures with correlations, which is a very efficient moment estimation method for models with any inputs. The proposed method can precisely estimate the probability distributions of performance functions for structures with correlations. Besides, the number of function evaluations of the proposed method in reliability analysis, which is determined by UT, is really small. Several examples are employed to illustrate the accuracy and advantages of the proposed method.

  16. Low Carbon-Oriented Optimal Reliability Design with Interval Product Failure Analysis and Grey Correlation Analysis

    Directory of Open Access Journals (Sweden)

    Yixiong Feng

    2017-03-01

    Full Text Available The problem of large amounts of carbon emissions causes wide concern across the world, and it has become a serious threat to the sustainable development of the manufacturing industry. The intensive research into technologies and methodologies for green product design has significant theoretical meaning and practical value in reducing the emissions of the manufacturing industry. Therefore, a low carbon-oriented product reliability optimal design model is proposed in this paper: (1 The related expert evaluation information was prepared in interval numbers; (2 An improved product failure analysis considering the uncertain carbon emissions of the subsystem was performed to obtain the subsystem weight taking the carbon emissions into consideration. The interval grey correlation analysis was conducted to obtain the subsystem weight taking the uncertain correlations inside the product into consideration. Using the above two kinds of subsystem weights and different caution indicators of the decision maker, a series of product reliability design schemes is available; (3 The interval-valued intuitionistic fuzzy sets (IVIFSs were employed to select the optimal reliability and optimal design scheme based on three attributes, namely, low carbon, correlation and functions, and economic cost. The case study of a vertical CNC lathe proves the superiority and rationality of the proposed method.

  17. The reliability of commonly used electrophysiology measures.

    Science.gov (United States)

    Brown, K E; Lohse, K R; Mayer, I M S; Strigaro, G; Desikan, M; Casula, E P; Meunier, S; Popa, T; Lamy, J-C; Odish, O; Leavitt, B R; Durr, A; Roos, R A C; Tabrizi, S J; Rothwell, J C; Boyd, L A; Orth, M

    Electrophysiological measures can help understand brain function both in healthy individuals and in the context of a disease. Given the amount of information that can be extracted from these measures and their frequent use, it is essential to know more about their inherent reliability. To understand the reliability of electrophysiology measures in healthy individuals. We hypothesized that measures of threshold and latency would be the most reliable and least susceptible to methodological differences between study sites. Somatosensory evoked potentials from 112 control participants; long-latency reflexes, transcranial magnetic stimulation with resting and active motor thresholds, motor evoked potential latencies, input/output curves, and short-latency sensory afferent inhibition and facilitation from 84 controls were collected at 3 visits over 24 months at 4 Track-On HD study sites. Reliability was assessed using intra-class correlation coefficients for absolute agreement, and the effects of reliability on statistical power are demonstrated for different sample sizes and study designs. Measures quantifying latencies, thresholds, and evoked responses at high stimulator intensities had the highest reliability, and required the smallest sample sizes to adequately power a study. Very few between-site differences were detected. Reliability and susceptibility to between-site differences should be evaluated for electrophysiological measures before including them in study designs. Levels of reliability vary substantially across electrophysiological measures, though there are few between-site differences. To address this, reliability should be used in conjunction with theoretical calculations to inform sample size and ensure studies are adequately powered to detect true change in measures of interest. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Validity and Reliability of the Questionnaire for Assessing Women’s Reproductive History in Azar Cohort Study

    Directory of Open Access Journals (Sweden)

    Mohammad Zakaria Pezeshki

    2017-06-01

    Full Text Available This study was done to evaluate the validity and reliability of women’s reproductive history questionnaire which will be used in Azar Cohort study; a cohort that is conducted by Tabriz University of Medical Science in Shabestar county for identifying risk factors of no communicable diseases. Content and face validity were evaluated by ten experts in the field and quantified as content validity index (CVI and content validity ratio (CVR. To assess the reliability, using test-retest approach, kappa statistic was calculated for categorical variables and intra-class correlation coefficient (ICC was used for the quantitative items. The calculated CVI and CVR were 0.91and 0.94, respectively. Reliability for all items was high. The ICC was 0.99 and kappa statistic was equal to 1. The final version of questionnaire was redesigned in 26 items with 7 subscales.

  19. Test-Retest Reliability of Measurements of Hand-Grip Strength Obtained by Dynamometry from Older Adults: A Systematic Review of Research in the PubMed Database.

    Science.gov (United States)

    Bohannon, R W

    2017-01-01

    A systematic review was performed to summarize literature describing the test-retest reliability of grip strength measures obtained from older adults. Relevant literature was identified via a PubMed search. Seventeen articles were deemed appropriate based on inclusion and exclusion criteria. The relative test-retest reliability of grip strength measures obtained by dynamometry was good to excellent (intra-class correlation coefficients > 0.80) in all but 3 studies, which involved older adults with severe dementia. Absolute reliability, as indicated by summary statistics such as the minimum detectable change (95%), was more variable. As a percentage, that change ranged from 14.5% to 98.5%. Consequently, clinicians can be confident in the relative reliability of grip strength measures obtained from at risk older adults. However, relatively large percentage changes in grip strength may be necessary to conclude with confidence that a real change has occurred over time in some populations.

  20. Reliability assessment of a peer evaluation instrument in a team-based learning course

    Directory of Open Access Journals (Sweden)

    Wahawisan J

    2016-03-01

    Full Text Available Objective: To evaluate the reliability of a peer evaluation instrument in a longitudinal team-based learning setting. Methods: Student pharmacists were instructed to evaluate the contributions of their peers. Evaluations were analyzed for the variance of the scores by identifying low, medium, and high scores. Agreement between performance ratings within each group of students was assessed via intra-class correlation coefficient (ICC. Results: We found little variation in the standard deviation (SD based on the score means among the high, medium, and low scores within each group. The lack of variation in SD of results between groups suggests that the peer evaluation instrument produces precise results. The ICC showed strong concordance among raters. Conclusions: Findings suggest that our student peer evaluation instrument provides a reliable method for peer assessment in team-based learning settings.

  1. The reliability of the Adelaide in-shoe foot model.

    Science.gov (United States)

    Bishop, Chris; Hillier, Susan; Thewlis, Dominic

    2017-07-01

    Understanding the biomechanics of the foot is essential for many areas of research and clinical practice such as orthotic interventions and footwear development. Despite the widespread attention paid to the biomechanics of the foot during gait, what largely remains unknown is how the foot moves inside the shoe. This study investigated the reliability of the Adelaide In-Shoe Foot Model, which was designed to quantify in-shoe foot kinematics and kinetics during walking. Intra-rater reliability was assessed in 30 participants over five walking trials whilst wearing shoes during two data collection sessions, separated by one week. Sufficient reliability for use was interpreted as a coefficient of multiple correlation and intra-class correlation coefficient of >0.61. Inter-rater reliability was investigated separately in a second sample of 10 adults by two researchers with experience in applying markers for the purpose of motion analysis. The results indicated good consistency in waveform estimation for most kinematic and kinetic data, as well as good inter-and intra-rater reliability. The exception is the peak medial ground reaction force, the minimum abduction angle and the peak abduction/adduction external hindfoot joint moments which resulted in less than acceptable repeatability. Based on our results, the Adelaide in-shoe foot model can be used with confidence for 24 commonly measured biomechanical variables during shod walking. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Intra-unit correlations in seroconversion to Actinobacillus pleuropneumoniae and Mycoplasma hyopneumoniae at different levels in Danish multi-site pig production facilities

    DEFF Research Database (Denmark)

    Vigre, Håkan; Dohoo, I.R.; Stryhn, H.

    2004-01-01

    2) and Mycoplasma hyopneumoniae (Mh). Based on the estimated variances, three newly described computational methods (model linearisation, simulation and linear modelling) and the standard method (latent-variable approach) were used to estimate the correlations (intra-class correlation components...

  3. Reliability and Correlation of Static and Dynamic Foot Arch Measurement in a Healthy Pediatric Population.

    Science.gov (United States)

    Scholz, Timo; Zech, Astrid; Wegscheider, Karl; Lezius, Susanne; Braumann, Klaus-Michael; Sehner, Susanne; Hollander, Karsten

    2017-09-01

    Measurement of the medial longitudinal foot arch in children is a controversial topic, as there are many different methods without a definite standard procedure. The purpose of this study was to 1) investigate intraday and interrater reliability regarding dynamic arch index and static arch height, 2) explore the correlation between both arch indices, and 3) examine the variation of the medial longitudinal arch at two different times of the day. Eighty-six children (mean ± SD age, 8.9 ± 1.9 years) participated in the study. Dynamic footprint data were captured with a pedobarographic platform. For static arch measurements, a specially constructed caliper was used to assess heel-to-toe length and dorsum height. A mixed model was established to determine reliability and variation. Reliability was found to be excellent for the static arch height index in sitting (intraday, 0.90; interrater, 0.80) and standing positions (0.88 and 0.85) and for the dynamic arch index (both 1.00). There was poor correlation between static and dynamic assessment of the medial longitudinal arch (standing dynamic arch index, r = -0.138; sitting dynamic arch index, r = -0.070). Static measurements were found to be significantly influenced by the time of day (P body mass index (P mind. For clinical purposes, static and dynamic arch data should be interpreted separately.

  4. Is gait variability reliable in older adults and Parkinson's disease? Towards an optimal testing protocol.

    Science.gov (United States)

    Galna, Brook; Lord, Sue; Rochester, Lynn

    2013-04-01

    Despite the widespread use of gait variability in research and clinical studies, testing protocols designed to optimise its reliability have not been established. This study evaluates the impact of testing protocol and pathology on the reliability of gait variability. To (i) estimate the reliability of gait variability during continuous and intermittent walking protocols in older adults and people with Parkinson's disease (PD), (ii) determine optimal number of steps for acceptable levels of reliability of gait variability and (iii) provide sample size estimates for use in clinical trials. Gait variability was measured twice, one week apart, in 27 older adults and 25 PD participants. Participants walked at their preferred pace during: (i) a continuous 2 min walk and (ii) 3 intermittent walks over a 12 m walkway. Gait variability was calculated as the within-person standard deviation for step velocity, length and width, and step, stance and swing duration. Reliability of gait variability ranged from poor to excellent (intra class correlations .041-.860; relative limits of agreement 34-89%). Gait variability was more reliable during continuous walks. Control and PD participants demonstrated similar reliability. Increasing the number of steps improved reliability, with most improvement seen across the first 30 steps. In this study, we identified testing protocols that improve the reliability of measuring gait variability. We recommend using a continuous walking protocol and to collect no fewer than 30 steps. Early PD does not appear to impact negatively on the reliability of gait variability. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. The Depression Anxiety Stress Scales-21 (DASS-21): further examination of dimensions, scale reliability, and correlates.

    Science.gov (United States)

    Osman, Augustine; Wong, Jane L; Bagge, Courtney L; Freedenthal, Stacey; Gutierrez, Peter M; Lozano, Gregorio

    2012-12-01

    We conducted two studies to examine the dimensions, internal consistency reliability estimates, and potential correlates of the Depression Anxiety Stress Scales-21 (DASS-21; Lovibond & Lovibond, 1995). Participants in Study 1 included 887 undergraduate students (363 men and 524 women, aged 18 to 35 years; mean [M] age = 19.46, standard deviation [SD] = 2.17) recruited from two public universities to assess the specificity of the individual DASS-21 items and to evaluate estimates of internal consistency reliability. Participants in a follow-up study (Study 2) included 410 students (168 men and 242 women, aged 18 to 47 years; M age = 19.65, SD = 2.88) recruited from the same universities to further assess factorial validity and to evaluate potential correlates of the original DASS-21 total and scale scores. Item bifactor and confirmatory factor analyses revealed that a general factor accounted for the greatest proportion of common variance in the DASS-21 item scores (Study 1). In Study 2, the fit statistics showed good fit for the bifactor model. In addition, the DASS-21 total scale score correlated more highly with scores on a measure of mixed depression and anxiety than with scores on the proposed specific scales of depression or anxiety. Coefficient omega estimates for the DASS-21 scale scores were good. Further investigations of the bifactor structure and psychometric properties of the DASS-21, specifically its incremental and discriminant validity, using known clinical groups are needed. © 2012 Wiley Periodicals, Inc.

  6. Reliability of Various Measurement Stations for Determining Plantar Fascia Thickness and Echogenicity

    Directory of Open Access Journals (Sweden)

    Adebisi Bisi-Balogun

    2016-04-01

    Full Text Available This study aimed to determine the relative and absolute reliability of ultrasound (US measurements of the thickness and echogenicity of the plantar fascia (PF at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of ≥0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC.

  7. Reliability of Various Measurement Stations for Determining Plantar Fascia Thickness and Echogenicity.

    Science.gov (United States)

    Bisi-Balogun, Adebisi; Cassel, Michael; Mayer, Frank

    2016-04-13

    This study aimed to determine the relative and absolute reliability of ultrasound (US) measurements of the thickness and echogenicity of the plantar fascia (PF) at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet) were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of ≥0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs) did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC.

  8. MIDAS and HIT-6 French translation: reliability and correlation between tests.

    Science.gov (United States)

    Magnoux, E; Freeman, M A; Zlotnik, G

    2008-01-01

    The aim was to evaluate the test-retest reliability of the French translation of the Migraine Disability Assessment (MIDAS) and Headache Impact Test (HIT)-6 questionnaires as applied to episodic and chronic headaches and to assess the correlation between these two questionnaires. The MIDAS and HIT-6 questionnaires, which assess the degree of migraine-related functional disability, are widely used in headache treatment clinics. The French translation has not been checked for test-retest reliability. MIDAS involves recall, over the previous 3 months, of the number of days with functional disability with regard to work and to home and social life. HIT-6 involves a more subjective and general assessment of headache-related disability over the previous 4 weeks. We expect that there may be greater impact recall bias for chronic headaches than for episodic headaches and considered it important to be able to determine if the reliability of these questionnaires is equally good for these two patient populations. Given that both questionnaires have the same objective, that of assessing headache impact, it was thought useful to determine if their results might show a correlation and if they could thus be used interchangeably. The study was approved by an external ethics committee. The subjects were patients who regularly visit the Clinique de la Migraine de Montréal, which specializes in the treatment of headaches. The MIDAS and HIT-6 questionnaires were completed by the patients during their regular visit. Twelve days later, the same questionnaires were mailed with a prepaid return envelope. Sixty-five patients were required in both the episodic and chronic headache groups, assuming an 80% questionnaire return rate. One hundred and eighty-five patients were enrolled, and 143 completed the study, 75 with episodic headaches and 68 with chronic headaches. The questionnaire return rate was 78.9%. On average, questionnaires were completed a second time 21 days after the first

  9. Patient Assessment of Constipation Quality of Life Questionnaire: Translation, Cultural Adaptation, Reliability, and Validity of the Persian Version.

    Science.gov (United States)

    Nikjooy, Afsaneh; Jafari, Hassan; Saba, Maryam A; Ebrahimi, Naghmeh; Mirzaei, Rezvan

    2018-05-01

    The Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaire is the most validated and the most specific tool for measuring the quality of life of patients with constipation. Over 120 million people live in countries whose official language is Persian. There is no reported Persian version of the PAC-QOL questionnaire yet. The aim of this study was to translate and culturally adapt the PAC-QOL questionnaire and to assess its reliability and validity among Persian patients with chronic constipation. Following the translation and cultural adaptation of the PAC-QOL questionnaire to Persian, 100 patients (mean±SD age=40.51±13.67) with constipation were recruited for validity measurement and 20 patients were re-examined for reliability. Content validity was assessed based on the opinions of an expert committee and the floor/ceiling effect. Construct validity was evaluated according to the hypothesis test. The SF-36 questionnaire was used for concurrent criterion validity, intra-class correlation coefficient for reliability, and Cronbach's alpha for internal consistency. The content validity of the PAC-QOL questionnaire was proven, and there was no floor/ceiling effect. Construct validity also was confirmed based on the hypothesis test. The overall Cronbach's alpha of the PAC-QOL questionnaire was 0.92 (range=0.72-0.92), and the overall intra-class correlation coefficient of the questionnaire was 0.88 (range=0.69-0.87). The correlation between the SF-36 and PAC-QOL questionnaires was moderate. The Persian version of the PAC-QOL questionnaire demonstrated good validity and reliability properties in chronic constipation. Accordingly, Persian researchers and clinicians can benefit from this questionnaire in further research and assessment of treatment outcomes.

  10. Reliability of the Alzheimer's disease assessment scale (ADAS-Cog) in longitudinal studies.

    Science.gov (United States)

    Khan, Anzalee; Yavorsky, Christian; DiClemente, Guillermo; Opler, Mark; Liechti, Stacy; Rothman, Brian; Jovic, Sofija

    2013-11-01

    Considering the scarcity of longitudinal assessments of reliability, there is need for a more precise understanding of cognitive decline in Alzheimer's Disease (AD). The primary goal was to assess longitudinal changes in inter-rater reliability, test retest reliability and internal consistency of scores of the ADAS-Cog. 2,618 AD subjects were enrolled in seven randomized, double-blind, placebo-controlled, multicenter-trials from 1986 to 2009. Reliability, internal-consistency and cross-sectional analysis of ADAS-Cog and MMSE across seven visits were examined. Intra-class correlation (ICC) for ADAS-Cog was moderate to high supporting their reliability. Absolute Agreement ICCs 0.392 (Visit-7) to 0.806 (Visit-2) showed a progressive decrease in correlations across time. Item analysis revealed a decrease in item correlations, with the lowest correlations for Visit 7 for Commands (ICC=0.148), Comprehension (ICC=0.092), Spoken Language (ICC=0.044). Suitable assessment of AD treatments is maintained through accurate measurement of clinically significant outcomes. Targeted rater education ADAS-Cog items over-time can improve ability to administer and score the scale.

  11. Post-event human decision errors: operator action tree/time reliability correlation

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R E; Fragola, J; Wreathall, J

    1982-11-01

    This report documents an interim framework for the quantification of the probability of errors of decision on the part of nuclear power plant operators after the initiation of an accident. The framework can easily be incorporated into an event tree/fault tree analysis. The method presented consists of a structure called the operator action tree and a time reliability correlation which assumes the time available for making a decision to be the dominating factor in situations requiring cognitive human response. This limited approach decreases the magnitude and complexity of the decision modeling task. Specifically, in the past, some human performance models have attempted prediction by trying to emulate sequences of human actions, or by identifying and modeling the information processing approach applicable to the task. The model developed here is directed at describing the statistical performance of a representative group of hypothetical individuals responding to generalized situations.

  12. Post-event human decision errors: operator action tree/time reliability correlation

    International Nuclear Information System (INIS)

    Hall, R.E.; Fragola, J.; Wreathall, J.

    1982-11-01

    This report documents an interim framework for the quantification of the probability of errors of decision on the part of nuclear power plant operators after the initiation of an accident. The framework can easily be incorporated into an event tree/fault tree analysis. The method presented consists of a structure called the operator action tree and a time reliability correlation which assumes the time available for making a decision to be the dominating factor in situations requiring cognitive human response. This limited approach decreases the magnitude and complexity of the decision modeling task. Specifically, in the past, some human performance models have attempted prediction by trying to emulate sequences of human actions, or by identifying and modeling the information processing approach applicable to the task. The model developed here is directed at describing the statistical performance of a representative group of hypothetical individuals responding to generalized situations

  13. The reliability and clinical correlates of figure-ground perception in schizophrenia.

    Science.gov (United States)

    Malaspina, Dolores; Simon, Naomi; Goetz, Raymond R; Corcoran, Cheryl; Coleman, Eliza; Printz, David; Mujica-Parodi, Lilianne; Wolitzky, Rachel

    2004-01-01

    Schizophrenia subjects are impaired in a number of visual attention paradigms. However, their performance on tests of figure-ground visual perception (FGP), which requires subjects to visually discriminate figures embedded in a rival background, is relatively unstudied. We examined FGP in 63 schizophrenia patients and 27 control subjects and found that the patients performed the FGP test reliably and had significantly lower FGP scores than the control subjects. Figure-ground visual perception was significantly correlated with other neuropsychological test scores and was inversely related to negative symptoms. It was unrelated to antipsychotic medication treatment. Figure-ground visual perception depends on "top down" processing of visual stimuli, and thus this data suggests that dysfunction in the higher-level pathways that modulate visual perceptual processes may also be related to a core defect in schizophrenia.

  14. Correlating neutron yield and reliability for selecting experimental parameters for a plasma focus machine

    International Nuclear Information System (INIS)

    Pross, G.

    Possibilities of optimizing focus machines with a given energy content in the sense of high neutron yield and high reliability of the discharges are investigated experimentally. For this purpose, a focus machine of the Mather type with an energy content of 12 kJ was constructed. The following experimental parameters were varied: the material of the insulator in the ignition zone, the structure of the outside electrode, the length of the inside electrode, the filling pressure and the amount and polarity of the battery voltage. An important part of the diagnostic program consists of measurements of the azimuthal and axial current distribution in the accelerator, correlated with short-term photographs of the luminous front as a function of time. The results are given. A functional schematic has been drafted for focus discharge as an aid in extensive optimization of focus machines, combining findings from theory and experiments. The schematic takes into account the multiparameter character of the discharge and clarifies relationships between the experimental parameters and the target variables neutron yield and reliability

  15. Confiabilidade de medidas volumétricas de estruturas temporais mesiais Reliability of mesial temporal lobe volumetric measures

    Directory of Open Access Journals (Sweden)

    Renato L. Marchetti

    2002-06-01

    Full Text Available MOTIVO DO ESTUDO: O desenvolvimento de técnicas confiáveis para a realização de medidas volumétricas de estruturas temporais mesiais (amígdala, hipocampo e giro para-hipocampal em exames de ressonância magnética (RM pode fornecer dados para o estudo de vários transtornos neuropsiquiátricos, particularmente epilepsia do lobo temporal, doença de Alzheimer e esquizofrenia. MÉTODO: Investigamos essas técnicas realizando estudo de confiabilidade intra-observador (IO e entre-observador (EO, envolvendo controles normais, pacientes com epilepsia e pacientes com doença de Alzheimer, através do coeficiente de correlação intra-classe (CCI. RESULTADOS: A confiabilidade IO para as estruturas analisadas variou de 0,93 a 0,99 (pRATIONALE: The development of reliable techniques for volumetric measurement of mesial temporal structures (amygdala, hypocampus and parahypocampal gyrus on magnetic resonance imaging (MRI can provide data for the study of neuropsychiatric disorders, mainly temporal lobe epilepsy, Alzheimer´s disease and schizophrenia. METHOD: We investigated these techniques performing intraobserver and interobserver reliability study concerning normal controls, epilepsy and Alzheimer's disease patients using the intra-class correlation coefficient. RESULTS: Intra-observer reliability of evaluated structures ranged from 0.93 to 0.99 (p<0.001. Inter-observer reliability ranged from 0.70 to 0.95 (p <= 0.001. CONCLUSION: The results suggest that the technique of MRI morphometry of mesial temporal regions can be considered a reliable tool which may help in the investigation of neuropsychiatric disorders, since used by adequately trained clinicians and researchers.

  16. Functional claudication distance: a reliable and valid measurement to assess functional limitation in patients with intermittent claudication

    Directory of Open Access Journals (Sweden)

    Prins Martin H

    2009-03-01

    Full Text Available Abstract Background Disease severity and functional impairment in patients with intermittent claudication is usually quantified by the measurement of pain-free walking distance (intermittent claudication distance, ICD and maximal walking distance (absolute claudication distance, ACD. However, the distance at which a patient would prefer to stop because of claudication pain seems a definition that is more correspondent with the actual daily life walking distance. We conducted a study in which the distance a patient prefers to stop was defined as the functional claudication distance (FCD, and estimated the reliability and validity of this measurement. Methods In this clinical validity study we included patients with intermittent claudication, following a supervised exercise therapy program. The first study part consisted of two standardised treadmill tests. During each test ICD, FCD and ACD were determined. Primary endpoint was the reliability as represented by the calculated intra-class correlation coefficients. In the second study part patients performed a standardised treadmill test and filled out the Rand-36 questionnaire. Spearman's rho was calculated to assess validity. Results The intra-class correlation coefficients of ICD, FCD and ACD were 0.940, 0.959, and 0.975 respectively. FCD correlated significantly with five out of nine domains, namely physical function (rho = 0.571, physical role (rho = 0.532, vitality (rho = 0.416, pain (rho = 0.416 and health change (rho = 0.414. Conclusion FCD is a reliable and valid measurement for determining functional capacity in trained patients with intermittent claudication. Furthermore it seems that FCD better reflects the actual functional impairment. In future studies, FCD could be used alongside ICD and ACD.

  17. Computing Inter-Rater Reliability for Observational Data: An Overview and Tutorial

    Directory of Open Access Journals (Sweden)

    Kevin A. Hallgren

    2012-02-01

    Full Text Available Many research designs require the assessment of inter-rater reliability (IRR to demonstrate consistency among observational ratings provided by multiple coders. However, many studies use incorrect statistical procedures, fail to fully report the information necessary to interpret their results, or do not address how IRR affects the power of their subsequent analyses for hypothesis testing. This paper provides an overview of methodological issues related to the assessment of IRR with a focus on study design, selection of appropriate statistics, and the computation, interpretation, and reporting of some commonly-used IRR statistics. Computational examples include SPSS and R syntax for computing Cohen’s kappa and intra-class correlations to assess IRR.

  18. Reliability of anthropometric measurements in young male and female artistic gymnasts.

    Science.gov (United States)

    Siatras, Theophanis; Skaperda, Malamati; Mameletzi, Dimitra

    2010-12-01

    Body dimensions and body composition of children participating in artistic activities, such as gymnastics and many types of dancing, are important factors in performance improvement. The present study aimed to determine the reliability of a series of selected anthropometric measurements in young male and female gymnasts. Segment lengths, body breadths, circumferences, and skinfold thickness were measured in 20 young gymnasts by the same experienced examiner, using portable and easy-to-use instruments. All parameters were measured twice (test-retest) under the same conditions within a week's period. The high intra-class correlation coefficient (ICC) values ranging from 0.87 to 0.99, as well as the low coefficient of variation (CV) values (artistic gymnasts. Therefore, these measurements could contribute to further research in this field of investigation, helping to monitor young artistic gymnasts' growth status and identify specific characteristics for increased performance in this sport.

  19. A Correlated Model for Evaluating Performance and Energy of Cloud System Given System Reliability

    Directory of Open Access Journals (Sweden)

    Hongli Zhang

    2015-01-01

    Full Text Available The serious issue of energy consumption for high performance computing systems has attracted much attention. Performance and energy-saving have become important measures of a computing system. In the cloud computing environment, the systems usually allocate various resources (such as CPU, Memory, Storage, etc. on multiple virtual machines (VMs for executing tasks. Therefore, the problem of resource allocation for running VMs should have significant influence on both system performance and energy consumption. For different processor utilizations assigned to the VM, there exists the tradeoff between energy consumption and task completion time when a given task is executed by the VMs. Moreover, the hardware failure, software failure and restoration characteristics also have obvious influences on overall performance and energy. In this paper, a correlated model is built to analyze both performance and energy in the VM execution environment given the reliability restriction, and an optimization model is presented to derive the most effective solution of processor utilization for the VM. Then, the tradeoff between energy-saving and task completion time is studied and balanced when the VMs execute given tasks. Numerical examples are illustrated to build the performance-energy correlated model and evaluate the expected values of task completion time and consumed energy.

  20. The Reliability of Individualized Load-Velocity Profiles.

    Science.gov (United States)

    Banyard, Harry G; Nosaka, K; Vernon, Alex D; Haff, G Gregory

    2017-11-15

    This study examined the reliability of peak velocity (PV), mean propulsive velocity (MPV), and mean velocity (MV) in the development of load-velocity profiles (LVP) in the full depth free-weight back squat performed with maximal concentric effort. Eighteen resistance-trained men performed a baseline one-repetition maximum (1RM) back squat trial and three subsequent 1RM trials used for reliability analyses, with 48-hours interval between trials. 1RM trials comprised lifts from six relative loads including 20, 40, 60, 80, 90, and 100% 1RM. Individualized LVPs for PV, MPV, or MV were derived from loads that were highly reliable based on the following criteria: intra-class correlation coefficient (ICC) >0.70, coefficient of variation (CV) ≤10%, and Cohen's d effect size (ES) 0.05) between trials, movement velocities, or between linear regression versus second order polynomial fits. PV 20-100% , MPV 20-90% , and MV 20-90% are reliable and can be utilized to develop LVPs using linear regression. Conceptually, LVPs can be used to monitor changes in movement velocity and employed as a method for adjusting sessional training loads according to daily readiness.

  1. Reliability and validity of a talent identification test battery for seated and standing Paralympic throws.

    Science.gov (United States)

    Spathis, Jemima Grace; Connick, Mark James; Beckman, Emma Maree; Newcombe, Peter Anthony; Tweedy, Sean Michael

    2015-01-01

    Paralympic throwing events for athletes with physical impairments comprise seated and standing javelin, shot put, discus and seated club throwing. Identification of talented throwers would enable prediction of future success and promote participation; however, a valid and reliable talent identification battery for Paralympic throwing has not been reported. This study evaluates the reliability and validity of a talent identification battery for Paralympic throws. Participants were non-disabled so that impairment would not confound analyses, and results would provide an indication of normative performance. Twenty-eight non-disabled participants (13 M; 15 F) aged 23.6 years (±5.44) performed five kinematically distinct criterion throws (three seated, two standing) and nine talent identification tests (three anthropometric, six motor); 23 were tested a second time to evaluate test-retest reliability. Talent identification test-retest reliability was evaluated using Intra-class Correlation Coefficient (ICC) and Bland-Altman plots (Limits of Agreement). Spearman's correlation assessed strength of association between criterion throws and talent identification tests. Reliability was generally acceptable (mean ICC = 0.89), but two seated talent identification tests require more extensive familiarisation. Correlation strength (mean rs = 0.76) indicated that the talent identification tests can be used to validly identify individuals with competitively advantageous attributes for each of the five kinematically distinct throwing activities. Results facilitate further research in this understudied area.

  2. Reliability assessment and correlation analysis of evaluating orthodontic treatment outcome in Chinese patients.

    Science.gov (United States)

    Song, Guang-Ying; Zhao, Zhi-He; Ding, Yin; Bai, Yu-Xing; Wang, Lin; He, Hong; Shen, Gang; Li, Wei-Ran; Baumrind, Sheldon; Geng, Zhi; Xu, Tian-Min

    2014-03-01

    This study aimed to assess the reliability of experienced Chinese orthodontists in evaluating treatment outcome and to determine the correlations between three diagnostic information sources. Sixty-nine experienced Chinese orthodontic specialists each evaluated the outcome of orthodontic treatment of 108 Chinese patients. Three different information sources: study casts (SC), lateral cephalometric X-ray images (LX) and facial photographs (PH) were generated at the end of treatment for 108 patients selected randomly from six orthodontic treatment centers throughout China. Six different assessments of treatment outcome were made by each orthodontist using data from the three information sources separately and in combination. Each assessment included both ranking and grading for each patient. The rankings of each of the 69 judges for the 108 patients were correlated with the rankings of each of the other judges yielding 13 873 Spearman rs values, ranging from -0.08 to +0.85. Of these, 90% were greater than 0.4, showing moderate-to-high consistency among the 69 orthodontists. In the combined evaluations, study casts were the most significant predictive component (R(2)=0.86, P<0.000 1), while the inclusion of lateral cephalometric films and facial photographs also contributed to a more comprehensive assessment (R(2)=0.96, P<0.000 1). Grading scores for SC+LX and SC+PH were highly significantly correlated with those for SC+LX+PH (r(SC+LX)vs.(SC+LX+PH)=0.96, r(SC+PH)vs.(SC+LX+PH)=0.97), showing that either SC+LX or SC+PH is an excellent substitute for all three combined assessment.

  3. An Appropriate Wind Model for Wind Integrated Power Systems Reliability Evaluation Considering Wind Speed Correlations

    Directory of Open Access Journals (Sweden)

    Rajesh Karki

    2013-02-01

    Full Text Available Adverse environmental impacts of carbon emissions are causing increasing concerns to the general public throughout the world. Electric energy generation from conventional energy sources is considered to be a major contributor to these harmful emissions. High emphasis is therefore being given to green alternatives of energy, such as wind and solar. Wind energy is being perceived as a promising alternative. This source of energy technology and its applications have undergone significant research and development over the past decade. As a result, many modern power systems include a significant portion of power generation from wind energy sources. The impact of wind generation on the overall system performance increases substantially as wind penetration in power systems continues to increase to relatively high levels. It becomes increasingly important to accurately model the wind behavior, the interaction with other wind sources and conventional sources, and incorporate the characteristics of the energy demand in order to carry out a realistic evaluation of system reliability. Power systems with high wind penetrations are often connected to multiple wind farms at different geographic locations. Wind speed correlations between the different wind farms largely affect the total wind power generation characteristics of such systems, and therefore should be an important parameter in the wind modeling process. This paper evaluates the effect of the correlation between multiple wind farms on the adequacy indices of wind-integrated systems. The paper also proposes a simple and appropriate probabilistic analytical model that incorporates wind correlations, and can be used for adequacy evaluation of multiple wind-integrated systems.

  4. Reliability of peripheral arterial tonometry in patients with heart failure, diabetic nephropathy and arterial hypertension.

    Science.gov (United States)

    Weisrock, Fabian; Fritschka, Max; Beckmann, Sebastian; Litmeier, Simon; Wagner, Josephine; Tahirovic, Elvis; Radenovic, Sara; Zelenak, Christine; Hashemi, Djawid; Busjahn, Andreas; Krahn, Thomas; Pieske, Burkert; Dinh, Wilfried; Düngen, Hans-Dirk

    2017-08-01

    Endothelial dysfunction plays a major role in cardiovascular diseases and pulse amplitude tonometry (PAT) offers a non-invasive way to assess endothelial dysfunction. However, data about the reliability of PAT in cardiovascular patient populations are scarce. Thus, we evaluated the test-retest reliability of PAT using the natural logarithmic transformed reactive hyperaemia index (LnRHI). Our cohort consisted of 91 patients (mean age: 65±9.7 years, 32% female), who were divided into four groups: those with heart failure with preserved ejection fraction (HFpEF) ( n=25), heart failure with reduced ejection fraction (HFrEF) ( n=22), diabetic nephropathy ( n=21), and arterial hypertension ( n=23). All subjects underwent two separate PAT measurements at a median interval of 7 days (range 4-14 days). LnRHI derived by PAT showed good reliability in subjects with diabetic nephropathy (intra-class correlation (ICC) = 0.863) and satisfactory reliability in patients with both HFpEF (ICC = 0.557) and HFrEF (ICC = 0.576). However, in subjects with arterial hypertension, reliability was poor (ICC = 0.125). We demonstrated that PAT is a reliable technique to assess endothelial dysfunction in adults with diabetic nephropathy, HFpEF or HFrEF. However, in subjects with arterial hypertension, we did not find sufficient reliability, which can possibly be attributed to variations in heart rate and the respective time of the assessments. Clinical Trial Registration Identifier: NCT02299960.

  5. Reliability of ultrasound thickness measurement of the abdominal muscles during clinical isometric endurance tests.

    Science.gov (United States)

    ShahAli, Shabnam; Arab, Amir Massoud; Talebian, Saeed; Ebrahimi, Esmaeil; Bahmani, Andia; Karimi, Noureddin; Nabavi, Hoda

    2015-07-01

    The study was designed to evaluate the intra-examiner reliability of ultrasound (US) thickness measurement of abdominal muscles activity when supine lying and during two isometric endurance tests in subjects with and without Low back pain (LBP). A total of 19 women (9 with LBP, 10 without LBP) participated in the study. Within-day reliability of the US thickness measurements at supine lying and the two isometric endurance tests were assessed in all subjects. The intra-class correlation coefficient (ICC) was used to assess the relative reliability of thickness measurement. The standard error of measurement (SEM), minimal detectable change (MDC) and the coefficient of variation (CV) were used to evaluate the absolute reliability. Results indicated high ICC scores (0.73-0.99) and also small SEM and MDC scores for within-day reliability assessment. The Bland-Altman plots of agreement in US measurement of the abdominal muscles during the two isometric endurance tests demonstrated that 95% of the observations fall between the limits of agreement for test and retest measurements. Together the results indicate high intra-tester reliability for the US measurement of the thickness of abdominal muscles in all the positions tested. According to the study's findings, US imaging can be used as a reliable method for assessment of abdominal muscles activity in supine lying and the two isometric endurance tests employed, in participants with and without LBP. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Reliability of environmental sampling culture results using the negative binomial intraclass correlation coefficient.

    Science.gov (United States)

    Aly, Sharif S; Zhao, Jianyang; Li, Ben; Jiang, Jiming

    2014-01-01

    The Intraclass Correlation Coefficient (ICC) is commonly used to estimate the similarity between quantitative measures obtained from different sources. Overdispersed data is traditionally transformed so that linear mixed model (LMM) based ICC can be estimated. A common transformation used is the natural logarithm. The reliability of environmental sampling of fecal slurry on freestall pens has been estimated for Mycobacterium avium subsp. paratuberculosis using the natural logarithm transformed culture results. Recently, the negative binomial ICC was defined based on a generalized linear mixed model for negative binomial distributed data. The current study reports on the negative binomial ICC estimate which includes fixed effects using culture results of environmental samples. Simulations using a wide variety of inputs and negative binomial distribution parameters (r; p) showed better performance of the new negative binomial ICC compared to the ICC based on LMM even when negative binomial data was logarithm, and square root transformed. A second comparison that targeted a wider range of ICC values showed that the mean of estimated ICC closely approximated the true ICC.

  7. Reliability And Validity Of Turkish Version Of Motor Activity Log-28

    Directory of Open Access Journals (Sweden)

    Burcu Ersöz Hüseyinsinoğlu

    2011-06-01

    Full Text Available OBJECTIVE: The aim of this study was to adapt the Motor Activity Log-28 (MAL-28 into Turkish and probe the reliability and validity of this questionnaire in stroke patients. METHODS: Following the translation of the MAL-28 into Turkish, its reliability and construct validity was examined in 30 stroke patients. For the reliability study, patients were interviewed twice within a three day period, during which no rehabilitative activities were undertaken. The test-retest reliability was determined by using intra-class correlation coefficient (ICC and Spearman correlation coefficient (r; internal consistency was determined by Cronbach's alpha (α. The construct validity was examined by comparing MAL-28 Quality Of Movement (QOM scale and Amount Of Use (AOU scale with Wolf Motor Function Test (WMFT-Performance Time (PT and Functional Ability (FA scores. Furthermore, item-to-scale correlations of AOU and QOM scales were determined and correlation between totol scores of two scales was examined. RESULTS: Turkish version of MAL-28 AOU and QOM scales were reliable (ICC scores were 0.97 and 0.96, respectively and internally consistent (Cronbach’s α value was 0.96 for both scales. Test-retest reliability was supported (AOU, r=0.94; QOM, r=0.93. WMFT FA scores was correlated with both scales (r=0.63. Correlation between WMFT PT and AOU and QOM scales were -0.56 and -0.55. AOU and QOM scales were highly correlated (r=0.95. CONCLUSION: The findings indicate that Turkish version of MAL-28 is reliable and valid in individuals with stroke. Further investigation about its responsiveness is needed before using that version as a primary measurement in clinical trials

  8. Integration of external estimated breeding values and associated reliabilities using correlations among traits and effects.

    Science.gov (United States)

    Vandenplas, J; Colinet, F G; Glorieux, G; Bertozzi, C; Gengler, N

    2015-12-01

    Based on a Bayesian view of linear mixed models, several studies showed the possibilities to integrate estimated breeding values (EBV) and associated reliabilities (REL) provided by genetic evaluations performed outside a given evaluation system into this genetic evaluation. Hereafter, the term "internal" refers to this given genetic evaluation system, and the term "external" refers to all other genetic evaluations performed outside the internal evaluation system. Bayesian approaches integrate external information (i.e., external EBV and associated REL) by altering both the mean and (co)variance of the prior distributions of the additive genetic effects based on the knowledge of this external information. Extensions of the Bayesian approaches to multivariate settings are interesting because external information expressed on other scales, measurement units, or trait definitions, or associated with different heritabilities and genetic parameters than the internal traits, could be integrated into a multivariate genetic evaluation without the need to convert external information to the internal traits. Therefore, the aim of this study was to test the integration of external EBV and associated REL, expressed on a 305-d basis and genetically correlated with a trait of interest, into a multivariate genetic evaluation using a random regression test-day model for the trait of interest. The approach we used was a multivariate Bayesian approach. Results showed that the integration of external information led to a genetic evaluation for the trait of interest for, at least, animals associated with external information, as accurate as a bivariate evaluation including all available phenotypic information. In conclusion, the multivariate Bayesian approaches have the potential to integrate external information correlated with the internal phenotypic traits, and potentially to the different random regressions, into a multivariate genetic evaluation. This allows the use of different

  9. Reliable and valid assessment of Lichtenstein hernia repair skills.

    Science.gov (United States)

    Carlsen, C G; Lindorff-Larsen, K; Funch-Jensen, P; Lund, L; Charles, P; Konge, L

    2014-08-01

    Lichtenstein hernia repair is a common surgical procedure and one of the first procedures performed by a surgical trainee. However, formal assessment tools developed for this procedure are few and sparsely validated. The aim of this study was to determine the reliability and validity of an assessment tool designed to measure surgical skills in Lichtenstein hernia repair. Key issues were identified through a focus group interview. On this basis, an assessment tool with eight items was designed. Ten surgeons and surgical trainees were video recorded while performing Lichtenstein hernia repair, (four experts, three intermediates, and three novices). The videos were blindly and individually assessed by three raters (surgical consultants) using the assessment tool. Based on these assessments, validity and reliability were explored. The internal consistency of the items was high (Cronbach's alpha = 0.97). The inter-rater reliability was very good with an intra-class correlation coefficient (ICC) = 0.93. Generalizability analysis showed a coefficient above 0.8 even with one rater. The coefficient improved to 0.92 if three raters were used. One-way analysis of variance found a significant difference between the three groups which indicates construct validity, p fashion with the new procedure-specific assessment tool. We recommend this tool for future assessment of trainees performing Lichtenstein hernia repair to ensure that the objectives of competency-based surgical training are met.

  10. Reliability of reflectance measures in passive filters

    Science.gov (United States)

    Saldiva de André, Carmen Diva; Afonso de André, Paulo; Rocha, Francisco Marcelo; Saldiva, Paulo Hilário Nascimento; Carvalho de Oliveira, Regiani; Singer, Julio M.

    2014-08-01

    Measurements of optical reflectance in passive filters impregnated with a reactive chemical solution may be transformed to ozone concentrations via a calibration curve and constitute a low cost alternative for environmental monitoring, mainly to estimate human exposure. Given the possibility of errors caused by exposure bias, it is common to consider sets of m filters exposed during a certain period to estimate the latent reflectance on n different sample occasions at a certain location. Mixed models with sample occasions as random effects are useful to analyze data obtained under such setups. The intra-class correlation coefficient of the mean of the m measurements is an indicator of the reliability of the latent reflectance estimates. Our objective is to determine m in order to obtain a pre-specified reliability of the estimates, taking possible outliers into account. To illustrate the procedure, we consider an experiment conducted at the Laboratory of Experimental Air Pollution, University of São Paulo, Brazil (LPAE/FMUSP), where sets of m = 3 filters were exposed during 7 days on n = 9 different occasions at a certain location. The results show that the reliability of the latent reflectance estimates for each occasion obtained under homoskedasticity is km = 0.74. A residual analysis suggests that the within-occasion variance for two of the occasions should be different from the others. A refined model with two within-occasion variance components was considered, yielding km = 0.56 for these occasions and km = 0.87 for the remaining ones. To guarantee that all estimates have a reliability of at least 80% we require measurements on m = 10 filters on each occasion.

  11. Relative and Absolute Reliability of Timed Up and Go Test in Community Dwelling Older Adult and Healthy Young People

    Directory of Open Access Journals (Sweden)

    Farhad Azadi

    2014-01-01

    Full Text Available Objectives: Relative and absolute reliability are psychometric properties of the test that many clinical decisions are based on them. In many cases, only relative reliability takes into consideration while the absolute reliability is also very important. Methods & Materials: Eleven community-dwelling older adults aged 65 years and older (69.64±3.58 and 20 healthy young in the age range 20 to 35 years (28.80±4.15 using three versions of Timed Up and Go test were evaluated twice with an interval of 2 to 5 days. Results: Generally, the non-homogeneity of the study population was stratified to increase the Intra-class Correlation Coefficient (ICC this coefficient in elderly people is greater than young people and with a secondary task is reduced. In This study, absolute reliability indices using different data sources and equations lead to in more or less similar results. At general, in test–retest situations, the elderly more than the young people must be changed to be interpreted as a real change, not random. The random error contribution is slightly greater in elderly than young and with a secondary task is increased.It seems, heterogeneity leads to moderation in absolute reliability indices. Conclusion: In relative reliability studies, researchers and clinicians should pay attention to factors such as homogeneity of population and etc. As well as, absolute reliability beside relative reliability is needed and necessary in clinical decision making.

  12. Reliability of histologic assessment in patients with eosinophilic oesophagitis.

    Science.gov (United States)

    Warners, M J; Ambarus, C A; Bredenoord, A J; Verheij, J; Lauwers, G Y; Walsh, J C; Katzka, D A; Nelson, S; van Viegen, T; Furuta, G T; Gupta, S K; Stitt, L; Zou, G; Parker, C E; Shackelton, L M; D Haens, G R; Sandborn, W J; Dellon, E S; Feagan, B G; Collins, M H; Jairath, V; Pai, R K

    2018-04-01

    The validity of the eosinophilic oesophagitis (EoE) histologic scoring system (EoEHSS) has been demonstrated, but only preliminary reliability data exist. Formally assess the reliability of the EoEHSS and additional histologic features. Four expert gastrointestinal pathologists independently reviewed slides from adult patients with EoE (N = 45) twice, in random order, using standardised training materials and scoring conventions for the EoEHSS and additional histologic features agreed upon during a modified Delphi process. Intra- and inter-rater reliability for scoring the EoEHSS, a visual analogue scale (VAS) of overall histopathologic disease severity, and additional histologic features were assessed using intra-class correlation coefficients (ICCs). Almost perfect intra-rater reliability was observed for the composite EoEHSS scores and the VAS. Inter-rater reliability was also almost perfect for the composite EoEHSS scores and substantial for the VAS. Of the EoEHSS items, eosinophilic inflammation was associated with the highest ICC estimates and consistent with almost perfect intra- and inter-rater reliability. With the exception of dyskeratotic epithelial cells and surface epithelial alteration, ICC estimates for the remaining EoEHSS items were above the benchmarks for substantial intra-rater, and moderate inter-rater reliability. Estimation of peak eosinophil count and number of lamina propria eosinophils were associated with the highest ICC estimates among the exploratory items. The composite EoEHSS and most component items are associated with substantial reliability when assessed by central pathologists. Future studies should assess responsiveness of the score to change after a therapeutic intervention to facilitate its use in clinical trials. © 2018 John Wiley & Sons Ltd.

  13. Testing the reliability of the Fall Risk Screening Tool in an elderly ambulatory population.

    Science.gov (United States)

    Fielding, Susan J; McKay, Michael; Hyrkas, Kristiina

    2013-11-01

    To identify and test the reliability of a fall risk screening tool in an ambulatory outpatient clinic. The Fall Risk Screening Tool (Albert Lea Medical Center, MN, USA) was scripted for an interview format. Two interviewers separately screened a convenience sample of 111 patients (age ≥ 65 years) in an ambulatory outpatient clinic in a northeastern US city. The interviewers' scoring of fall risk categories was similar. There was good internal consistency (Cronbach's α = 0.834-0.889) and inter-rater reliability [intra-class correlation coefficients (ICC) = 0.824-0.881] for total, Risk Factor and Client's Health Status subscales. The Physical Environment scores indicated acceptable internal consistency (Cronbach's α = 0.742) and adequate reliability (ICC = 0.688). Two Physical Environment items (furniture and medical equipment condition) had low reliabilities [Kappa (K) = 0.323, P = 0.08; K = -0.078, P = 0.648), respectively. The scripted Fall Risk Screening Tool demonstrated good reliability in this sample. Rewording two Physical Environment items will be considered. A reliable instrument such as the scripted Fall Risk Screening Tool provides a standardised assessment for identifying high fall risk patients. This tool is especially useful because it assesses personal, behavioural and environmental factors specific to community-dwelling patients; the interview format also facilitates patient-provider interaction. © 2013 John Wiley & Sons Ltd.

  14. Rater reliability and concurrent validity of the Keyboard Personal Computer Style instrument (K-PeCS).

    Science.gov (United States)

    Baker, Nancy A; Cook, James R; Redfern, Mark S

    2009-01-01

    This paper describes the inter-rater and intra-rater reliability, and the concurrent validity of an observational instrument, the Keyboard Personal Computer Style instrument (K-PeCS), which assesses stereotypical postures and movements associated with computer keyboard use. Three trained raters independently rated the video clips of 45 computer keyboard users to ascertain inter-rater reliability, and then re-rated a sub-sample of 15 video clips to ascertain intra-rater reliability. Concurrent validity was assessed by comparing the ratings obtained using the K-PeCS to scores developed from a 3D motion analysis system. The overall K-PeCS had excellent reliability [inter-rater: intra-class correlation coefficients (ICC)=.90; intra-rater: ICC=.92]. Most individual items on the K-PeCS had from good to excellent reliability, although six items fell below ICC=.75. Those K-PeCS items that were assessed for concurrent validity compared favorably to the motion analysis data for all but two items. These results suggest that most items on the K-PeCS can be used to reliably document computer keyboarding style.

  15. Correlation Relationship of Performance Shaping Factors (PSFs) for Human Reliability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bheka, M. Khumalo; Kim, Jonghyun [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-10-15

    At TMI-2, operators permitted thousands of gallons of water to escape from the reactor plant before realizing that the coolant pumps were behaving abnormally. The coolant pumps were then turned off, which in turn led to the destruction of the reactor itself as cooling was completely lost within the core. Human also plays a role in many aspects of complex systems e.g. in design and manufacture of hardware, interface between human and system and also in maintaining such systems as well as for coping with unusual events that place the NPP system at a risk. This is why human reliability analysis (HRA) - an aspect of risk assessments which systematically identifies and analyzes the causes and consequences of human decisions and actions - is important in nuclear power plant operations. It either upgrades or degrades human performance; therefore it has an impact on the possibility of error. These PSFs can be used in various HRA methods to estimate Human Error Probabilities (HEPs). There are many current HRA methods who propose sets of PSFs for normal operation mode of NPP. Some of these PSFs in the sets have some degree of dependency and overlap. Overlapping PSFs introduce error in HEP evaluations due to the fact that some elements are counted more than once in data; this skews the relationship amongst PSF and masks the way that the elements interact to affect performance. This study uses a causal model that represents dependencies and relationships amongst PSFs for HEP evaluation during normal NPP operational states. The model is built taking into consideration the dependencies among PSFs and thus eliminating overlap. The use of an interdependent model of PSFs is expected to produce more accurate HEPs compared to other current methods. PSF sets produced in this study can be further used as nodes (variables) and directed arcs (causal influence between nodes) in HEP evaluation methods such as Bayesian belief (BN) networks. This study was done to estimate the relationships

  16. Test-retest reliability of pulse amplitude tonometry measures of vascular endothelial function: implications for clinical trial design.

    Science.gov (United States)

    McCrea, Cindy E; Skulas-Ray, Ann C; Chow, Mosuk; West, Sheila G

    2012-02-01

    Endothelial dysfunction is an important outcome for assessing vascular health in intervention studies. However, reliability of the standard non-invasive method (flow-mediated dilation) is a significant challenge for clinical applications and multicenter trials. We evaluated the repeatability of pulse amplitude tonometry (PAT) to measure change in pulse wave amplitude during reactive hyperemia (Itamar Medical Ltd, Caesarea, Israel). Twenty healthy adults completed two PAT tests (mean interval = 19.5 days) under standardized conditions. PAT-derived measures of endothelial function (reactive hyperemia index, RHI) and arterial stiffness (augmentation index, AI) showed strong repeatability (intra-class correlations = 0.74 and 0.83, respectively). To guide future research, we also analyzed sample size requirements for a range of effect sizes. A crossover design powered at 0.90 requires 28 participants to detect a 15% change in RHI. Our study is the first to show that PAT measurements are repeatable in adults over an interval greater than 1 week.

  17. Reliability of fetal cardiac volumetry using spatiotemporal image correlation: assessment of in-vivo and in-vitro measurements

    NARCIS (Netherlands)

    Uittenbogaard, L.B.; Haak, M.C.; Tromp, C.H.N.; Terwee, C.B.; van Vugt, J.M.G.

    2010-01-01

    Objective To assess the reliability of measurement of fetal cardiac ventricular volume, stroke volume, and ejection fraction with four-dimensional ultrasound using spatiotemporal image correlation (STIC). Methods Volume datasets were collected from two sources: 24 from fetuses over a range of

  18. Reliability of intra-oral quantitative sensory testing (QST) in patients with atypical odontalgia and healthy controls - a multicentre study.

    Science.gov (United States)

    Baad-Hansen, L; Pigg, M; Yang, G; List, T; Svensson, P; Drangsholt, M

    2015-02-01

    The reliability of comprehensive intra-oral quantitative sensory testing (QST) protocol has not been examined systematically in patients with chronic oro-facial pain. The aim of the present multicentre study was to examine test-retest and interexaminer reliability of intra-oral QST measures in terms of absolute values and z-scores as well as within-session coefficients of variation (CV) values in patients with atypical odontalgia (AO) and healthy pain-free controls. Forty-five patients with AO and 68 healthy controls were subjected to bilateral intra-oral gingival QST and unilateral extratrigeminal QST (thenar) on three occasions (twice on 1 day by two different examiners and once approximately 1 week later by one of the examiners). Intra-class correlation coefficients and kappa values for interexaminer and test-retest reliability were computed. Most of the standardised intra-oral QST measures showed fair to excellent interexaminer (9-12 of 13 measures) and test-retest (7-11 of 13 measures) reliability. Furthermore, no robust differences in reliability measures or within-session variability (CV) were detected between patients with AO and the healthy reference group. These reliability results in chronic orofacial pain patients support earlier suggestions based on data from healthy subjects that intra-oral QST is sufficiently reliable for use as a part of a comprehensive evaluation of patients with somatosensory disturbances or neuropathic pain in the trigeminal region. © 2014 John Wiley & Sons Ltd.

  19. reliability reliability

    African Journals Online (AJOL)

    eobe

    Corresponding author, Tel: +234-703. RELIABILITY .... V , , given by the code of practice. However, checks must .... an optimization procedure over the failure domain F corresponding .... of Concrete Members based on Utility Theory,. Technical ...

  20. Reliability of ultrasonographic measurements in suspected patients of developmental dysplasia of the hip and correlation with the acetabular index

    Directory of Open Access Journals (Sweden)

    Cem Copuroglu

    2011-01-01

    Full Text Available Background: Ultrasonography is accepted as a useful imaging modality in the early detection of developmental dysplasia of the hip (DDH. Early detection and early treatment of DDH prevents hip dislocation and related physical, social, economic, and psychological problems. The purpose of this study was to evaluate the reliability of ultrasonographic and roentgenographic measurements measured by seven different observers. Materials and Methods: The alpha angles of 66 hips in 33 patients were measured using the Graf method by seven different observers. Acetabular index degrees on plane roentgenograms were measured in order to assess the correlation between the ultrasonographic alpha angle and the radiographic acetabular index, which both show the bony acetabular depth, retrospectively. Results: The interclass correlation coefficient, measuring the interobserver reliability, was high and statistically significant for the ultrasonographic measurements. There was a negative correlation between the alpha angle and the acetabular index. Conclusions: Ultrasonography, when applied properly, is a reliable technique between different observers, in the diagnosis and follow up of DDH. When assessed concomitantly with the roentgenographic measurements, the results are reliable and statistically meaningful.

  1. Reliability and Validity of the Multidimensional Scale of Perceived Social Support (MSPSS): Thai Version.

    Science.gov (United States)

    Wongpakaran, Tinakon; Wongpakaran, Nahathai; Ruktrakul, Ruk

    2011-01-01

    This study examines the Thai version of the Multidimensional Scale of Perceived Social Support (MSPSS) for its psychometric properties. In total 462 participants were recruited - 310 medical students from Chiang Mai University and 152 psychiatric patients, and they completed the Thai version of the MSPSS, the State Trait Anxiety Inventory (STAI), the Rosenberg Self-Esteem Scale (RSES) and the Thai Depression Inventory (TDI). Test-retest reliability was conducted over a four week period. Factor analysis produced three-factor solutions for both patient (PG) and student groups (SG), and overall the model demonstrated adequate fit indices. The mean total score and the sub-scale score for the SG were statistically higher than those in the PG, except for 'Significant Others'. The internal consistency of the scale was good, with a Cronbach's alpha of 0.91 for the SG and 0.87 for the PG. After a four week retest for reliability exercise, the intra-class correlation coefficient (ICC) was found to be 0.84. The Thai-MSPSS was found to have a negative correlation with the STAI and the TDI, but was positively correlated with the RSES. The Thai MSPSS is a reliable and valid instrument to use.

  2. The Reliability of Anthropometric Measurements Used Preoperatively in Aesthetic Breast Surgery.

    Science.gov (United States)

    Isaac, Kathryn V; Murphy, Blake D; Beber, Brett; Brown, Mitchell

    2016-04-01

    Patient outcomes in aesthetic breast surgery are highly dependent on breast measurements used in preoperative planning. The purpose of this study is to determine the reliability of anthropometric breast measurements. Four raters measured 28 women using 7 measurements: sternal notch to nipple distance (Sn-N), nipple to midline (N-M), nipple to inframammary-fold distance under maximal stretch (N-IMF), breast base width (BW), soft tissue pinch thickness of the upper pole (STPT:UP), STPT at the inframammary fold (STPT:IMF), and anterior pull skin stretch (APSS). Reliability was assessed using intra-class correlation coefficients (ICCs). Inter-rater reliability was excellent for Sn-N, N-M, and BW (ICC = 0.94, 0.90, and 0.76, respectively) and was good for N-IMF (ICC = 0.70). The STPT:UP, STPT:IMF, and APSS measurements were not reliable between raters (ICC reliability was excellent for Sn-N, N-M, and BW for all raters (all ICC > 0.75). The N-IMF intra-rater reliability was excellent in senior raters (ICC > 0.75) and good in junior raters (ICC > 0.6). The STPT:UP, STPT:IMF, and APSS measurements showed fair or poor reliability for most raters (ICC reliable. Dynamic measurements including APSS, STPT:UP, and STUP:IMF are unreliable. N-IMF is the only reliable dynamic measurement, and its reliability improves with increasing clinical experience. The variable reliability of preoperative measurements must be considered in the planning of aesthetic breast surgery. 4 Diagnostic. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  3. Reliability of concentrations of organophosphate pesticide metabolites in serial urine specimens from pregnancy in the Generation R study

    Science.gov (United States)

    Spaan, Suzanne; Pronk, Anjoeka; Koch, Holger M.; Jusko, Todd A.; Jaddoe, Vincent W.V.; Shaw, Pamela A.; Tiemeier, Henning M.; Hofman, Albert; Pierik, Frank H.; Longnecker, Matthew P.

    2014-01-01

    The widespread use of organophosphate (OP) pesticides has resulted in ubiquitous exposure in humans, primarily through their diet. Exposure to OP pesticides may have adverse health effects, including neurobehavioral deficits in children. The optimal design of new studies requires data on the reliability of urinary measures of exposure. In the present study, urinary concentrations of six dialkyl phosphate (DAP) metabolites, the main urinary metabolites of OP pesticides, were determined in 120 pregnant women participating in the Generation R Study in Rotterdam. Intra-class correlation coefficients (ICCs) across serial urine specimens taken at 25 weeks of pregnancy were determined to assess reliability. Geometric mean total DAP metabolite concentrations were 229 (GSD 2.2), 240 (GSD 2.1), and 224 (GSD 2.2) nmol/g creatinine across the three periods of gestation. Metabolite concentrations from the serial urine specimens in general correlated moderately. The ICCs for the six DAP metabolites ranged from 0.14 to 0.38 (0.30 for total DAPs), indicating weak to moderate reliability. Although the DAP metabolite levels observed in this study are slightly higher and slightly more correlated than in previous studies, the low to moderate reliability indicates a high degree of within-person variability, which presents challenges for designing well-powered epidemiologic studies. PMID:25515376

  4. Further Investigation of the SI Scale of the MMPI: Reliabilities, Correlates, and Subscale Utility.

    Science.gov (United States)

    Williams, Carolyn L.

    1983-01-01

    Administered the SI scale of the Minnesota Multiphasic Personality Inventory (MMPI) and several measures typically used in social skills and assertiveness training research to college students (N=218). Results demonstrated acceptable reliability and support for the utility of the subscales of the SI scale of the MMPI. (LLL)

  5. Integration of external estimated breeding values and associated reliabilities using correlations among traits and effects

    NARCIS (Netherlands)

    Vandenplas, J.; Colinet, F.G.; Glorieux, G.; Bertozzi, C.; Gengler, N.

    2015-01-01

    Based on a Bayesian view of linear mixed models, several studies showed the possibilities to integrate estimated breeding values (EBV) and associated reliabilities (REL) provided by genetic evaluations performed outside a given evaluation system into this genetic evaluation. Hereafter, the term

  6. The Korean version of relative and absolute reliability of gait and balance assessment tools for patients with dementia in day care center and nursing home.

    Science.gov (United States)

    Lee, Han Suk; Park, Sun Wook; Chung, Hyung Kuk

    2017-11-01

    [Purpose] This study was aimed to determine the relative and absolute reliability of Korean version tools of the Berg Balance Scale (BBS), the Timed Up and Go (TUG), the Four-Meter Walking Test (4MWT) and the Groningen Meander Walking Test (GMWT) in patients with dementia. [Subjects and Methods] A total of 53 patients with dementia were tested on TUG, BBS, 4MWT and GMWT with a prospective cohort methodological design. Intra-class Correlation Coefficients (ICCs) to assess relative reliability and the standard error of measurement (SEM), minimal detectable change (MDC 95 ) and its percentage (MDC % ) to analyze the absolute reliability were calculated. [Results] Inter-rater reliability (ICC (2,3) ) of TUG, BBS and GMWT was 0.99 and that of 4MWT was 0.82. Inter-rater reliability was high for TUG, BBS and GMWT, with low SEM, MDC 95 , and MDC % . Inter-rater reliability was low for 4MWT, with high SEM, MDC 95 , and MDC % . Test-retest (ICC (2,3) ) of TUG, BBS and GMWT was 0.96-0.99 and Test-retest (ICC (2,3) ) of 4MWT was 0.85. The test-retest was high for TUG, BBS and GMWT, with low SEM, MDC 95 , and MDC % , but it was low for 4MWT, with high SEM, MDC 95 , and MDC % . [Conclusion] The relative reliability was high for all the assessment tools. The absolute reliability has a reasonable level of stability except the 4MWT.

  7. The validity and reliability of the Persian version of the Revised Fibromyalgia Impact Questionnaire.

    Science.gov (United States)

    Ghavidel Parsa, Banafsheh; Amir Maafi, Alireza; Haghdoost, Afrooz; Arabi, Yasaman; Khojamli, Monire; Chatrnour, Gelayol; Bidari, Ali

    2014-02-01

    The Revised Fibromyalgia Impact Questionnaire (FIQR), an updated version of the Fibromyalgia Impact Questionnaire (FIQ) achieved a better balance among different domains (i.e., function, overall impact, and symptom severity) and attempts to address the limitations of FIQ. As there is no Persian version of the FIQR available, we aimed to investigate the validity and reliability of a Persian translation of the FIQR in Iranian patients. After translating the FIQR into Persian, it was administered to 77 female patients with fibromyalgia syndrome. All of the patients filled out the questionnaire together with a Persian version of the FIQ, short form-12 (SF-12). The tender-point count was also calculated. One week later, FM patients filled out the Persian FIQR at their second visit. Reliability was analyzed by internal consistency and reproducibility including Cronbach's α coefficient and intra-class correlation coefficient. Construct validity was evaluated by Spearman's correlation coefficient and Pearson's correlation coefficient. Statistical analysis was performed using SPSS for Windows version 17.0. All patients included in this study were female, and the mean age was 38.23 ± 10.68 years. The total scores of the FIQR and FIQ were 49.77 ± 18.27 and 54.05 ± 14.00 that were closely correlated (r = 0.63, p FIQ domains (r = 0.36-0.63, p fibromyalgia.

  8. Reliability of Coulomb stress changes inferred from correlated uncertainties of finite-fault source models

    KAUST Repository

    Woessner, J.

    2012-07-14

    Static stress transfer is one physical mechanism to explain triggered seismicity. Coseismic stress-change calculations strongly depend on the parameterization of the causative finite-fault source model. These models are uncertain due to uncertainties in input data, model assumptions, and modeling procedures. However, fault model uncertainties have usually been ignored in stress-triggering studies and have not been propagated to assess the reliability of Coulomb failure stress change (ΔCFS) calculations. We show how these uncertainties can be used to provide confidence intervals for co-seismic ΔCFS-values. We demonstrate this for the MW = 5.9 June 2000 Kleifarvatn earthquake in southwest Iceland and systematically map these uncertainties. A set of 2500 candidate source models from the full posterior fault-parameter distribution was used to compute 2500 ΔCFS maps. We assess the reliability of the ΔCFS-values from the coefficient of variation (CV) and deem ΔCFS-values to be reliable where they are at least twice as large as the standard deviation (CV ≤ 0.5). Unreliable ΔCFS-values are found near the causative fault and between lobes of positive and negative stress change, where a small change in fault strike causes ΔCFS-values to change sign. The most reliable ΔCFS-values are found away from the source fault in the middle of positive and negative ΔCFS-lobes, a likely general pattern. Using the reliability criterion, our results support the static stress-triggering hypothesis. Nevertheless, our analysis also suggests that results from previous stress-triggering studies not considering source model uncertainties may have lead to a biased interpretation of the importance of static stress-triggering.

  9. Reliability of a computer and Internet survey (Computer User Profile) used by adults with and without traumatic brain injury (TBI).

    Science.gov (United States)

    Kilov, Andrea M; Togher, Leanne; Power, Emma

    2015-01-01

    To determine test-re-test reliability of the 'Computer User Profile' (CUP) in people with and without TBI. The CUP was administered on two occasions to people with and without TBI. The CUP investigated the nature and frequency of participants' computer and Internet use. Intra-class correlation coefficients and kappa coefficients were conducted to measure reliability of individual CUP items. Descriptive statistics were used to summarize content of responses. Sixteen adults with TBI and 40 adults without TBI were included in the study. All participants were reliable in reporting demographic information, frequency of social communication and leisure activities and computer/Internet habits and usage. Adults with TBI were reliable in 77% of their responses to survey items. Adults without TBI were reliable in 88% of their responses to survey items. The CUP was practical and valuable in capturing information about social, leisure, communication and computer/Internet habits of people with and without TBI. Adults without TBI scored more items with satisfactory reliability overall in their surveys. Future studies may include larger samples and could also include an exploration of how people with/without TBI use other digital communication technologies. This may provide further information on determining technology readiness for people with TBI in therapy programmes.

  10. Correlation and Reliability of Cervical Sagittal Alignment Parameters between Lateral Cervical Radiograph and Lateral Whole-Body EOS Stereoradiograph

    Science.gov (United States)

    Singhatanadgige, Weerasak; Kang, Daniel G.; Luksanapruksa, Panya; Peters, Colleen; Riew, K. Daniel

    2015-01-01

    Study Design  Retrospective analysis. Objective  To evaluate the correlation and reliability of cervical sagittal alignment parameters obtained from lateral cervical radiographs (XRs) compared with lateral whole-body stereoradiographs (SRs). Methods  We evaluated adults with cervical deformity using both lateral XRs and lateral SRs obtained within 1 week of each other between 2010 and 2014. XR and SR images were measured by two independent spine surgeons using the following sagittal alignment parameters: C2–C7 sagittal Cobb angle (SCA), C2–C7 sagittal vertical axis (SVA), C1–C7 translational distance (C1–7), T1 slope (T1-S), neck tilt (NT), and thoracic inlet angle (TIA). Pearson correlation and paired t test were used for statistical analysis, with intra- and interrater reliability analyzed using intraclass correlation coefficient (ICC). Results  A total of 35 patients were included in the study. We found excellent intrarater reliability for all sagittal alignment parameters in both the XR and SR groups with ICC ranging from 0.799 to 0.994 for XR and 0.791 to 0.995 for SR. Interrater reliability was also excellent for all parameters except NT and TIA, which had fair reliability. We also found excellent correlations between XR and SR measurements for most sagittal alignment parameters; SCA, SVA, and C1–C7 had r > 0.90, and only NT had r < 0.70. There was a significant difference between groups, with SR having lower measurements compared with XR for both SVA (0.68 cm lower, p < 0.001) and C1–C7 (1.02 cm lower, p < 0.001). There were no differences between groups for SCA, T1-S, NT, and TIA. Conclusion  Whole-body stereoradiography appears to be a viable alternative for measuring cervical sagittal alignment parameters compared with standard radiography. XR and SR demonstrated excellent correlation for most sagittal alignment parameters except NT. However, SR had significantly lower average SVA and C1–C7 measurements than XR

  11. Content Validity and Reliability of Multiple Intelligences Developmental Assessment Scales (MIDAS Translated into Persian

    Directory of Open Access Journals (Sweden)

    Mahnaz Saeidi

    2012-11-01

    Full Text Available This study aimed to translate MIDAS questionnaire from English into Persian and determine its content validity and reliability. MIDAS was translated and validated on a sample (N = 110 of Iranian adult population. The participants were both male and female with the age range of 17-57. They were at different educational levels and from different ethnic groups in Iran. A translating team, consisting of five members, bilingual in English and Persian and familiar with multiple intelligences (MI theory and practice, were involved in translating and determining content validity, which included the processes of forward translation, back-translation, review, final proof-reading, and testing. The statistical analyses of inter-scale correlation were performed using the Cronbach's alpha coefficient. In an intra-class correlation, the Cronbach's alpha was high for all of the questions. Translation and content validity of MIDAS questionnaire was completed by a proper process leading to high reliability and validity. The results suggest that Persian MIDAS (P-MIDAS could serve as a valid and reliable instrument for measuring Iranian adults MIs.

  12. Reliability of cervical lordosis and global sagittal spinal balance measurements in adolescent idiopathic scoliosis.

    Science.gov (United States)

    Vidal, Christophe; Ilharreborde, Brice; Azoulay, Robin; Sebag, Guy; Mazda, Keyvan

    2013-06-01

    Radiological reproducibility study. To assess intra and interobserver reliability of radiographic measurements for global sagittal balance parameters and sagittal spine curves, including cervical spine. Sagittal spine balance in adolescent idiopathic scoliosis (AIS) is a main issue and many studies have been reported, showing that coronal and sagittal deformities often involve sagittal cervical unbalance. Global sagittal balance aims to obtain a horizontal gaze and gravity line at top of hips when subject is in a static position, involving adjustment of each spine curvature in the sagittal plane. To our knowledge, no study did use a methodologically validated imaging analysis tool able to appreciate sagittal spine contours and distances in AIS and especially in the cervical region. Lateral full-spine low-dose EOS radiographs were performed in 75 patients divided in three groups (control subjects, AIS, operated AIS). Three observers digitally analyzed twice each radiograph and 11 sagittal measures were collected for each image. Reliability was assessed calculating intraobserver Pearson's r correlation coefficient, interobserver intra-class correlation coefficient (ICC) completed with a two-by-two Bland-Altman plot analysis. This measurement method has shown excellent intra and interobserver reliability in all parameters, sagittal curvatures, pelvic parameters and global sagittal balance. This study validated a simple and efficient tool in AIS sagittal contour analysis. It defined new relevant landmarks allowing to characterize cervical segmental curvatures and cervical involvement in global balance.

  13. Chest computed tomography-based scoring of thoracic sarcoidosis: Inter-rater reliability of CT abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Heuvel, D.A.V. den; Es, H.W. van; Heesewijk, J.P. van; Spee, M. [St. Antonius Hospital Nieuwegein, Department of Radiology, Nieuwegein (Netherlands); Jong, P.A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Zanen, P.; Grutters, J.C. [University Medical Center Utrecht, Division Heart and Lungs, Utrecht (Netherlands); St. Antonius Hospital Nieuwegein, Center of Interstitial Lung Diseases, Department of Pulmonology, Nieuwegein (Netherlands)

    2015-09-15

    To determine inter-rater reliability of sarcoidosis-related computed tomography (CT) findings that can be used for scoring of thoracic sarcoidosis. CT images of 51 patients with sarcoidosis were scored by five chest radiologists for various abnormal CT findings (22 in total) encountered in thoracic sarcoidosis. Using intra-class correlation coefficient (ICC) analysis, inter-rater reliability was analysed and reported according to the Guidelines for Reporting Reliability and Agreement Studies (GRRAS) criteria. A pre-specified sub-analysis was performed to investigate the effect of training. Scoring was trained in a distinct set of 15 scans in which all abnormal CT findings were represented. Median age of the 51 patients (36 men, 70 %) was 43 years (range 26 - 64 years). All radiographic stages were present in this group. ICC ranged from 0.91 for honeycombing to 0.11 for nodular margin (sharp versus ill-defined). The ICC was above 0.60 in 13 of the 22 abnormal findings. Sub-analysis for the best-trained observers demonstrated an ICC improvement for all abnormal findings and values above 0.60 for 16 of the 22 abnormalities. In our cohort, reliability between raters was acceptable for 16 thoracic sarcoidosis-related abnormal CT findings. (orig.)

  14. Reliability and consistency of plantarflexor stretch-shortening cycle function using an adapted force sledge apparatus

    International Nuclear Information System (INIS)

    Furlong, Laura-Anne M; Harrison, Andrew J

    2013-01-01

    There are various limitations to existing methods of studying plantarflexor stretch-shortening cycle (SSC) function and muscle-tendon unit (MTU) mechanics, predominantly related to measurement validity and reliability. This study utilizes an innovative adaptation to a force sledge which isolates the plantarflexors and ankle for analysis. The aim of this study was to determine the sledge loading protocol to be used, most appropriate method of data analysis and measurement reliability in a group of healthy, non-injured subjects. Twenty subjects (11 males, 9 females; age: 23.5 ±2.3 years; height: 1.73 ±0.08 m; mass: 74.2 ±11.3 kg) completed 11 impacts at five different loadings rated on a scale of perceived exertion from 1 to 5, where 5 is a loading that the subject could only complete the 11 impacts using the adapted sledge. Analysis of impacts 4–8 or 5–7 using loading 2 provided consistent results that were highly reliable (single intra-class correlation, ICC > 0.85, average ICC > 0.95) and replicated kinematics found in hopping and running. Results support use of an adapted force sledge apparatus as an ecologically valid, reliable method of investigating plantarflexor SSC function and MTU mechanics in a dynamic controlled environment. (paper)

  15. Reliability of the CMT neuropathy score (second version) in Charcot-Marie-Tooth disease.

    LENUS (Irish Health Repository)

    Murphy, Sinéad M

    2011-09-01

    The Charcot-Marie-Tooth neuropathy score (CMTNS) is a reliable and valid composite score comprising symptoms, signs, and neurophysiological tests, which has been used in natural history studies of CMT1A and CMT1X and as an outcome measure in treatment trials of CMT1A. Following an international workshop on outcome measures in Charcot-Marie-Tooth disease (CMT), the CMTNS was modified to attempt to reduce floor and ceiling effects and to standardize patient assessment, aiming to improve its sensitivity for detecting change over time and the effect of an intervention. After agreeing on the modifications made to the CMTNS (CMTNS2), three examiners evaluated 16 patients to determine inter-rater reliability; one examiner evaluated 18 patients twice within 8 weeks to determine intra-rater reliability. Three examiners evaluated 63 patients using the CMTNS and the CMTNS2 to determine how the modifications altered scoring. For inter- and intra-rater reliability, intra-class correlation coefficients (ICCs) were ≥0.96 for the CMT symptom score and the CMT examination score. There were small but significant differences in some of the individual components of the CMTNS compared with the CMTNS2, mainly in the components that had been modified the most. A longitudinal study is in progress to determine whether the CMTNS2 is more sensitive than the CMTNS for detecting change over time.

  16. Reliability and smallest real difference of the ankle lunge test post ankle fracture.

    Science.gov (United States)

    Simondson, David; Brock, Kim; Cotton, Susan

    2012-02-01

    This study aimed to determine the reliability and the smallest real difference of the Ankle Lunge test in an ankle fracture patient population. In the post immobilisation stage of ankle fracture, ankle dorsiflexion is an important measure of progress and outcome. The Ankle Lunge test measures weight bearing dorsiflexion, resulting in negative scores (knee to wall distance) and positive scores (toe to wall distance), for which the latter has proven reliability in normal subjects only. A consecutive sample of ankle fracture patients with permission to commence weight bearing, were recruited to the study. Three measurements of the Ankle Lunge Test were performed each by two raters, one senior and one junior physiotherapist. These occurred prior to therapy sessions in the second week after plaster removal. A standardised testing station was utilised and allowed for both knee to wall distance and toe to wall distance measurement. Data was collected from 10 individuals with ankle fracture, with an average age of 36 years (SD 14.8). Seventy seven percent of observations were negative. Intra and inter-rater reliability yielded intra class correlations at or above 0.97, p Ankle Lunge test is a practical and reliable tool for measuring weightbearing dorsiflexion post ankle fracture. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Chest computed tomography-based scoring of thoracic sarcoidosis: Inter-rater reliability of CT abnormalities

    International Nuclear Information System (INIS)

    Heuvel, D.A.V. den; Es, H.W. van; Heesewijk, J.P. van; Spee, M.; Jong, P.A. de; Zanen, P.; Grutters, J.C.

    2015-01-01

    To determine inter-rater reliability of sarcoidosis-related computed tomography (CT) findings that can be used for scoring of thoracic sarcoidosis. CT images of 51 patients with sarcoidosis were scored by five chest radiologists for various abnormal CT findings (22 in total) encountered in thoracic sarcoidosis. Using intra-class correlation coefficient (ICC) analysis, inter-rater reliability was analysed and reported according to the Guidelines for Reporting Reliability and Agreement Studies (GRRAS) criteria. A pre-specified sub-analysis was performed to investigate the effect of training. Scoring was trained in a distinct set of 15 scans in which all abnormal CT findings were represented. Median age of the 51 patients (36 men, 70 %) was 43 years (range 26 - 64 years). All radiographic stages were present in this group. ICC ranged from 0.91 for honeycombing to 0.11 for nodular margin (sharp versus ill-defined). The ICC was above 0.60 in 13 of the 22 abnormal findings. Sub-analysis for the best-trained observers demonstrated an ICC improvement for all abnormal findings and values above 0.60 for 16 of the 22 abnormalities. In our cohort, reliability between raters was acceptable for 16 thoracic sarcoidosis-related abnormal CT findings. (orig.)

  18. The Test-Retest Reliability of New Generation Power Indices of Wingate All-Out Test

    Directory of Open Access Journals (Sweden)

    Ozgur Ozkaya

    2018-04-01

    Full Text Available Although reliability correlations of traditional power indices of the Wingate test have been well documented, no study has analyzed new generation power indices based on milliseconds obtained from a Peak Bike. The purpose of this study was to investigate the retest reliability of new generation power indices. Thirty-two well-trained male athletes who were specialized in basketball, football, tennis, or track and field volunteered to take part in the study (age: 24.3 ± 2.2 years; body mass: 77 ± 8.3 kg; height: 180.3 ± 6.3 cm. Participants performed two Wingate all-out sessions on two separate days. Intra-class correlation coefficient (ICC, standard error measurement (SEM, smallest real differences (SRD and coefficient of variation (CV scores were analyzed based on the test and retest data. Reliability results of traditional power indices calculated based on 5-s means such as peak power, average power, power drop, and fatigue index ratio were similar with the previous findings in literature (ICC ≥ 0.94; CV ≤ 2.8%; SEM ≤ 12.28; SRD% ≤ 7.7%. New generation power indices such as peak power, average power, lowest power, power drop, fatigue index, power decline, maximum speed as rpm, and amount of total energy expenditure demonstrated high reliability (ICC ≥ 0.94; CV ≤ 4.3%; SEM ≤ 10.36; SRD% ≤ 8.8%. Time to peak power, time at maximum speed, and power at maximum speed showed a moderate level of reliability (ICC ≥ 0.73; CV ≤ 8.9%; SEM ≤ 63.01; SRD% ≤ 22.4%. The results of this study indicate that reliability correlations and SRD% of new generation power and fatigue-related indices are similar with traditional 5-s means. However, new time-related indices are very sensitive and moderately reliable.

  19. Neighborhood walkability scale (News - Brazil: Back translation and Reliability

    Directory of Open Access Journals (Sweden)

    Jorge Both

    2007-12-01

    Full Text Available Existem, no Brasil, poucos instrumentos para avaliar a relação entre o ambiente físico e a prática de atividades físicas. O objetivo do estudo foi analisar a tradução, a retradução e a reprodutibilidade do questionário NEWS (Neighborhood Environment Walkability Scale para o português do Brasil. Os procedimentos metodológicos foram estruturados em duas etapas. Primeiramente, efetuou-se a tradução e a retradução do NEWS com o intuito de verificar a linguagem do instrumento. Em seguida, realizou-se a reprodutibilidade do questionário por meio de teste e re-teste. A amostra desta pesquisa teve a participação de 75 pessoas (45 mulheres e 30 homens, com média de 33 ± 15 anos. A correlação intraclasse, a fidedignidade para as dimensões, o teste de correlação de Spearman e a correlação intraclasse para os indicadores de cada dimensão deste instrumento foram analisados com o auxílio do pacote estatístico SPSS (versão 11.0. O nível de significância adotado foi de p ABSTRACT In Brazil, there are few validated scales that establish the relationship between environmental barriers and physical activity. Therefore, the aim of this study was to analyze the translation, back translation and reliability of the Neighborhood Environment Walkability Scale (NEWS into Brazilian Portuguese. The methodological procedures were structured in two phases. The first phase was to translate and back translate NEWS to verify the instrument language. The second phase was he test and re-test reliability of the questionnaire. The sample was composed of 75 people (45 women and 30 men, mean age of 33 ± 15 years. The statistical analyses to verify the Brazilian NEWS were performed with the SPSS program (version 11.0 for intra-class correlation and reliability for the dimensions; Spearman correlation test and intra-class correlation for all indicators from this questionnaire. The significance level adopted in this survey was p<0.05. The results in

  20. Reliable Evaluation of Temperature-Independent Parameters in Correlation of Vapour–Liquid Equilibrium Data.

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Jan; Wichterle, Ivan

    2007-01-01

    Roč. 260, 1 (2007) , s. 70-73 ISSN 0378-3812 R&D Projects: GA ČR(CZ) GA104/03/1555 Institutional research plan: CEZ:AV0Z40720504 Keywords : temperature dependence of parameters * isometric pentanols * correlation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.506, year: 2007

  1. Examining the Reliability of Interval Level Data Using Root Mean Square Differences and Concordance Correlation Coefficients

    Science.gov (United States)

    Barchard, Kimberly A.

    2012-01-01

    This article introduces new statistics for evaluating score consistency. Psychologists usually use correlations to measure the degree of linear relationship between 2 sets of scores, ignoring differences in means and standard deviations. In medicine, biology, chemistry, and physics, a more stringent criterion is often used: the extent to which…

  2. The Validity and Reliability Test of the Indonesian Version of Gastroesophageal Reflux Disease Quality of Life (GERD-QOL) Questionnaire.

    Science.gov (United States)

    Siahaan, Laura A; Syam, Ari F; Simadibrata, Marcellus; Setiati, Siti

    2017-01-01

    to obtain a valid and reliable GERD-QOL questionnaire for Indonesian application. at the initial stage, the GERD-QOL questionnaire was first translated into Indonesian language and the translated questionnaire was subsequently translated back into the original language (back-to-back translation). The results were evaluated by the researcher team and therefore, an Indonesian version of GERD-QOL questionnaire was developed. Ninety-one patients who had been clinically diagnosed with GERD based on the Montreal criteria were interviewed using the Indonesian version of GERD-QOL questionnaire and the SF 36 questionnaire. The validity was evaluated using a method of construct validity and external validity, and reliability can be tested by the method of internal consistency and test retest. the Indonesian version of GERD-QOL questionnaire had a good internal consistency reliability with a Cronbach Alpha of 0.687-0.842 and a good test retest reliability with an intra-class correlation coefficient of 0.756-0.936; pGERD-QOL questionnaire has been proven valid and reliable to evaluate the quality of life of GERD patients.

  3. Validity and reliability of a low-cost digital dynamometer for measuring isometric strength of lower limb.

    Science.gov (United States)

    Romero-Franco, Natalia; Jiménez-Reyes, Pedro; Montaño-Munuera, Juan A

    2017-11-01

    Lower limb isometric strength is a key parameter to monitor the training process or recognise muscle weakness and injury risk. However, valid and reliable methods to evaluate it often require high-cost tools. The aim of this study was to analyse the concurrent validity and reliability of a low-cost digital dynamometer for measuring isometric strength in lower limb. Eleven physically active and healthy participants performed maximal isometric strength for: flexion and extension of ankle, flexion and extension of knee, flexion, extension, adduction, abduction, internal and external rotation of hip. Data obtained by the digital dynamometer were compared with the isokinetic dynamometer to examine its concurrent validity. Data obtained by the digital dynamometer from 2 different evaluators and 2 different sessions were compared to examine its inter-rater and intra-rater reliability. Intra-class correlation (ICC) for validity was excellent in every movement (ICC > 0.9). Intra and inter-tester reliability was excellent for all the movements assessed (ICC > 0.75). The low-cost digital dynamometer demonstrated strong concurrent validity and excellent intra and inter-tester reliability for assessing isometric strength in the main lower limb movements.

  4. Validity and reliability of a novel immunosuppressive adverse effects scoring system in renal transplant recipients.

    Science.gov (United States)

    Meaney, Calvin J; Arabi, Ziad; Venuto, Rocco C; Consiglio, Joseph D; Wilding, Gregory E; Tornatore, Kathleen M

    2014-06-12

    After renal transplantation, many patients experience adverse effects from maintenance immunosuppressive drugs. When these adverse effects occur, patient adherence with immunosuppression may be reduced and impact allograft survival. If these adverse effects could be prospectively monitored in an objective manner and possibly prevented, adherence to immunosuppressive regimens could be optimized and allograft survival improved. Prospective, standardized clinical approaches to assess immunosuppressive adverse effects by health care providers are limited. Therefore, we developed and evaluated the application, reliability and validity of a novel adverse effects scoring system in renal transplant recipients receiving calcineurin inhibitor (cyclosporine or tacrolimus) and mycophenolic acid based immunosuppressive therapy. The scoring system included 18 non-renal adverse effects organized into gastrointestinal, central nervous system and aesthetic domains developed by a multidisciplinary physician group. Nephrologists employed this standardized adverse effect evaluation in stable renal transplant patients using physical exam, review of systems, recent laboratory results, and medication adherence assessment during a clinic visit. Stable renal transplant recipients in two clinical studies were evaluated and received immunosuppressive regimens comprised of either cyclosporine or tacrolimus with mycophenolic acid. Face, content, and construct validity were assessed to document these adverse effect evaluations. Inter-rater reliability was determined using the Kappa statistic and intra-class correlation. A total of 58 renal transplant recipients were assessed using the adverse effects scoring system confirming face validity. Nephrologists (subject matter experts) rated the 18 adverse effects as: 3.1 ± 0.75 out of 4 (maximum) regarding clinical importance to verify content validity. The adverse effects scoring system distinguished 1.75-fold increased gastrointestinal adverse

  5. Spectrum-energy Correlations in GRBs: Update, Reliability, and the Long/Short Dichotomy

    Science.gov (United States)

    Zhang, Z. B.; Zhang, C. T.; Zhao, Y. X.; Luo, J. J.; Jiang, L. Y.; Wang, X. L.; Han, X. L.; Terheide, R. K.

    2018-05-01

    Spectrum-energy correlations of peak energy with total prompt γ-ray emission energies, namely {E}p,i-{E}{iso}, {E}p,i-{E}γ , and {E}p,i-{L}p, had been studied for long gamma-ray bursts (GRBs) previously by many authors. These energy correlations were proposed to measure the universe and classify GRBs as useful probes. However, most of these relations were built by non-Swift bursts. The spectrum-energy correlations of short bursts have not been systematically established yet; in particular, how the newly found GRB170817A matches these energy relations is unknown to date. We will first refresh the three spectrum-energy relations of Swift/BAT and Fermi/GBM long bursts and build the corresponding relations of short bursts. Then, we confirm whether they are commonly available as a discriminator of short and long GRBs. Some potential violators to these relations will be investigated. Combining with the plane of peak energy versus fluence, we select 31 short and 252 long GRBs with well-measured peak energy and redshift to study the issue of GRB classifications connected with the above energy relations statistically. We find that the three energy relations do exist in our new GRB samples and they are marginally consistent with some previous results. We report for the first time that short GRBs hold the three corresponding energy relations having the consistent power-law indices with long GRBs. It is found that these energy relations can be adopted to discriminate GRBs successfully if they are put in the peak energy versus fluence plane. Excitingly, we point out that GRB090510 matches the energy relations of {E}p,i-{E}{iso} and {E}p,i-{L}p, but violates the {E}p,i-{E}γ relation. More excitingly, we find that GRB170817A is an outlier to all the three energy correlations.

  6. Reliability of gadolinium-enhanced magnetic resonance imaging findings and their correlation with clinical outcome in patients with sciatica.

    Science.gov (United States)

    el Barzouhi, Abdelilah; Vleggeert-Lankamp, Carmen L A M; Lycklama à Nijeholt, Geert J; Van der Kallen, Bas F; van den Hout, Wilbert B; Koes, Bart W; Peul, Wilco C

    2014-11-01

    Gadolinium-enhanced magnetic resonance imaging (Gd-MRI) is often performed in the evaluation of patients with persistent sciatica after lumbar disc surgery. However, correlation between enhancement and clinical findings is debated, and limited data are available regarding the reliability of enhancement findings. To evaluate the reliability of Gd-MRI findings and their correlation with clinical findings in patients with sciatica. Prospective observational evaluation of patients who were enrolled in a randomized trial with 1-year follow-up. Patients with 6- to 12-week sciatica, who participated in a multicentre randomized clinical trial comparing an early surgery strategy with prolonged conservative care with surgery if needed. In total 204 patients underwent Gd-MRI at baseline and after 1 year. Patients were assessed by means of the Roland Disability Questionnaire (RDQ) for sciatica, visual analog scale (VAS) for leg pain, and patient-reported perceived recovery at 1 year. Kappa coefficients were used to assess interobserver reliability. In total, 204 patients underwent Gd-MRI at baseline and after 1 year. Magnetic resonance imaging findings were correlated to the outcome measures using the Mann-Whitney U test for continuous data and Fisher exact tests for categorical data. Poor-to-moderate agreement was observed regarding Gd enhancement of the herniated disc and compressed nerve root (kappa0.95). Of the 59 patients with an enhancing herniated disc at 1 year, 86% reported recovery compared with 100% of the 12 patients with nonenhancing herniated discs (p=.34). Of the 12 patients with enhancement of the most affected nerve root at 1 year, 83% reported recovery compared with 85% of the 192 patients with no enhancement (p=.69). Patients with and without enhancing herniated discs or nerve roots at 1 year reported comparable outcomes on RDQ and VAS-leg pain. Reliability of Gd-MRI findings was poor-to-moderate and no correlation was observed between enhancement and

  7. The reliability of three psoriasis assessment tools: Psoriasis area and severity index, body surface area and physician global assessment.

    Science.gov (United States)

    Bożek, Agnieszka; Reich, Adam

    2017-08-01

    A wide variety of psoriasis assessment tools have been proposed to evaluate the severity of psoriasis in clinical trials and daily practice. The most frequently used clinical instrument is the psoriasis area and severity index (PASI); however, none of the currently published severity scores used for psoriasis meets all the validation criteria required for an ideal score. The aim of this study was to compare and assess the reliability of 3 commonly used assessment instruments for psoriasis severity: the psoriasis area and severity index (PASI), body surface area (BSA) and physician global assessment (PGA). On the scoring day, 10 trained dermatologists evaluated 9 adult patients with plaque-type psoriasis using the PASI, BSA and PGA. All the subjects were assessed twice by each physician. Correlations between the assessments were analyzed using the Pearson correlation coefficient. Intra-class correlation coefficient (ICC) was calculated to analyze intra-rater reliability, and the coefficient of variation (CV) was used to assess inter-rater variability. Significant correlations were observed among the 3 scales in both assessments. In all 3 scales the ICCs were > 0.75, indicating high intra-rater reliability. The highest ICC was for the BSA (0.96) and the lowest one for the PGA (0.87). The CV for the PGA and PASI were 29.3 and 36.9, respectively, indicating moderate inter-rater variability. The CV for the BSA was 57.1, indicating high inter-rater variability. Comparing the PASI, PGA and BSA, it was shown that the PGA had the highest inter-rater reliability, whereas the BSA had the highest intra-rater reliability. The PASI showed intermediate values in terms of interand intra-rater reliability. None of the 3 assessment instruments showed a significant advantage over the other. A reliable assessment of psoriasis severity requires the use of several independent evaluations simultaneously.

  8. Development, reliability, and validity testing of Toddler NutriSTEP: a nutrition risk screening questionnaire for children 18-35 months of age.

    Science.gov (United States)

    Randall Simpson, Janis; Gumbley, Jillian; Whyte, Kylie; Lac, Jane; Morra, Crystal; Rysdale, Lee; Turfryer, Mary; McGibbon, Kim; Beyers, Joanne; Keller, Heather

    2015-09-01

    Nutrition is vital for optimal growth and development of young children. Nutrition risk screening can facilitate early intervention when followed by nutritional assessment and treatment. NutriSTEP (Nutrition Screening Tool for Every Preschooler) is a valid and reliable nutrition risk screening questionnaire for preschoolers (aged 3-5 years). A need was identified for a similar questionnaire for toddlers (aged 18-35 months). The purpose was to develop a reliable and valid Toddler NutriSTEP. Toddler NutriSTEP was developed in 4 phases. Content and face validity were determined with a literature review, parent focus groups (n = 6; 48 participants), and experts (n = 13) (phase A). A draft questionnaire was refined with key intercept interviews of 107 parents/caregivers (phase B). Test-retest reliability (phase C), based on intra-class correlations (ICC), Kappa (κ) statistics, and Wilcoxon tests was assessed with 133 parents/caregivers. Criterion validity (phase D) was assessed using Receiver Operating Characteristic (ROC) curves by comparing scores on the Toddler NutriSTEP to a comprehensive nutritional assessment of 200 toddlers with a registered dietitian (RD). The Toddler NutriSTEP was reliable between 2 administrations (ICC = 0.951, F = 20.53, p Toddler NutriSTEP were correlated (r = 0.67, p Toddler NutriSTEP questionnaire is both reliable and valid for screening for nutritional risk in toddlers.

  9. Reliability and cross-cultural validation of the Turkish version of Manual Ability Classification System (MACS) for children with cerebral palsy.

    Science.gov (United States)

    Akpinar, Pinar; Tezel, Canan G; Eliasson, Ann-Christin; Icagasioglu, Afitap

    2010-01-01

    To determine the reliability and cross-cultural validation of the Turkish translation of the Manual Ability Classification System (MACS) for children with cerebral palsy (CP) and to investigate the relation to gross motor function and other comorbidities. After the forward and backward translation procedures, inter-rater and test-retest reliability was assessed between parents, physiotherapists and physicians using the intra-class correlation coefficient (ICC). Children (N = 118, 4 to 18 years, mean age 9 years 4 months; 68 boys, 50 girls) with various types of CP were classified. Additional data on the Gross Motor Function Classification System (GMFCS), intellectual delay, visual acuity, and epilepsy were collected. The inter-rater reliability was high; the ICC ranged from 0.89 to 0.96 among different professionals and parents. Between two persons of the same profession it ranged from 0.97 to 0.98. For the test-retest reliability it ranged from 0.91 to 0.98. Total agreement between the GMFCS and the MACS occurred in only 45% of the children. The level of the MACS was found to correlate with the accompanying comorbidities, namely intellectual delay and epilepsy. The Turkish version of the MACS is found to be valid and reliable, and is suggested to be appropriate for the assessment of manual ability within the Turkish population.

  10. Test of gross motor development-2 for Filipino children with intellectual disability: validity and reliability.

    Science.gov (United States)

    Capio, Catherine M; Eguia, Kathlynne F; Simons, Johan

    2016-01-01

    This study aimed to examine aspects of validity and reliability of the Test of Gross Motor Development-2 (TGMD-2) in Filipino children with intellectual disability. Content and construct validity were verified, as well as inter-rater and intra-rater reliability. Two paediatric physiotherapists tested 81 children with intellectual disability (mean age = 9.29 ± 2.71 years) on locomotor and object control skills. Analysis of covariance, confirmatory factor analysis and analysis of variance were used to test validity, while Cronbach's alpha, intra-class correlation coefficients (ICC) and Bland-Altman plots were used to examine reliability. Age was a significant predictor of locomotor and object control scores (P = 0.004). The data fit the hypothesised two-factor model with fit indices as follows: χ(2) = 33.525, DF = 34, P = 0.491, χ(2)/DF = 0.986. As hypothesised, gender was a significant predictor for object control skills (P = 0.038). Participants' mean scores were significantly below mastery (locomotor, P intellectual disability.

  11. Between-day reliability of a method for non-invasive estimation of muscle composition.

    Science.gov (United States)

    Simunič, Boštjan

    2012-08-01

    Tensiomyography is a method for valid and non-invasive estimation of skeletal muscle fibre type composition. The validity of selected temporal tensiomyographic measures has been well established recently; there is, however, no evidence regarding the method's between-day reliability. Therefore it is the aim of this paper to establish the between-day repeatability of tensiomyographic measures in three skeletal muscles. For three consecutive days, 10 healthy male volunteers (mean±SD: age 24.6 ± 3.0 years; height 177.9 ± 3.9 cm; weight 72.4 ± 5.2 kg) were examined in a supine position. Four temporal measures (delay, contraction, sustain, and half-relaxation time) and maximal amplitude were extracted from the displacement-time tensiomyogram. A reliability analysis was performed with calculations of bias, random error, coefficient of variation (CV), standard error of measurement, and intra-class correlation coefficient (ICC) with a 95% confidence interval. An analysis of ICC demonstrated excellent agreement (ICC were over 0.94 in 14 out of 15 tested parameters). However, lower CV was observed in half-relaxation time, presumably because of the specifics of the parameter definition itself. These data indicate that for the three muscles tested, tensiomyographic measurements were reproducible across consecutive test days. Furthermore, we indicated the most possible origin of the lowest reliability detected in half-relaxation time. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Electromigration-induced Plasticity: Texture Correlation and Implications for Reliability Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Budiman, A.S.; Besser, P.R.; Hau-Riege, C.S.; Marathe, A.; Joo, Y.-C.; Tamura, N.; Patel, J.R.; Nix, W.D.

    2008-05-29

    Plastic behavior has previously been observed in metallic interconnects undergoing high current density electromigration (EM) loading. In this study of Cu interconnects, using the synchrotron technique of white beam X-ray microdiffraction, we have further found preliminary evidence of a texture correlation. In lines with strong (111) textures, the extent of plastic deformation is found to be relatively large compared to that of weaker textures. We suggest that this strong (111) texture may lead to an extra path of mass transport in addition to the dominant interface diffusion in Cu EM. When this extra mass transport begins to affect the overall transport process, then the effective diffusivity, D{sub eff}, of the EM process is expected to deviate from that of interface diffusion only. This would have fundamental implications. We have some preliminary observations that this might be the case, and we report its implications for EM lifetime assessment in this manuscript.

  13. Internalized Homophobia Scale for Gay Chinese Men: Conceptualization, Factor Structure, Reliability, and Associations With Hypothesized Correlates.

    Science.gov (United States)

    Ren, Zhengjia; Hood, Ralph W

    2018-04-01

    This study reports the development of an inventory to assess the perceived internalized homophobia of gay men in a collectivistic Chinese cultural context. The results of exploratory and confirmatory factor analyses using two samples suggested the viability and stability of a three-factor model: internalized heteronormativity (IHN), family-oriented identity (FOI), and socially oriented identity (SOI). The 11-item internalized homophobia inventory demonstrated good internal consistency and construct validity. Internalized homophobia was related positively to the extent of a sense of loneliness and negatively to self-evaluation and the discrepancy in self-identification as a gay man. In addition, the participants' internalized SOI consistently predicted their coming out choices in their social surroundings, while their FOI predicted their decisions to enter into heterosexual marriages. The findings suggest that sexual self-prejudice was correlated with IHN, family values, and social norms. The present research demonstrates that a culturally sensitive scale is necessary to understand the cultural and family-oriented values that influence gay Chinese men's everyday lives, self-constructs, and behavioral choices.

  14. An Efficient and Reliable Statistical Method for Estimating Functional Connectivity in Large Scale Brain Networks Using Partial Correlation.

    Science.gov (United States)

    Wang, Yikai; Kang, Jian; Kemmer, Phebe B; Guo, Ying

    2016-01-01

    Currently, network-oriented analysis of fMRI data has become an important tool for understanding brain organization and brain networks. Among the range of network modeling methods, partial correlation has shown great promises in accurately detecting true brain network connections. However, the application of partial correlation in investigating brain connectivity, especially in large-scale brain networks, has been limited so far due to the technical challenges in its estimation. In this paper, we propose an efficient and reliable statistical method for estimating partial correlation in large-scale brain network modeling. Our method derives partial correlation based on the precision matrix estimated via Constrained L1-minimization Approach (CLIME), which is a recently developed statistical method that is more efficient and demonstrates better performance than the existing methods. To help select an appropriate tuning parameter for sparsity control in the network estimation, we propose a new Dens-based selection method that provides a more informative and flexible tool to allow the users to select the tuning parameter based on the desired sparsity level. Another appealing feature of the Dens-based method is that it is much faster than the existing methods, which provides an important advantage in neuroimaging applications. Simulation studies show that the Dens-based method demonstrates comparable or better performance with respect to the existing methods in network estimation. We applied the proposed partial correlation method to investigate resting state functional connectivity using rs-fMRI data from the Philadelphia Neurodevelopmental Cohort (PNC) study. Our results show that partial correlation analysis removed considerable between-module marginal connections identified by full correlation analysis, suggesting these connections were likely caused by global effects or common connection to other nodes. Based on partial correlation, we find that the most significant

  15. Test-retest reliability of jump execution variables using mechanography: a comparison of jump protocols.

    Science.gov (United States)

    Fitzgerald, John S; Johnson, LuAnn; Tomkinson, Grant; Stein, Jesse; Roemmich, James N

    2018-05-01

    Mechanography during the vertical jump may enhance screening and determining mechanistic causes underlying physical performance changes. Utility of jump mechanography for evaluation is limited by scant test-retest reliability data on force-time variables. This study examined the test-retest reliability of eight jump execution variables assessed from mechanography. Thirty-two women (mean±SD: age 20.8 ± 1.3 yr) and 16 men (age 22.1 ± 1.9 yr) attended a familiarization session and two testing sessions, all one week apart. Participants performed two variations of the squat jump with squat depth self-selected and controlled using a goniometer to 80º knee flexion. Test-retest reliability was quantified as the systematic error (using effect size between jumps), random error (using coefficients of variation), and test-retest correlations (using intra-class correlation coefficients). Overall, jump execution variables demonstrated acceptable reliability, evidenced by small systematic errors (mean±95%CI: 0.2 ± 0.07), moderate random errors (mean±95%CI: 17.8 ± 3.7%), and very strong test-retest correlations (range: 0.73-0.97). Differences in random errors between controlled and self-selected protocols were negligible (mean±95%CI: 1.3 ± 2.3%). Jump execution variables demonstrated acceptable reliability, with no meaningful differences between the controlled and self-selected jump protocols. To simplify testing, a self-selected jump protocol can be used to assess force-time variables with negligible impact on measurement error.

  16. Reliability and validity of a Chinese version of the Diagnostic Interview for Borderlines-Revised.

    Science.gov (United States)

    Wang, Lanlan; Yuan, Chenmei; Qiu, Jianying; Gunderson, John; Zhang, Min; Jiang, Kaida; Leung, Freedom; Zhong, Jie; Xiao, Zeping

    2014-09-01

    Borderline personality disorder (BPD) is the most studied of the axis II disorders. One of the most widely used diagnostic instruments is the Diagnostic Interview for Borderline Patients-Revised (DIB-R). The aim of this study was to test the reliability and validity of DIB-R for use in the Chinese culture. The reliability and validity of the DIB-R Chinese version were assessed in a sample of 236 outpatients with a probable BPD diagnosis. The Structured Clinical Interview for DSM-IV Personality Disorders (SCID-II) was used as a standard. Test-retest reliability was tested six months later with 20 patients, and inter-rater reliability was tested on 32 patients. The Chinese version of the DIB-R showed good internal global consistency (Cronbach's α of 0.916), good test-retest reliability (Pearson correlation of 0.704), good inter-rater reliability (intra-class correlation coefficient of 0.892 and kappa of 0.861). When compared with the DSM-IV diagnosis as measured by the SCID-II, the DIB-R showed relatively good sensitivity (0.768) and specificity (0.891) at the cutoff of 7, moderate diagnostic convergence (kappa of 0.631), as well as good discriminating validity. The Chinese version of the DIB-R has good psychometric properties, which renders it a valuable method for examining the presence, the severity, and component phenotypes of BPD in Chinese samples. © 2013 Wiley Publishing Asia Pty Ltd.

  17. A reliability assessment of constrained spherical deconvolution-based diffusion-weighted magnetic resonance imaging in individuals with chronic stroke.

    Science.gov (United States)

    Snow, Nicholas J; Peters, Sue; Borich, Michael R; Shirzad, Navid; Auriat, Angela M; Hayward, Kathryn S; Boyd, Lara A

    2016-01-15

    Diffusion-weighted magnetic resonance imaging (DW-MRI) is commonly used to assess white matter properties after stroke. Novel work is utilizing constrained spherical deconvolution (CSD) to estimate complex intra-voxel fiber architecture unaccounted for with tensor-based fiber tractography. However, the reliability of CSD-based tractography has not been established in people with chronic stroke. Establishing the reliability of CSD-based DW-MRI in chronic stroke. High-resolution DW-MRI was performed in ten adults with chronic stroke during two separate sessions. Deterministic region of interest-based fiber tractography using CSD was performed by two raters. Mean fractional anisotropy (FA), apparent diffusion coefficient (ADC), tract number, and tract volume were extracted from reconstructed fiber pathways in the corticospinal tract (CST) and superior longitudinal fasciculus (SLF). Callosal fiber pathways connecting the primary motor cortices were also evaluated. Inter-rater and test-retest reliability were determined by intra-class correlation coefficients (ICCs). ICCs revealed excellent reliability for FA and ADC in ipsilesional (0.86-1.00; preliability for all metrics in callosal fibers (0.85-1.00; preliable approach to evaluate FA and ADC in major white matter pathways, in chronic stroke. Future work should address the reproducibility and utility of CSD-based metrics of tract number and tract volume. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Measuring reliable change in cognition using the Edinburgh Cognitive and Behavioural ALS Screen (ECAS).

    Science.gov (United States)

    Crockford, Christopher; Newton, Judith; Lonergan, Katie; Madden, Caoifa; Mays, Iain; O'Sullivan, Meabhdh; Costello, Emmet; Pinto-Grau, Marta; Vajda, Alice; Heverin, Mark; Pender, Niall; Al-Chalabi, Ammar; Hardiman, Orla; Abrahams, Sharon

    2018-02-01

    Cognitive impairment affects approximately 50% of people with amyotrophic lateral sclerosis (ALS). Research has indicated that impairment may worsen with disease progression. The Edinburgh Cognitive and Behavioural ALS Screen (ECAS) was designed to measure neuropsychological functioning in ALS, with its alternate forms (ECAS-A, B, and C) allowing for serial assessment over time. The aim of the present study was to establish reliable change scores for the alternate forms of the ECAS, and to explore practice effects and test-retest reliability of the ECAS's alternate forms. Eighty healthy participants were recruited, with 57 completing two and 51 completing three assessments. Participants were administered alternate versions of the ECAS serially (A-B-C) at four-month intervals. Intra-class correlation analysis was employed to explore test-retest reliability, while analysis of variance was used to examine the presence of practice effects. Reliable change indices (RCI) and regression-based methods were utilized to establish change scores for the ECAS alternate forms. Test-retest reliability was excellent for ALS Specific, ALS Non-Specific, and ECAS Total scores of the combined ECAS A, B, and C (all > .90). No significant practice effects were observed over the three testing sessions. RCI and regression-based methods produced similar change scores. The alternate forms of the ECAS possess excellent test-retest reliability in a healthy control sample, with no significant practice effects. The use of conservative RCI scores is recommended. Therefore, a change of ≥8, ≥4, and ≥9 for ALS Specific, ALS Non-Specific, and ECAS Total score is required for reliable change.

  19. Reliability and criterion validity of measurements using a smart phone-based measurement tool for the transverse rotation angle of the pelvis during single-leg lifting.

    Science.gov (United States)

    Jung, Sung-Hoon; Kwon, Oh-Yun; Jeon, In-Cheol; Hwang, Ui-Jae; Weon, Jong-Hyuck

    2018-01-01

    The purposes of this study were to determine the intra-rater test-retest reliability of a smart phone-based measurement tool (SBMT) and a three-dimensional (3D) motion analysis system for measuring the transverse rotation angle of the pelvis during single-leg lifting (SLL) and the criterion validity of the transverse rotation angle of the pelvis measurement using SBMT compared with a 3D motion analysis system (3DMAS). Seventeen healthy volunteers performed SLL with their dominant leg without bending the knee until they reached a target placed 20 cm above the table. This study used a 3DMAS, considered the gold standard, to measure the transverse rotation angle of the pelvis to assess the criterion validity of the SBMT measurement. Intra-rater test-retest reliability was determined using the SBMT and 3DMAS using intra-class correlation coefficient (ICC) [3,1] values. The criterion validity of the SBMT was assessed with ICC [3,1] values. Both the 3DMAS (ICC = 0.77) and SBMT (ICC = 0.83) showed excellent intra-rater test-retest reliability in the measurement of the transverse rotation angle of the pelvis during SLL in a supine position. Moreover, the SBMT showed an excellent correlation with the 3DMAS (ICC = 0.99). Measurement of the transverse rotation angle of the pelvis using the SBMT showed excellent reliability and criterion validity compared with the 3DMAS.

  20. The reliability of dual-energy X-ray absorptiometry measurements of bone mineral density in the metatarsals

    International Nuclear Information System (INIS)

    Fuller, Joel T.; Buckley, Jonathan D.; Tsiros, Margarita D.; Thewlis, Dominic; Archer, Jane

    2016-01-01

    To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA). BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability. Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97; coefficient of variation [CV] ≤1.5 %; limits of agreement [LOA] ≤4.2 %). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90; CV ≤4.2 %; LOA ≤11.9 %). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64; CV ≤8.2 %; LOA ≤23.6 %) and fourth metatarsals (ICC ≥0.67; CV ≤9.6 %; LOA ≤27.5 %). BMD was greatest in the first and second metatarsals (P < 0.01). Reliable measurements of BMD were achieved for the first, second and fifth metatarsals. (orig.)

  1. The reliability of dual-energy X-ray absorptiometry measurements of bone mineral density in the metatarsals

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Joel T.; Buckley, Jonathan D.; Tsiros, Margarita D.; Thewlis, Dominic [University of South Australia, Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, GPO Box 2471, Adelaide, South Australia (Australia); Archer, Jane [University of South Australia, Medical Radiation, School of Health Sciences, Adelaide (Australia)

    2016-01-15

    To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA). BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability. Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97; coefficient of variation [CV] ≤1.5 %; limits of agreement [LOA] ≤4.2 %). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90; CV ≤4.2 %; LOA ≤11.9 %). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64; CV ≤8.2 %; LOA ≤23.6 %) and fourth metatarsals (ICC ≥0.67; CV ≤9.6 %; LOA ≤27.5 %). BMD was greatest in the first and second metatarsals (P < 0.01). Reliable measurements of BMD were achieved for the first, second and fifth metatarsals. (orig.)

  2. The reliability of dual-energy X-ray absorptiometry measurements of bone mineral density in the metatarsals.

    Science.gov (United States)

    Fuller, Joel T; Archer, Jane; Buckley, Jonathan D; Tsiros, Margarita D; Thewlis, Dominic

    2016-01-01

    To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA). BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability. Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97; coefficient of variation [CV] ≤1.5%; limits of agreement [LOA] ≤4.2%). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90; CV ≤4.2%; LOA ≤11.9%). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64; CV ≤8.2%; LOA ≤23.6%) and fourth metatarsals (ICC ≥0.67; CV ≤9.6%; LOA ≤27.5%). BMD was greatest in the first and second metatarsals (P Reliable measurements of BMD were achieved for the first, second and fifth metatarsals.

  3. Validity and reliability of a Malay version of the Lawton instrumental activities of daily living scale among the Malay speaking elderly in Malaysia.

    Science.gov (United States)

    Kadar, Masne; Ibrahim, Suhaili; Razaob, Nor Afifi; Chai, Siaw Chui; Harun, Dzalani

    2018-02-01

    The Lawton Instrumental Activities of Daily Living Scale is a tool often used to assess independence among elderly at home. Its suitability to be used with the elderly population in Malaysia has not been validated. This current study aimed to assess the validity and reliability of the Lawton Instrumental Activities of Daily Living Scale - Malay Version to Malay speaking elderly in Malaysia. This study was divided into three phases: (1) translation and linguistic validity involving both forward and backward translations; (2) establishment of face validity and content validity; and (3) establishment of reliability involving inter-rater, test-retest and internal consistency analyses. Data used for these analyses were obtained by interviewing 65 elderly respondents. Percentages of Content Validity Index for 4 criteria were from 88.89 to 100.0. The Cronbach α coefficient for internal consistency was 0.838. Intra-class Correlation Coefficient of inter-rater reliability and test-retest reliability was 0.957 and 0.950 respectively. The result shows that the Lawton Instrumental Activities of Daily Living Scale - Malay Version has excellent reliability and validity for use with the Malay speaking elderly people in Malaysia. This scale could be used by professionals to assess functional ability of elderly who live independently in community. © 2018 Occupational Therapy Australia.

  4. The reliability of a modified Kalamazoo Consensus Statement Checklist for assessing the communication skills of multidisciplinary clinicians in the simulated environment.

    Science.gov (United States)

    Peterson, Eleanor B; Calhoun, Aaron W; Rider, Elizabeth A

    2014-09-01

    With increased recognition of the importance of sound communication skills and communication skills education, reliable assessment tools are essential. This study reports on the psychometric properties of an assessment tool based on the Kalamazoo Consensus Statement Essential Elements Communication Checklist. The Gap-Kalamazoo Communication Skills Assessment Form (GKCSAF), a modified version of an existing communication skills assessment tool, the Kalamazoo Essential Elements Communication Checklist-Adapted, was used to assess learners in a multidisciplinary, simulation-based communication skills educational program using multiple raters. 118 simulated conversations were available for analysis. Internal consistency and inter-rater reliability were determined by calculating a Cronbach's alpha score and intra-class correlation coefficients (ICC), respectively. The GKCSAF demonstrated high internal consistency with a Cronbach's alpha score of 0.844 (faculty raters) and 0.880 (peer observer raters), and high inter-rater reliability with an ICC of 0.830 (faculty raters) and 0.89 (peer observer raters). The Gap-Kalamazoo Communication Skills Assessment Form is a reliable method of assessing the communication skills of multidisciplinary learners using multi-rater methods within the learning environment. The Gap-Kalamazoo Communication Skills Assessment Form can be used by educational programs that wish to implement a reliable assessment and feedback system for a variety of learners. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Reliability and Validity of the Beijing Version of the Montreal Cognitive Assessment in the Evaluation of Cognitive Function of Adult Patients with OSAHS.

    Science.gov (United States)

    Chen, Xiong; Zhang, Rui; Xiao, Ying; Dong, Jiaqi; Niu, Xun; Kong, Weijia

    2015-01-01

    The patients with obstructive sleep apnea hypopnea syndrome (OSAHS) tend to develop cognitive deficits, which usually go unrecognized, and can affect their daily life. The Beijing version of the Montreal cognitive assessment (MoCA-BJ), a Chinese version of MoCA, has been used for the assessment of cognitive functions of OSAHS patients in clinical practice. So far, its reliability and validity have not been tested. This study examined the reliability and validity of MoCA-BJ in a cohort of adult OSAHS patients. 152 OSAHS patients, ranging from mild, moderate to severe, 49 primary snoring subjects and 40 normal controls were evaluated for cognitive functions by employing both MoCA-BJ and the Mini Mental State Examination (MMSE). Forty of them were re-tested by MoCA-BJ 14 days after the first test. Internal consistency, test-retest reliability, discriminate and concurrent validity of MoCA-BJ were analyzed. Internal consistency reliability by Cronbach's alpha was adequate (0.73). Intra-class correlation coefficient (ICC), an measure of test-retest reliability, was 0.87 (Preliable and stable. The MoCA-BJ was capable of detecting cognitive dysfunction by visuospatial and total MoCA-BJ score.

  6. Reliability of oscillometric central hemodynamic responses to an orthostatic challenge.

    Science.gov (United States)

    Stoner, Lee; Bonner, Chantel; Credeur, Daniel; Lambrick, Danielle; Faulkner, James; Wadsworth, Daniel; Williams, Michelle A

    2015-08-01

    Monitoring central hemodynamic responses to an orthostatic challenge may provide important insight into autonomic nervous system function. Oscillometric pulse wave analysis devices have recently emerged, presenting clinically viable options for investigating central hemodynamic properties. The purpose of the current study was to determine whether oscillometric pulse wave analysis can be used to reliably (between-day) assess central blood pressure and central pressure augmentation (augmentation index) responses to a 5 min orthostatic challenge (modified tilt-table). Twenty healthy adults (26.4 y (SD 5.2), 55% F, 24.7 kg/m(2) (SD 3.8)) were tested on 3 different mornings in the fasted state, separated by a maximum of 7 days. Central hemodynamic variables were assessed on the left arm using an oscillometric device. Repeated measures analysis of variance indicated a significant main effect of the modified tilt-table for all central hemodynamic variables (P response to the tilt, central diastolic pressure increased by 4.5 mmHg (CI: 2.6, 6.4), central systolic blood pressure increased by 2.3 (CI: 4.4, 0.16) mmHg, and augmentation index decreased by an absolute - 5.3%, (CI: -2.7, -7.9%). The intra-class correlation coefficient values for central diastolic pressure (0.83-0.86), central systolic blood pressure (0.80-0.87) and AIx (0.79-0.82) were above the 0.75 criterion in both the supine and tilted positions, indicating excellent between-day reliability. Central hemodynamic responses to an orthostatic challenge can be assessed with acceptable between-day reliability using oscillometric pulse wave analysis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Reliability and validity of the transport and physical activity questionnaire (TPAQ) for assessing physical activity behaviour.

    Science.gov (United States)

    Adams, Emma J; Goad, Mary; Sahlqvist, Shannon; Bull, Fiona C; Cooper, Ashley R; Ogilvie, David

    2014-01-01

    No current validated survey instrument allows a comprehensive assessment of both physical activity and travel behaviours for use in interdisciplinary research on walking and cycling. This study reports on the test-retest reliability and validity of physical activity measures in the transport and physical activity questionnaire (TPAQ). The TPAQ assesses time spent in different domains of physical activity and using different modes of transport for five journey purposes. Test-retest reliability of eight physical activity summary variables was assessed using intra-class correlation coefficients (ICC) and Kappa scores for continuous and categorical variables respectively. In a separate study, the validity of three survey-reported physical activity summary variables was assessed by computing Spearman correlation coefficients using accelerometer-derived reference measures. The Bland-Altman technique was used to determine the absolute validity of survey-reported time spent in moderate-to-vigorous physical activity (MVPA). In the reliability study, ICC for time spent in different domains of physical activity ranged from fair to substantial for walking for transport (ICC = 0.59), cycling for transport (ICC = 0.61), walking for recreation (ICC = 0.48), cycling for recreation (ICC = 0.35), moderate leisure-time physical activity (ICC = 0.47), vigorous leisure-time physical activity (ICC = 0.63), and total physical activity (ICC = 0.56). The proportion of participants estimated to meet physical activity guidelines showed acceptable reliability (k = 0.60). In the validity study, comparison of survey-reported and accelerometer-derived time spent in physical activity showed strong agreement for vigorous physical activity (r = 0.72, ptravel behaviours and may be suitable for wider use. Its physical activity summary measures have comparable reliability and validity to those of similar existing questionnaires.

  8. Validity and reliability of a Nigerian-Yoruba version of the stroke-specific quality of life scale 2.0.

    Science.gov (United States)

    Odetunde, Marufat Oluyemisi; Akinpelu, Aderonke Omobonike; Odole, Adesola Christiana

    2017-10-19

    Psychometric evidence is necessary to establish scientific integrity and clinical usefulness of translations and cultural adaptations of the Stroke-Specific Quality of Life (SS-QoL) scale. However, the limited evidence on psychometrics of Yoruba version of SS-QoL 2.0 (SS-QoL(Y)) is a significant shortcoming. This study assessed the test-retest reliability, internal consistency, convergent, divergent, discriminant and known-group validity of the SS-QoL(Y). Yoruba version of the WHOQoL-BREF was used to test the convergent and divergent validity of the SS-QoL(Y) among 100 consenting stroke survivors. The WHOQoL-BREF and SS-QoL(Y) was administered randomly in order to eliminate bias. The test-retest reliability of the SS-QoL(Y) was carried out among 68 of the respondents within an interval of 7 days. All respondents were purposively recruited from selected secondary and tertiary health facilities in South-west Nigeria. Data were analysed using descriptive statistics of mean and standard deviation, and inferential statistics of Spearman correlation, Cronbach's alpha, Intra-class Correlation Coefficient (ICC), Independent t-test and One-way ANOVA. Alpha level was set at p validity of SS-QoL(Y) showed that items' r value ranged from 0.711 to 0.920 with their hypothesized domains. The scale demonstrated moderate to strong test-retest reliability with Intra-class correlation coefficient (ICC) for the domains and overall scores (r = 0.47 to 0.81) and moderate to high internal consistency (Cronbach's alpha =0.61 to 0.82) for domains scores. These correlations were also significant for the domains and overall scores (p validity, test-retest reliability and internal consistency of the Yoruba version of the Stroke Specific Quality of Life 2.0 are adequate while the convergent and divergent validity are low but acceptable. The SS-QoL(Y) is recommended for assessing health-related quality of life among Yoruba stroke survivors.

  9. Stability of person ability measures in people with acquired brain injury in the use of everyday technology: the test-retest reliability of the Management of Everyday Technology Assessment (META).

    Science.gov (United States)

    Malinowsky, Camilla; Kassberg, Ann-Charlotte; Larsson-Lund, Maria; Kottorp, Anders

    2016-01-01

    To evaluate the test-retest reliability of the Management of Everyday Technology Assessment (META) in a sample of people with acquired brain injury (ABI). The META was administered twice within a two-week period to 25 people with ABI. A Rasch measurement model was used to convert the META ordinal raw scores into equal-interval linear measures of each participant's ability to manage everyday technology (ET). Test-retest reliability of the stability of the person ability measures in the META was examined by a standardized difference Z-test and an intra-class correlations analysis (ICC 1). The results showed that the paired person ability measures generated from the META were stable over the test-retest period for 22 of the 25 subjects. The ICC 1 correlation was 0.63, which indicates good overall reliability. The META demonstrated acceptable test-retest reliability in a sample of people with ABI. The results illustrate the importance of using sufficiently challenging ETs (relative to a person's abilities) to generate stable META measurements over time. Implications for Rehabilitation The findings add evidence regarding the test-retest reliability of the person ability measures generated from the observation assessment META in a sample of people with ABI. The META might support professionals in the evaluation of interventions that are designed to improve clients' performance of activities including the ability to manage ET.

  10. Novel Methods to Enhance Precision and Reliability in Muscle Synergy Identification during Walking

    Science.gov (United States)

    Kim, Yushin; Bulea, Thomas C.; Damiano, Diane L.

    2016-01-01

    Muscle synergies are hypothesized to reflect modular control of muscle groups via descending commands sent through multiple neural pathways. Recently, the number of synergies has been reported as a functionally relevant indicator of motor control complexity in individuals with neurological movement disorders. Yet the number of synergies extracted during a given activity, e.g., gait, varies within and across studies, even for unimpaired individuals. With no standardized methods for precise determination, this variability remains unexplained making comparisons across studies and cohorts difficult. Here, we utilize k-means clustering and intra-class and between-level correlation coefficients to precisely discriminate reliable from unreliable synergies. Electromyography (EMG) was recorded bilaterally from eight leg muscles during treadmill walking at self-selected speed. Muscle synergies were extracted from 20 consecutive gait cycles using non-negative matrix factorization. We demonstrate that the number of synergies is highly dependent on the threshold when using the variance accounted for by reconstructed EMG. Beyond use of threshold, our method utilized a quantitative metric to reliably identify four or five synergies underpinning walking in unimpaired adults and revealed synergies having poor reproducibility that should not be considered as true synergies. We show that robust and unreliable synergies emerge similarly, emphasizing the need for careful analysis in those with pathology. PMID:27695403

  11. A Compact Forearm Crutch Based on Force Sensors for Aided Gait: Reliability and Validity.

    Science.gov (United States)

    Chamorro-Moriana, Gema; Sevillano, José Luis; Ridao-Fernández, Carmen

    2016-06-21

    Frequently, patients who suffer injuries in some lower member require forearm crutches in order to partially unload weight-bearing. These lesions cause pain in lower limb unloading and their progression should be controlled objectively to avoid significant errors in accuracy and, consequently, complications and after effects in lesions. The design of a new and feasible tool that allows us to control and improve the accuracy of loads exerted on crutches during aided gait is necessary, so as to unburden the lower limbs. In this paper, we describe such a system based on a force sensor, which we have named the GCH System 2.0. Furthermore, we determine the validity and reliability of measurements obtained using this tool via a comparison with the validated AMTI (Advanced Mechanical Technology, Inc., Watertown, MA, USA) OR6-7-2000 Platform. An intra-class correlation coefficient demonstrated excellent agreement between the AMTI Platform and the GCH System. A regression line to determine the predictive ability of the GCH system towards the AMTI Platform was found, which obtained a precision of 99.3%. A detailed statistical analysis is presented for all the measurements and also segregated for several requested loads on the crutches (10%, 25% and 50% of body weight). Our results show that our system, designed for assessing loads exerted by patients on forearm crutches during assisted gait, provides valid and reliable measurements of loads.

  12. A Compact Forearm Crutch Based on Force Sensors for Aided Gait: Reliability and Validity

    Directory of Open Access Journals (Sweden)

    Gema Chamorro-Moriana

    2016-06-01

    Full Text Available Frequently, patients who suffer injuries in some lower member require forearm crutches in order to partially unload weight-bearing. These lesions cause pain in lower limb unloading and their progression should be controlled objectively to avoid significant errors in accuracy and, consequently, complications and after effects in lesions. The design of a new and feasible tool that allows us to control and improve the accuracy of loads exerted on crutches during aided gait is necessary, so as to unburden the lower limbs. In this paper, we describe such a system based on a force sensor, which we have named the GCH System 2.0. Furthermore, we determine the validity and reliability of measurements obtained using this tool via a comparison with the validated AMTI (Advanced Mechanical Technology, Inc., Watertown, MA, USA OR6-7-2000 Platform. An intra-class correlation coefficient demonstrated excellent agreement between the AMTI Platform and the GCH System. A regression line to determine the predictive ability of the GCH system towards the AMTI Platform was found, which obtained a precision of 99.3%. A detailed statistical analysis is presented for all the measurements and also segregated for several requested loads on the crutches (10%, 25% and 50% of body weight. Our results show that our system, designed for assessing loads exerted by patients on forearm crutches during assisted gait, provides valid and reliable measurements of loads.

  13. Validity and reliability of the Turkish version of the pressure ulcer prevention knowledge assessment instrument.

    Science.gov (United States)

    Tulek, Zeliha; Polat, Cansu; Ozkan, Ilknur; Theofanidis, Dimitris; Togrol, Rifat Erdem

    2016-11-01

    Sound knowledge of pressure ulcers is important to enable good prevention. There are limited instruments assessing pressure ulcer knowledge. The Pressure Ulcer Prevention Knowledge Assessment Instrument is among the scales of which psychometric properties have been studied rigorously and reflects the latest evidence. This study aimed to evaluate the validity and reliability of the Turkish version of the Pressure Ulcer Prevention Knowledge Assessment Instrument (PUPKAI-T), an instrument that assesses knowledge of pressure ulcer prevention by using multiple-choice questions. Linguistic validity was verified through front-to-back translation. Psychometric properties of the instrument were studied on a sample of 150 nurses working in a tertiary hospital in Istanbul, Turkey. The content validity index of the translated instrument was 0.94, intra-class correlation coefficients were between 0.37 and 0.80, item difficulty indices were between 0.21 and 0.88, discrimination indices were 0.20-0.78, and the Kuder Richardson for the internal consistency was 0.803. The PUPKAI-T was found to be a valid and reliable tool to evaluate nurses' knowledge on pressure ulcer prevention. The PUPKAI-T may be a useful tool for determining educational needs of nurses on pressure ulcer prevention. Copyright © 2016 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  14. Reliability of Phase Velocity Measurements of Flexural Acoustic Waves in the Human Tibia In-Vivo.

    Science.gov (United States)

    Vogl, Florian; Schnüriger, Karin; Gerber, Hans; Taylor, William R

    2016-01-01

    Axial-transmission acoustics have shown to be a promising technique to measure individual bone properties and detect bone pathologies. With the ultimate goal being the in-vivo application of such systems, quantification of the key aspects governing the reliability is crucial to bring this method towards clinical use. This work presents a systematic reliability study quantifying the sources of variability and their magnitudes of in-vivo measurements using axial-transmission acoustics. 42 healthy subjects were measured by an experienced operator twice per week, over a four-month period, resulting in over 150000 wave measurements. In a complementary study to assess the influence of different operators performing the measurements, 10 novice operators were trained, and each measured 5 subjects on a single occasion, using the same measurement protocol as in the first part of the study. The estimated standard error for the measurement protocol used to collect the study data was ∼ 17 m/s (∼ 4% of the grand mean) and the index of dependability, as a measure of reliability, was Φ = 0.81. It was shown that the method is suitable for multi-operator use and that the reliability can be improved efficiently by additional measurements with device repositioning, while additional measurements without repositioning cannot improve the reliability substantially. Phase velocity values were found to be significantly higher in males than in females (p < 10-5) and an intra-class correlation coefficient of r = 0.70 was found between the legs of each subject. The high reliability of this non-invasive approach and its intrinsic sensitivity to mechanical properties opens perspectives for the rapid and inexpensive clinical assessment of bone pathologies, as well as for monitoring programmes without any radiation exposure for the patient.

  15. Allied health clinicians using translational research in action to develop a reliable stroke audit tool.

    Science.gov (United States)

    Abery, Philip; Kuys, Suzanne; Lynch, Mary; Low Choy, Nancy

    2018-05-23

    To design and establish reliability of a local stroke audit tool by engaging allied health clinicians within a privately funded hospital. Design: Two-stage study involving a modified Delphi process to inform stroke audit tool development and inter-tester reliability. Allied health clinicians. A modified Delphi process to select stroke guideline recommendations for inclusion in the audit tool. Reliability study: 1 allied health representative from each discipline audited 10 clinical records with sequential admissions to acute and rehabilitation services. Recommendations were admitted to the audit tool when 70% agreement was reached, with 50% set as the reserve agreement. Inter-tester reliability was determined using intra-class correlation coefficients (ICCs) across 10 clinical records. Twenty-two participants (92% female, 50% physiotherapists, 17% occupational therapists) completed the modified Delphi process. Across 6 voting rounds, 8 recommendations reached 70% agreement and 2 reached 50% agreement. Two recommendations (nutrition/hydration; goal setting) were added to ensure representation for all disciplines. Substantial consistency across raters was established for the audit tool applied in acute stroke (ICC .71; range .48 to .90) and rehabilitation (ICC.78; range .60 to .93) services. Allied health clinicians within a privately funded hospital generally agreed in an audit process to develop a reliable stroke audit tool. Allied health clinicians agreed on stroke guideline recommendations to inform a stroke audit tool. The stroke audit tool demonstrated substantial consistency supporting future use for service development. This process, which engages local clinicians, could be adopted by other facilities to design reliable audit tools to identify local service gaps to inform changes to clinical practice. © 2018 John Wiley & Sons, Ltd.

  16. Student Practice Evaluation Form-Revised Edition online comment bank: development and reliability analysis.

    Science.gov (United States)

    Rodger, Sylvia; Turpin, Merrill; Copley, Jodie; Coleman, Allison; Chien, Chi-Wen; Caine, Anne-Maree; Brown, Ted

    2014-08-01

    The reliable evaluation of occupational therapy students completing practice education placements along with provision of appropriate feedback is critical for both students and for universities from a quality assurance perspective. This study describes the development of a comment bank for use with an online version of the Student Practice Evaluation Form-Revised Edition (SPEF-R Online) and investigates its reliability. A preliminary bank of 109 individual comments (based on previous students' placement performance) was developed via five stages. These comments reflected all 11 SPEF-R domains. A purpose-designed online survey was used to examine the reliability of the comment bank. A total of 37 practice educators returned surveys, 31 of which were fully completed. Participants were asked to rate each individual comment using the five-point SPEF-R rating scale. One hundred and two of 109 comments demonstrated satisfactory agreement with their respective default ratings that were determined by the development team. At each domain level, the intra-class correlation coefficients (ranging between 0.86 and 0.96) also demonstrated good to excellent inter-rater reliability. There were only seven items that required rewording prior to inclusion in the final SPEF-R Online comment bank. The development of the SPEF-R Online comment bank offers a source of reliable comments (consistent with the SPEF-R rating scale across different domains) and aims to assist practice educators in providing reliable and timely feedback to students in a user-friendly manner. © 2014 Occupational Therapy Australia.

  17. Reliability of Soft Tissue Model Based Implant Surgical Guides; A Methodological Mistake.

    Science.gov (United States)

    Sabour, Siamak; Dastjerdi, Elahe Vahid

    2012-08-20

    Abstract We were interested to read the paper by Maney P and colleagues published in the July 2012 issue of J Oral Implantol. The authors aimed to assess the reliability of soft tissue model based implant surgical guides reported that the accuracy was evaluated using software. 1 I found the manuscript title of Maney P, et al. incorrect and misleading. Moreover, they reported twenty-two sites (46.81%) were considered accurate (13 of 24 maxillary and 9 of 23 mandibular sites). As the authors point out in their conclusion, Soft tissue models do not always provide sufficient accuracy for implant surgical guide fabrication.Reliability (precision) and validity (accuracy) are two different methodological issues in researches. Sensitivity, specificity, PPV, NPV, likelihood ratio positive (true positive/false negative) and likelihood ratio negative (false positive/ true negative) as well as odds ratio (true results\\false results - preferably more than 50) are among the tests to evaluate the validity (accuracy) of a single test compared to a gold standard.2-4 It is not clear that the reported twenty-two sites (46.81%) which were considered accurate related to which of the above mentioned estimates for validity analysis. Reliability (repeatability or reproducibility) is being assessed by different statistical tests such as Pearson r, least square and paired t.test which all of them are among common mistakes in reliability analysis 5. Briefly, for quantitative variable Intra Class Correlation Coefficient (ICC) and for qualitative variables weighted kappa should be used with caution because kappa has its own limitation too. Regarding reliability or agreement, it is good to know that for computing kappa value, just concordant cells are being considered, whereas discordant cells should also be taking into account in order to reach a correct estimation of agreement (Weighted kappa).2-4 As a take home message, for reliability and validity analysis, appropriate tests should be

  18. Inter- and intra-operator reliability and repeatability of shear wave elastography in the liver: a study in healthy volunteers.

    Science.gov (United States)

    Hudson, John M; Milot, Laurent; Parry, Craig; Williams, Ross; Burns, Peter N

    2013-06-01

    This study assessed the reproducibility of shear wave elastography (SWE) in the liver of healthy volunteers. Intra- and inter-operator reliability and repeatability were quantified in three different liver segments in a sample of 15 subjects, scanned during four independent sessions (two scans on day 1, two scans 1 wk later) by two operators. A total of 1440 measurements were made. Reproducibility was assessed using the intra-class correlation coefficient (ICC) and a repeated measures analysis of variance. The shear wave speed was measured and used to estimate Young's modulus using the Supersonics Imagine Aixplorer. The median Young's modulus measured through the inter-costal space was 5.55 ± 0.74 kPa. The intra-operator reliability was better for same-day evaluations (ICC = 0.91) than the inter-operator reliability (ICC = 0.78). Intra-observer agreement decreased when scans were repeated on a different day. Inter-session repeatability was between 3.3% and 9.9% for intra-day repeated scans, compared with to 6.5%-12% for inter-day repeated scans. No significant difference was observed in subjects with a body mass index greater or less than 25 kg/m(2). Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  19. Reliability and responsiveness of a goniometric device for measuring the range of motion in the dart-throwing motion plane.

    Science.gov (United States)

    Kasubuchi, Kenji; Dohi, Yoshihiro; Fujita, Hiroyuki; Fukumoto, Takahiko

    2018-02-26

    Dart-throwing motion (DTM) is an important component of wrist function and, consequently, has the potential to become an evaluation tool in rehabilitation. However, no measurement method is currently available to reliably measure range of motion (ROM) of the wrist in the DTM plane. To determine the reliability and responsiveness of a goniometric device to measure wrist ROM in the DTM plane. ROM of the wrist in the DTM plane was measured in 70 healthy participants. The intra-class correlation coefficient (ICC) was used to evaluate the relative reliability of measurement, and a Bland-Altman analysis conducted to establish its absolute reliability, including the 95% limits of agreement (95% LOA). The standard error of the measurement (SEM) and minimal detectable change at the 95% confidence level (MDC 95 ) were calculated as measures of responsiveness. The intra-rater ICC was 0.87, and an inter-rater ICC of 0.71. There was no evidence of a fixed or proportional bias. For intra- and inter-rater reliability, 95% LOA ranged from -13.83 to 11.12 and from -17.75 to 16.19, respectively. The SEM and MDC 95 were 4.5° and 12.4°, respectively, for intra-rater reliability, and 6.0° and 16.6°, respectively, for inter-rater reliability. The ROM of the wrist in the DTM plane was measured with fair-to-good reliability and responsiveness and, therefore, has the potential to become an evaluation tool for rehabilitation.

  20. Reliability of the Pictorial Scale of Perceived Movement Skill Competence in 2 Diverse Samples of Young Children.

    Science.gov (United States)

    Barnett, Lisa M; Robinson, Leah E; Webster, E Kipling; Ridgers, Nicola D

    2015-08-01

    The purpose was to determine the reliability of an instrument designed to assess young children's perceived movement skill competence in 2 diverse samples. A pictorial instrument assessed 12 perceived Fundamental Movement Skills (FMS) based on the Test of Gross Motor Development 2nd edition. Intra-Class Correlations (ICC) and internal consistency analyses were conducted. Paired sample t tests assessed change in mean perceived skill scores. Bivariate correlations between the intertrial difference and the mean of the trials explored proportional bias. Sample 1 (S1) were culturally diverse Australian children (n = 111; 52% boys) aged 5 to 8 years (mean = 6.4, SD = 1.0) with educated parents. Sample 2 (S2) were racially diverse and socioeconomically disadvantaged American children (n = 110; 57% boys) aged 5 to 10 years (mean = 6.8, SD = 1.1). For all children, the internal consistency for 12 FMS was acceptable (S1 = 0.72, 0.75, S2 = 0.66, 0.67). ICCs were higher in S1 (0.73) than S2 (0.50). Mean changes between trials were small. There was little evidence of proportional bias. Lower values in S2 may be due to differences in study demographic and execution. While the instrument demonstrated reliability/internal consistency, further work is recommended in diverse samples.

  1. Validity and Reliability of Gait and Postural Control Analysis Using the Tri-axial Accelerometer of the iPod Touch.

    Science.gov (United States)

    Kosse, Nienke M; Caljouw, Simone; Vervoort, Danique; Vuillerme, Nicolas; Lamoth, Claudine J C

    2015-08-01

    Accelerometer-based assessments can identify elderly with an increased fall risk and monitor interventions. Smart devices, like the iPod Touch, with built-in accelerometers are promising for clinical gait and posture assessments due to easy use and cost-effectiveness. The aim of the present study was to establish the validity and reliability of the iPod Touch for gait and posture assessment. Sixty healthy participants (aged 18-75 years) were measured with an iPod Touch and stand-alone accelerometer while they walked under single- and dual-task conditions, and while standing in parallel and semi-tandem stance with eyes open, eyes closed and when performing a dual task. Cross-correlation values (CCV) showed high correspondence of anterior-posterior and medio-lateral signal patterns (CCV's ≥ 0.88). Validity of gait parameters (foot contacts, index of harmonicity, and amplitude variability) and standing posture parameters [root mean square of accelerations, median power frequency (MPF) and sway area] as indicated by intra-class correlation (ICC) was high (ICC = 0.85-0.99) and test-retest reliability was good (ICC = 0.81-0.97), except for MPF (ICC = 0.59-0.87). Overall, the iPod Touch obtained valid and reliable measures of gait and postural control in healthy adults of all ages under different conditions. Additionally, smart devices have the potential to be used for clinical gait and posture assessments.

  2. Evaluating the reliability of Persian version of ankylosing spondylitis quality of life (ASQoL) questionnaire and related clinical and demographic parameters in patients with ankylosing spondylitis.

    Science.gov (United States)

    Fallahi, Sasan; Jamshidi, Ahmad Reza; Bidad, Katayoon; Qorbani, Mostafa; Mahmoudi, Mahdi

    2014-06-01

    Ankylosing spondylitis quality of life (ASQoL) is an instrument for assessing quality of life (QoL). The aims of this study were to assess the reliability of Persian version of ASQoL questionnaire and evaluation of QoL status and related factors in ankylosing spondylitis (AS). One hundred and sixty-three Iranian patients with AS who fulfilled modified New York criteria were enrolled. Patients were evaluated using questionnaires including demographic and clinical variables, Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), fatigue, Bath AS Metrology Index, pain and ASQoL. Reliability and validity of Persian version of ASQoL were evaluated by test-re-test agreement, internal consistency and correlation with specific scales. Relationship of parameters with ASQoL was analyzed by multiple regression. Age, disease duration and ASQoL score (mean ± SD) were 37.74 ± 9.88, 14.49 ± 8.47 and 8.02 ± 5.28 years, respectively. Test-re-test reproducibility for ASQoL was good as assessed by intra-class correlation coefficient (ICC: 0.97, P educational level, r = -0.37). Persian version of ASQoL is a valid and reliable scale to assess QoL in AS. Function, fatigue, mood, hip mobility and education are the factors which should be noted to achieve the best QoL.

  3. Validity and reliability of 3D US for the detection of erosions in patients with rheumatoid arthritis using MRI as the gold standard

    DEFF Research Database (Denmark)

    Ellegaard, K; Bliddal, H; Møller Døhn, U

    2014-01-01

    PURPOSE: To test the reliability and validity of a 3D US erosion score in RA using MRI as the gold standard. MATERIALS AND METHODS: RA patients were examined with 3D US and 3 T MRI over the 2nd and 3rd metacarpophalangeal joints. 3D blocks were evaluated by two investigators. The erosions were...... estimated according to a semi-quantitative score (SQS) (0 - 3) and a quantitative score (QS) (mm²). MRI was evaluated according to the RAMRIS score. For the estimation of reliability, intra-class correlation coefficients (ICC) were used. Validity was tested using Spearman's rho (rs). The sensitivity...... and specificity were also calculated. RESULTS: 28 patients with RA were included. The ICC for the inter-observer reliability in the QS was 0.41 and 0.13 for the metacarpal bone and phalangeal bone, respectively, and 0.86 and 0.16, respectively, in the SQS.  The ICC for the intra-observer reliability in the QS...

  4. Reliability of a retail food store survey and development of an accompanying retail scoring system to communicate survey findings and identify vendors for healthful food and marketing initiatives.

    Science.gov (United States)

    Ghirardelli, Alyssa; Quinn, Valerie; Sugerman, Sharon

    2011-01-01

    To develop a retail grocery instrument with weighted scoring to be used as an indicator of the food environment. Twenty six retail food stores in low-income areas in California. Observational. Inter-rater reliability for grocery store survey instrument. Description of store scoring methodology weighted to emphasize availability of healthful food. Type A intra-class correlation coefficients (ICC) with absolute agreement definition or a κ test for measures using ranges as categories. Measures of availability and price of fruits and vegetables performed well in reliability testing (κ = 0.681-0.800). Items for vegetable quality were better than for fruit (ICC 0.708 vs 0.528). Kappa scores indicated low to moderate agreement (0.372-0.674) on external store marketing measures and higher scores for internal store marketing. "Next to" the checkout counter was more reliable than "within 6 feet." Health departments using the store scoring system reported it as the most useful communication of neighborhood findings. There was good reliability of the measures among the research pairs. The local store scores can show the need to bring in resources and to provide access to fruits and vegetables and other healthful food. Copyright © 2011 Society for Nutrition Education. Published by Elsevier Inc. All rights reserved.

  5. Reliability and validity of the multimedia activity recall in children and adults (MARCA) in people with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Hunt, Toby; Williams, Marie T; Olds, Tim S

    2013-01-01

    To determine the reliability and validity of the Multimedia Activity Recall for Children and Adults (MARCA) in people with chronic obstructive pulmonary disease (COPD). People with COPD and their carers completed the Multimedia Activity Recall for Children and Adults (MARCA) for four, 24-hour periods (including test-retest of 2 days) while wearing a triaxial accelerometer (Actigraph GT3X+®), a multi-sensor armband (Sensewear Pro3®) and a pedometer (New Lifestyles 1000®). Self reported activity recalls (MARCA) and objective activity monitoring (Accelerometry) were recorded under free-living conditions. 24 couples were included in the analysis (COPD; age 74.4 ± 7.9 yrs, FEV1 54 ± 13% Carer; age 69.6 ± 10.9 yrs, FEV1 99 ± 24%). Not applicable. Test-retest reliability was compared for MARCA activity domains and different energy expenditure zones. Validity was assessed between MARCA-derived physical activity level (in metabolic equivalent of task (MET) per minute), duration of moderate to vigorous physical activity (min) and related data from the objective measurement devices. Analysis included intra-class correlation coefficients (ICC), Bland-Altman analyses, paired t-tests (p) and Spearman's rank correlation coefficients (rs). Reliability between occasions of recall for all activity domains was uniformly high, with test-retest correlations consistently >0.9. Validity correlations were moderate to strong (rs = 0.43-0.80) across all comparisons. The MARCA yields comparable PAL estimates and slightly higher moderate to vigorous physical activity (MVPA) estimates. In older adults with chronic illness, the MARCA is a valid and reliable tool for capturing not only the time and energy expenditure associated with physical and sedentary activities but also information on the types of activities.

  6. Assessing the relative and absolute reliability of the Falls Efficacy Scale-International questionnaire in elderly individuals with increased fall risk and the questionnaire's convergent validity in elderly women with osteoporosis.

    Science.gov (United States)

    Halvarsson, A; Franzén, E; Ståhle, A

    2013-06-01

    The Falls Efficacy Scale-International (FES-I) is a highly reliable questionnaire for assessing fear of falling in elderly individuals with increased fall risk and has low or no convergent validity with balance performance tests and health-related quality of life (HRQL) among elderly women with osteoporosis, which indicates that both measurements should be included as they are measuring different components. Fear of falling is increased in elderly individuals with osteoporosis and FES-I is a widely used questionnaire to assess fear of falling. There is limited evidence of the reliability and convergent validity in elderly with increased risk of falling and osteoporosis. Reliability and validity study of the FES-I. Community-dwelling elderly with increased fall risk, 59 subjects, were recruited to the reliability assessment, and 81 women with osteoporosis, in the validity assessment. For the reliability assessment, two postal surveys were used. For the validity assessment, we used baseline data from an on-going study in women with osteoporosis. The FES-I was correlated to a single-item question regarding fear of falling, self-reported history of falls, balance performance tests and health-related quality of life. The FES-I had very good relative reliability (intra-class correlation 0.88) and internal consistency reliability (Cronbach's alpha 0.94). The value for absolute reliability was a standard error of measure 2.9 (10.6 %), smallest real difference 7.9 (29 %). There was "little if any" to "low" correlation between the FES-I and the single-item question regarding fear of falling and self-reported history of falls, HRQL and balance performance tests. The FES-I seems to be a highly reliable questionnaire for assessing fear of falling in elderly with increased fall risk but has low relation to/convergent validity with balance performance and HRQL among elderly women with osteoporosis.

  7. Intra-tester Reliability and Construct Validity of a Hip Abductor Eccentric Strength Test.

    Science.gov (United States)

    Brindle, Richard A; Ebaugh, D David; Milner, Clare E

    2017-11-15

    Side-lying hip abductor strength tests are commonly used to evaluate muscle strength. In a 'break' test the tester applies sufficient force to lower the limb to the table while the patient resists. The peak force is postulated to occur while the leg is lowering, thus representing the participant's eccentric muscle strength. However, it is unclear whether peak force occurs before or after the leg begins to lower. To determine intra-rater reliability and construct validity of a hip abductor eccentric strength test. Intra-rater reliability and construct validity study. Twenty healthy adults (26 ±6 years; 1.66 ±0.06 m; 62.2 ±8.0 kg) made two visits to the laboratory at least one week apart. During the hip abductor eccentric strength test, a hand-held dynamometer recorded peak force and time to peak force and limb position was recorded via a motion capture system. Intra-rater reliability was determined using intra-class correlation (ICC), standard error of measurement (SEM), and minimal detectable difference (MDD). Construct validity was assessed by determining if peak force occurred after the start of the lowering phase using a one-sample t-test. The hip abductor eccentric strength test had substantial intra-rater reliability (ICC( 3,3 ) = 0.88; 95% confidence interval: 0.65-0.95), SEM of 0.9%BWh, and a MDD of 2.5%BWh. Construct validity was established as peak force occurred 2.1s (±0.6s; range 0.7s to 3.7s) after the start of the lowering phase of the test (p ≤ 0.001). The hip abductor eccentric strength test is a valid and reliable measure of eccentric muscle strength. This test may be used clinically to assess changes in eccentric muscle strength over time.

  8. Reliability and validity of the Performance Recorder 1 for measuring isometric knee flexor and extensor strength.

    Science.gov (United States)

    Neil, Sarah E; Myring, Alec; Peeters, Mon Jef; Pirie, Ian; Jacobs, Rachel; Hunt, Michael A; Garland, S Jayne; Campbell, Kristin L

    2013-11-01

    Muscular strength is a key parameter of rehabilitation programs and a strong predictor of functional capacity. Traditional methods to measure strength, such as manual muscle testing (MMT) and hand-held dynamometry (HHD), are limited by the strength and experience of the tester. The Performance Recorder 1 (PR1) is a strength assessment tool attached to resistance training equipment and may be a time- and cost-effective tool to measure strength in clinical practice that overcomes some limitations of MMT and HHD. However, reliability and validity of the PR1 have not been reported. Test-retest and inter-rater reliability was assessed using the PR1 in healthy adults (n  =  15) during isometric knee flexion and extension. Criterion-related validity was assessed through comparison of values obtained from the PR1 and Biodex® isokinetic dynamometer. Test-retest reliability was excellent for peak knee flexion (intra-class correlation coefficient [ICC] of 0.96, 95% CI: 0.85, 0.99) and knee extension (ICC  =  0.96, 95% CI: 0.87, 0.99). Inter-rater reliability was also excellent for peak knee flexion (ICC  =  0.95, 95% CI: 0.85, 0.99) and peak knee extension (ICC  =  0.97, 95% CI: 0.91, 0.99). Validity was moderate for peak knee flexion (ICC  =  0.75, 95% CI: 0.38, 0.92) but poor for peak knee extension (ICC  =  0.37, 95% CI: 0, 0.73). The PR1 provides a reliable measure of isometric knee flexor and extensor strength in healthy adults that could be used in the clinical setting, but absolute values may not be comparable to strength assessment by gold-standard measures.

  9. Test-retest reliability of sensor-based sit-to-stand measures in young and older adults.

    Science.gov (United States)

    Regterschot, G Ruben H; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren

    2014-01-01

    This study investigated test-retest reliability of sensor-based sit-to-stand (STS) peak power and other STS measures in young and older adults. In addition, test-retest reliability of the sensor method was compared to test-retest reliability of the Timed Up and Go Test (TUGT) and Five-Times-Sit-to-Stand Test (FTSST) in older adults. Ten healthy young female adults (20-23 years) and 31 older adults (21 females; 73-94 years) participated in two assessment sessions separated by 3-8 days. Vertical peak power was assessed during three (young adults) and five (older adults) normal and fast STS trials with a hybrid motion sensor worn on the hip. Older adults also performed the FTSST and TUGT. The average sensor-based STS peak power of the normal STS trials and the average sensor-based STS peak power of the fast STS trials showed excellent test-retest reliability in young adults (intra-class correlation (ICC)≥0.90; zero in 95% confidence interval of mean difference between test and retest (95%CI of D); standard error of measurement (SEM)≤6.7% of mean peak power) and older adults (ICC≥0.91; zero in 95%CI of D; SEM≤9.9%). Test-retest reliability of sensor-based STS peak power and TUGT (ICC=0.98; zero in 95%CI of D; SEM=8.5%) was comparable in older adults, test-retest reliability of the FTSST was lower (ICC=0.73; zero outside 95%CI of D; SEM=14.4%). Sensor-based STS peak power demonstrated excellent test-retest reliability and may therefore be useful for clinical assessment of functional status and fall risk. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. The modified patient enablement instrument: a Portuguese cross-cultural adaptation, validity and reliability study.

    Science.gov (United States)

    Remelhe, Mafalda; Teixeira, Pedro M; Lopes, Irene; Silva, Luís; Correia de Sousa, Jaime

    2017-01-12

    Enabling patients with asthma to obtain the knowledge, confidence and skills they need in order to assume a major role in the management of their disease is cost effective. It should be an integral part of any plan for long-term control of asthma. The modified Patient Enablement Instrument (mPEI) is an easily administered questionnaire that was adapted in the United Kingdom to measure patient enablement in asthma, but its applicability in Portugal is not known. Validity and reliability of questionnaires should be tested before use in settings different from those of the original version. The purpose of this study was to test the applicability of the mPEI to Portuguese asthma patients after translation and cross-cultural adaptation, and to verify the structural validity, internal consistency and reproducibility of the instrument. The mPEI was translated to Portuguese and back translated to English. Its content validity was assessed by a debriefing interview with 10 asthma patients. The translated instrument was then administered to a random sample of 142 patients with persistent asthma. Structural validity and internal consistency were assessed. For reproducibility analysis, 86 patients completed the instrument again 7 days later. Item-scale correlations and exploratory factor analysis were used to assess structural validity. Cronbach's alpha was used to test internal consistency, and the intra-class correlation coefficient was used for the analysis of reproducibility. All items of the Portuguese version of the mPEI were found to be equivalent to the original English version. There were strong item-scale correlations that confirmed construct validity, with a one component structure and good internal consistency (Cronbach's alpha >0.8) as well as high test-retest reliability (ICC=0.85). The mPEI showed sound psychometric properties for the evaluation of enablement in patients with asthma making it a reliable instrument for use in research and clinical practice in

  11. Developing and Evaluating Validity and Reliability of Persian Version of “Dichotic Fused Rhymed Word Test”

    Directory of Open Access Journals (Sweden)

    Nasrin Ghanbari

    2015-10-01

    Full Text Available Objective: The aim of the present study is to develope and evaluate validity and reliability of Persian version of Dichotic Fused Rhymed Words Test in 18-25 years old normal population. Materials & Methods: The Persian version of Dichotic Fused Rhymed Words Test consisted of 15 pairs of monosyllable rhymed words. These paired words are set in 4 lists of 30 items that simultaneously were presented one to the left and another to the right ear so that they lead to perception of a single fusion concept. After selecting the test material from Moin Persian dictionary according to the intended criteria and pairing the rhymed words, content validity was assessed through lawshe method by 10 expert persons, words with high validity were selected and lists were set. Then, the words of each list were recorded on CD in a dichotic mode. Thereafter, the study was performed in 124 normal individuals (68 females and 56 males within ages ranging from 18 to 25 years and the scores were recorded on a designed scoring form. To examine reliability of test, the test was performed on 15 individuals again two weeks after the initial test and the Pearson correlation was assessed. Results: There are significant differences between mean scores of right and left ears (P<0.001. Content Validity Ratio was 0.8-1 for every item. Pearson correlation was 0.83 for test-retest (P<0.001. Cronbach’s alpha and Intra Class Correlation (ICC was 0.81 and 0.84 for internal correlation between scores of lists of test. The result showed that there is significant correlation between the lists. Conclusion: Based on the obtained results, the Persian version of Dichotic Fused Rhymed Words Test has a good content validity and reliability. It can be used in detecting function of corpus callosum, lateralization of the cerebral hemispheres and assessment of central auditory processing.

  12. Validity and reliability of isometric muscle strength measurements of hip abduction and abduction with external hip rotation in a bent-hip position using a handheld dynamometer with a belt.

    Science.gov (United States)

    Aramaki, Hidefumi; Katoh, Munenori; Hiiragi, Yukinobu; Kawasaki, Tsubasa; Kurihara, Tomohisa; Ohmi, Yorikatsu

    2016-07-01

    [Purpose] This study aimed to investigate the relatedness, reliability, and validity of isometric muscle strength measurements of hip abduction and abduction with an external hip rotation in a bent-hip position using a handheld dynamometer with a belt. [Subjects and Methods] Twenty healthy young adults, with a mean age of 21.5 ± 0.6 years were included. Isometric hip muscle strength in the subjects' right legs was measured under two posture positions using two devices: a handheld dynamometer with a belt and an isokinetic dynamometer. Reliability was evaluated using an intra-class correlation coefficient (ICC); relatedness and validity were evaluated using Pearson's product moment correlation coefficient. Differences in measurements of devices were assessed by two-way ANOVA. [Results] ICC (1, 1) was ≥0.9; significant positive correlations in measurements were found between the two devices under both conditions. No main effect was found between the measurement values. [Conclusion] Our findings revealed that there was relatedness, reliability, and validity of this method for isometric muscle strength measurements using a handheld dynamometer with a belt.

  13. The reliability and validity study of the Kinesthetic and Visual Imagery Questionnaire in individuals with Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Yousef Moghadas Tabrizi

    2013-12-01

    Full Text Available OBJECTIVE: Motor imagery (MI has been recently considered as an adjunct to physical rehabilitation in patients with multiple sclerosis (MS. It is necessary to assess MI abilities and benefits in patients with MS by using a reliable tool. The Kinesthetic and Visual Imagery Questionnaire (KVIQ was recently developed to assess MI ability in patients with stroke and other disabilities. Considering the different underlying pathologies, the present study aimed to examine the validity and reliability of the KVIQ in MS patients. METHOD: Fifteen MS patients were assessed using the KVIQ in 2 sessions (5-14days apart by the same examiner. In the second session, the participants also completed a revised MI questionnaire (MIQ-R as the gold standard. Intra-class correlation coefficients (ICCs were measured to determine test-retest reliability. Spearman's correlation analysis was performed to assess concurrent validity with the MIQ-R. Furthermore, the internal consistency (Cronbach's alpha and factorial structure of the KVIQ were studied. RESULTS: The test-retest reliability for the KVIQ was good (ICCs: total KVIQ=0.89, visual KVIQ=0.85, and kinesthetic KVIQ=0.93, and the concurrent validity between the KVIQ and MIQ-R was good (r=0.79. The KVIQ had good internal consistency, with high Cronbach's alpha (alpha=0.84. Factorial analysis showed the bi-factorial structure of the KVIQ, which was explained by visual=57.6% and kinesthetic=32.4%. CONCLUSIONS: The results of the present study revealed that the KVIQ is a valid and reliable tool for assessing MI in MS patients.

  14. The reliability and validity study of the Kinesthetic and Visual Imagery Questionnaire in individuals with multiple sclerosis.

    Science.gov (United States)

    Tabrizi, Yousef Moghadas; Zangiabadi, Nasser; Mazhari, Shahrzad; Zolala, Farzaneh

    2013-01-01

    Motor imagery (MI) has been recently considered as an adjunct to physical rehabilitation in patients with multiple sclerosis (MS). It is necessary to assess MI abilities and benefits in patients with MS by using a reliable tool. The Kinesthetic and Visual Imagery Questionnaire (KVIQ) was recently developed to assess MI ability in patients with stroke and other disabilities. Considering the different underlying pathologies, the present study aimed to examine the validity and reliability of the KVIQ in MS patients. Fifteen MS patients were assessed using the KVIQ in 2 sessions (5-14 days apart) by the same examiner. In the second session, the participants also completed a revised MI questionnaire (MIQ-R) as the gold standard. Intra-class correlation coefficients (ICCs) were measured to determine test-retest reliability. Spearman's correlation analysis was performed to assess concurrent validity with the MIQ-R. Furthermore, the internal consistency (Cronbach's alpha) and factorial structure of the KVIQ were studied. The test-retest reliability for the KVIQ was good (ICCs: total KVIQ=0.89, visual KVIQ=0.85, and kinesthetic KVIQ=0.93), and the concurrent validity between the KVIQ and MIQ-R was good (r=0.79). The KVIQ had good internal consistency, with high Cronbach's alpha (alpha=0.84). Factorial analysis showed the bi-factorial structure of the KVIQ, which was explained by visual=57.6% and kinesthetic=32.4%. The results of the present study revealed that the KVIQ is a valid and reliable tool for assessing MI in MS patients.

  15. The Children's Global Assessment Scale (CGAS) and Global Assessment of Psychosocial Disability (GAPD) in clinical practice--substance and reliability as judged by intraclass correlations

    DEFF Research Database (Denmark)

    Dyrborg, J; Larsen, F W; Nielsen, S

    2000-01-01

    Studies on the inter-rater reliability on the Children's Global Assessment Scale (CGAS) and the Global Assessment of Psychosocial Disability (GAPD) involving different subgroups of 145 outpatients from 4 to 16 years of age showed fair to substantial intraclass correlations of 0.59 to 0.90. Raters...

  16. Validation and reliability of a modified sphygmomanometer for the assessment of handgrip strength in Parkinson´s disease

    Directory of Open Access Journals (Sweden)

    Soraia M. Silva

    2015-04-01

    Full Text Available BACKGROUND: Handgrip strength is currently considered a predictor of overall muscle strength and functional capacity. Therefore, it is important to find reliable and affordable instruments for this analysis, such as the modified sphygmomanometer test (MST. OBJECTIVES: To assess the concurrent criterion validity of the MST, to compare the MST with the Jamar dynamometer, and to analyze the reproducibility (i.e. reliability and agreement of the MST in individuals with Parkinson's disease (PD. METHOD: The authors recruited 50 subjects, 24 with PD (65.5±6.2 years of age and 26 healthy elderly subjects (63.4±7.2 years of age. The handgrip strength was measured using the Jamar dynamometer and modified sphygmomanometer. The concurrent criterion validity was analyzed using Pearson's correlation coefficient and a simple linear regression test. The reproducibility of the MST was evaluated with the coefficient of intra-class correlation (ICC2,1, the standard error of measurement (SEM, the minimal detectable change (MDC, and the Bland-Altman plot. For all of the analyses, α≤0.05 was considered a risk. RESULTS: There was a significant correlation of moderate magnitude (r≥0.45 between the MST and the Jamar dynamometer. The MST had excellent reliability (ICC2,1≥0.7. The SEM and the MDC were adequate; however, the Bland-Altman plot indicated an unsatisfactory interrater agreement. CONCLUSIONS: The MST exhibited adequate validity and excellent reliability and is, therefore, suitable for monitoring the handgrip strength in PD. However, if the goal is to compare the measurements between examiners, the authors recommend that the data be interpreted with caution.

  17. Tutorial on use of intraclass correlation coefficients for assessing intertest reliability and its application in functional near-infrared spectroscopy-based brain imaging.

    Science.gov (United States)

    Li, Lin; Zeng, Li; Lin, Zi-Jing; Cazzell, Mary; Liu, Hanli

    2015-05-01

    Test-retest reliability of neuroimaging measurements is an important concern in the investigation of cognitive functions in the human brain. To date, intraclass correlation coefficients (ICCs), originally used in interrater reliability studies in behavioral sciences, have become commonly used metrics in reliability studies on neuroimaging and functional near-infrared spectroscopy (fNIRS). However, as there are six popular forms of ICC, the adequateness of the comprehensive understanding of ICCs will affect how one may appropriately select, use, and interpret ICCs toward a reliability study. We first offer a brief review and tutorial on the statistical rationale of ICCs, including their underlying analysis of variance models and technical definitions, in the context of assessment on intertest reliability. Second, we provide general guidelines on the selection and interpretation of ICCs. Third, we illustrate the proposed approach by using an actual research study to assess interest reliability of fNIRS-based, volumetric diffuse optical tomography of brain activities stimulated by a risk decision-making protocol. Last, special issues that may arise in reliability assessment using ICCs are discussed and solutions are suggested.

  18. Tutorial on use of intraclass correlation coefficients for assessing intertest reliability and its application in functional near-infrared spectroscopy-based brain imaging

    Science.gov (United States)

    Li, Lin; Zeng, Li; Lin, Zi-Jing; Cazzell, Mary; Liu, Hanli

    2015-05-01

    Test-retest reliability of neuroimaging measurements is an important concern in the investigation of cognitive functions in the human brain. To date, intraclass correlation coefficients (ICCs), originally used in inter-rater reliability studies in behavioral sciences, have become commonly used metrics in reliability studies on neuroimaging and functional near-infrared spectroscopy (fNIRS). However, as there are six popular forms of ICC, the adequateness of the comprehensive understanding of ICCs will affect how one may appropriately select, use, and interpret ICCs toward a reliability study. We first offer a brief review and tutorial on the statistical rationale of ICCs, including their underlying analysis of variance models and technical definitions, in the context of assessment on intertest reliability. Second, we provide general guidelines on the selection and interpretation of ICCs. Third, we illustrate the proposed approach by using an actual research study to assess intertest reliability of fNIRS-based, volumetric diffuse optical tomography of brain activities stimulated by a risk decision-making protocol. Last, special issues that may arise in reliability assessment using ICCs are discussed and solutions are suggested.

  19. Test-retest reliability and agreement of the Satisfaction with the Assistive Technology Services (SATS) instrument in two Nordic countries.

    Science.gov (United States)

    Sund, Terje; Iwarsson, Susanne; Anttila, Heidi; Helle, Tina; Brandt, Ase

    2014-07-01

    The purpose of this study was to investigate test-retest reliability, agreement, internal consistency, and floor- and ceiling effects of the Danish and Finnish versions of the Satisfaction with the Assistive Technology Services (SATS) instrument among adult users of powered wheelchairs (PWCs) or powered scooters (scooters). Test-retest design, two telephone interviews 7-18 days apart of 40 informants, with mean age of 67.5 (SD 13.09) years in the Danish; and 54 informants with mean age of 55.6 (SD 12.09) years in the Finnish sample. The intra-class correlation coefficient varied between 0.57 and 0.93 for items in the Danish and between 0.41 and 0.93 in the Finnish sample. The percentage agreement varied between 54.2 and 79.5 for items in the Danish and between 69.2 and 81.1 in the Finnish sample, while the Cronbach's alpha values varied between 0.87 and 0.96 in the two samples. A ceiling effect was found in all items of both samples. This study indicates that the SATS may be reliably administered for telephone interviews among adult PWC and scooter users, and give information about aspects of the service delivery process for quality development improvement purposes. Further psychometric testing of the SATS is required.

  20. Test-retest reliability of speech-evoked auditory brainstem response in healthy children at a low sensation level.

    Science.gov (United States)

    Zakaria, Mohd Normani; Jalaei, Bahram

    2017-11-01

    Auditory brainstem responses evoked by complex stimuli such as speech syllables have been studied in normal subjects and subjects with compromised auditory functions. The stability of speech-evoked auditory brainstem response (speech-ABR) when tested over time has been reported but the literature is limited. The present study was carried out to determine the test-retest reliability of speech-ABR in healthy children at a low sensation level. Seventeen healthy children (6 boys, 11 girls) aged from 5 to 9 years (mean = 6.8 ± 3.3 years) were tested in two sessions separated by a 3-month period. The stimulus used was a 40-ms syllable /da/ presented at 30 dB sensation level. As revealed by pair t-test and intra-class correlation (ICC) analyses, peak latencies, peak amplitudes and composite onset measures of speech-ABR were found to be highly replicable. Compared to other parameters, higher ICC values were noted for peak latencies of speech-ABR. The present study was the first to report the test-retest reliability of speech-ABR recorded at low stimulation levels in healthy children. Due to its good stability, it can be used as an objective indicator for assessing the effectiveness of auditory rehabilitation in hearing-impaired children in future studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Test-retest reliability and responsiveness of the Barthel Index-based Supplementary Scales in patients with stroke.

    Science.gov (United States)

    Lee, Ya-Chen; Yu, Wan-Hui; Hsueh, I-Ping; Chen, Sheng-Shiung; Hsieh, Ching-Lin

    2017-10-01

    A lack of evidence on the test-retest reliability and responsiveness limits the utility of the BI-based Supplementary Scales (BI-SS) in both clinical and research settings. To examine the test-retest reliability and responsiveness of the BI-based Supplementary Scales (BI-SS) in patients with stroke. A repeated-assessments design (1 week apart) was used to examine the test-retest reliability of the BI-SS. For the responsiveness study, the participants were assessed with the BI-SS and BI (treated as an external criterion) at admission to and discharge from rehabilitation wards. Seven outpatient rehabilitation units and one inpatient rehabilitation unit. Outpatients with chronic stroke. Eighty-four outpatients with chronic stroke participated in the test-retest reliability study. Fifty-seven inpatients completed baseline and follow-up assessments in the responsiveness study. For the test-retest reliability study, the values of the intra-class correlation coefficient and the overall percentage of minimal detectable change for the Ability Scale and Self-perceived Difficulty Scale were 0.97, 12.8%, and 0.78, 35.8%, respectively. For the responsiveness study, the standardized effect size and standardized response mean (representing internal responsiveness) of the Ability Scale and Self-perceived Difficulty Scale were 1.17 and 1.56, and 0.78 and 0.89, respectively. Regarding external responsiveness, the change in score of the Ability Scale had significant and moderate association with that of the BI (r=0.61, Ptest-retest reliability and sufficient responsiveness for patients with stroke. However, the Self-perceived Difficulty Scale of the BI-SS has substantial random measurement error and insufficient external responsiveness, which may affect its utility in clinical settings. The findings of this study provide empirical evidence of psychometric properties of the BI-SS for assessing ability and self-perceived difficulty of ADL in patients with stroke.

  2. Reliability and convergent validity of the five-step test in people with chronic stroke.

    Science.gov (United States)

    Ng, Shamay S M; Tse, Mimi M Y; Tam, Eric W C; Lai, Cynthia Y Y

    2018-01-10

    (i) To estimate the intra-rater, inter-rater and test-retest reliabilities of the Five-Step Test (FST), as well as the minimum detectable change in FST completion times in people with stroke. (ii) To estimate the convergent validity of the FST with other measures of stroke-specific impairments. (iii) To identify the best cut-off times for distinguishing FST performance in people with stroke from that of healthy older adults. A cross-sectional study. University-based rehabilitation centre. Forty-eight people with stroke and 39 healthy controls. None. The FST, along with (for the stroke survivors only) scores on the Fugl-Meyer Lower Extremity Assessment (FMA-LE), the Berg Balance Scale (BBS), Limits of Stability (LOS) tests, and Activities-specific Balance Confidence (ABC) scale were tested. The FST showed excellent intra-rater (intra-class correlation coefficient; ICC = 0.866-0.905), inter-rater (ICC = 0.998), and test-retest (ICC = 0.838-0.842) reliabilities. A minimum detectable change of 9.16 s was found for the FST in people with stroke. The FST correlated significantly with the FMA-LE, BBS, and LOS results in the forward and sideways directions (r = -0.411 to -0.716, p people with stroke and healthy older adults. The FST is a reliable, easy-to-administer clinical test for assessing stroke survivors' ability to negotiate steps and stairs.

  3. Reliability of panoramic ultrasound imaging in simultaneously examining muscle size and quality of the hamstring muscles in young, healthy males and females.

    Science.gov (United States)

    Palmer, Ty B; Akehi, Kazuma; Thiele, Ryan M; Smith, Doug B; Thompson, Brennan J

    2015-03-01

    The purpose of this study was to examine the reliability of ultrasound (US) measures of cross-sectional area (CSA), muscle thickness (MT) and echo intensity (EI) of the hamstrings, with comparisons between males and females. In 20 healthy participants (10 males, 10 females), CSA, MT and EI were measured from panoramic US scans of the hamstrings on 2 separate days. The intra-class correlation coefficients and standard errors of measurement as a percentage of the mean for CSA, MT and EI ranged from 0.715 to 0.984 and from 3.145 to 12.541% in the males and from 0.724 to 0.977 and from 4.571 to 17.890% in the females, respectively. The males had greater CSAs and MTs and lower EIs than the females (p = 0.002-0.049), and significant relationships were observed between CSA and MT (r = 0.714-0.938, p ≤ 0.001-0.023). From an overall reliability standpoint, these findings suggest that panoramic US may be a reliable technique for examining muscle size and quality of the hamstrings in both males and females. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  4. "Cross-Cultural Adaptation Of The Multiple Sclerosis Impact Scale (MSIS-29 For Iranian MS Patients, Evaluation Of Reliability And Validity "

    Directory of Open Access Journals (Sweden)

    P. Ayatollahi

    2006-05-01

    Full Text Available Background and Aim: Measuring the outcome of chronic diseases such as multiple sclerosis is an important factor in assessment of disease impact on different dimensions of quality of life and in evaluation of therapeutic interventions. The aim of this study was to perform the cross-cultural adaptation of the MSIS-29 which is a MS-specific outcome measure for Iranian patients. Materials and Methods: The Iranian adaptation process of the MSIS-29 included 5 steps. To evaluate psychometric properties of the translated version, the questionnaire was administered to a consecutive sample of 96 patients with clinically definite MS referred to our out-patient clinic. Test-retest reliability was assessed in a sub-sample consisted of 30 patients. These patients completed the questionnaire on two occasions separated by a 7-day interval. The Iranian version of the SF-36 was also administered to this sub-sample in order to evaluate the validity of translated MSIS-29. Results: Statistical analysis indicated that the Persian version of the MSIS-29 had high internal consistency (cronbach’s alpha coefficients > 0.70 and test-retest reliability (intra-class correlation coefficients >0.70 and a good validity. Conclusion: The Persian version of the MSIS-29 is a reliable and valid instrument for measuring MS outcome in Iranian patients. It can be used in clinical trials and cross-sectional studies.

  5. Practice effects and test-re-test reliability of the Five Digit Test in patients with stroke over four serial assessments.

    Science.gov (United States)

    Chiu, En-Chi; Koh, Chia-Lin; Tsai, Chia-Yin; Lu, Wen-Shian; Sheu, Ching-Fan; Hsueh, I-Ping; Hsieh, Ching-Lin

    2014-01-01

    To investigate practice effect and test-re-test reliability of the Five Digit Test (FDT) over four serial assessments in patients with stroke. Single-group repeated measures design. Twenty-five patients with stroke were administered the FDT in four consecutive assessments every 2 weeks. The FDT contains four parts with five indices: 'basic measures of attention and processing speed', 'selective attention', 'alternating attention', 'ability of inhibition' and 'ability of switching'. The five indices of the FDT showed trivial-to-small practice effects (Cohen's d = 0.03-0.47) and moderate-to-excellent test-re-test reliability (intra-class correlation coefficient = 0.59-0.97). Practice effects of the five indices all appeared cumulative, but one index, 'basic measures of attention and processing speed', reached a plateau after the second assessment. The minimum and maximum values of the 90% confidence interval (CI) of reliable change index modified for practice (RCIp) for this index were [-17.6, 11.2]. One of five indices of the FDT reached a plateau, whose minimum and maximum values of the 90% CI RCIp are useful to determine whether the change in an individual's score is real. However, clinicians and researchers should be cautious when interpreting the test results of these four indices over repeated assessments.

  6. Validity, reliability and support for implementation of independence-scaled procedural assessment in laparoscopic surgery.

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    Kramp, Kelvin H; van Det, Marc J; Veeger, Nic J G M; Pierie, Jean-Pierre E N

    2016-06-01

    There is no widely used method to evaluate procedure-specific laparoscopic skills. The first aim of this study was to develop a procedure-based assessment method. The second aim was to compare its validity, reliability and feasibility with currently available global rating scales (GRSs). An independence-scaled procedural assessment was created by linking the procedural key steps of the laparoscopic cholecystectomy to an independence scale. Subtitled and blinded videos of a novice, an intermediate and an almost competent trainee, were evaluated with GRSs (OSATS and GOALS) and the independence-scaled procedural assessment by seven surgeons, three senior trainees and six scrub nurses. Participants received a short introduction to the GRSs and independence-scaled procedural assessment before assessment. The validity was estimated with the Friedman and Wilcoxon test and the reliability with the intra-class correlation coefficient (ICC). A questionnaire was used to evaluate user opinion. Independence-scaled procedural assessment and GRS scores improved significantly with surgical experience (OSATS p = 0.001, GOALS p < 0.001, independence-scaled procedural assessment p < 0.001). The ICCs of the OSATS, GOALS and independence-scaled procedural assessment were 0.78, 0.74 and 0.84, respectively, among surgeons. The ICCs increased when the ratings of scrub nurses were added to those of the surgeons. The independence-scaled procedural assessment was not considered more of an administrative burden than the GRSs (p = 0.692). A procedural assessment created by combining procedural key steps to an independence scale is a valid, reliable and acceptable assessment instrument in surgery. In contrast to the GRSs, the reliability of the independence-scaled procedural assessment exceeded the threshold of 0.8, indicating that it can also be used for summative assessment. It furthermore seems that scrub nurses can assess the operative competence of surgical trainees.

  7. Inter-assessor reliability of practice based biomechanical assessment of the foot and ankle

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    Jarvis Hannah L

    2012-06-01

    Full Text Available Abstract Background There is no consensus on which protocols should be used to assess foot and lower limb biomechanics in clinical practice. The reliability of many assessments has been questioned by previous research. The aim of this investigation was to (i identify (through consensus what biomechanical examinations are used in clinical practice and (ii evaluate the inter-assessor reliability of some of these examinations. Methods Part1: Using a modified Delphi technique 12 podiatrists derived consensus on the biomechanical examinations used in clinical practice. Part 2: Eleven podiatrists assessed 6 participants using a subset of the assessment protocol derived in Part 1. Examinations were compared between assessors. Results Clinicians choose to estimate rather than quantitatively measure foot position and motion. Poor inter-assessor reliability was recorded for all examinations. Intra-class correlation coefficient values (ICC for relaxed calcaneal stance position were less than 0.23 and were less than 0.14 for neutral calcaneal stance position. For the examination of ankle joint dorsiflexion, ICC values suggest moderate reliability (less than 0.61. The results of a random effects ANOVA highlight that participant (up to 5.7°, assessor (up to 5.8° and random (up to 5.7° error all contribute to the total error (up to 9.5° for relaxed calcaneal stance position, up to 10.7° for the examination of ankle joint dorsiflexion. Kappa Fleiss values for categorisation of first ray position and mobility were less than 0.05 and for limb length assessment less than 0.02, indicating slight agreement. Conclusion Static biomechanical assessment of the foot, leg and lower limb is an important protocol in clinical practice, but the key examinations used to make inferences about dynamic foot function and to determine orthotic prescription are unreliable.

  8. Quantitative outcome measures for systemic sclerosis-related Microangiopathy - Reliability of image acquisition in Nailfold Capillaroscopy.

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    Dinsdale, Graham; Moore, Tonia; O'Leary, Neil; Berks, Michael; Roberts, Christopher; Manning, Joanne; Allen, John; Anderson, Marina; Cutolo, Maurizio; Hesselstrand, Roger; Howell, Kevin; Pizzorni, Carmen; Smith, Vanessa; Sulli, Alberto; Wildt, Marie; Taylor, Christopher; Murray, Andrea; Herrick, Ariane L

    2017-09-01

    Nailfold capillaroscopic parameters hold increasing promise as outcome measures for clinical trials in systemic sclerosis (SSc). Their inclusion as outcomes would often naturally require capillaroscopy images to be captured at several time points during any one study. Our objective was to assess repeatability of image acquisition (which has been little studied), as well as of measurement. 41 patients (26 with SSc, 15 with primary Raynaud's phenomenon) and 10 healthy controls returned for repeat high-magnification (300×) videocapillaroscopy mosaic imaging of 10 digits one week after initial imaging (as part of a larger study of reliability). Images were assessed in a random order by an expert blinded observer and 4 outcome measures extracted: (1) overall image grade and then (where possible) distal vessel locations were marked, allowing (2) vessel density (across the whole nailfold) to be calculated (3) apex width measurement and (4) giant vessel count. Intra-rater, intra-visit and intra-rater inter-visit (baseline vs. 1week) reliability were examined in 475 and 392 images respectively. A linear, mixed-effects model was used to estimate variance components, from which intra-class correlation coefficients (ICCs) were determined. Intra-visit and inter-visit reliability estimates (ICCs) were (respectively): overall image grade, 0.97 and 0.90; vessel density, 0.92 and 0.65; mean vessel width, 0.91 and 0.79; presence of giant capillary, 0.68 and 0.56. These estimates were conditional on each parameter being measurable. Within-operator image analysis and acquisition are reproducible. Quantitative nailfold capillaroscopy, at least with a single observer, provides reliable outcome measures for clinical studies including randomised controlled trials. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Reliability of widefield capillary microscopy to measure nailfold capillary density in systemic sclerosis.

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    Hudson, M; Masetto, A; Steele, R; Arthurs, E; Baron, M

    2010-01-01

    To determine intra- and inter-observer reliability of widefield microscopy to measure nailfold capillary density in patients with systemic sclerosis (SSc). Five SSc patients were examined with a STEMV-8 Zeiss biomicroscope with 50x magnification. The nailfold of the second, third, fourth and fifth fingers of both hands of each patient were photographed twice by each of two observers, once in the morning and again in the afternoon (total of 32 pictures). Two raters reviewed the photographs to produce capillary density readings. Intra- and inter-rater reliability of the readings were computed using intra-class correlations (ICC). Additional analyses were undertaken to determine the impact of other sources of variability in the data, namely patient, finger, technician and time. Intra-and inter-rater reliability were substantial (ICC 0.72-0.84) when raters were reading the same photographs or photographs taken at the same time of day. Agreement was only fair between morning and afternoon density readings (ICC 0.30-0.37). Patients, individual fingers and technician accounted for a large part of the variability in the data (combined variance component of 7.69 out of the total 12.23). The coefficient of variation of widefield microscopy was 24%. Although intra- and inter-rater reliability of nailfold capillary density measurements using widefield microscopy are good, proper standardisation of the conditions under which capillaroscopy is done and better imaging of nailfold capillary abnormalities should be considered if nailfold capillary density is to be used as an outcome measure in multi-centre clinical trials in SSc.

  10. Manual Ability Classification System (MACS: reliability between therapists and parents in Brazil

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    Daniela B. R. Silva

    2015-02-01

    Full Text Available BACKGROUND: The Manual Ability Classification System (MACS has been widely used to describe the manual ability of children with cerebral palsy (CP; however its reliability has not been verified in Brazil. OBJECTIVE: To establish the inter- and intra-rater reliability of the Portuguese-Brazil version of the MACS by comparing the classifications given by therapists and parents of children with CP. METHOD: Data were obtained from 90 children with CP between the ages of 4 and 18 years, who were treated at the neurology and rehabilitation clinics of a Brazilian hospital. Therapists (an occupational therapist and a student classified manual ability (MACS through direct observation and information provided by parents. Therapists and parents used the Portuguese-Brazil version of the MACS. Intra- and inter-rater reliability was obtained using unweighted Kappa coefficient (k and intra-class correlation coefficient (ICC. The Chi-square test was used to identify the predominance of disagreements in the classification of parents and therapists. RESULTS: An almost perfect agreement resulted among therapists [K=0.90 (95% CI 0.83-0.97; ICC=0.97 (95%CI 0.96-0.98], as well as with intra-rater (therapists, with Kappa ranging between 0.83 and 0.95 and ICC between 0.96 and 0.99 for the evaluator with more and less experience in rehabilitation, respectively. The agreement between therapists and parents was fair [K=0.36 (95% CI 0.22-0.50; ICC=0.79 (95% CI 0.70-0.86]. CONCLUSIONS: The Portuguese version of the MACS is a reliable instrument to be used jointly by parents and therapists.

  11. Reliability of an instrument to determine lower limb comfort in professional football

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    Michael Kinchington

    2010-06-01

    Full Text Available Michael Kinchington1, Kevin Ball1, Geraldine Naughton21School of Human Movement, Recreation and Performance, Victoria University, Melbourne, Australia; 2The Centre of Physical Activity Across the Lifespan (COPAAL, Australian Catholic University, Victoria, AustraliaAims and Objectives: This study extends previous work in the field of injury awareness using a novel lower limb comfort index (LLCI, which was developed to assess comfort in professional football. Participants rated comfort for designated anatomical segments of the lower limb utilizing a seven point Likert scale. The aims of the study were (i to assess the reliability of the LLCI in a competitive football environment (Australian Rules and Rugby League, and (ii to assess whether LLCI measurements were responsive to changes in lower limb comfort over time.Methods and Results: The reliability of the LLCI was observed in two professional football environments: Training Week (mean difference 0.1 point, intra-class correlation coefficient, ICC 0.99 for n = 41 participants; and Match Day (mean difference 0.2 points, ICC 0.97 for n = 22 players. Measurements of lower limb comfort were responsive to changes in comfort over time. Within-player differences were not significant for periods 0–8 hrs (P > 0.05 but, generally, significant for time periods 0–24 hrs (P < 0.05, and significant between 24–96 hrs (P < 0.01. The results indicate that the LLCI was reliable when tested for repeated measures and indicated how the index measures lower limb comfort changes over time.Conclusion: This study shows that the use of a lower limb comfort index, when used in a competitive football environment, is both reliable and responsive to change during both a training week and under match day conditions.Keywords: lower limb comfort, musculoskeletal, football, injury

  12. Reliability of sagittal plane hip, knee, and ankle joint angles from a single frame of video data using the GAITRite camera system.

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    Ross, Sandy A; Rice, Clinton; Von Behren, Kristyn; Meyer, April; Alexander, Rachel; Murfin, Scott

    2015-01-01

    The purpose of this study was to establish intra-rater, intra-session, and inter-rater, reliability of sagittal plane hip, knee, and ankle angles with and without reflective markers using the GAITRite walkway and single video camera between student physical therapists and an experienced physical therapist. This study included thirty-two healthy participants age 20-59, stratified by age and gender. Participants performed three successful walks with and without markers applied to anatomical landmarks. GAITRite software was used to digitize sagittal hip, knee, and ankle angles at two phases of gait: (1) initial contact; and (2) mid-stance. Intra-rater reliability was more consistent for the experienced physical therapist, regardless of joint or phase of gait. Intra-session reliability was variable, the experienced physical therapist showed moderate to high reliability (intra-class correlation coefficient (ICC) = 0.50-0.89) and the student physical therapist showed very poor to high reliability (ICC = 0.07-0.85). Inter-rater reliability was highest during mid-stance at the knee with markers (ICC = 0.86) and lowest during mid-stance at the hip without markers (ICC = 0.25). Reliability of a single camera system, especially at the knee joint shows promise. Depending on the specific type of reliability, error can be attributed to the testers (e.g. lack of digitization practice and marker placement), participants (e.g. loose fitting clothing) and camera systems (e.g. frame rate and resolution). However, until the camera technology can be upgraded to a higher frame rate and resolution, and the software can be linked to the GAITRite walkway, the clinical utility for pre/post measures is limited.

  13. Cross-cultural adaptation, reliability, and validity of the Persian version of the Cumberland Ankle Instability Tool.

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    Hadadi, Mohammad; Ebrahimi Takamjani, Ismail; Ebrahim Mosavi, Mohammad; Aminian, Gholamreza; Fardipour, Shima; Abbasi, Faeze

    2017-08-01

    The purpose of the present study was to translate and to cross-culturally adapt the Cumberland Ankle Instability Tool (CAIT) into Persian language and to evaluate its psychometric properties. The International Quality of Life Assessment process was pursued to translate CAIT into Persian. Two groups of Persian-speaking individuals, 105 participants with a history of ankle sprain and 30 participants with no history of ankle sprain, were asked to fill out Persian version of CAIT (CAIT-P), Foot and Ankle Ability Measure (FAAM), and Visual Analog Scale (VAS). Data obtained from the first administration of CAIT were used to evaluate floor and ceiling effects, internal consistency, dimensionality, and criterion validity. To determine the test-retest reliability, 45 individuals re-filled CAIT 5-7 days after the first session. Cronbach's alpha was over the cutoff point of 0.70 for both ankles and in both groups. The intra-class correlation coefficient was high for right (0.95) and left (0.91) ankles. There was a strong correlation between each item and the total score of the CAIT-P. Although the CAIT-P had strong correlation with VAS, its correlation with both subscales of FAAM was moderate. The CAIT-P has good validity and reliability and it can be used by clinicians and researchers for identification and investigation of functional ankle instability. Implications for Rehabilitation Chronic ankle instability is one of the most common consequences of acute ankle sprain. Cumberland Ankle Instability Tool is an acceptable measure to determine functional ankle instability and its severity. The Persian version of Cumberland Ankle Instability Tool is a valid and reliable tool for clinical and research purpose in Persian-speaking individuals.

  14. The Korean Version of the Cognitive Assessment Scale for Stroke Patients (K-CASP): A Reliability and Validity Study.

    Science.gov (United States)

    Park, Kwon-Hee; Lee, Hee-Won; Park, Kee-Boem; Lee, Jin-Youn; Cho, Ah-Ra; Oh, Hyun-Mi; Park, Joo Hyun

    2017-06-01

    To develop the Korean version of the Cognitive Assessment Scale for Stroke Patients (K-CASP) and to evaluate the test reliability and validity of the K-CASP in stroke patients. The original CASP was translated into Korean, back-translated into English, then reviewed and compared with the original version. Thirty-three stroke patients were assessed independently by two examiners using the K-CASP twice, with a one-day interval, for a total of four test results. To evaluate the reliability of the K-CASP, intra-class correlation coefficients were used. Pearson correlations were calculated and simple regression analyses performed with the Korean version of Mini-Mental State Examination (K-MMSE) and the aphasia quotient (AQ) to assess the validity. The mean score was 24.42±9.47 (total score 36) for the K-CASP and 21.50±7.01 (total score 30) for the K-MMSE. The inter-rater correlation coefficients of the K-CASP were 0.992 on the first day and 0.995 on the second day. The intra-rater correlation coefficients of the K-CASP were 0.997 for examiner 1 and 0.996 for examiner 2. In the Pearson correlation analysis, the K-CASP score significantly correlated with the K-MMSE score (r=0.825, preliable and valid instrument for cognitive dysfunction screening in post-stroke patients. It is more applicable than other cognitive assessment tools in stroke patients with aphasia.

  15. Reliability and validity of the adapted Resistance Training Skills Battery for Children.

    Science.gov (United States)

    Furzer, Bonnie J; Bebich-Philip, Marc D; Wright, Kemi E; Reid, Siobhan L; Thornton, Ashleigh L

    2017-12-29

    Resistance training (RT) is emerging as a training modality to improve motor function and facilitate physical activity participation in children across the motor proficiency spectrum. Although RT competency assessments have been established and validated among adolescent cohorts, the extent to which these methods are suitable for assessing children's RT skills is unknown. This project aimed to assess the psychometric properties of the adapted Resistance Training Skills Battery for Children (RTSBc), in children with varying motor proficiency. Repeated measures design with 40 participants (M age=8.2±1.7years) displaying varying levels of motor proficiency. Participants performed the adapted RTSBc on two occasions, receiving a score for their execution of each component, in addition to an overall RT skill quotient child (RTSQc). Cronbach's alpha, intra-class correlation (ICC), Bland-Altman analysis, and typical error were used to assess test-retest reliability. To examine construct validity, exploratory factor analysis was performed alongside computing correlations between participants' muscle strength, motor proficiency, age, lean muscle mass, and RTSQc. The RTSBc displayed an acceptable level of internal consistency (alpha=0.86) and test-retest reliability (ICC range=0.86-0.99). Exploratory factor analysis supported internal test structure, with all six RT skills loading strongly on a single factor (range 0.56-0.89). Analyses of structural validity revealed positive correlations for RTSQc in relation to motor proficiency (r=0.52, preliability of the RTSBc, providing preliminary evidence that the RTSBc is appropriate for use in the assessment of children's RT competency. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. Test Re-Test Reliability of Four Versions of the 3-Cone Test in Non-Athletic Men

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    Jason G. Langley, Robert D. Chetlin

    2017-03-01

    Full Text Available Until recently, measurement and evaluation in sport science, especially agility testing, has not always included key elements of proper test construction. Often tests are published without reporting reliability and validity analysis for a specific population. The purpose of the present study was to examine the test re-test reliability of four versions of the 3-Cone Test (3CT, and provide guidance on proper test construction for testing agility in athletic populations. Forty male students enrolled in classes in the Department of Physical Education at a mid-Atlantic university participated. On each of test day participants performed 10 trials. In random order, they performed three trials to the right (3CTR, standard test, three to the left (3CTL, and two modified trials (3CTAR and 3CTAL, which included a reactive component in which a visual cue was given to indicate direction. Intra-class correlation coefficients (ICC indicated a moderate to high reliability for the four tests, 3CTR 0.79 (0.64-0.88, 95%CI, 3CTL 0.73 (0.55-0.85, 3CTAR 0.85(0.74-0.92, and 3CTAL 0.79 (0.64-0.88. Small standard error of the measurement (SEM was found; range 0.09 to 0.10. Pearson correlations between tests were high (0.82-0.92 on day one as well as day two (0.72-0.85. These results indicate each version of the 3-Cone Test is reliable; however, further tests are needed with specific athletic populations. Only the 3CTAR and 3CTAL are tests of agility due to the inclusion of a reactive component. Future studies examining agility testing and training should incorporate technological elements, including automated timing systems and motion capture analysis. Such instrumentation will allow for optimal design of tests that simulate sport-specific game conditions.

  17. Test–Retest Reliability of Self-Reported Sexual Behavior History in Urbanized Nigerian Women

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    Eileen O. Dareng

    2017-07-01

    Full Text Available BackgroundStudies assessing risk of sexual behavior and disease are often plagued by questions about the reliability of self-reported sexual behavior. In this study, we evaluated the reliability of self-reported sexual history among urbanized women in a prospective study of cervical HPV infections in Nigeria.MethodsWe examined test–retest reliability of sexual practices using questionnaires administered at study entry and at follow-up visits. We used the root mean squared approach to calculate within-person coefficient of variation (CVw and calculated the intra-class correlation coefficient (ICC using two way, mixed effects models for continuous variables and (κ^ statistics for discrete variables. To evaluate the potential predictors of reliability, we used linear regression and log binomial regression models for the continuous and categorical variables, respectively.ResultsWe found that self-reported sexual history was generally reliable, with overall ICC ranging from 0.7 to 0.9; however, the reliability varied by nature of sexual behavior evaluated. Frequency reports of non-vaginal sex (agreement = 63.9%, 95% CI: 47.5–77.6% were more reliable than those of vaginal sex (agreement = 59.1%, 95% CI: 55.2–62.8%. Reports of time-invariant behaviors were also more reliable than frequency reports. The CVw for age at sexual debut was 10.7 (95% CI: 10.6–10.7 compared with the CVw for lifetime number of vaginal sex partners, which was 35.2 (95% CI: 35.1–35.3. The test–retest interval was an important predictor of reliability of responses, with longer intervals resulting in increased inconsistency (average change in unreliability for each 1 month increase = 0.04, 95% CI = 0.07–0.38, p = 0.005.ConclusionOur findings suggest that overall, the self-reported sexual history among urbanized Nigeran women is reliable.

  18. Validity and Reliability of Persian Version of HIV/AIDS Related Stigma Scale for People Living With HIV/AIDS in Iran

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    Davoud Pourmarzi

    2016-04-01

    Full Text Available Objective: To assess the perceived HIV/AIDS related stigma a comprehensive and well developed stigma instrument is necessary. This study aimed to assess validity and reliability of the Persian version of HIV/AIDS related stigma scale which was developed by Kang et al for people living with HIV/AIDS in Iran.Materials and methods: Thescale was forward translatedby two bilingual academic members then both translations were discussed by expert team. Back-translation was done by two other bilingual translators then we carried out discussion with both of them. To evaluate understandability the scale was administered to 10 Persons Living with HIV/AIDS (PLWHA. Final Persian version was administered to 80 PLWHA in Qom, Iran in 2014. Test–retest reliability was assessed in a sample of 20 PLWHA after a week by intra-class correlation coefficient (ICC.Results: Cronbach’s alpha coefficient for overall scale was 0.85. Also Cronbach’s alpha coefficients for the five subscales were as follows: social rejection (9 items, α = 0.84, negative self-worth (4 items, α = 0.70, perceived interpersonal insecurity (2 items, α = 0.57, financial insecurity (3 items, α = 0.70, discretionary disclosure (2 items, α = 0.83. Test–retest reliability was also approved with ICC = 0.78. Correlation between items and their hypothesized subscale is greater than 0.5. Correlation between an item and its own subscale was significantly higher than its correlation with other subscales.Conclusion: This study demonstrate that the Persian version of HIV/AIDS related stigma scale is valid and reliable to assess HIV/AIDS related stigma perceived by people living whit HIV/AIDS in Iran.

  19. Test-retest reliability of fMRI-based graph theoretical properties during working memory, emotion processing, and resting state.

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    Cao, Hengyi; Plichta, Michael M; Schäfer, Axel; Haddad, Leila; Grimm, Oliver; Schneider, Michael; Esslinger, Christine; Kirsch, Peter; Meyer-Lindenberg, Andreas; Tost, Heike

    2014-01-01

    The investigation of the brain connectome with functional magnetic resonance imaging (fMRI) and graph theory analyses has recently gained much popularity, but little is known about the robustness of these properties, in particular those derived from active fMRI tasks. Here, we studied the test-retest reliability of brain graphs calculated from 26 healthy participants with three established fMRI experiments (n-back working memory, emotional face-matching, resting state) and two parcellation schemes for node definition (AAL atlas, functional atlas proposed by Power et al.). We compared the intra-class correlation coefficients (ICCs) of five different data processing strategies and demonstrated a superior reliability of task-regression methods with condition-specific regressors. The between-task comparison revealed significantly higher ICCs for resting state relative to the active tasks, and a superiority of the n-back task relative to the face-matching task for global and local network properties. While the mean ICCs were typically lower for the active tasks, overall fair to good reliabilities were detected for global and local connectivity properties, and for the n-back task with both atlases, smallworldness. For all three tasks and atlases, low mean ICCs were seen for the local network properties. However, node-specific good reliabilities were detected for node degree in regions known to be critical for the challenged functions (resting-state: default-mode network nodes, n-back: fronto-parietal nodes, face-matching: limbic nodes). Between-atlas comparison demonstrated significantly higher reliabilities for the functional parcellations for global and local network properties. Our findings can inform the choice of processing strategies, brain atlases and outcome properties for fMRI studies using active tasks, graph theory methods, and within-subject designs, in particular future pharmaco-fMRI studies. © 2013 Elsevier Inc. All rights reserved.

  20. Use of a tibial accelerometer to measure ground reaction force in running: A reliability and validity comparison with force plates.

    Science.gov (United States)

    Raper, Damian P; Witchalls, Jeremy; Philips, Elissa J; Knight, Emma; Drew, Michael K; Waddington, Gordon

    2018-01-01

    The use of microsensor technologies to conduct research and implement interventions in sports and exercise medicine has increased recently. The objective of this paper was to determine the validity and reliability of the ViPerform as a measure of load compared to vertical ground reaction force (GRF) as measured by force plates. Absolute reliability assessment, with concurrent validity. 10 professional triathletes ran 10 trials over force plates with the ViPerform mounted on the mid portion of the medial tibia. Calculated vertical ground reaction force data from the ViPerform was matched to the same stride on the force plate. Bland-Altman (BA) plot of comparative measure of agreement was used to assess the relationship between the calculated load from the accelerometer and the force plates. Reliability was calculated by intra-class correlation coefficients (ICC) with 95% confidence intervals. BA plot indicates minimal agreement between the measures derived from the force plate and ViPerform, with variation at an individual participant plot level. Reliability was excellent (ICC=0.877; 95% CI=0.825-0.917) in calculating the same vertical GRF in a repeated trial. Standard error of measure (SEM) equalled 99.83 units (95% CI=82.10-119.09), which, in turn, gave a minimum detectable change (MDC) value of 276.72 units (95% CI=227.32-330.07). The ViPerform does not calculate absolute values of vertical GRF similar to those measured by a force plate. It does provide a valid and reliable calculation of an athlete's lower limb load at constant velocity. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Test-retest reliability and construct validity of the ENERGY-child questionnaire on energy balance-related behaviours and their potential determinants: the ENERGY-project

    Science.gov (United States)

    2011-01-01

    Background Insight in children's energy balance-related behaviours (EBRBs) and their determinants is important to inform obesity prevention research. Therefore, reliable and valid tools to measure these variables in large-scale population research are needed. Objective To examine the test-retest reliability and construct validity of the child questionnaire used in the ENERGY-project, measuring EBRBs and their potential determinants among 10-12 year old children. Methods We collected data among 10-12 year old children (n = 730 in the test-retest reliability study; n = 96 in the construct validity study) in six European countries, i.e. Belgium, Greece, Hungary, the Netherlands, Norway, and Spain. Test-retest reliability was assessed using the intra-class correlation coefficient (ICC) and percentage agreement comparing scores from two measurements, administered one week apart. To assess construct validity, the agreement between questionnaire responses and a subsequent face-to-face interview was assessed using ICC and percentage agreement. Results Of the 150 questionnaire items, 115 (77%) showed good to excellent test-retest reliability as indicated by ICCs > .60 or percentage agreement ≥ 75%. Test-retest reliability was moderate for 34 items (23%) and poor for one item. Construct validity appeared to be good to excellent for 70 (47%) of the 150 items, as indicated by ICCs > .60 or percentage agreement ≥ 75%. From the other 80 items, construct validity was moderate for 39 (26%) and poor for 41 items (27%). Conclusions Our results demonstrate that the ENERGY-child questionnaire, assessing EBRBs of the child as well as personal, family, and school-environmental determinants related to these EBRBs, has good test-retest reliability and moderate to good construct validity for the large majority of items. PMID:22152048

  2. The test-retest reliability of the latent construct of executive function depends on whether tasks are represented as formative or reflective indicators.

    Science.gov (United States)

    Willoughby, Michael T; Kuhn, Laura J; Blair, Clancy B; Samek, Anya; List, John A

    2017-10-01

    This study investigates the test-retest reliability of a battery of executive function (EF) tasks with a specific interest in testing whether the method that is used to create a battery-wide score would result in differences in the apparent test-retest reliability of children's performance. A total of 188 4-year-olds completed a battery of computerized EF tasks twice across a period of approximately two weeks. Two different approaches were used to create a score that indexed children's overall performance on the battery-i.e., (1) the mean score of all completed tasks and (2) a factor score estimate which used confirmatory factor analysis (CFA). Pearson and intra-class correlations were used to investigate the test-retest reliability of individual EF tasks, as well as an overall battery score. Consistent with previous studies, the test-retest reliability of individual tasks was modest (rs ≈ .60). The test-retest reliability of the overall battery scores differed depending on the scoring approach (r mean  = .72; r factor_ score  = .99). It is concluded that the children's performance on individual EF tasks exhibit modest levels of test-retest reliability. This underscores the importance of administering multiple tasks and aggregating performance across these tasks in order to improve precision of measurement. However, the specific strategy that is used has a large impact on the apparent test-retest reliability of the overall score. These results replicate our earlier findings and provide additional cautionary evidence against the routine use of factor analytic approaches for representing individual performance across a battery of EF tasks.

  3. Test-retest reliability and construct validity of the ENERGY-child questionnaire on energy balance-related behaviours and their potential determinants: the ENERGY-project

    Directory of Open Access Journals (Sweden)

    Singh Amika S

    2011-12-01

    Full Text Available Abstract Background Insight in children's energy balance-related behaviours (EBRBs and their determinants is important to inform obesity prevention research. Therefore, reliable and valid tools to measure these variables in large-scale population research are needed. Objective To examine the test-retest reliability and construct validity of the child questionnaire used in the ENERGY-project, measuring EBRBs and their potential determinants among 10-12 year old children. Methods We collected data among 10-12 year old children (n = 730 in the test-retest reliability study; n = 96 in the construct validity study in six European countries, i.e. Belgium, Greece, Hungary, the Netherlands, Norway, and Spain. Test-retest reliability was assessed using the intra-class correlation coefficient (ICC and percentage agreement comparing scores from two measurements, administered one week apart. To assess construct validity, the agreement between questionnaire responses and a subsequent face-to-face interview was assessed using ICC and percentage agreement. Results Of the 150 questionnaire items, 115 (77% showed good to excellent test-retest reliability as indicated by ICCs > .60 or percentage agreement ≥ 75%. Test-retest reliability was moderate for 34 items (23% and poor for one item. Construct validity appeared to be good to excellent for 70 (47% of the 150 items, as indicated by ICCs > .60 or percentage agreement ≥ 75%. From the other 80 items, construct validity was moderate for 39 (26% and poor for 41 items (27%. Conclusions Our results demonstrate that the ENERGY-child questionnaire, assessing EBRBs of the child as well as personal, family, and school-environmental determinants related to these EBRBs, has good test-retest reliability and moderate to good construct validity for the large majority of items.

  4. The reliability of the quantitative timed up and go test (QTUG) measured over five consecutive days under single and dual-task conditions in community dwelling older adults.

    Science.gov (United States)

    Smith, Erin; Walsh, Lorcan; Doyle, Julie; Greene, Barry; Blake, Catherine

    2016-01-01

    The timed up and go (TUG) test is a commonly used assessment in older people with variations including the addition of a motor or cognitive dual-task, however in high functioning older adults it is more difficult to assess change. The quantified TUG (QTUG) uses inertial sensors to detect test and gait parameters during the test. If it is to be used in the longitudinal assessment of older adults, it is important that we know which parameters are reliable and under which conditions. This study aims to examine the relative reliability of the QTUG over five consecutive days under single, motor and cognitive dual-task conditions. Twelve community dwelling older adults (10 females, mean age 74.17 (3.88)) performed the QTUG under three conditions for five consecutive days. The relative reliability of each of the gait parameters was assessed using intra-class correlation coefficient (ICC 3,1) and standard error of measurement (SEM). Five of the measures demonstrated excellent reliability (ICC>0.70) under all three conditions (time to complete test, walk time, number of gait cycles, number of steps and return from turn time). Measures of variability and turn derived parameters demonstrated weak reliability under all three conditions (ICC=0.05-0.49). For the most reliable parameters under single-task conditions, the addition of a cognitive task resulted in a reduction in reliability suggesting caution when interpreting results under these conditions. Certain sensor derived parameters during the QTUG test may provide an additional resource in the longitudinal assessment of older people and earlier identification of falls risk. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. The reliability and validity of the short version of the WHO Quality of Life Instrument in an Arab general population

    International Nuclear Information System (INIS)

    Ohaeri, Jude U; Awadallab, Abdel W

    2009-01-01

    There is rising interest in quality of life (QOL) research in Arabian countries. The aim of this study was to assess in a nationwide sample of Kuwaiti subjects the reliability and validity of the World Health Organization Quality of Life (WHOQOL-BREF), a shorter version of the widely used QOL assessment instrument that comprises 26 items in the domains of physical health, psychological health, social relationships, and the environment. A one-in-three systematic random proportionate sample of consenting Kuwaiti nationals attending large cooperative stores and municipal government offices in the six governorates completed the Arabic translation of the questionnaire. The indices assessed included test-retest reliability, internal consistency, item internal consistency (2C), item discriminant validity (IDV), known-groups and construct validity. There were 3303 participants (44.8% males, 55.2% females, mean age 35.4 years, range 16 to 87 years). The intra-class correlation for the test-retest statistic and the internal consistency values for the full questionnaire and the domains had a Cronbach's alpha > - 0.7. Of the 24 items that constitute the domains, 21 met the 2 C requirement of correlation > - 0.4 with the corresponding domain, while 16 met the IDV criterion of having a higher correlation with their corresponding domain than other domains. Domain scores discriminated significantly between well and sick groups. In the factor analysis, four strong factors emerged with the same construct as in the WHO report. The Arabic translation of the WHOQOL-BREF has impressive reliability and validity indices. The poor IDV findings are due to the multidimensional nature of the questionnaire. The highly significant validity indices should reassure researchers that the questionnaire represents the same constructs across cultures. Negatively worded items possibly need refinement. (author)

  6. Reliability and validity of psychosocial and environmental correlates measures of physical activity and screen-based behaviors among Chinese children in Hong Kong

    Directory of Open Access Journals (Sweden)

    Salmon Jo

    2011-03-01

    Full Text Available Abstract Background Insufficient participation in physical activity and excessive screen time have been observed among Chinese children. The role of social and environmental factors in shaping physical activity and sedentary behaviors among Chinese children is under-investigated. The purpose of the present study was to assess the reliability and validity of a questionnaire to measure child- and parent-reported psychosocial and environmental correlates of physical activity and screen-based behaviors among Chinese children in Hong Kong. Methods A total of 303 schoolchildren aged 9-14 years and their parents volunteered to participate in this study and 160 of them completed the questionnaire twice within an interval of 10 days. Intraclass correlation coefficients (ICCs, kappa statistics, and percent agreement were performed to evaluate test-retest reliability of the continuous and categorical variables, respectively. Exploratory factor analyses (EFAs were conducted to assess convergent validity of the emergent scales. Cronbach's alpha and ICCs were performed to assess internal and test-retest reliability of the emergent scales. Criterion validity was assessed by correlating psychosocial and environmental measures with self-reported physical activity and screen-based behaviors, measured by a validated questionnaire. Results Reliability statistics for both child- and parent-reported continuous variables showed acceptable consistency for all of the ICC values greater than 0.70. Kappa statistics showed fair to perfect test-retest reliability for the categorical items. Adequate internal consistency and test-retest reliability were observed in most of the emergent scales. Criterion validity assessed by correlating psychosocial and environmental measures with child-reported physical activity found associations with physical activity in the self-efficacy scale (r = 0.25, P r = 0.25, P r = 0.14, P r = -0.22, P r = 0.12, P = 0.053. Conclusions The findings

  7. Time-dependent Reliability of Dynamic Systems using Subset Simulation with Splitting over a Series of Correlated Time Intervals

    Science.gov (United States)

    2013-08-01

    cost due to potential warranty costs, repairs and loss of market share. Reliability is the probability that the system will perform its intended...MCMC and splitting sampling schemes. Our proposed SS/ STP method is presented in Section 4, including accuracy bounds and computational effort

  8. Behavioral and ERP measures of attentional bias to threat in the dot-probe task: Poor reliability and lack of correlation with anxiety

    Directory of Open Access Journals (Sweden)

    Emily S. Kappenman

    2014-12-01

    Full Text Available The dot-probe task is often considered a gold standard in the field for investigating attentional bias to threat. However, serious issues with the task have been raised. Specifically, a number of studies have demonstrated that the traditional reaction time measure of attentional bias to threat in the dot-probe task has poor internal reliability and poor test-retest reliability. In addition, although threatening stimuli capture attention in other paradigms, attentional bias to threat has not usually been found in typical research participants in the dot-probe task. However, when attention is measured in the dot-probe task with the N2pc component of the event-related potential (ERP waveform, substantial attentional orienting to threat is observed, and the internal reliability is moderate. To provide a rigorous comparison of the reliability of this N2pc measure and the conventional behavioral measure, as well as to examine the relationship of these measures to anxiety, the present study examined the N2pc in conjunction with reaction time in the dot-probe task in a large sample of participants (N = 96. As in previous studies, reaction time showed no bias to threatening images across the sample and exhibited poor internal reliability. Moreover, this measure did not relate to trait anxiety. By contrast, the N2pc revealed a significant initial shift of attention to threat, and this measure was internally reliable. However, the N2pc was not correlated with trait anxiety, indicating that it does not provide a meaningful index of individual differences in anxiety in the dot-probe task. Together, these results indicate a serious need to develop new tasks and methods to more reliably investigate attentional bias to threat and its relationship to anxiety in both clinical and non-clinical populations.

  9. Test-retest reliability of a handheld dynamometer for measurement of isometric cervical muscle strength.

    Science.gov (United States)

    Vannebo, Katrine Tranaas; Iversen, Vegard Moe; Fimland, Marius Steiro; Mork, Paul Jarle

    2018-03-02

    There is a lack of test-retest reliability studies of measurements of cervical muscle strength, taking into account gender and possible learning effects. To investigate test-retest reliability of measurement of maximal isometric cervical muscle strength by handheld dynamometry. Thirty women (age 20-58 years) and 28 men (age 20-60 years) participated in the study. Maximal isometric strength (neck flexion, neck extension, and right/left lateral flexion) was measured on three separate days at least five days apart by one evaluator. Intra-rater consistency tended to improve from day 1-2 measurements to day 2-3 measurements in both women and men. In women, the intra-class correlation coefficients (ICC) for day 2 to day 3 measurements were 0.91 (95% confidence interval [CI], 0.82-0.95) for neck flexion, 0.88 (95% CI, 0.76-0.94) for neck extension, 0.84 (95% CI, 0.68-0.92) for right lateral flexion, and 0.89 (95% CI, 0.78-0.95) for left lateral flexion. The corresponding ICCs among men were 0.86 (95% CI, 0.72-0.93) for neck flexion, 0.93 (95% CI, 0.85-0.97) for neck extension, 0.82 (95% CI, 0.65-0.91) for right lateral flexion and 0.73 (95% CI, 0.50-0.87) for left lateral flexion. This study describes a reliable and easy-to-administer test for assessing maximal isometric cervical muscle strength.

  10. Validity and Reliability of the Hebrew Version of the SpREUK Questionnaire for Religiosity, Spirituality and Health: An Application for Oral Diseases

    Directory of Open Access Journals (Sweden)

    Harold D. Sgan-Cohen

    2010-12-01

    Full Text Available Background: Research has examined the connection between religiosity, spirituality (SpR and health, and the potential of these variables to prevent, heal and cope with disease. Research indicated that participation in religious meetings or services was associated with a lower risk of developing oral disease. We intended to test a Hebrew version of the SpREUK 1.1 questionnaire, which is reported to be a reliable and valid measure of distinctive issues of SpR, and to test its relevance in the context of oral illness among a Jewish population. Methods: In order to validate the SpREUK-Hebrew instrument, minor translational and cultural/religious adaptations were applied. Reliability and factor analyses were performed, using standard procedures, among 134 Jewish Israeli subjects (mean age 38.4 years. Results: Analysis of reliability for internal consistency demonstrated an intra-class correlation of Cronbach's alpha = 0.90 for the intrinsic religiosity/spiritual and the appraisal scales, and of 0.90 for the support through spirituality/religiosity scales. Inter reliability agreement by kappa ranged between 0.7 and 0.9. We were able to approve the previously described factorial structure, albeit with some unique characteristics in the Jewish population. Individuals´ time spent on spiritual activity correlated with the SpREUK scales. The instrument discriminated well between religious subgroups (i.e., ultra Orthodox, conventional religious and less-religious. Preliminary results indicate an association between measures of spirituality and oral health. Conclusions: The traditional and cultural adaptation of the tool was found to be appropriate. SpREUK-Hebrew was reliable and valid among a Jewish population. This method could therefore be employed in comparative studies among different cultural and religious backgrounds.

  11. Cross-Cultural adaption, validity and reliability of a Hindi version of the Corah’s Dental Anxiety Scale

    Directory of Open Access Journals (Sweden)

    Meena Jain

    2018-04-01

    Full Text Available Background: An appropriate scale to assess the dental anxiety of Hindi speaking population is lacking. This study, therefore, aims to evaluate the psychometric properties of Hindi version of one of the oldest dental anxiety scale, Corah’s Dental Anxiety Scale (CDAS in Hindi speaking Indian adults.Methods: A total of 348 subjects from the outpatient department of a dental hospital in Indiaparticipated in this cross-sectional study. The scale was cross-culturally adapted by forward and backward translation, committee review and pretesting method. The construct validity of the translated scale was explored with exploratory factor analysis. The correlation of the Hindi version of CDAS with visual analogue scale (VAS was used to measure the convergent validity.Reliability was assessed through calculations of Cronbach’s alpha and intra class correlation 48 forms were completed for test-retest.Results: Prevalence of dental anxiety in the sample within the age range of 18-80 years was 85.63% [95% CI: 0.815-0.891]. The response rate was 100 %. Kaiser-Meyer-Olkin (KMO test value was 0.776. After factor analysis, a single factor (dental anxiety was obtained with 4 items.The single factor model explained 61% variance. Pearson correlation coefficient between CDASand VAS was 0.494. Test-retest showed the Cronbach’s alpha value of 0.814. The test-retest intraclass correlation coefficient of the total CDAS score was 0.881 [95% CI: 0.318-0.554].Conclusion: Hindi version of CDAS is a valid and reliable scale to assess dental anxiety in Hindi speaking population. Convergent validity is well recognized but discriminant validity is limited and requires further study.

  12. Cross-Cultural adaption, validity and reliability of a Hindi version of the Corah’s Dental Anxiety Scale

    Science.gov (United States)

    Jain, Meena; Tandon, Shourya; Sharma, Ankur; Jain, Vishal; Rani Yadav, Nisha

    2018-01-01

    Background: An appropriate scale to assess the dental anxiety of Hindi speaking population is lacking. This study, therefore, aims to evaluate the psychometric properties of Hindi version of one of the oldest dental anxiety scale, Corah’s Dental Anxiety Scale (CDAS) in Hindi speaking Indian adults. Methods: A total of 348 subjects from the outpatient department of a dental hospital in India participated in this cross-sectional study. The scale was cross-culturally adapted by forward and backward translation, committee review and pretesting method. The construct validity of the translated scale was explored with exploratory factor analysis. The correlation of the Hindi version of CDAS with visual analogue scale (VAS) was used to measure the convergent validity. Reliability was assessed through calculations of Cronbach’s alpha and intra class correlation 48 forms were completed for test-retest. Results: Prevalence of dental anxiety in the sample within the age range of 18-80 years was 85.63% [95% CI: 0.815-0.891]. The response rate was 100 %. Kaiser-Meyer-Olkin (KMO) test value was 0.776. After factor analysis, a single factor (dental anxiety) was obtained with 4 items.The single factor model explained 61% variance. Pearson correlation coefficient between CDASand VAS was 0.494. Test-retest showed the Cronbach’s alpha value of 0.814. The test-retest intraclass correlation coefficient of the total CDAS score was 0.881 [95% CI: 0.318-0.554]. Conclusion: Hindi version of CDAS is a valid and reliable scale to assess dental anxiety in Hindi speaking population. Convergent validity is well recognized but discriminant validity is limited and requires further study. PMID:29744307

  13. Cross-Cultural adaption, validity and reliability of a Hindi version of the Corah's Dental Anxiety Scale.

    Science.gov (United States)

    Jain, Meena; Tandon, Shourya; Sharma, Ankur; Jain, Vishal; Rani Yadav, Nisha

    2018-01-01

    Background: An appropriate scale to assess the dental anxiety of Hindi speaking population is lacking. This study, therefore, aims to evaluate the psychometric properties of Hindi version of one of the oldest dental anxiety scale, Corah's Dental Anxiety Scale (CDAS) in Hindi speaking Indian adults. Methods: A total of 348 subjects from the outpatient department of a dental hospital in India participated in this cross-sectional study. The scale was cross-culturally adapted by forward and backward translation, committee review and pretesting method. The construct validity of the translated scale was explored with exploratory factor analysis. The correlation of the Hindi version of CDAS with visual analogue scale (VAS) was used to measure the convergent validity. Reliability was assessed through calculations of Cronbach's alpha and intra class correlation 48 forms were completed for test-retest. Results: Prevalence of dental anxiety in the sample within the age range of 18-80 years was 85.63% [95% CI: 0.815-0.891]. The response rate was 100 %. Kaiser-Meyer-Olkin (KMO) test value was 0.776. After factor analysis, a single factor (dental anxiety) was obtained with 4 items.The single factor model explained 61% variance. Pearson correlation coefficient between CDASand VAS was 0.494. Test-retest showed the Cronbach's alpha value of 0.814. The test-retest intraclass correlation coefficient of the total CDAS score was 0.881 [95% CI: 0.318-0.554]. Conclusion: Hindi version of CDAS is a valid and reliable scale to assess dental anxiety in Hindi speaking population. Convergent validity is well recognized but discriminant validity is limited and requires further study.

  14. Cross-cultural adaptation and determination of the reliability and validity of PRTEE-S (Patientskattad Utvärdering av Tennisarmbåge, a questionnaire for patients with lateral epicondylalgia, in a Swedish population

    Directory of Open Access Journals (Sweden)

    Baigi Amir

    2008-06-01

    Full Text Available Abstract Background In Sweden, as well as in Scandinavia, there is no easy way to evaluate patients' difficulties when they suffer from lateral epicondylitis/epicondylalgia. However, there is a Canadian questionnaire, in English, that could make the evaluation of a patient's pain and functional loss both quick and inexpensive. Therefore, the aim of this study was to translate and cross-culturally adapt the questionnaire "Patient-rated Tennis Elbow Evaluation" into Swedish (PRTEE-S; "Patientskattad Utvärdering av Tennisarmbåge", and to evaluate the reliability and validity of the test. Methods The Patient-rated Tennis Elbow Evaluation was cross-culturally adapted for the Swedish language according to well-established guidelines. Fifty-four patients with unilateral epicondylitis/epicondylalgia were assessed using the PRTEE-S (Patientskattad Utvärdering av Tennisarmbåge, the Disabilities of Arm, Shoulder, and Hand questionnaire, and the Roles & Maudsley score to establish the validity and reliability of the PRTEE-S. Reliability was determined via calculation of the intra-class correlation coefficient (ICC the internal consistency was assessed by Cronbach's alpha, and validity was calculated using Spearman's correlation coefficient. Results The test-retest reliability, using the PRTEE-S (Patientskattad Utvärdering av Tennisarmbåge intraclass correlation coefficient, was 0.95 and the internal consistency was 0.94. The PRTEE-S correlated well with the Disabilities of the Arm, Shoulder, and Hand questionnaire (r = 0.88 and the Roles & Maudsley score (r = 0.78. Conclusion The PRTEE-S (Patientskattad Utvärdering av Tennisarmbåge represents a reliable and valid instrument to evaluate the subjective outcome in Swedish speaking patients with lateral epicondylitis/epicondylalgia, and can be used in both research and clinical settings.

  15. Development and reliability of a Motivational Interviewing Scenarios Tool for Eating Disorders (MIST-ED) using a skills-based intervention among caregivers.

    Science.gov (United States)

    Sepulveda, Ana R; Wise, Caroline; Zabala, Maria; Todd, Gill; Treasure, Janet

    2013-12-01

    The aims of this study were to develop an eating disorder scenarios tool to assess the motivational interviewing (MI) skills of caregivers and evaluate the coding reliability of the instrument, and to test the sensitivity to change through a pre/post/follow-up design. The resulting Motivational Interview Scenarios Tool for Eating Disorders (MIST-ED) was administered to caregivers (n = 66) who were asked to provide oral and written responses before and after a skills-based intervention, and at a 3-month follow-up. Raters achieved excellent inter-rater reliability (intra-class correlations of 91.8% on MI adherent and 86.1% for MI non-adherent statements for written scenarios and 89.2%, and 85.3% for oral scenarios). Following the intervention, MI adherent statements increased (baseline = 9.4%, post = 61.5% and follow-up 47.2%) and non-MI adherent statements decreased (baseline = 90.6%, post = 38.5% and follow-up = 52.8%). This instrument can be used as a simple method to measure the acquisition of MI skills to improve coping and both response methods are adequate. The tool shows good sensitivity to improved skills. © 2013.

  16. Reliability and Validity of a New Test of Change-of-Direction Speed for Field-Based Sports: the Change-of-Direction and Acceleration Test (CODAT).

    Science.gov (United States)

    Lockie, Robert G; Schultz, Adrian B; Callaghan, Samuel J; Jeffriess, Matthew D; Berry, Simon P

    2013-01-01

    Field sport coaches must use reliable and valid tests to assess change-of-direction speed in their athletes. Few tests feature linear sprinting with acute change- of-direction maneuvers. The Change-of-Direction and Acceleration Test (CODAT) was designed to assess field sport change-of-direction speed, and includes a linear 5-meter (m) sprint, 45° and 90° cuts, 3- m sprints to the left and right, and a linear 10-m sprint. This study analyzed the reliability and validity of this test, through comparisons to 20-m sprint (0-5, 0-10, 0-20 m intervals) and Illinois agility run (IAR) performance. Eighteen Australian footballers (age = 23.83 ± 7.04 yrs; height = 1.79 ± 0.06 m; mass = 85.36 ± 13.21 kg) were recruited. Following familiarization, subjects completed the 20-m sprint, CODAT, and IAR in 2 sessions, 48 hours apart. Intra-class correlation coefficients (ICC) assessed relative reliability. Absolute reliability was analyzed through paired samples t-tests (p ≤ 0.05) determining between-session differences. Typical error (TE), coefficient of variation (CV), and differences between the TE and smallest worthwhile change (SWC), also assessed absolute reliability and test usefulness. For the validity analysis, Pearson's correlations (p ≤ 0.05) analyzed between-test relationships. Results showed no between-session differences for any test (p = 0.19-0.86). CODAT time averaged ~6 s, and the ICC and CV equaled 0.84 and 3.0%, respectively. The homogeneous sample of Australian footballers meant that the CODAT's TE (0.19 s) exceeded the usual 0.2 x standard deviation (SD) SWC (0.10 s). However, the CODAT is capable of detecting moderate performance changes (SWC calculated as 0.5 x SD = 0.25 s). There was a near perfect correlation between the CODAT and IAR (r = 0.92), and very large correlations with the 20-m sprint (r = 0.75-0.76), suggesting that the CODAT was a valid change-of-direction speed test. Due to movement specificity, the CODAT has value for field sport

  17. Measuring the quality of life in mild to very severe dementia: testing the inter-rater and intra-rater reliability of the German version of the QUALIDEM.

    Science.gov (United States)

    Dichter, Martin Nikolaus; Schwab, Christian G G; Meyer, Gabriele; Bartholomeyczik, Sabine; Dortmann, Olga; Halek, Margareta

    2014-05-01

    Quality of life (Qol) is an increasingly used outcome measure in dementia research. The QUALIDEM is a dementia-specific and proxy-rated Qol instrument. We aimed to determine the inter-rater and intra-rater reliability in residents with dementia in German nursing homes. The QUALIDEM consists of nine subscales that were applied to a sample of 108 people with mild to severe dementia and six consecutive subscales that were applied to a sample of 53 people with very severe dementia. The proxy raters were 49 registered nurses and nursing assistants. Inter-rater and intra-rater reliability scores were calculated on the subscale and item level. None of the QUALIDEM subscales showed strong inter-rater reliability based on the single-measure Intra-Class Correlation Coefficient (ICC) for absolute agreement ≥ 0.70. Based on the average-measure ICC for four raters, eight subscales for people with mild to severe dementia (care relationship, positive affect, negative affect, restless tense behavior, social relations, social isolation, feeling at home and having something to do) and five subscales for very severe dementia (care relationship, negative affect, restless tense behavior, social relations and social isolation) yielded a strong inter-rater agreement (ICC: 0.72-0.86). All of the QUALIDEM subscales, regardless of dementia severity, showed strong intra-rater agreement. The ICC values ranged between 0.70 and 0.79 for people with mild to severe dementia and between 0.75 and 0.87 for people with very severe dementia. This study demonstrated insufficient inter-rater reliability and sufficient intra-rater reliability for all subscales of both versions of the German QUALIDEM. The degree of inter-rater reliability can be improved by collaborative Qol rating by more than one nurse. The development of a measurement manual with accurate item definitions and a standardized education program for proxy raters is recommended.

  18. Cross-cultural adaptation, reliability, and validation of the Korean version of the identification functional ankle instability (IdFAI).

    Science.gov (United States)

    Ko, Jupil; Rosen, Adam B; Brown, Cathleen N

    2017-09-12

    To cross-culturally adapt the Identification Functional Ankle Instability for use with Korean-speaking participants. The English version of the IdFAI was cross-culturally adapted into Korean based on the guidelines. The psychometric properties in the Korean version of the IdFAI were measured for test-retest reliability, internal consistency, criterion-related validity, discriminative validity, and measurement error 181 native Korean-speakers. Intra-class correlation coefficients (ICC 2,1 ) between the English and Korean versions of the IdFAI for test-retest reliability was 0.98 (standard error of measurement = 1.41). The Cronbach's alpha coefficient was 0.89 for the Korean versions of IdFAI. The Korean versions of the IdFAI had a strong correlation with the SF-36 (r s  = -0.69, p 10 was the optimal cutoff score to distinguish between the group memberships. The minimally detectable change of the Korean versions of the IdFAI score was 3.91. The Korean versions of the IdFAI have shown to be an excellent, reliable, and valid instrument. The Korean versions of the IdFAI can be utilized to assess the presence of Chronic Ankle Instability by researchers and clinicians working among Korean-speaking populations. Implications for rehabilitation The high recurrence rate of sprains may result into Chronic Ankle Instability (CAI). The Identification of Functional Ankle Instability Tool (IdFAI) has been validated and recommended to identify patients with Chronic Ankle Instability (CAI). The Korean version of the Identification of Functional Ankle Instability Tool (IdFAI) may be also recommend to researchers and clinicians for assessing the presence of Chronic Ankle Instability (CAI) in Korean-speaking population.

  19. Reliability and validity of a novel tool to comprehensively assess food and beverage marketing in recreational sport settings.

    Science.gov (United States)

    Prowse, Rachel J L; Naylor, Patti-Jean; Olstad, Dana Lee; Carson, Valerie; Mâsse, Louise C; Storey, Kate; Kirk, Sara F L; Raine, Kim D

    2018-05-31

    Current methods for evaluating food marketing to children often study a single marketing channel or approach. As the World Health Organization urges the removal of unhealthy food marketing in children's settings, methods that comprehensively explore the exposure and power of food marketing within a setting from multiple marketing channels and approaches are needed. The purpose of this study was to test the inter-rater reliability and the validity of a novel settings-based food marketing audit tool. The Food and beverage Marketing Assessment Tool for Settings (FoodMATS) was developed and its psychometric properties evaluated in five public recreation and sport facilities (sites) and subsequently used in 51 sites across Canada for a cross-sectional analysis of food marketing. Raters recorded the count of food marketing occasions, presence of child-targeted and sports-related marketing techniques, and the physical size of marketing occasions. Marketing occasions were classified by healthfulness. Inter-rater reliability was tested using Cohen's kappa (κ) and intra-class correlations (ICC). FoodMATS scores for each site were calculated using an algorithm that represented the theoretical impact of the marketing environment on food preferences, purchases, and consumption. Higher FoodMATS scores represented sites with higher exposure to, and more powerful (unhealthy, child-targeted, sports-related, large) food marketing. Validity of the scoring algorithm was tested through (1) Pearson's correlations between FoodMATS scores and facility sponsorship dollars, and (2) sequential multiple regression for predicting "Least Healthy" food sales from FoodMATS scores. Inter-rater reliability was very good to excellent (κ = 0.88-1.00, p marketing in recreation facilities, the FoodMATS provides a novel means to comprehensively track changes in food marketing environments that can assist in developing and monitoring the impact of policies and interventions.

  20. Test-Retest Reliability and Minimal Detectable Change of the D2 Test of Attention in Patients with Schizophrenia.

    Science.gov (United States)

    Lee, Posen; Lu, Wen-Shian; Liu, Chin-Hsuan; Lin, Hung-Yu; Hsieh, Ching-Lin

    2017-12-08

    The d2 Test of Attention (D2) is a commonly used measure of selective attention for patients with schizophrenia. However, its test-retest reliability and minimal detectable change (MDC) are unknown in patients with schizophrenia, limiting its utility in both clinical and research settings. The aim of the present study was to examine the test-retest reliability and MDC of the D2 in patients with schizophrenia. A rater administered the D2 on 108 patients with schizophrenia twice at a 1-month interval. Test-retest reliability was determined through the calculation of the intra-class correlation coefficient (ICC). We also carried out Bland-Altman analysis, which included a scatter plot of the differences between test and retest against their mean. Systematic biases were evaluated by use of a paired t-test. The ICCs for the D2 ranged from 0.78 to 0.94. The MDCs (MDC%) of the seven subscores were 102.3 (29.7), 19.4 (85.0), 7.2 (94.6), 21.0 (69.0), 104.0 (33.1), 105.0 (35.8), and 7.8 (47.8), which represented limited-to-acceptable random measurement error. Trends in the Bland-Altman plots of the omissions (E1), commissions (E2), and errors (E) were noted, presenting that the data had heteroscedasticity. According to the results, the D2 had good test-retest reliability, especially in the scores of TN, TN-E, and CP. For the further research, finding a way to improve the administration procedure to reduce random measurement error would be important for the E1, E2, E, and FR subscores. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Isometric and isokinetic muscle strength in the upper extremity can be reliably measured in persons with chronic stroke.

    Science.gov (United States)

    Ekstrand, Elisabeth; Lexell, Jan; Brogårdh, Christina

    2015-09-01

    To evaluate the test-retest reliability of isometric and isokinetic muscle strength measurements in the upper extremity after stroke. A test-retest design. Forty-five persons with mild to moderate paresis in the upper extremity > 6 months post-stroke. Isometric arm strength (shoulder abduction, elbow flexion), isokinetic arm strength (elbow extension/flexion) and isometric grip strength were measured with electronic dynamometers. Reliability was evaluated with intra-class correlation coefficients (ICC), changes in the mean, standard error of measurements (SEM) and smallest real differences (SRD). Reliability was high (ICCs: 0.92-0.97). The absolute and relative (%) SEM ranged from 2.7 Nm (5.6%) to 3.0 Nm (9.4%) for isometric arm strength, 2.6 Nm (7.4%) to 2.9 Nm (12.6%) for isokinetic arm strength, and 22.3 N (7.6%) to 26.4 N (9.2%) for grip strength. The absolute and relative (%) SRD ranged from 7.5 Nm (15.5%) to 8.4 Nm (26.1%) for isometric arm strength, 7.1 Nm (20.6%) to 8.0 Nm (34.8%) for isokinetic arm strength, and 61.8 N (21.0%) to 73.3 N (25.6%) for grip strength. Muscle strength in the upper extremity can be reliably measured in persons with chronic stroke. Isometric measurements yield smaller measurement errors than isokinetic measurements and might be preferred, but the choice depends on the research question.

  2. Follow-up of CT-derived airway wall thickness: Correcting for changes in inspiration level improves reliability

    Energy Technology Data Exchange (ETDEWEB)

    Pompe, Esther, E-mail: e.pompe@umcutrecht.nl [Department of Respiratory Medicine, University Medical Center Utrecht, Utrecht (Netherlands); Rikxoort, Eva M. van [Department of Radiology, Radboud University Medical Center, Nijmegen (Netherlands); Mets, Onno M. [Department of Radiology, University Medical Center Utrecht, Utrecht (Netherlands); Charbonnier, Jean-Paul [Department of Radiology, Radboud University Medical Center, Nijmegen (Netherlands); Kuhnigk, Jan-Martin [Institute for Medical Image Computing, Fraunhofer MEVIS, Bremen (Germany); Koning, Harry J. de [Department of Public Health, Erasmus Medical Center, Rotterdam (Netherlands); Oudkerk, Matthijs [University of Groningen, University Medical Center Groningen, Groningen, Department of Radiology (Netherlands); Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Groningen, Department of Radiology (Netherlands); University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Groningen (Netherlands); Zanen, Pieter; Lammers, Jan-Willem J. [Department of Respiratory Medicine, University Medical Center Utrecht, Utrecht (Netherlands); Ginneken, Bram van [Department of Radiology, Radboud University Medical Center, Nijmegen (Netherlands); Jong, Pim A. de; Mohamed Hoesein, Firdaus A.A. [Department of Radiology, University Medical Center Utrecht, Utrecht (Netherlands)

    2016-11-15

    Objectives: Airway wall thickness (AWT) is affected by changes in lung volume. This study evaluated whether correcting AWT on computed tomography (CT) for differences in inspiration level improves measurement agreement, reliability, and power to detect changes over time. Methods: Participants of the Dutch-Belgian lung cancer screening trial who underwent 3-month repeat CT for an indeterminate pulmonary nodule were included. AWT on CT was calculated by the square root of the wall area at a theoretical airway with an internal perimeter of 10 mm (Pi10). The scan with the highest lung volume was labelled as the reference scan and the scan with the lowest lung volume was labelled as the comparison scan. Pi10 derived from the comparison scan was corrected by multiplying it with the ratio of CT lung volume of the comparison scan to CT lung volume on the reference scan. Agreement of uncorrected and corrected Pi10 was studied with the Bland-Altman method, reliability with intra-class correlation coefficients (ICC), and power to detect changes over time was calculated. Results: 315 male participants were included. Limit of agreement and reliability for Pi10 was −0.61 to 0.57 mm (ICC = 0.87), which improved to −0.38 to 0.37 mm (ICC = 0.94) after correction for inspiration level. To detect a 15% change over 3 months, 71 subjects are needed for Pi10 and 26 subjects for Pi10 adjusted for inspiration level. Conclusions: Correcting Pi10 for differences in inspiration level improves reliability, agreement, and power to detect changes over time.

  3. A Community Based Study to Test the Reliability and Validity of Physical Activity Measurement Techniques

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    Puneet Misra

    2014-01-01

    Full Text Available Introduction: Physical activity (PA is protective against non-communicable diseases and it can reduce premature mortality. However, it is difficult to assess the frequency, duration, type and intensity of PA. The global physical activity questionnaire (GPAQ has been developed by World Health Organization with the aim of having valid and reliable estimates of PA. The primary aim of this study is to assess the repeatability of the GPAQ instrument and the secondary aim is to validate it against International Physical Activity Questionnaire (IPAQ and against an objective measure of PA (i.e., using pedometers in both rural and peri-urban areas of North India. Methods: A total of 262 subjects were recruited by random selection from Ballabgarh Block of Haryana State in India. For test retest repeatability of GPAQ and IPAQ, the instruments were administered on two occasions separated by at least 3 days. For concurrent validity, both questionnaires were administered in random order and for criterion validity step counters were used. Spearman′s correlation coefficient, intra-class correlation (ICC and Cohen′s kappa was used in the analysis. Results: For GPAQ validity, the spearman′s Rho ranged from 0.40 to 0.59 and ICC ranged from 0.43 to 0.81 while for IPAQ validity, spearman correlation coefficient ranged from 0.42 to 0.43 and ICC ranged from 0.56 to 0.68. The observed concurrent validity coefficients suggested that both the questionnaires had reasonable agreement (Spearman Rho of >0.90; P < 0.0001; ICC: 0.76-0.91, P < 0.05. Conclusions: GPAQ is similar to IPAQ in measuring PA and can be used for measurement of PA in community settings.

  4. Validity and reliability of a modified english version of the physical activity questionnaire for adolescents.

    Science.gov (United States)

    Aggio, Daniel; Fairclough, Stuart; Knowles, Zoe; Graves, Lee

    2016-01-01

    Adaptation of physical activity self-report questionnaires is sometimes required to reflect the activity behaviours of diverse populations. The processes used to modify self-report questionnaires though are typically underreported. This two-phased study used a formative approach to investigate the validity and reliability of the Physical Activity Questionnaire for Adolescents (PAQ-A) in English youth. Phase one examined test content and response process validity and subsequently informed a modified version of the PAQ-A. Phase two assessed the validity and reliability of the modified PAQ-A. In phase one, focus groups (n = 5) were conducted with adolescents (n = 20) to investigate test content and response processes of the original PAQ-A. Based on evidence gathered in phase one, a modified version of the questionnaire was administered to participants (n = 169, 14.5 ± 1.7 years) in phase two. Internal consistency and test-retest reliability were assessed using Cronbach's alpha and intra-class correlations, respectively. Spearman correlations were used to assess associations between modified PAQ-A scores and accelerometer-derived physical activity, self-reported fitness and physical activity self-efficacy. Phase one revealed that the original PAQ-A was unrepresentative for English youth and that item comprehension varied. Contextual and population/cultural-specific modifications were made to the PAQ-A for use in the subsequent phase. In phase two, modified PAQ-A scores had acceptable internal consistency (α = 0.72) and test-retest reliability (ICC = 0.78). Modified PAQ-A scores were significantly associated with objectively assessed moderate-to-vigorous physical activity (r = 0.39), total physical activity (r = 0.42), self-reported fitness (r = 0.35), and physical activity self-efficacy (r = 0.32) (p ≤ 0.01). The modified PAQ-A had acceptable internal consistency and test-retest reliability. Modified PAQ-A scores

  5. Reliability and Validity of the Early Years Physical Activity Questionnaire (EY-PAQ

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    Daniel D. Bingham

    2016-05-01

    Full Text Available Measuring physical activity (PA and sedentary time (ST in young children (<5 years is complex. Objective measures have high validity but require specialist expertise, are expensive, and can be burdensome for participants. A proxy-report instrument for young children that accurately measures PA and ST is needed. The aim of this study was to assess the reliability and validity of the Early Years Physical Activity Questionnaire (EY-PAQ. In a setting where English and Urdu are the predominant languages spoken by parents of young children, a sample of 196 parents and their young children (mean age 3.2 ± 0.8 years from Bradford, UK took part in the study. A total of 156 (79.6% questionnaires were completed in English and 40 (20.4% were completed in transliterated Urdu. A total of 109 parents took part in the reliability aspect of the study, which involved completion of the EY-PAQ on two occasions (7.2 days apart; standard deviation (SD = 1.1. All 196 participants took part in the validity aspect which involved comparison of EY-PAQ scores against accelerometry. Validty anaylsis used all data and data falling with specific MVPA and ST boundaries. Reliability was assessed using intra-class correlations (ICC and validity by Bland–Altman plots and rank correlation coefficients. The test re-test reliability of the EY-PAQ was moderate for ST (ICC = 0.47 and fair for moderate-to-vigorous physical activity (MVPA(ICC = 0.35. The EY-PAQ had poor agreement with accelerometer-determined ST (mean difference = −87.5 min·day−1 and good agreement for MVPA (mean difference = 7.1 min·day−1 limits of agreement were wide for all variables. The rank correlation coefficient was non-significant for ST (rho = 0.19 and significant for MVPA (rho = 0.30. The EY-PAQ has comparable validity and reliability to other PA self-report tools and is a promising population-based measure of young children’s habitual MVPA but not ST. In situations when objective methods are not

  6. Reliability of semiquantitative 18F-FDG PET parameters derived from simultaneous brain PET/MRI: A feasibility study

    International Nuclear Information System (INIS)

    Jena, Amarnath; Taneja, Sangeeta; Goel, Reema; Renjen, Pushpendranath; Negi, Pradeep

    2014-01-01

    Purpose: Simultaneous brain PET/MRI faces an important issue of validation of accurate MRI based attenuation correction (AC) method for precise quantitation of brain PET data unlike in PET/CT systems where the use of standard, validated CT based AC is routinely available. The aim of this study was to investigate the feasibility of evaluation of semiquantitative 18 F-FDG PET parameters derived from simultaneous brain PET/MRI using ultrashort echo time (UTE) sequences for AC and to assess their agreement with those obtained from PET/CT examination. Methods: Sixteen patients (age range 18–73 years; mean age 49.43 (19.3) years; 13 men 3 women) underwent simultaneous brain PET/MRI followed immediately by PET/CT. Quantitative analysis of brain PET images obtained from both studies was undertaken using Scenium v.1 brain analysis software package. Twenty ROIs for various brain regions were system generated and 6 semiquantitative parameters including maximum standardized uptake value (SUV max), SUV mean, minimum SUV (SUV min), minimum standard deviation (SD min), maximum SD (SD max) and SD from mean were calculated for both sets of PET data for each patient. Intra-class correlation coefficients (ICCs) were determined to assess agreement between the various semiquantitative parameters for the two PET data sets. Results: Intra-class co-relation between the two PET data sets for SUV max, SUV mean and SD max was highly significant (p < 0.00) for all the 20 predefined brain regions with ICC > 0.9. SD from mean was also found to be statistically significant for all the predefined brain regions with ICC > 0.8. However, SUV max and SUV mean values obtained from PET/MRI were significantly lower compared to those of PET/CT for all the predefined brain regions. Conclusion: PET quantitation accuracy using the MRI based UTE sequences for AC in simultaneous brain PET/MRI is reliable in a clinical setting, being similar to that obtained using PET/CT

  7. The Internalized Homophobia Scale for Vietnamese Sexual Minority Women: Conceptualization, Factor Structure, Reliability, and Associations With Hypothesized Correlates.

    Science.gov (United States)

    Nguyen, Trang Quynh; Poteat, Tonia; Bandeen-Roche, Karen; German, Danielle; Nguyen, Yen Hai; Vu, Loan Kieu-Chau; Nguyen, Nam Thi-Thu; Knowlton, Amy R

    2016-08-01

    We developed the first Vietnamese Internalized Homophobia (IH) scale for use with Vietnamese sexual minority women (SMW). Drawing from existing IH scales in the international literature and based on prior qualitative research about SMW in the Viet Nam context, the scale covers two domains: self-stigma (negative attitudes toward oneself as a sexual minority person) and sexual prejudice (negative attitudes toward homosexuality/same-sex relations in general). Scale items, including items borrowed from existing scales and items based on local expressions, were reviewed and confirmed by members of the target population. Quantitative evaluation used data from an anonymous web-based survey of Vietnamese SMW, including those who identified as lesbian (n = 1187), or as bisexual (n = 641) and those who were unsure about their sexual identity (n = 353). The scale was found to consist of two highly correlated factors reflecting self-stigma (not normal/wholesome and self-reproach and wishing away same-sex sexuality) and one factor reflecting sexual prejudice, and to have excellent internal consistency. Construct validity was evidenced by subscale associations with a wide range of hypothesized correlates, including perceived sexual stigma, outness, social support, connection to other SMW, relationship quality, psychological well-being, anticipation of heterosexual marriage, and endorsement of same-sex marriage legalization. Self-stigma was more strongly associated with psychosocial correlates, and sexual prejudice was more associated with endorsement of legal same-sex marriage. The variations in these associations across the hypothesized correlates and across sexual identity groups were consistent with the minority stress model and the IH literature, and exhibited context-specific features, which are discussed.

  8. Manual muscle testing and hand-held dynamometry in people with inflammatory myopathy: An intra- and interrater reliability and validity study.

    Science.gov (United States)

    Baschung Pfister, Pierrette; de Bruin, Eling D; Sterkele, Iris; Maurer, Britta; de Bie, Rob A; Knols, Ruud H

    2018-01-01

    Manual muscle testing (MMT) and hand-held dynamometry (HHD) are commonly used in people with inflammatory myopathy (IM), but their clinimetric properties have not yet been sufficiently studied. To evaluate the reliability and validity of MMT and HHD, maximum isometric strength was measured in eight muscle groups across three measurement events. To evaluate reliability of HHD, intra-class correlation coefficients (ICC), the standard error of measurements (SEM) and smallest detectable changes (SDC) were calculated. To measure reliability of MMT linear Cohen`s Kappa was computed for single muscle groups and ICC for total score. Additionally, correlations between MMT8 and HHD were evaluated with Spearman Correlation Coefficients. Fifty people with myositis (56±14 years, 76% female) were included in the study. Intra-and interrater reliability of HHD yielded excellent ICCs (0.75-0.97) for all muscle groups, except for interrater reliability of ankle extension (0.61). The corresponding SEMs% ranged from 8 to 28% and the SDCs% from 23 to 65%. MMT8 total score revealed excellent intra-and interrater reliability (ICC>0.9). Intrarater reliability of single muscle groups was substantial for shoulder and hip abduction, elbow and neck flexion, and hip extension (0.64-0.69); moderate for wrist (0.53) and knee extension (0.49) and fair for ankle extension (0.35). Interrater reliability was moderate for neck flexion (0.54) and hip abduction (0.44); fair for shoulder abduction, elbow flexion, wrist and ankle extension (0.20-0.33); and slight for knee extension (0.08). Correlations between the two tests were low for wrist, knee, ankle, and hip extension; moderate for elbow flexion, neck flexion and hip abduction; and good for shoulder abduction. In conclusion, the MMT8 total score is a reliable assessment to consider general muscle weakness in people with myositis but not for single muscle groups. In contrast, our results confirm that HHD can be recommended to evaluate strength of

  9. Reliability of the Social Phobia and Anxiety Inventory (SPAI Portuguese version in a heterogeneous sample of Brazilian university students Fidedignidade da versão em português do Inventário de Ansiedade e Fobia Social (SPAI em amostra heterogênea de estudantes universitários brasileiros

    Directory of Open Access Journals (Sweden)

    Patrícia Picon

    2005-06-01

    Full Text Available OBJECTIVE: To evaluate internal consistency and temporal stability trough test re-test reliability of the Portuguese version of the Social Phobia and Anxiety Inventory (SPAI in a heterogeneous Brazilian sample. METHODS: After informed consent, the translated and adapted version of the SPAI Portuguese was tested and re-tested at a 14-day interval in a sample of 225 university students, both genders, from 4 different undergraduate courses. After double data entry, statistical analysis included Cronbach's alphas, Pearson and intra-class correlation coefficients. RESULTS: The studied sample consisted of 213 students from 4 sub-samples: 95 law students, 31 social communication students, 54 civil engineering students and 33 dental medicine students. The mean age was 23 (±6 years and 110 (51.6% were female. The Cronbach' alpha was 0.96, no difference for both genders. The differential (total score of the SPAI Portuguese showed Pearson coefficient 0.83 (95% CI 0.78-0.87 and Intra-class coefficient 0.83 (95% CI 0.78-0.86. There was no statistical difference in Pearson coefficients between genders (p = 0.121 and the 4 sub-samples (p = 0.258. CONCLUSION: The results do not ensure validity, however, the SPAI Portuguese version presented a good content homogeneity with satisfactory level of internal consistency. The temporal stability evaluated was substantial. The results showed that the Portuguese SPAI presents perfectly acceptable reliability for both genders and suggest that it can be used in Brazilian populationsOBJETIVO: Avaliar consistência interna e estabilidade temporal, através de fidedignidade teste-reteste, da versão em português do Inventário de Ansiedade e Fobia Social (SPAI, em uma amostra brasileira heterogênea. MÉTODOS: Após consentimento informado, a versão traduzida e adaptada para o português do SPAI foi testada e re-testada, com 14 dias de intervalo, em uma amostra de 225 estudantes universitários de ambos os gêneros, de

  10. Reliability engineering

    International Nuclear Information System (INIS)

    Lee, Chi Woo; Kim, Sun Jin; Lee, Seung Woo; Jeong, Sang Yeong

    1993-08-01

    This book start what is reliability? such as origin of reliability problems, definition of reliability and reliability and use of reliability. It also deals with probability and calculation of reliability, reliability function and failure rate, probability distribution of reliability, assumption of MTBF, process of probability distribution, down time, maintainability and availability, break down maintenance and preventive maintenance design of reliability, design of reliability for prediction and statistics, reliability test, reliability data and design and management of reliability.

  11. Measuring functional, interactive and critical health literacy of Chinese secondary school students: reliable, valid and feasible?

    Science.gov (United States)

    Guo, Shuaijun; Davis, Elise; Yu, Xiaoming; Naccarella, Lucio; Armstrong, Rebecca; Abel, Thomas; Browne, Geoffrey; Shi, Yanqin

    2018-04-01

    Health literacy is an increasingly important topic in the global context. In mainland China, health literacy measures mainly focus on health knowledge and practices or on the functional domain for adolescents. However, little is known about interactive and critical domains. This study aimed to adopt a skills-based and three-domain (functional, interactive and critical) instrument to measure health literacy in Chinese adolescents and to examine the status and determinants of each domain. Using a systematic review, the eight-item Health Literacy Assessment Tool (HLAT-8) was selected and translated from English to Chinese (c-HLAT-8). Following the translation process, a cross-sectional study was conducted in four secondary schools in Beijing, China. A total of 650 students in Years 7-9 were recruited to complete a self-administered questionnaire that assessed socio-demographics, self-efficacy, social support, school environment, community environment and health literacy. Results showed that the c-HLAT-8 had satisfactory reliability (Cronbach's α = 0.79; intra-class correlation coefficient = 0.72) and strong validity (translation validity index (TVI) ≥0.95; χ 2 / df = 3.388, p students had an average score of 26.37 (±5.89) for the c-HLAT-8. When the determinants of each domain of health literacy were examined, social support was the strongest predictor of interactive and critical health literacy. On the contrary, self-efficacy and school environment played more dominant roles in predicting functional health literacy. The c-HLAT-8 was demonstrated to be a reliable, valid and feasible instrument for measuring functional, interactive and critical health literacy among Chinese students. The current findings indicate that increasing self-efficacy, social support and creating supportive environments are important for promoting health literacy in secondary school settings in China.

  12. Reliability and Discriminative Ability of a New Method for Soccer Kicking Evaluation

    Science.gov (United States)

    Radman, Ivan; Wessner, Barbara; Bachl, Norbert; Ruzic, Lana; Hackl, Markus; Baca, Arnold; Markovic, Goran

    2016-01-01

    The study aimed to evaluate the test–retest reliability of a newly developed 356 Soccer Shooting Test (356-SST), and the discriminative ability of this test with respect to the soccer players' proficiency level and leg dominance. Sixty-six male soccer players, divided into three groups based on their proficiency level (amateur, n = 24; novice semi-professional, n = 18; and experienced semi-professional players, n = 24), performed 10 kicks following a two-step run up. Forty-eight of them repeated the test on a separate day. The following shooting variables were derived: ball velocity (BV; measured via radar gun), shooting accuracy (SA; average distance from the ball-entry point to the goal centre), and shooting quality (SQ; shooting accuracy divided by the time elapsed from hitting the ball to the point of entry). No systematic bias was evident in the selected shooting variables (SA: 1.98±0.65 vs. 2.00±0.63 m; BV: 24.6±2.3 vs. 24.5±1.9 m s-1; SQ: 2.92±1.0 vs. 2.93±1.0 m s-1; all p>0.05). The intra-class correlation coefficients were high (ICC = 0.70–0.88), and the coefficients of variation were low (CV = 5.3–5.4%). Finally, all three 356-SST variables identify, with adequate sensitivity, differences in soccer shooting ability with respect to the players' proficiency and leg dominance. The results suggest that the 356-SST is a reliable and sensitive test of specific shooting ability in men’s soccer. Future studies should test the validity of these findings in a fatigued state, as well as in other populations. PMID:26812247

  13. Reliability, validity, and responsiveness of the Persian version of Shoulder Activity Scale in a group of patients with shoulder disorders.

    Science.gov (United States)

    Negahban, Hossein; Mohtasebi, Elham; Goharpey, Shahin

    2015-01-01

    The aim of this methodological study was to cross-culturally translate the Shoulder Activity Scale (SAS) into the Persian and determine its clinimetric properties including reliability, validity, and responsiveness in patients with shoulder disorders. Persian version of the SAS was obtained after standard forward-backward translation. Three questionnaires were completed by the respondents: SAS, shoulder pain and disability index (SPADI), and Short-Form 36 Health Survey (SF-36). The patients completed the SAS, 1 week after the first visit to evaluate the test-retest reliability. Construct validity was evaluated by examining the associations between the scores on the SAS and the scores obtained from the SPADI, SF-36, and age of the patients. To assess responsiveness, data were collected in the first visit and then again after 4 weeks physiotherapy intervention. Test-retest reliability and internal consistency were assessed using Intra-class Correlation Coefficient (ICC) and Cronbach's alpha, respectively. To evaluate construct validity, Spearman's rank correlation was used. The ability of the SAS to detect changes was evaluated by the receiver-operating characteristics method. No problem or language difficulties were reported during translation process. Test-retest reliability of the SAS was excellent with an ICC of 0.98. Also, the marginal Cronbach's alpha level of 0.64 was obtained. The correlation between the SAS and the SPADI was low, proving divergent validity, whereas the correlations between the SAS and the SF-36/age were moderate proving convergent validity. A marginally acceptable responsiveness was achieved for the Persian SAS. The study provides some evidences to support the test-retest reliability, internal consistency, construct validity, and responsiveness of the Persian version of the SAS in patients with shoulder disorders. Therefore, it seems that this instrument is a useful measure of shoulder activity level in research setting and clinical practice

  14. The Unsupported Upper Limb Exercise Test in People Without Disabilities: Assessing the Within-Day Test-Retest Reliability and the Effects of Age and Gender.

    Science.gov (United States)

    Oliveira, Ana; Cruz, Joana; Jácome, Cristina; Marques, Alda

    2018-01-01

    Purpose: To estimate the within-day test-retest reliability and standard error of measurement (SEM) of the unsupported upper limb exercise test (UULEX) in adults without disabilities and to determine the effects of age and gender on performance of the UULEX. Method: A cross-sectional study was conducted with 100 adults without disabilities (44 men, mean age 44.2 [SD 26] y; 56 women, mean age 38.1 [SD 24.1] y). Participants performed three UULEX tests to establish within-day reliability, measured using an intra-class correlation coefficient (ICC) model 2 (two-way random effects) with a single rater (ICC[2,1]) and SEM. The effects of age and gender were examined using two-factor mixed-design analysis of variance (ANOVA) and one-way repeated-measures ANOVA. For analysis purposes, four sub-groups were created: younger adults, older adults, men, and women. Results: Excellent within-day reliability and a small SEM were found in the four sub-groups (younger adults: ICC[2,1]=0.88; 95% CI: 0.82, 0.92; SEM∼40 s; older adults: ICC[2,1]=0.82; 95% CI: 0.72, 0.90; SEM∼50 s; men: ICC[2,1]=0.93; 95% CI: 0.88, 0.96; SEM∼30 s; women: ICC[2,1]=0.85; 95% CI: 0.78, 0.91; SEM∼45 s). Younger adults took, on average, 308.24 seconds longer than older adults to perform the test; older adults performed significantly better on the third test ( p 0.05). Conclusion: The within-day test-retest reliability and SEM values of the UULEX may be used to define the magnitude of the error obtained with repeated measures. One UULEX test seems to be adequate for younger adults to achieve reliable results, whereas three tests seem to be needed for older adults.

  15. Testing the reliability and efficiency of the pilot Mixed Methods Appraisal Tool (MMAT) for systematic mixed studies review.

    Science.gov (United States)

    Pace, Romina; Pluye, Pierre; Bartlett, Gillian; Macaulay, Ann C; Salsberg, Jon; Jagosh, Justin; Seller, Robbyn

    2012-01-01

    Systematic literature reviews identify, select, appraise, and synthesize relevant literature on a particular topic. Typically, these reviews examine primary studies based on similar methods, e.g., experimental trials. In contrast, interest in a new form of review, known as mixed studies review (MSR), which includes qualitative, quantitative, and mixed methods studies, is growing. In MSRs, reviewers appraise studies that use different methods allowing them to obtain in-depth answers to complex research questions. However, appraising the quality of studies with different methods remains challenging. To facilitate systematic MSRs, a pilot Mixed Methods Appraisal Tool (MMAT) has been developed at McGill University (a checklist and a tutorial), which can be used to concurrently appraise the methodological quality of qualitative, quantitative, and mixed methods studies. The purpose of the present study is to test the reliability and efficiency of a pilot version of the MMAT. The Center for Participatory Research at McGill conducted a systematic MSR on the benefits of Participatory Research (PR). Thirty-two PR evaluation studies were appraised by two independent reviewers using the pilot MMAT. Among these, 11 (34%) involved nurses as researchers or research partners. Appraisal time was measured to assess efficiency. Inter-rater reliability was assessed by calculating a kappa statistic based on dichotomized responses for each criterion. An appraisal score was determined for each study, which allowed the calculation of an overall intra-class correlation. On average, it took 14 min to appraise a study (excluding the initial reading of articles). Agreement between reviewers was moderate to perfect with regards to MMAT criteria, and substantial with respect to the overall quality score of appraised studies. The MMAT is unique, thus the reliability of the pilot MMAT is promising, and encourages further development. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. 3D photography is a reliable burn wound area assessment tool compared to digital planimetry in very young children.

    Science.gov (United States)

    Gee Kee, E L; Kimble, R M; Stockton, K A

    2015-09-01

    Reliability and validity of 3D photography (3D LifeViz™ System) compared to digital planimetry (Visitrak™) has been established in a compliant cohort of children with acute burns. Further research is required to investigate these assessment tools in children representative of the general pediatric burns population, specifically children under the age of three years. To determine if 3D photography is a reliable wound assessment tool compared to Visitrak™ in children of all ages with acute burns ≤10% TBSA. Ninety-six children (median age 1 year 9 months) who presented to the Royal Children's Hospital Brisbane with an acute burn ≤10% TBSA were recruited into the study. Wounds were measured at the first dressing change using the Visitrak™ system and 3D photography. All measurements were completed by one investigator and level of agreement between wound surface area measurements was calculated. Wound surface area measurements were complete (i.e. participants had measurements from both techniques) for 75 participants. Level of agreement between wound surface area measurements calculated using an intra-class correlation coefficient (ICC) was excellent (ICC 0.96, 95% CI 0.93, 0.97). Visitrak™ tracings could not be completed in 19 participants with 16 aged less than two years. 3D photography could not be completed for one participant. Barriers to completing tracings were: excessive movement, pain, young age or wound location (e.g. face or perineum). This study has confirmed 3D photography as a reliable alternative to digital planimetry in children of all ages with acute burns ≤10% TBSA. In addition, 3D photography is more suitable for very young children given its non-invasive nature. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  17. The Yo-Yo intermittent recovery test level 1 is reliable in young high-level soccer players

    Directory of Open Access Journals (Sweden)

    Dieter Deprez

    2014-11-01

    Full Text Available The aim of the study was to investigate test reliability of the Yo-Yo intermittent recovery test level 1 (YYIR1 in 36 high-level youth soccer players, aged between 13 and 18 years. Players were divided into three age groups (U15, U17 and U19 and completed three YYIR1 in three consecutive weeks. Pairwise comparisons were used to investigate test reliability (for distances and heart rate responses using technical error (TE, coefficient of variation (CV, intra-class correlation (ICC and limits of agreement (LOA with Bland-Altman plots. The mean YYIR1 distances for the U15, U17 and U19 groups were 2024 ± 470 m, 2404 ± 347 m and 2547 ± 337 m, respectively. The results revealed that the TEs varied between 74 and 172 m, CVs between 3.0 and 7.5%, and ICCs between 0.87 and 0.95 across all age groups for the YYIR1 distance. For heart rate responses, the TEs varied between 1 and 6 bpm, CVs between 0.7 and 4.8%, and ICCs between 0.73 and 0.97. The small ratio LOA revealed that any two YYIR1 performances in one week will not differ by more than 9 to 28% due to measurement error. In summary, the YYIR1 performance and the physiological responses have proven to be highly reliable in a sample of Belgian high-level youth soccer players, aged between 13 and 18 years. The demonstrated high level of intermittent endurance capacity in all age groups may be used for comparison of other prospective young soccer players.

  18. Between-Day Reliability of Pre-Participation Screening Components in Pre-Professional Ballet and Contemporary Dancers.

    Science.gov (United States)

    Kenny, Sarah J; Palacios-Derflingher, Luz; Owoeye, Oluwatoyosi B A; Whittaker, Jackie L; Emery, Carolyn A

    2018-03-15

    Critical appraisal of research investigating risk factors for musculoskeletal injury in dancers suggests high quality reliability studies are lacking. The purpose of this study was to determine between-day reliability of pre-participation screening (PPS) components in pre-professional ballet and contemporary dancers. Thirty-eight dancers (35 female, 3 male; median age; 18 years; range: 11 to 30 years) participated. Screening components (Athletic Coping Skills Inventory-28, body mass index, percent total body fat, total bone mineral density, Foot Posture Index-6, hip and ankle range of motion, three lumbopelvic control tasks, unipedal dynamic balance, and the Y-Balance Test) were conducted one week apart. Intra-class correlation coefficients (ICCs: 95% confidence intervals), standard error of measurement, minimal detectable change (MDC), Bland-Altman methods of agreement [95% limits of agreement (LOA)], Cohen's kappa coefficients, standard error, and percent agreements were calculated. Depending on the screening component, ICC estimates ranged from 0.51 to 0.98, kappa coefficients varied between -0.09 and 0.47, and percent agreement spanned 71% to 95%. Wide 95% LOA were demonstrated by Foot Posture Index-6 (right: -6.06, 7.31), passive hip external rotation (right: -9.89, 16.54), and passive supine turnout (left: -15.36, 17.58). The PPS components examined demonstrated moderate to excellent relative reliability with mean between-day differences less than MDC, or sufficient percent agreement, across all assessments. However, due to wide 95% limits of agreement, the Foot Posture Index-6 and passive hip range of motion are not recommended for screening injury risk in pre-professional dancers.

  19. Reliability and validity of the transport and physical activity questionnaire (TPAQ for assessing physical activity behaviour.

    Directory of Open Access Journals (Sweden)

    Emma J Adams

    Full Text Available No current validated survey instrument allows a comprehensive assessment of both physical activity and travel behaviours for use in interdisciplinary research on walking and cycling. This study reports on the test-retest reliability and validity of physical activity measures in the transport and physical activity questionnaire (TPAQ.The TPAQ assesses time spent in different domains of physical activity and using different modes of transport for five journey purposes. Test-retest reliability of eight physical activity summary variables was assessed using intra-class correlation coefficients (ICC and Kappa scores for continuous and categorical variables respectively. In a separate study, the validity of three survey-reported physical activity summary variables was assessed by computing Spearman correlation coefficients using accelerometer-derived reference measures. The Bland-Altman technique was used to determine the absolute validity of survey-reported time spent in moderate-to-vigorous physical activity (MVPA.In the reliability study, ICC for time spent in different domains of physical activity ranged from fair to substantial for walking for transport (ICC = 0.59, cycling for transport (ICC = 0.61, walking for recreation (ICC = 0.48, cycling for recreation (ICC = 0.35, moderate leisure-time physical activity (ICC = 0.47, vigorous leisure-time physical activity (ICC = 0.63, and total physical activity (ICC = 0.56. The proportion of participants estimated to meet physical activity guidelines showed acceptable reliability (k = 0.60. In the validity study, comparison of survey-reported and accelerometer-derived time spent in physical activity showed strong agreement for vigorous physical activity (r = 0.72, p<0.001, fair but non-significant agreement for moderate physical activity (r = 0.24, p = 0.09 and fair agreement for MVPA (r = 0.27, p = 0.05. Bland-Altman analysis showed a mean

  20. Reliability and Validity of the Transport and Physical Activity Questionnaire (TPAQ) for Assessing Physical Activity Behaviour

    Science.gov (United States)

    Adams, Emma J.; Goad, Mary; Sahlqvist, Shannon; Bull, Fiona C.; Cooper, Ashley R.; Ogilvie, David

    2014-01-01

    Background No current validated survey instrument allows a comprehensive assessment of both physical activity and travel behaviours for use in interdisciplinary research on walking and cycling. This study reports on the test-retest reliability and validity of physical activity measures in the transport and physical activity questionnaire (TPAQ). Methods The TPAQ assesses time spent in different domains of physical activity and using different modes of transport for five journey purposes. Test-retest reliability of eight physical activity summary variables was assessed using intra-class correlation coefficients (ICC) and Kappa scores for continuous and categorical variables respectively. In a separate study, the validity of three survey-reported physical activity summary variables was assessed by computing Spearman correlation coefficients using accelerometer-derived reference measures. The Bland-Altman technique was used to determine the absolute validity of survey-reported time spent in moderate-to-vigorous physical activity (MVPA). Results In the reliability study, ICC for time spent in different domains of physical activity ranged from fair to substantial for walking for transport (ICC = 0.59), cycling for transport (ICC = 0.61), walking for recreation (ICC = 0.48), cycling for recreation (ICC = 0.35), moderate leisure-time physical activity (ICC = 0.47), vigorous leisure-time physical activity (ICC = 0.63), and total physical activity (ICC = 0.56). The proportion of participants estimated to meet physical activity guidelines showed acceptable reliability (k = 0.60). In the validity study, comparison of survey-reported and accelerometer-derived time spent in physical activity showed strong agreement for vigorous physical activity (r = 0.72, pphysical activity (r = 0.24, p = 0.09) and fair agreement for MVPA (r = 0.27, p = 0.05). Bland-Altman analysis showed a mean overestimation of MVPA of 87.6 min/week (p

  1. The reliability, validity and responsiveness of the Thai version of Systemic Lupus Erythematosus Quality of Life (SLEQOL-TH) instrument.

    Science.gov (United States)

    Kasitanon, N; Wangkaew, S; Puntana, S; Sukitawut, W; Leong, K P; Louthrenoo, W

    2013-03-01

    The English version of the Systemic Lupus Erythematosus Quality of Life Questionnaire (SLEQOL) is a validated disease-specific quality of life instrument. The aim of this study was to evaluate the psychometric properties of the Thai version of the SLEQOL (SLEQOL-TH). Two independent translators translated the SLEQOL into Thai. The back translation of this version was performed by two other independent translators. The final version, SLEQOL-TH, was completed after resolving the discrepancies revealed by the back translation. One hundred and nine patients with SLE were enrolled to test the reliability, construct validity, floor and ceiling effects, and sensitivity to the changes of the SLEQOL-TH at six months. The differential item functioning (DIF) between the Thai and English versions was analyzed using the partial gamma. The internal consistency of the SLEQOL-TH was satisfactory with the overall Cronbach's alpha of 0.86. The test-retest reliability of the SLEQOL-TH was acceptable with the intra-class correlation coefficient of 0.86. Low correlations between the SLEQOL-TH and SLEDAI were observed. The total score of the SLEQOL-TH was moderately responsive to changes in quality of life, with a standardized response mean of 0.50. When comparing the SLEQOL-TH from Thai SLE patients with the original SLEQOL version obtained from Singapore SLE patients, 11 out of 40 items showed a moderate to large DIF. The SLEQOL-TH has acceptable psychometric properties and shows construct validity. In comparison with the English version of SLEQOL, there are some items that showed DIF. The applicability of the SLEQOL-TH in real-life clinical practice and clinical trials needs to be determined.

  2. Reliability and validity study of the Gujarati version of the Oswestry Disability Index 2.1a.

    Science.gov (United States)

    Shah, Sweni; Balaganapathy, M

    2017-09-22

    Among all musculoskeletal disorders back pain is the most common reason for functional limitation in working age. It is due to low back pain (LBP) that the ODI has become one of the principal outcome measures for evaluation of disability and has been widely used in research as well as in clinical practice. So far, validated Gujarati version of the ODI 2.1a has not been reported. To accomplish the translation and validation of the Oswestry Disability Index (ODI) version 2.1a into the Gujarati language. Cross-sectional study. The validation of the ODI-Gujarati was tested in 120 patients diagnosed with non-specific LBP, who were receiving physiotherapy at a clinic in Gujarat, India. Data was collected at on initial visit and after 48 hours. During both visits, patients completed the Oswestry Disability Index-Gujarati (ODI-G), Roland-Morris Disability Questionnaire-Gujarati (RMDQ-G), and Visual Analogue Scale-Pain (VAS-P). Internal consistency was measured by Cronbach's alpha. The Gujarati version indicated high internal consistency (α= 0.96). Test-retest reliability was measured by intra-class correlation coefficient and it revealed very high correlation (ICC = 0.92). Construct validity was confirmed by strong correlation with RMDQ-G (r= 0.76), and concurrent validity indicated moderate correlation with VAS-P (r= 0.50). Factor analysis explained that the ODI was loaded on 1 factor. The Oswestry disability index version 2.1a was successfully translated into Gujarati language, showing excellent psychometric properties. Therefore, it can be used in evaluating the disability amongst Gujarati population with LBP for both clinical and research purposes.

  3. Development of a valid and reliable test to assess trauma radiograph interpretation performance

    International Nuclear Information System (INIS)

    Neep, M.J.; Steffens, T.; Riley, V.; Eastgate, P.; McPhail, S.M.

    2017-01-01

    Objectives: The purpose of this investigation was to develop and examine the preliminary validity and reliability among radiographers of a test to assess trauma radiograph interpretation performance suitable for use among health professionals. Methods: Stage 1 examined 14,159 consecutive appendicular and axial examinations from a hospital emergency department over a 12 month period to quantify a typical anatomical region case-mix of trauma radiographs. A sample of radiographic cases representative of affected anatomical regions was then developed into the Image Interpretation Test (IIT). Stage 2 involved prospective investigations of the IIT's reliability (inter-rater, intra-rater, internal consistency) and validity (concurrent) among 41 radiographers. Results: The IIT included 60 cases. The median (interquartile range) clinical experience of participants was 5 (2–10) years. Case scores were internally consistent (Cronbach's alpha = 0.90). Favourable inter-rater reliability (kappa > 0.70 for 58/60 cases, Intra-class correlation coefficient (ICC) > 0.99 for total score) and intra-rater reliability (kappa > 0.90 for 60/60 cases, ICC > 0.99 for total score) was observed. There was a positive association between radiographers' confidence in image interpretation and IIT score (coefficient = 1.52, r-squared = 0.60, p < 0.001). Conclusions: The IIT developed during this investigation included a selection of radiographic cases consistent with anatomical regions represented in an adult trauma case-mix. This study has also provided foundational preliminary evidence to support the reliability and validity of the IIT among radiographers. The findings suggest that it is possible to assess image interpretation performance of adult trauma radiographs with this test. - Highlights: • Development of an Image Interpretation Test (IIT). • Cases consistent with anatomical regions represented in a typical adult trauma case-mix. • Development of a

  4. An automated process for building reliable and optimal in vitro/in vivo correlation models based on Monte Carlo simulations.

    Science.gov (United States)

    Sutton, Steven C; Hu, Mingxiu

    2006-05-05

    Many mathematical models have been proposed for establishing an in vitro/in vivo correlation (IVIVC). The traditional IVIVC model building process consists of 5 steps: deconvolution, model fitting, convolution, prediction error evaluation, and cross-validation. This is a time-consuming process and typically a few models at most are tested for any given data set. The objectives of this work were to (1) propose a statistical tool to screen models for further development of an IVIVC, (2) evaluate the performance of each model under different circumstances, and (3) investigate the effectiveness of common statistical model selection criteria for choosing IVIVC models. A computer program was developed to explore which model(s) would be most likely to work well with a random variation from the original formulation. The process used Monte Carlo simulation techniques to build IVIVC models. Data-based model selection criteria (Akaike Information Criteria [AIC], R2) and the probability of passing the Food and Drug Administration "prediction error" requirement was calculated. To illustrate this approach, several real data sets representing a broad range of release profiles are used to illustrate the process and to demonstrate the advantages of this automated process over the traditional approach. The Hixson-Crowell and Weibull models were often preferred over the linear. When evaluating whether a Level A IVIVC model was possible, the model selection criteria AIC generally selected the best model. We believe that the approach we proposed may be a rapid tool to determine which IVIVC model (if any) is the most applicable.

  5. Validity and Reliability of the 30-s Continuous Jump for Anaerobic Power and Capacity Assessment in Combat Sport

    Directory of Open Access Journals (Sweden)

    Drazen Čular

    2018-05-01

    Full Text Available Cycling test such Wingate anaerobic test (WAnT is used to measure anaerobic power (AP, but not anaerobic capacity (AC, i.e., the metabolic energy demand. However, in sports that do not involve cycling movements (Karate, the continuous jump for 30 s (vertical jumps for 30 s has been extensively used to measure anaerobic performance in all young athletes. Limited information’s are available concerning its validity and reliability especially in children. As such, the current study aimed to test validity and reliability of a continuous jumps test (the CJ30s, using WAnT as a reference. Thirteen female Karate kids (age: 11.07 ± 1.32 years; mass: 41.76 ± 15.32 kg; height: 152 ± 11.52 cm; training experience: 4.38 ± 2.14 years were tested on three separate sessions. The first and second sessions were used to assess the reliability using Intra-class correlation coefficient (ICC of CJ30s, whereas on the third session WAnT was administered. Following CJ30s and WAnT, we assessed AP (1/CJ30s, as jump height [JH], fatigue index [FI], and blood lactate [BL]; 2/WAnT, as mechanical power [P], FI, and BL and AC as the excess post-exercise oxygen consumption (EPOC. Large/highly significant correlations were found between CJ30s and WAnT EPOCs (r = 0.730, P = 0.003, and BLs (r = 0.713, P = 0.009. Moderate/significant correlations were found between CJ30s and WAnT FIs (r = 0.640, P = 0.014, CJ30s first four jumps mean JH and WAnT peak P (r = 0.572, P = 0.032, and CJ30s mean JH and WAnT mean P (r = 0.589, P = 0.021. CJ30s showed excellent and moderate reliability (ICC for AP (maximal JH 0.884, mean JH 0.742, FI 0.657, BL 0.653 and AC (EPOC 0.788, respectively. Correlations observed especially in terms of AC between CJ30s and WAnT provide evidence that former may adequately assess anaerobic performance for the young combat athlete. CJ30 is a reliable test and allow an easy assessment of AP and AC in karate children.

  6. The reliability, validity and responsiveness of the Dutch version of the Oxford elbow score

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    Patka Peter

    2011-07-01

    Full Text Available Abstract Background The Oxford elbow score (OES is an English questionnaire that measures the patients' subjective experience of elbow surgery. The OES comprises three domains: elbow function, pain, and social-psychological effects. This questionnaire can be completed by the patient and used as an outcome measure after elbow surgery. The aim of this study was to develop and evaluate the Dutch version of the translated OES for reliability, validity and responsiveness with respect to patients after elbow trauma and surgery. Methods The 12 items of the English-language OES were translated into Dutch and then back-translated; the back-translated questionnaire was then compared to the original English version. The OES Dutch version was completed by 69 patients (group A, 60 of whom had an elbow luxation, four an elbow fracture and five an epicondylitis. QuickDASH, the visual analogue pain scale (VAS and the Mayo Elbow Performance Index (MEPI were also completed to examine the convergent validity of the OES in group A. To calculate the test-retest reliability and responsiveness of the OES, this questionnaire was completed three times by 43 different patients (group B. An average of 52 days elapsed between therapy and the administration of the third OES (SD = 24.1. Results The Cronbach's α coefficients for the function, pain and social-psychological domains were 0.90, 0.87 and 0.90, respectively. The intra-class correlation coefficients for the domains were 0.87 for function, 0.89 for pain and 0.87 for social-psychological. The standardised response means for the domains were 0.69, 0.46 and 0.60, respectively, and the minimal detectable changes were 27.6, 21.7 and 24.0, respectively. The convergent validity for the function, pain and social-psychological domains, which were measured as the Spearman's correlation of the OES domains with the MEPI, were 0.68, 0.77 and 0.77, respectively. The Spearman's correlations of the OES domains with QuickDASH were

  7. Test-retest reliability and construct validity of the ENERGY-parent questionnaire on parenting practices, energy balance-related behaviours and their potential behavioural determinants: the ENERGY-project

    Directory of Open Access Journals (Sweden)

    Singh Amika S

    2012-08-01

    Full Text Available Abstract Background Insight in parental energy balance-related behaviours, their determinants and parenting practices are important to inform childhood obesity prevention. Therefore, reliable and valid tools to measure these variables in large-scale population research are needed. The objective of the current study was to examine the test-retest reliability and construct validity of the parent questionnaire used in the ENERGY-project, assessing parental energy balance-related behaviours, their determinants, and parenting practices among parents of 10–12 year old children. Findings We collected data among parents (n = 316 in the test-retest reliability study; n = 109 in the construct validity study of 10–12 year-old children in six European countries, i.e. Belgium, Greece, Hungary, the Netherlands, Norway, and Spain. Test-retest reliability was assessed using the intra-class correlation coefficient (ICC and percentage agreement comparing scores from two measurements, administered one week apart. To assess construct validity, the agreement between questionnaire responses and a subsequent interview was assessed using ICC and percentage agreement. All but one item showed good to excellent test-retest reliability as indicated by ICCs > .60 or percentage agreement ≥ 75%. Construct validity appeared to be good to excellent for 92 out of 121 items, as indicated by ICCs > .60 or percentage agreement ≥ 75%. From the other 29 items, construct validity was moderate for 24 and poor for 5 items. Conclusions The reliability and construct validity of the items of the ENERGY-parent questionnaire on multiple energy balance-related behaviours, their potential determinants, and parenting practices appears to be good. Based on the results of the validity study, we strongly recommend adapting parts of the ENERGY-parent questionnaire if used in future research.

  8. Reliability and validity of the Bowel Function Index for evaluating opioid-induced constipation: translation, cultural adaptation and validation of the Portuguese version (BFI-P).

    Science.gov (United States)

    Dueñas, María; Mendonça, Liliane; Sampaio, Rute; Gouvinhas, Cláudia; Oliveira, Daniela; Castro-Lopes, José Manuel; Azevedo, Luís Filipe

    2017-03-01

    The Bowel Function Index (BFI) is a simple and sound bowel function and opioid-induced constipation (OIC) screening tool. We aimed to develop the translation and cultural adaptation of this measure (BFI-P) and to assess its reliability and validity for the Portuguese language and a chronic pain population. The BFI-P was created after a process including translation, back translation and cultural adaptation. Participants (n = 226) were recruited in a chronic pain clinic and were assessed at baseline and after one week. Internal consistency, test-retest reliability, responsiveness, construct (convergent and known groups) and factorial validity were assessed. Test-retest reliability had an intra-class correlation of 0.605 for BFI mean score. Internal consistency of BFI had Cronbach's alpha of 0.865. The construct validity of BFI-P was shown to be excellent and the exploratory factor analysis confirmed its unidimensional structure. The responsiveness of BFI-P was excellent, with a suggested 17-19 point and 8-12 point change in score constituting a clinically relevant change in constipation for patients with and without previous constipation, respectively. This study had some limitations, namely, the criterion validity of BFI-P was not directly assessed; and the absence of a direct criterion for OIC precluded the assessment of the criterion based responsiveness of BFI-P. Nevertheless, BFI may importantly contribute to better OIC screening and its Portuguese version (BFI-P) has been shown to have excellent reliability, internal consistency, validity and responsiveness. Further suggestions regarding statistically and clinically important change cut-offs for this instrument are presented.

  9. Cardiac valve calcifications on low-dose unenhanced ungated chest computed tomography: inter-observer and inter-examination reliability, agreement and variability

    Energy Technology Data Exchange (ETDEWEB)

    Hamersvelt, Robbert W. van; Willemink, Martin J.; Takx, Richard A.P.; Eikendal, Anouk L.M.; Budde, Ricardo P.J.; Leiner, Tim; Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Mol, Christian P.; Isgum, Ivana [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)

    2014-07-15

    To determine inter-observer and inter-examination variability for aortic valve calcification (AVC) and mitral valve and annulus calcification (MC) in low-dose unenhanced ungated lung cancer screening chest computed tomography (CT). We included 578 lung cancer screening trial participants who were examined by CT twice within 3 months to follow indeterminate pulmonary nodules. On these CTs, AVC and MC were measured in cubic millimetres. One hundred CTs were examined by five observers to determine the inter-observer variability. Reliability was assessed by kappa statistics (κ) and intra-class correlation coefficients (ICCs). Variability was expressed as the mean difference ± standard deviation (SD). Inter-examination reliability was excellent for AVC (κ = 0.94, ICC = 0.96) and MC (κ = 0.95, ICC = 0.90). Inter-examination variability was 12.7 ± 118.2 mm{sup 3} for AVC and 31.5 ± 219.2 mm{sup 3} for MC. Inter-observer reliability ranged from κ = 0.68 to κ = 0.92 for AVC and from κ = 0.20 to κ = 0.66 for MC. Inter-observer ICC was 0.94 for AVC and ranged from 0.56 to 0.97 for MC. Inter-observer variability ranged from -30.5 ± 252.0 mm{sup 3} to 84.0 ± 240.5 mm{sup 3} for AVC and from -95.2 ± 210.0 mm{sup 3} to 303.7 ± 501.6 mm{sup 3} for MC. AVC can be quantified with excellent reliability on ungated unenhanced low-dose chest CT, but manual detection of MC can be subject to substantial inter-observer variability. Lung cancer screening CT may be used for detection and quantification of cardiac valve calcifications. (orig.)

  10. Intra- and inter-rater reliabilities of measurement of ultrasound imaging for muscle thickness and pennation angle of tibialis anterior muscle in stroke patients.

    Science.gov (United States)

    Cho, Ki Hun; Lee, Hwang Jae; Lee, Wan Hee

    2017-07-01

    Dysfunction of skeletal muscle has been commonly reported in stroke patients. The purpose of this study was to investigate the intra- and inter-rater reliabilities of measurement of ultrasound imaging (USI) for pennation angle (PA) and muscle thickness (MT) of tibialis anterior muscle in stroke patients. Thirty-four stroke patients (19 men) participated in this study. USI was used for measurement of PA and MT of the tibialis anterior muscles at rest and during maximum voluntary contraction (MVC). Two examiners acquired images from all participants during two separate testing sessions, seven days apart. Intra-class correlation coefficients (ICCs), confidence interval (CI), standard error of measurement, minimal detectable change, and Bland-Altman plots were used for estimation of reliability. In the intra-rater reliability between measures, for all variables (PA and MT of the paretic and non-paretic sides of tibialis anterior muscles at rest and during MVC), the ICCs ranged between 0.639 and 0.998 and the CI was within an acceptable range of 0.388-0.999. In inter-rater reliability between examiners for the two tests, for all variables, the ICCs ranged between 0.690 and 0.995 and the CI was within an acceptable range of 0.463-0.997. In addition, significant difference was observed between the paretic and non-paretic sides of the tibialis anterior muscle architecture (p stroke patients. In addition, objective and quantitative measurements of tibialis anterior muscle using USI may provide appropriate management for the walking recovery of stroke patients.

  11. Cardiac valve calcifications on low-dose unenhanced ungated chest computed tomography: inter-observer and inter-examination reliability, agreement and variability

    International Nuclear Information System (INIS)

    Hamersvelt, Robbert W. van; Willemink, Martin J.; Takx, Richard A.P.; Eikendal, Anouk L.M.; Budde, Ricardo P.J.; Leiner, Tim; Jong, Pim A. de; Mol, Christian P.; Isgum, Ivana

    2014-01-01

    To determine inter-observer and inter-examination variability for aortic valve calcification (AVC) and mitral valve and annulus calcification (MC) in low-dose unenhanced ungated lung cancer screening chest computed tomography (CT). We included 578 lung cancer screening trial participants who were examined by CT twice within 3 months to follow indeterminate pulmonary nodules. On these CTs, AVC and MC were measured in cubic millimetres. One hundred CTs were examined by five observers to determine the inter-observer variability. Reliability was assessed by kappa statistics (κ) and intra-class correlation coefficients (ICCs). Variability was expressed as the mean difference ± standard deviation (SD). Inter-examination reliability was excellent for AVC (κ = 0.94, ICC = 0.96) and MC (κ = 0.95, ICC = 0.90). Inter-examination variability was 12.7 ± 118.2 mm 3 for AVC and 31.5 ± 219.2 mm 3 for MC. Inter-observer reliability ranged from κ = 0.68 to κ = 0.92 for AVC and from κ = 0.20 to κ = 0.66 for MC. Inter-observer ICC was 0.94 for AVC and ranged from 0.56 to 0.97 for MC. Inter-observer variability ranged from -30.5 ± 252.0 mm 3 to 84.0 ± 240.5 mm 3 for AVC and from -95.2 ± 210.0 mm 3 to 303.7 ± 501.6 mm 3 for MC. AVC can be quantified with excellent reliability on ungated unenhanced low-dose chest CT, but manual detection of MC can be subject to substantial inter-observer variability. Lung cancer screening CT may be used for detection and quantification of cardiac valve calcifications. (orig.)

  12. Reliability and Construct Validity of the Psychopathic Personality Inventory-Revised in a Swedish Non-Criminal Sample - A Multimethod Approach including Psychophysiological Correlates of Empathy for Pain.

    Directory of Open Access Journals (Sweden)

    Karolina Sörman

    Full Text Available Cross-cultural investigation of psychopathy measures is important for clarifying the nomological network surrounding the psychopathy construct. The Psychopathic Personality Inventory-Revised (PPI-R is one of the most extensively researched self-report measures of psychopathic traits in adults. To date however, it has been examined primarily in North American criminal or student samples. To address this gap in the literature, we examined PPI-R's reliability, construct validity and factor structure in non-criminal individuals (N = 227 in Sweden, using a multimethod approach including psychophysiological correlates of empathy for pain. PPI-R construct validity was investigated in subgroups of participants by exploring its degree of overlap with (i the Psychopathy Checklist: Screening Version (PCL:SV, (ii self-rated empathy and behavioral and physiological responses in an experiment on empathy for pain, and (iii additional self-report measures of alexithymia and trait anxiety. The PPI-R total score was significantly associated with PCL:SV total and factor scores. The PPI-R Coldheartedness scale demonstrated significant negative associations with all empathy subscales and with rated unpleasantness and skin conductance responses in the empathy experiment. The PPI-R higher order Self-Centered Impulsivity and Fearless Dominance dimensions were associated with trait anxiety in opposite directions (positively and negatively, respectively. Overall, the results demonstrated solid reliability (test-retest and internal consistency and promising but somewhat mixed construct validity for the Swedish translation of the PPI-R.

  13. Reliability of inertial sensors in the assessment of patients with vestibular disorders: a feasibility study

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    Sathish K. Sankarpandi

    2017-02-01

    Full Text Available Abstract Background Vestibular disorders affect an individual’s stability, balance, and gait and predispose them to falls. Traditional laboratory-based semi-objective vestibular assessments are intrusive and cumbersome provide little information about their functional ability. Commercially available wearable inertial sensors allow us to make this real life assessments objective, with a detailed view of their functional abilities. Timed Up and Go (TUG and Postural Sway tests are commonly used tests for gait and balance assessments. Our aim was to assess the feasibility, test-retest reliability and ability to classify fall status in individuals with vestibular disorders using parameters derived from the commercially available wearable system (inertial sensors and the Mobility Lab Software, APDM, Inc.. Methods We recruited 27 individuals diagnosed either with unilateral or bilateral vestibular loss on vestibular function testing. Instrumented Timed Up and Go (iTUG and Postural Sway (iSway were administered three times during the first session and then repeated at a similar time the following week. To evaluate within and between sessions reliability of the parameters the Intra-Class Correlation coefficient (ICC was used. Subsequently, the ability of reliable parameters (ICC ≥ 0.8 to classify fallers from non-fallers was estimated. Results The iTUG test parameters showed good within and between sessions’ reliability with mean ICC (between-sessions values of 0.81 ± 0.17 and 0.69 ± 0.15, respectively. For the iSway test, the relative figures were; 0.76 ± 0.13 and 0.71 ± 0.14, respectively. A retrospective falls classification analysis with past 12 months falls history data yielded an accuracy of 66.70% with an area under the curve of 0.79. Mean Distance from centre of COP (mm of accelerometer’s trajectory (m/s2 from the iSway test was the only significant parameter to classify fallers from non-fallers. Conclusions Using

  14. The reliability of the Hendrich Fall Risk Model in a geriatric hospital.

    Science.gov (United States)

    Heinze, Cornelia; Halfens, Ruud; Dassen, Theo

    2008-12-01

    Aims and objectives.  The purpose of this study was to test the interrater reliability of the Hendrich Fall Risk Model, an instrument to identify patients in a hospital setting with a high risk of falling. Background.  Falls are a serious problem in older patients. Valid and reliable fall risk assessment tools are required to identify high-risk patients and to take adequate preventive measures. Methods.  Seventy older patients were independently and simultaneously assessed by six pairs of raters made up of nursing staff members. Consensus estimates were calculated using simple percentage agreement and consistency estimates using Spearman's rho and intra class coefficient. Results.  Percentage agreement ranged from 0.70 to 0.92 between the six pairs of raters. Spearman's rho coefficients were between 0.54 and 0.80 and the intra class coefficients were between 0.46 and 0.92. Conclusions.  Whereas some pairs of raters obtained considerable interobserver agreement and internal consistency, the others did not. Therefore, it is concluded that the Hendrich Fall Risk Model is not a reliable instrument. The use of more unambiguous operationalized items is preferred. Relevance to clinical practice.  In practice, well operationalized fall risk assessment tools are necessary. Observer agreement should always be investigated after introducing a standardized measurement tool. © 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.

  15. Correlation of apparent diffusion coefficient ratio on 3.0 T MRI with prostate cancer Gleason score.

    Science.gov (United States)

    Jyoti, Rajeev; Jain, Tarun Pankaj; Haxhimolla, Hodo; Liddell, Heath; Barrett, Sean Edward

    2018-01-01

    The purpose was to investigate the usefulness of ADC ratio on Diffusion MRI to discriminate between benign and malignant lesions of Prostate. Images of patients who underwent in-gantry MRI guided prostate lesion biopsy were retrospectively analyzed. Prostate Cancers with 20% or more Gleason score (GS) pattern 3 + 3 = 6 in each core or any volume of higher Gleason score pattern were included. ADC ratio was calculated by two reviewers for each lesion. The ADC ratio was calculated for each lesion by dividing the lowest ADC value in a lesion and highest ADC value in normal prostate in peripheral zone (PZ). ADC ratio values were compared with the biopsy result. Data was analysed using independent samples T-test, Spearman correlation, intra-class correlation coefficient (ICC) and Receiver operating characteristic (ROC) curve. 45 lesions in 33 patients were analyzed. 12 lesions were in transitional zone (TZ) and 33 in perpheral zone PZ. All lesions demonstrated an ADC ratio of 0.45 or lower. GS demonstrated a negative correlation with both the ADC value and ADC ratio . However, ADC ratio (p correlation compared to ADC value alone (p = 0.014). There was no significant statistical difference between GS 3 + 4 and GS 4 + 3 mean ADC tumour value (p = 0.167). However when using ADC ratio , there was a significant difference (p = 0.032). ROC curve analysis demonstrated an area under the curve of 0.83 using ADC ratio and 0.76 when using ADC tumour value when discriminating Gleason 6 from Gleason ≥7 tumours. Inter-observer reliability in the calculation of ADC ratios was excellent, with ICC of 0.964. ADC ratio is a reliable and reproducible tool in quantification of diffusion restriction for clinically significant prostate cancer foci.

  16. Test-retest reliability of the different dynamometric variables used to evaluate pelvic floor musculature during the menstrual cycle.

    Science.gov (United States)

    Dos Reis Nagano, Reny C; Biasotto-Gonzalez, Daniela A; da Costa, Gilmar L; Amorim, Karina M; Fumagalli, Marco A; Amorim, César F; Politti, Fabiano

    2018-04-17

    The aim of this study was to evaluate the reliability of different dynamometric variables of the pelvic floor muscles (PFM) in healthy women during different periods of menstrual cycle. Vaginal dynamometric equipment was developed by the authors and its reproducibility was tested. The PFM contractions of 20 healthy women were collected by two independent examiners over three consecutive weeks, always on the same day, with a seven-day interval between readings, starting from the first day after the end of the menstrual period. For the measurements, the branch of the dynamometer was positioned first on the sagittal plane and then on the frontal plane. Baseline, peak time, maximum PFM strength, impulse contraction, and average contraction force were calculated. Reproducibility was tested using the intra-class correlation coefficient (ICC) and standard error of measurement. Repeated-measures ANOVA was used to compare the data from different days. For intra-day and inter-day reliability between examiners, all the parameters collected on the sagittal plane presented good and excellent reproducibility (ICC 2,1  = 0.60 to 0.98), whereas reproducibility on the frontal plane was respectively poor and excellent (ICC 2,1  = 0.23 to 0.97). The ANOVA revealed significant differences between sessions only for the impulse of contraction for the sagittal (P = 0.005) and frontal (P = 0.03) planes. Time and contraction force parameters of the PFM are not influenced by hormonal alterations that occur during the menstrual cycle. The impulse of contraction was the only variable to demonstrate a significant difference between the first and second week of the data collection protocol. The baseline, maximum strength value, impulse of contraction, and average contraction force variables presented good to excellent reproducibility and can be safely used as a method of PFM evaluation. © 2018 Wiley Periodicals, Inc.

  17. Reliability of a Malay-translated questionnaire for use in a hand-arm vibration syndrome study in Malaysia.

    Science.gov (United States)

    Su, T A; Hoe, V C W

    2008-12-01

    Validity and reliability of the information relating to hand-transmitted vibration exposure and vibration-related health outcome are very important for case finding in hand-arm vibration syndrome (HAVS) studies. In a local HAVS study among a group of construction workers in Kuala Lumpur, Malaysia, a questionnaire translated into Malay was created based on the Hand-transmitted Vibration Health Surveillance--Initial Questionnaire and Clinical Assessment, from Vibration Injury Network. This study was conducted to determine the reliability of standardised questions in the questionnaire used in the study. 15 subjects were selected randomly from the sampling frame of the HAVS study. Test-retest reliability was conducted on all items contained in parts 1-6 of the questionnaire and clinical assessment form, with an interval of 13-14 days between the first and second administration. Kappa coefficient and percentage agreement were calculated for all standardised questions. The kappa coefficient and percentage agreement for all standardised questions varied from -0.174 to 1.000 and 66.7 to 100.0 percent, respectively. The kappa coefficient for important questions related to current vibratory tool usage, tingling, numbness and hand grip weakness were 0.714, 0.432, -0.077 and -0.120, respectively, while the percentage agreement for current vibratory tool usage, finger colour change, tingling, numbness and hand grip weakness were 85.7 percent, 92.8 percent, 79.5 percent, 85.7 percent and 71.4 percent, respectively. Intra-rater reliability on the extent of vibration exposure was good, with the intra-class correlation coefficient (95 percent confidence interval) ranging from 0.786 (0.334-0.931) to 0.975 (0.923-0.992). Critical questions on vascular, neurological and musculoskeletal symptoms of HAVS were found to be reliable. The history on the extent of vibration exposure revealed good reliability when explored by the investigator alone. This questionnaire is considered reliable

  18. Reliability of accelerometer-determined physical activity and sedentary behavior in school-aged children: a 12-country study.

    Science.gov (United States)

    Barreira, T V; Schuna, J M; Tudor-Locke, C; Chaput, J-P; Church, T S; Fogelholm, M; Hu, G; Kuriyan, R; Kurpad, A; Lambert, E V; Maher, C; Maia, J; Matsudo, V; Olds, T; Onywera, V; Sarmiento, O L; Standage, M; Tremblay, M S; Zhao, P; Katzmarzyk, P T

    2015-12-01

    Focused on the accelerometer-determined physical activity and sedentary time metrics in 9-11-year-old children, we sought to determine the following: (i) number of days that are necessary to achieve reliable estimates (G⩾0.8); (ii) proportion of variance attributed to different facets (participants and days) of reliability estimates; and (iii) actual reliability of data as collected in The International Study of Childhood Obesity, Lifestyle and Environment (ISCOLE). The analytical sample consisted of 6025 children (55% girls) from sites in 12 countries. Physical activity and sedentary time metrics measures were assessed for up to 7 consecutive days for 24 h per day with a waist-worn ActiGraph GT3X+. Generalizability theory using R software was used to investigate the objectives i and ii. Intra-class correlation coefficients (ICC) were computed using SAS PROC GLM to inform objective iii. The estimated minimum number of days required to achieve a reliability estimate of G⩾0.8 ranged from 5 to 9 for boys and 3 to 11 for girls for light physical activity (LPA); 5 to 9 and 3 to 10, for moderate-to-vigorous physical activity (MVPA); 5 to 10 and 4 to 10 for total activity counts; and 7 to 11 and 6 to 11 for sedentary time, respectively. For all variables investigated, the 'participant' facet accounted for 30-50% of the variability, whereas the 'days' facet accounted for ⩽5%, and the interaction (P × D) accounted for 50-70% of the variability. The actual reliability for boys in ISCOLE ranged from ICCs of 0.78 to 0.86, 0.73 to 0.85 and 0.72 to 0.86 for LPA, MVPA and total activity counts, respectively, and 0.67 to 0.79 for sedentary time. The corresponding values for girls were 0.80-0.88, 0.70-0.89, 0.74-0.86 and 0.64-0.80. It was rare that only 4 days from all participants would be enough to achieve desirable reliability estimates. However, asking participants to wear the device for 7 days and requiring ⩾4 days of data to include the participant in the analysis

  19. Demonstration of the test-retest reliability and sensitivity of the Lower Limb Functional Index-10 as a measure of functional recovery post burn injury: a cross-sectional repeated measures study design.

    Science.gov (United States)

    Ryland, Margaret E; Grisbrook, Tiffany L; Wood, Fiona M; Phillips, Michael; Edgar, Dale W

    2016-01-01

    Lower limb burns can significantly delay recovery of function. Measuring lower limb functional outcomes is challenging in the unique burn patient population and necessitates the use of reliable and valid tools. The aims of this study were to examine the test-retest reliability, sensitivity, and internal consistency of Sections 1 and 3 of the Lower Limb Functional Index-10 (LLFI-10) questionnaire for measuring functional ability in patients with lower limb burns over time. Twenty-nine adult patients who had sustained a lower limb burn injury in the previous 12 months completed the test-retest procedure of the study. In addition, the minimal detectable change (MDC) was calculated for Section 1 and 3 of the LLFI-10. Section 1 is focused on the activity limitations experienced by patients with a lower limb disorder whereas Section 3 involves patients indicating their current percentage of pre-injury duties. Section 1 of the LLFI-10 demonstrated excellent test-retest reliability (intra-class correlation coefficient (ICC) 0.98, 95 % CI 0.96-0.99) whilst Section 3 demonstrated high test-retest reliability (ICC 0.88, 95 % CI 0.79-0.94). MDC scores for Sections 1 and 3 were 1.27 points and 30.22 %, respectively. Internal consistency was demonstrated with a significant negative association (r s  = -0.83) between Sections 1 and 3 of the LLFI-10 (p reliable for measuring functional ability in patients who have sustained lower limb burns in the previous 12 months, and furthermore, Section 1 is sensitive to changes in patient function over time.

  20. Development and reliability testing of a self-report instrument to measure the office layout as a correlate of occupational sitting

    Directory of Open Access Journals (Sweden)

    Duncan Mitch J

    2013-02-01

    Full Text Available Abstract Background Spatial configurations of office environments assessed by Space Syntax methodologies are related to employee movement patterns. These methods require analysis of floors plans which are not readily available in large population-based studies or otherwise unavailable. Therefore a self-report instrument to assess spatial configurations of office environments using four scales was developed. Methods The scales are: local connectivity (16 items, overall connectivity (11 items, visibility of co-workers (10 items, and proximity of co-workers (5 items. A panel cohort (N = 1154 completed an online survey, only data from individuals employed in office-based occupations (n = 307 were used to assess scale measurement properties. To assess test-retest reliability a separate sample of 37 office-based workers completed the survey on two occasions 7.7 (±3.2 days apart. Redundant scale items were eliminated using factor analysis; Chronbach’s α was used to evaluate internal consistency and test re-test reliability (retest-ICC. ANOVA was employed to examine differences between office types (Private, Shared, Open as a measure of construct validity. Generalized Linear Models were used to examine relationships between spatial configuration scales and the duration of and frequency of breaks in occupational sitting. Results The number of items on all scales were reduced, Chronbach’s α and ICCs indicated good scale internal consistency and test re-test reliability: local connectivity (5 items; α = 0.70; retest-ICC = 0.84, overall connectivity (6 items; α = 0.86; retest-ICC = 0.87, visibility of co-workers (4 items; α = 0.78; retest-ICC = 0.86, and proximity of co-workers (3 items; α = 0.85; retest-ICC = 0.70. Significant (p ≤ 0.001 differences, in theoretically expected directions, were observed for all scales between office types, except overall connectivity. Significant associations were

  1. Reliability Engineering

    International Nuclear Information System (INIS)

    Lee, Sang Yong

    1992-07-01

    This book is about reliability engineering, which describes definition and importance of reliability, development of reliability engineering, failure rate and failure probability density function about types of it, CFR and index distribution, IFR and normal distribution and Weibull distribution, maintainability and movability, reliability test and reliability assumption in index distribution type, normal distribution type and Weibull distribution type, reliability sampling test, reliability of system, design of reliability and functionality failure analysis by FTA.

  2. Reliable categorisation of visual scoring of coronary artery calcification on low-dose CT for lung cancer screening: validation with the standard Agatston score

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yi-Luan; Wu, Fu-Zong; Wang, Yen-Chi [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); Ju, Yu-Jeng [National Taiwan University, Department of Psychology, Taipei (China); Mar, Guang-Yuan [Kaohsiung Veterans General Hospital, Division of Cardiology, Department of Medicine, Kaohsiung 813 (China); Chuo, Chiung-Chen [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); Lin, Huey-Shyan [Fooyin University, School of Nursing, Kaohsiung (China); Wu, Ming-Ting [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); National Yang Ming University, Institute of Clinical Medicine, Taipei (China)

    2013-05-15

    To validate the reliability of the visual coronary artery calcification score (VCACS) on low-dose CT (LDCT) for concurrent screening of CAC and lung cancer. We enrolled 401 subjects receiving LDCT for lung cancer screening and ECG-gated CT for the Agatston score (AS). LDCT was reconstructed with 3- and 5-mm slice thickness (LDCT-3mm and LDCT-5mm respectively) for VCACS to obtain VCACS-3mm and VCACS-5mm respectively. After a training session comprising 32 cases, two observers performed four-scale VCACS (absent, mild, moderate, severe) of 369 data sets independently, the results were compared with four-scale AS (0, 1-100, 101-400, >400). CACs were present in 39.6 % (146/369) of subjects. The sensitivity of VCACS-3mm was higher than for VCACS-5mm (83.6 % versus 74.0 %). The median of AS of the 24 false-negative cases in VCACS-3mm was 2.3 (range 1.1-21.1). The false-negative rate for detecting AS {>=} 10 on LDCT-3mm was 1.9 %. VCACS-3mm had higher concordance with AS than VCACS-5mm (k = 0.813 versus k = 0.685). An extended test of VCACS-3mm for four junior observers showed high inter-observer reliability (intra-class correlation = 0.90) and good concordance with AS (k = 0.662-0.747). This study validated the reliability of VCACS on LDCT for lung cancer screening and showed that LDCT-3mm was more feasible than LDCT-5mm for CAD risk stratification. (orig.)

  3. Reliability of the measures of weight-bearing distribution obtained during quiet stance by digital scales in subjects with and without hemiparesis.

    Science.gov (United States)

    de Araujo-Barbosa, Paulo Henrique Ferreira; de Menezes, Lidiane Teles; Costa, Abraão Souza; Couto Paz, Clarissa Cardoso Dos Santos; Fachin-Martins, Emerson

    2015-05-01

    Described as an alternative way of assessing weight-bearing asymmetries, the measures obtained from digital scales have been used as an index to classify weight-bearing distribution. This study aimed to describe the intra-test and the test/retest reliability of measures in subjects with and without hemiparesis during quiet stance. The percentage of body weight borne by one limb was calculated for a sample of subjects with hemiparesis and for a control group that was matched by gender and age. A two-way analysis of variance was used to verify the intra-test reliability. This analysis was calculated using the differences between the averages of the measures obtained during single, double or triple trials. The intra-class correlation coefficient (ICC) was utilized and data plotted using the Bland-Altman method. The intra-test analysis showed significant differences, only observed in the hemiparesis group, between the measures obtained by single and triple trials. Excellent and moderate ICC values (0.69-0.84) between test and retest were observed in the hemiparesis group, while for control groups ICC values (0.41-0.74) were classified as moderate, progressing from almost poor for measures obtained by a single trial to almost excellent for those obtained by triple trials. In conclusion, good reliability ranging from moderate to excellent classifications was found for participants with and without hemiparesis. Moreover, an improvement of the repeatability was observed with fewer trials for participants with hemiparesis, and with more trials for participants without hemiparesis.

  4. Reliability and validity of pressure and temporal parameters recorded using a pressure-sensitive insole during running.

    Science.gov (United States)

    Mann, Robert; Malisoux, Laurent; Brunner, Roman; Gette, Paul; Urhausen, Axel; Statham, Andrew; Meijer, Kenneth; Theisen, Daniel

    2014-01-01

    Running biomechanics has received increasing interest in recent literature on running-related injuries, calling for new, portable methods for large-scale measurements. Our aims were to define running strike pattern based on output of a new pressure-sensitive measurement device, the Runalyser, and to test its validity regarding temporal parameters describing running gait. Furthermore, reliability of the Runalyser measurements was evaluated, as well as its ability to discriminate different running styles. Thirty-one healthy participants (30.3 ± 7.4 years, 1.78 ± 0.10 m and 74.1 ± 12.1 kg) were involved in the different study parts. Eleven participants were instructed to use a rearfoot (RFS), midfoot (MFS) and forefoot (FFS) strike pattern while running on a treadmill. Strike pattern was subsequently defined using a linear regression (R(2)=0.89) between foot strike angle, as determined by motion analysis (1000 Hz), and strike index (SI, point of contact on the foot sole, as a percentage of foot sole length), as measured by the Runalyser. MFS was defined by the 95% confidence interval of the intercept (SI=43.9-49.1%). High agreement (overall mean difference 1.2%) was found between stance time, flight time, stride time and duty factor as determined by the Runalyser and a force-measuring treadmill (n=16 participants). Measurements of the two devices were highly correlated (R ≥ 0.80) and not significantly different. Test-retest intra-class correlation coefficients for all parameters were ≥ 0.94 (n=14 participants). Significant differences (p<0.05) between FFS, RFS and habitual running were detected regarding SI, stance time and stride time (n=24 participants). The Runalyser is suitable for, and easily applicable in large-scale studies on running biomechanics. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Reliability and Validity of the Beijing Version of the Montreal Cognitive Assessment in the Evaluation of Cognitive Function of Adult Patients with OSAHS.

    Directory of Open Access Journals (Sweden)

    Xiong Chen

    Full Text Available The patients with obstructive sleep apnea hypopnea syndrome (OSAHS tend to develop cognitive deficits, which usually go unrecognized, and can affect their daily life. The Beijing version of the Montreal cognitive assessment (MoCA-BJ, a Chinese version of MoCA, has been used for the assessment of cognitive functions of OSAHS patients in clinical practice. So far, its reliability and validity have not been tested. This study examined the reliability and validity of MoCA-BJ in a cohort of adult OSAHS patients.152 OSAHS patients, ranging from mild, moderate to severe, 49 primary snoring subjects and 40 normal controls were evaluated for cognitive functions by employing both MoCA-BJ and the Mini Mental State Examination (MMSE. Forty of them were re-tested by MoCA-BJ 14 days after the first test. Internal consistency, test-retest reliability, discriminate and concurrent validity of MoCA-BJ were analyzed.Internal consistency reliability by Cronbach's alpha was adequate (0.73. Intra-class correlation coefficient (ICC, an measure of test-retest reliability, was 0.87 (P<0.001. The total MoCA-BJ scores were significant higher in normal controls than in OSAHS groups (p<0.05. The performances of visuospatial ability in severe OSAHS group were significantly weaker than in normal controls and primary snoring group. The performances of executive ability in severe OSAHS patients were weaker than in normal controls. An optimal cut-off between normal controls and non-normal subjects was at 26 points (total MoCA score. Moreover, cut-off between non-severe and severe OSAHS was at 2 points on visuospatial subscale. Analysis of the correlation between MoCA total scores and MMSE total scores revealed a statistically significant, though relatively weak, correlation (r=0.41, P<0.05.In conclusion, our study showed that the Beijing version of the MoCA was reliable and stable. The MoCA-BJ was capable of detecting cognitive dysfunction by visuospatial and total MoCA-BJ score.

  6. Quantitative and Qualitative Responses to Topical Cold in Healthy Caucasians Show Variance between Individuals but High Test-Retest Reliability.

    Directory of Open Access Journals (Sweden)

    Penny Moss

    Full Text Available Increased sensitivity to cold may be a predictor of persistent pain, but cold pain threshold is often viewed as unreliable. This study aimed to determine the within-subject reliability and between-subject variance of cold response, measured comprehensively as cold pain threshold plus pain intensity and sensation quality at threshold. A test-retest design was used over three sessions, one day apart. Response to cold was assessed at four sites (thenar eminence, volar forearm, tibialis anterior, plantar foot. Cold pain threshold was measured using a Medoc thermode and standard method of limits. Intensity of pain at threshold was rated using a 10cm visual analogue scale. Quality of sensation at threshold was quantified with indices calculated from subjects' selection of descriptors from a standard McGill Pain Questionnaire. Within-subject reliability for each measure was calculated with intra-class correlation coefficients and between-subject variance was evaluated as group coefficient of variation percentage (CV%. Gender and site comparisons were also made. Forty-five healthy adults participated: 20 male, 25 female; mean age 29 (range 18-56 years. All measures at all four test sites showed high within-subject reliability: cold pain thresholds r = 0.92-0.95; pain rating r = 0.93-0.97; McGill pain quality indices r = 0.87-0.85. In contrast, all measures showed wide between-subject variance (CV% between 51.4% and 92.5%. Upper limb sites were consistently more sensitive than lower limb sites, but equally reliable. Females showed elevated cold pain thresholds, although similar pain intensity and quality to males. Females were also more reliable and showed lower variance for all measures. Thus, although there was clear population variation, response to cold for healthy individuals was found to be highly reliable, whether measured as pain threshold, pain intensity or sensation quality. A comprehensive approach to cold response testing therefore may add

  7. Quantitative and Qualitative Responses to Topical Cold in Healthy Caucasians Show Variance between Individuals but High Test-Retest Reliability.

    Science.gov (United States)

    Moss, Penny; Whitnell, Jasmine; Wright, Anthony

    2016-01-01

    Increased sensitivity to cold may be a predictor of persistent pain, but cold pain threshold is often viewed as unreliable. This study aimed to determine the within-subject reliability and between-subject variance of cold response, measured comprehensively as cold pain threshold plus pain intensity and sensation quality at threshold. A test-retest design was used over three sessions, one day apart. Response to cold was assessed at four sites (thenar eminence, volar forearm, tibialis anterior, plantar foot). Cold pain threshold was measured using a Medoc thermode and standard method of limits. Intensity of pain at threshold was rated using a 10cm visual analogue scale. Quality of sensation at threshold was quantified with indices calculated from subjects' selection of descriptors from a standard McGill Pain Questionnaire. Within-subject reliability for each measure was calculated with intra-class correlation coefficients and between-subject variance was evaluated as group coefficient of variation percentage (CV%). Gender and site comparisons were also made. Forty-five healthy adults participated: 20 male, 25 female; mean age 29 (range 18-56) years. All measures at all four test sites showed high within-subject reliability: cold pain thresholds r = 0.92-0.95; pain rating r = 0.93-0.97; McGill pain quality indices r = 0.87-0.85. In contrast, all measures showed wide between-subject variance (CV% between 51.4% and 92.5%). Upper limb sites were consistently more sensitive than lower limb sites, but equally reliable. Females showed elevated cold pain thresholds, although similar pain intensity and quality to males. Females were also more reliable and showed lower variance for all measures. Thus, although there was clear population variation, response to cold for healthy individuals was found to be highly reliable, whether measured as pain threshold, pain intensity or sensation quality. A comprehensive approach to cold response testing therefore may add validity and

  8. Quantitative gait analysis under dual-task in older people with mild cognitive impairment: a reliability study

    Directory of Open Access Journals (Sweden)

    Gutmanis Iris

    2009-09-01

    Full Text Available Abstract Background Reliability of quantitative gait assessment while dual-tasking (walking while doing a secondary task such as talking in people with cognitive impairment is unknown. Dual-tasking gait assessment is becoming highly important for mobility research with older adults since better reflects their performance in the basic activities of daily living. Our purpose was to establish the test-retest reliability of assessing quantitative gait variables using an electronic walkway in older adults with mild cognitive impairment (MCI under single and dual-task conditions. Methods The gait performance of 11 elderly individuals with MCI was evaluated using an electronic walkway (GAITRite® System in two sessions, one week apart. Six gait parameters (gait velocity, step length, stride length, step time, stride time, and double support time were assessed under two conditions: single-task (sG: usual walking and dual-task (dG: counting backwards from 100 while walking. Test-retest reliability was determined using intra-class correlation coefficient (ICC. Gait variability was measured using coefficient of variation (CoV. Results Eleven participants (average age = 76.6 years, SD = 7.3 were assessed. They were high functioning (Clinical Dementia Rating Score = 0.5 with a mean Mini-Mental Status Exam (MMSE score of 28 (SD = 1.56, and a mean Montreal Cognitive Assessment (MoCA score of 22.8 (SD = 1.23. Under dual-task conditions, mean gait velocity (GV decreased significantly (sGV = 119.11 ± 20.20 cm/s; dGV = 110.88 ± 19.76 cm/s; p = 0.005. Additionally, under dual-task conditions, higher gait variability was found on stride time, step time, and double support time. Test-retest reliability was high (ICC>0.85 for the six parameters evaluated under both conditions. Conclusion In older people with MCI, variability of time-related gait parameters increased with dual-tasking suggesting cognitive control of gait performance. Assessment of quantitative gait

  9. Validity and Reliability of 10-Hz Global Positioning System to Assess In-line Movement and Change of Direction.

    Science.gov (United States)

    Nikolaidis, Pantelis T; Clemente, Filipe M; van der Linden, Cornelis M I; Rosemann, Thomas; Knechtle, Beat

    2018-01-01

    The objectives of the present study were to examine the validity and reliability of the 10 Hz Johan GPS unit in assessing in-line movement and change of direction. The validity was tested against the criterion measure of 200 m track-and-field (track-and-field athletes, n = 8) and 20 m shuttle run endurance test (female soccer players, n = 20). Intra-unit and inter-unit reliability was tested by intra-class correlation coefficient (ICC) and coefficient of variation (CV), respectively. An analysis of variance examined differences between the GPS measurement and five laps of 200 m at 15 km/h, and t -test examined differences between the GPS measurement and 20 m shuttle run endurance test. The difference between the GPS measurement and 200 m distance ranged from -0.13 ± 3.94 m (95% CI -3.42; 3.17) in the first lap to 2.13 ± 2.64 m (95% CI -0.08; 4.33) in the fifth lap. A good intra-unit reliability was observed in 200 m (ICC = 0.833, 95% CI 0.535; 0.962). Inter-unit CV ranged from 1.31% (fifth lap) to 2.20% (third lap). The difference between the GPS measurement and 20 m shuttle run endurance test ranged from 0.33 ± 4.16 m (95% CI -10.01; 10.68) in 11.5 km/h to 9.00 ± 5.30 m (95% CI 6.44; 11.56) in 8.0 km/h. A moderate intra-unit reliability was shown in the second and third stage of the 20 m shuttle run endurance test (ICC = 0.718, 95% CI 0.222;0.898) and good reliability in the fifth, sixth, seventh and eighth (ICC = 0.831, 95% CI -0.229;0.996). Inter-unit CV ranged from 2.08% (11.5 km/h) to 3.92% (8.5 km/h). Based on these findings, it was concluded that the 10 Hz Johan system offers an affordable valid and reliable tool for coaches and fitness trainers to monitor training and performance.

  10. Validity and Reliability of 10-Hz Global Positioning System to Assess In-line Movement and Change of Direction

    Directory of Open Access Journals (Sweden)

    Pantelis T. Nikolaidis

    2018-03-01

    Full Text Available The objectives of the present study were to examine the validity and reliability of the 10 Hz Johan GPS unit in assessing in-line movement and change of direction. The validity was tested against the criterion measure of 200 m track-and-field (track-and-field athletes, n = 8 and 20 m shuttle run endurance test (female soccer players, n = 20. Intra-unit and inter-unit reliability was tested by intra-class correlation coefficient (ICC and coefficient of variation (CV, respectively. An analysis of variance examined differences between the GPS measurement and five laps of 200 m at 15 km/h, and t-test examined differences between the GPS measurement and 20 m shuttle run endurance test. The difference between the GPS measurement and 200 m distance ranged from −0.13 ± 3.94 m (95% CI −3.42; 3.17 in the first lap to 2.13 ± 2.64 m (95% CI −0.08; 4.33 in the fifth lap. A good intra-unit reliability was observed in 200 m (ICC = 0.833, 95% CI 0.535; 0.962. Inter-unit CV ranged from 1.31% (fifth lap to 2.20% (third lap. The difference between the GPS measurement and 20 m shuttle run endurance test ranged from 0.33 ± 4.16 m (95% CI −10.01; 10.68 in 11.5 km/h to 9.00 ± 5.30 m (95% CI 6.44; 11.56 in 8.0 km/h. A moderate intra-unit reliability was shown in the second and third stage of the 20 m shuttle run endurance test (ICC = 0.718, 95% CI 0.222;0.898 and good reliability in the fifth, sixth, seventh and eighth (ICC = 0.831, 95% CI −0.229;0.996. Inter-unit CV ranged from 2.08% (11.5 km/h to 3.92% (8.5 km/h. Based on these findings, it was concluded that the 10 Hz Johan system offers an affordable valid and reliable tool for coaches and fitness trainers to monitor training and performance.

  11. Reliability and validity of a questionnaire to measure personal, social and environmental correlates of fruit and vegetable intake in 10-11-year-old children in five European countries

    DEFF Research Database (Denmark)

    De Bourdeaudhuij, I; Klepp, K-I; Due, P

    2005-01-01

    To investigate the internal consistency of the scales and the test-retest reliability and predictive validity of behaviour theory-based constructs measuring personal, social and environmental correlates of fruit and vegetable intake in 10-11-year-old children.......To investigate the internal consistency of the scales and the test-retest reliability and predictive validity of behaviour theory-based constructs measuring personal, social and environmental correlates of fruit and vegetable intake in 10-11-year-old children....

  12. Validity and reliability of a brief self-reported questionnaire assessing fruit and vegetable consumption among pregnant women

    Directory of Open Access Journals (Sweden)

    Lydi-Anne Vézina-Im

    2016-09-01

    Full Text Available Abstract Background Short instruments measuring frequency of specific foods, such as fruit and vegetable (FV, are increasingly used in interventions. The objective of the study was to verify the validity and test-retest reliability of such an instrument among pregnant women. Methods Pregnant women from the region of Quebec City, Quebec, Canada, were recruited through e-mails sent to female students and employees of the local university from October 2014 to April 2015. To assess the validity of the fruit and vegetable questionnaire (FVQ developed by Godin et al. (Can J Public Health 99: 494-498, 2008, pregnant women were asked in a first mailing to complete the FVQ assessing FV intake over the past 7 days and a 3-day estimated food record. A subsample (n = 33 also gave a fasting blood sample and completed a validated semi-quantitative FFQ administered by a trained registered dietitian during a visit at the research center. FV intakes for all instruments were calculated in terms of servings of FV based on Canada’s Food Guide definition of a serving of fruit or vegetable. In order to assess its test-retest reliability, respondents were asked to complete the FVQ 14 days later in a second mailing. Results Forty-eight pregnant women from all three trimesters completed the questionnaires in the first mailing. FV intake assessed using the FVQ was correlated to FV consumption measured using the food record (r = 0.34, p = 0.0180 and the FFQ (r = 0.61, p = 0.0002. Results were similar when controlling for energy intake and the experience of nausea in the past month. Only β-cryptoxanthin was significantly correlated to FV intake assessed by the FFQ when adjusted for the presence of nausea (r = 0.35, p = 0.0471. Data on the test-retest reliability was available for 44 women and the intra-class coefficient for the FVQ was 0.72 at a mean 28-day interval. Conclusions The FVQ has acceptable validity and test-retest reliability

  13. Validity and reliability of a brief self-reported questionnaire assessing fruit and vegetable consumption among pregnant women.

    Science.gov (United States)

    Vézina-Im, Lydi-Anne; Godin, Gaston; Couillard, Charles; Perron, Julie; Lemieux, Simone; Robitaille, Julie

    2016-09-15

    Short instruments measuring frequency of specific foods, such as fruit and vegetable (FV), are increasingly used in interventions. The objective of the study was to verify the validity and test-retest reliability of such an instrument among pregnant women. Pregnant women from the region of Quebec City, Quebec, Canada, were recruited through e-mails sent to female students and employees of the local university from October 2014 to April 2015. To assess the validity of the fruit and vegetable questionnaire (FVQ) developed by Godin et al. (Can J Public Health 99: 494-498, 2008), pregnant women were asked in a first mailing to complete the FVQ assessing FV intake over the past 7 days and a 3-day estimated food record. A subsample (n = 33) also gave a fasting blood sample and completed a validated semi-quantitative FFQ administered by a trained registered dietitian during a visit at the research center. FV intakes for all instruments were calculated in terms of servings of FV based on Canada's Food Guide definition of a serving of fruit or vegetable. In order to assess its test-retest reliability, respondents were asked to complete the FVQ 14 days later in a second mailing. Forty-eight pregnant women from all three trimesters completed the questionnaires in the first mailing. FV intake assessed using the FVQ was correlated to FV consumption measured using the food record (r = 0.34, p = 0.0180) and the FFQ (r = 0.61, p = 0.0002). Results were similar when controlling for energy intake and the experience of nausea in the past month. Only β-cryptoxanthin was significantly correlated to FV intake assessed by the FFQ when adjusted for the presence of nausea (r = 0.35, p = 0.0471). Data on the test-retest reliability was available for 44 women and the intra-class coefficient for the FVQ was 0.72 at a mean 28-day interval. The FVQ has acceptable validity and test-retest reliability values, but seems to underestimate FV servings in pregnant women

  14. Cross-cultural adaptation, reliability and validity of the Arabic version of the reduced Western Ontario and McMaster Universities Osteoarthritis index in patients with knee osteoarthritis.

    Science.gov (United States)

    Alghadir, Ahmad; Anwer, Shahnawaz; Iqbal, Zaheen Ahmed; Alsanawi, Hisham Abdulaziz

    2016-01-01

    We adapted the reduced Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index for the Arabic language and tested its metric properties in patients with knee osteoarthritis (OA). One hundred and twenty-one consecutive patients who were referred for physiotherapy to the outpatient department were asked to answer the Arabic version of the reduced WOMAC index (ArWOMAC). After the completion of the ArWOMAC, the intensity of knee pain and general health status were assessed using the visual analog scale (VAS) and the 12-item short form health survey (SF-12), respectively. A second assessment was performed at least 48 h after the first session to assess test-retest reliability. The test-retest reliability was quantified using the intra-class correlation coefficient (ICC), and Cronbach's alpha was calculated to assess the internal consistency of the Arabic questionnaire. The construct validity was assessed using Spearman rank correlation coefficients. The total ArWOMAC scale and pain and function subscales were internally consistent with Cronbach's coefficient alpha of 0.91, 0.89 and 0.90, respectively. Test-retest reliability was good to excellent with ICC of 0.91, 0.89 and 0.90, respectively. SF-12 and VAS score significantly correlated with ArWOMAC index (p < 0.01), which support the construct validity. The standard error of measurement (SEM) of the total scale was 2.94, based on repeated measurements for test-retest. The minimum detectable change based on the SEM for test-retest was 8.15. The ArWOMAC index is a reliable and valid instrument for evaluating the severity of knee OA, with metric properties in agreement with the original version. Although, the reduced WOMAC index has been clinically utilized within the Saudi population, the Arabic version of this instrument is not validated for an Arab population to measure lower limb functional disability caused by OA. The Arabic version of reduced WOMAC (ArWOMAC) index is a reliable and valid scale

  15. Impact of Alzheimer's Disease on Caregiver Questionnaire: internal consistency, convergent validity, and test-retest reliability of a new measure for assessing caregiver burden.

    Science.gov (United States)

    Cole, Jason C; Ito, Diane; Chen, Yaozhu J; Cheng, Rebecca; Bolognese, Jennifer; Li-McLeod, Josephine

    2014-09-04

    There is a lack of validated instruments to measure the level of burden of Alzheimer's disease (AD) on caregivers. The Impact of Alzheimer's Disease on Caregiver Questionnaire (IADCQ) is a 12-item instrument with a seven-day recall period that measures AD caregiver's burden across emotional, physical, social, financial, sleep, and time aspects. Primary objectives of this study were to evaluate psychometric properties of IADCQ administered on the Web and to determine most appropriate scoring algorithm. A national sample of 200 unpaid AD caregivers participated in this study by completing the Web-based version of IADCQ and Short Form-12 Health Survey Version 2 (SF-12v2™). The SF-12v2 was used to measure convergent validity of IADCQ scores and to provide an understanding of the overall health-related quality of life of sampled AD caregivers. The IADCQ survey was also completed four weeks later by a randomly selected subgroup of 50 participants to assess test-retest reliability. Confirmatory factor analysis (CFA) was implemented to test the dimensionality of the IADCQ items. Classical item-level and scale-level psychometric analyses were conducted to estimate psychometric characteristics of the instrument. Test-retest reliability was performed to evaluate the instrument's stability and consistency over time. Virtually none (2%) of the respondents had either floor or ceiling effects, indicating the IADCQ covers an ideal range of burden. A single-factor model obtained appropriate goodness of fit and provided evidence that a simple sum score of the 12 items of IADCQ can be used to measure AD caregiver's burden. Scales-level reliability was supported with a coefficient alpha of 0.93 and an intra-class correlation coefficient (for test-retest reliability) of 0.68 (95% CI: 0.50-0.80). Low-moderate negative correlations were observed between the IADCQ and scales of the SF-12v2. The study findings suggest the IADCQ has appropriate psychometric characteristics as a

  16. Reliability of the imaging software in the preoperative planning of the open-wedge high tibial osteotomy.

    Science.gov (United States)

    Lee, Yong Seuk; Kim, Min Kyu; Byun, Hae Won; Kim, Sang Bum; Kim, Jin Goo

    2015-03-01

    The purpose of this study was to verify a recently developed picture-archiving and communications system-photoshop method by comparing reliabilities between real-size paper template and the PACS-photoshop methods in preoperative planning of open-wedge high tibial osteotomy. A prospective case series was conducted, including patients with medial osteoarthritis undergoing open-wedge high tibial osteotomy. In the preoperative planning, the picture-archiving and communications system-photoshop method and real-size paper template method were used simultaneously in all patients. Preoperative hip-knee-ankle angle, height, and angle of the osteotomy were evaluated. The reliability of this newly devised method was evaluated, and the consistency between the two methods was also evaluated using intra-class correlation coefficient. Using the picture-archiving and communications system-photoshop method, the mean correction angle and height of osteotomy gap of rater-1 were 11.7° ± 3.6° and 10.7 ± 3.6 mm, respectively. The mean correction angle and height of osteotomy gap of rater-2 were 12.0 ± 2.6 and 10.8 ± 3.6, respectively. The inter- and intra-rater reliabilities of the correction angle were 0.956 ~ 0.979 and 0.980 ~ 0.992, respectively. The inter- and intra-rater reliabilities of the height of the osteotomy gap were 0.968 ~ 0.985 and 0.971 ~ 0.994, respectively (p photoshop method, mean values of the correction angle and height of the osteotomy gap were 11.9° ± 3.6° and 10.8 ± 3.6 mm, respectively. Consistency between the two methods by comparing the means of the correction angle and the height of the osteotomy gap were 0.985 and 0.985, respectively (p photoshop method enables direct measurement of the height of the osteotomy gap with high reliability.

  17. Reliability of a New Radiographic Classification for Developmental Dysplasia of the Hip.

    Science.gov (United States)

    Narayanan, Unni; Mulpuri, Kishore; Sankar, Wudbhav N; Clarke, Nicholas M P; Hosalkar, Harish; Price, Charles T

    2015-01-01

    Existing radiographic classification schemes (eg, Tönnis criteria) for DDH quantify the severity of disease based on the position of the ossific nucleus relative to Hilgenreiner's and Perkin's lines. By definition, this method requires the presence of an ossification centre, which can be delayed in appearance and eccentric in location within the femoral head. A new radiographic classification system has been developed by the International Hip Dysplasia Institute (IHDI), which uses the mid-point of the proximal femoral metaphysis as a reference landmark, and can therefore be applied to children of all ages. The purpose of this study was to compare the reliability of this new method with that of Tönnis, as the first step in establishing its validity and clinical utility. Twenty standardized anteroposterior pelvic radiographs of children with untreated DDH were selected purposefully to capture the spectrum of age (range, 3 to 32 mo) at presentation and disease severity. Each of the hips was classified separately by the IHDI and Tönnis methods by 6 experienced pediatric orthopaedists from the United States, Canada, Mexico, United Kingdom, and by 2 orthopaedic senior residents. The inter-rater reliability was tested using the Intra Class Correlation coefficient (ICC) to measure concordance between raters. All 40 hips were classifiable by the IHDI method by all raters. Ten of the 40 hips could not be classified by the Tönnis method because of the absence of the ossific nucleus on one or both sides. The ICC (95% confidence interval) for the IHDI method for all raters was 0.90 (0.83-0.95) and 0.95 (0.91-0.98) for the right and left hips, respectively. The corresponding ICCs for the Tönnis method were 0.63 (0.46-0.80) and 0.60 (0.43-0.78), respectively. There was no significant difference between the ICCs of the 6 experts and 2 trainees. The IHDI method of classification has excellent inter-rater reliability, both among experts and novices, and is more widely

  18. Feeding practice among 6-36 months old in Tanzania and Uganda: reliability and relationship with early childhood caries, ECC.

    Science.gov (United States)

    Masumo, Ray; Bardsen, Asgeir; Mashoto, Kijakazi; Åstrøm, Anne Nordrehaug

    2013-09-01

    To assess the reproducibility of caregivers' responses to dietary recall from birth and 24-h dietary recall with respect to infants' intake of sugared snacks and to assess whether those assessment methods provide comparable results for groups of infants. Re-test reliability and clinical covariates of time to first exposure of sugared snacks and time to termination of breastfeeding were also examined. It was hypothesized that time to first exposure/termination would vary according to socio-demographic profile and ECC. Interviews and clinical oral examinations were carried out in Kampala and Manyara, including 1221 and 816 child-caregiver pairs. Reproducibility was assessed using Cohen's kappa and Intra Class Correlation Coefficient, ICC. Adjusted Cox regression was used to model time to first exposure of sugared snacks and time to termination of breastfeeding. Cohen's kappa for intake of sugar items ranged from 0.40-1.0, with no differences observed between average intakes at test-re-test. Mean sugar score based on 24-h recall increased significantly by increasing quartiles of the sugar score based on recall from birth. Cox regression revealed that the odds ratio, OR, for early exposure to various sugared snacks and the ORs for early termination of breastfeeding were significantly smaller in infants with than without ECC. Fair-to-good reproducibility was established. Infant's sugar consumption emerge as early as 6 months of age. Survival of any breastfeeding and non-exposure to sugared snacks was most prolonged among infants with ECC. This has implications for interventions needed to improve feeding habits of infants and toddlers.

  19. Reliability of Ultrasound Diameter Measurements in Patients with a Small Asymptomatic Popliteal Artery Aneurysm: An Intra- and Inter-observer Agreement Study.

    Science.gov (United States)

    Zwiers, I; Hoogland, C M T; Mackaay, A J C

    2016-03-01

    In this study the intra- and inter-observer variability of ultrasound measurements of the diameter of the popliteal artery were tested in a group of patients under surveillance for a small (diameter 10-20 mm), asymptomatic popliteal artery aneurysm (PAA). From a group of patients under ultrasound surveillance for bilateral, asymptomatic PAAs, 13 consecutive patients agreed to participate in the study and provided informed consent. The maximum diameter of the popliteal arteries was assessed by a vascular technologist. The same assessment was repeated by a second vascular technologist, unaware of the results of the first measurement. After a week, this protocol was repeated. The intra- and inter-observer reliability of this measurement was calculated using intra-class correlation coefficients (ICCs) and Bland and Altman plots. Of the 10 patients with bilateral and three patients with unilateral PAA, 12 completed the 2 week protocol. A total of 86 measurements were analyzed. The mean diameter of the popliteal arteries was 13.5 ± 3.4 mm. The ICC for the intra-observer reliability of observer 1 was 0.96 (95% CI 0.92-0.99), p .47. The absolute magnitude of the systematic error of both observers was less than 0.135 mm (median 0.00). Ultrasound measurement of the maximum diameter of the popliteal artery is reproducible; hence, it is suitable for making a clinical treatment decision. Its use for surveillance of small, asymptomatic PAAs is justified. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  20. Validity and reliability of using photography for measuring knee range of motion: a methodological study

    Directory of Open Access Journals (Sweden)

    Adie Sam

    2011-04-01

    Full Text Available Abstract Background The clinimetric properties of knee goniometry are essential to appreciate in light of its extensive use in the orthopaedic and rehabilitative communities. Intra-observer reliability is thought to be satisfactory, but the validity and inter-rater reliability of knee goniometry often demonstrate unacceptable levels of variation. This study tests the validity and reliability of measuring knee range of motion using goniometry and photographic records. Methods Design: Methodology study assessing the validity and reliability of one method ('Marker Method' which uses a skin marker over the greater trochanter and another method ('Line of Femur Method' which requires estimation of the line of femur. Setting: Radiology and orthopaedic departments of two teaching hospitals. Participants: 31 volunteers (13 arthritic and 18 healthy subjects. Knee range of motion was measured radiographically and photographically using a goniometer. Three assessors were assessed for reliability and validity. Main outcomes: Agreement between methods and within raters was assessed using concordance correlation coefficient (CCCs. Agreement between raters was assessed using intra-class correlation coefficients (ICCs. 95% limits of agreement for the mean difference for all paired comparisons were computed. Results Validity (referenced to radiographs: Each method for all 3 raters yielded very high CCCs for flexion (0.975 to 0.988, and moderate to substantial CCCs for extension angles (0.478 to 0.678. The mean differences and 95% limits of agreement were narrower for flexion than they were for extension. Intra-rater reliability: For flexion and extension, very high CCCs were attained for all 3 raters for both methods with slightly greater CCCs seen for flexion (CCCs varied from 0.981 to 0.998. Inter-rater reliability: For both methods, very high ICCs (min to max: 0.891 to 0.995 were obtained for flexion and extension. Slightly higher coefficients were obtained

  1. Neighborhood walkability scale (news - brazilian version: validity and reliability

    Directory of Open Access Journals (Sweden)

    Leticia de Matos Malavasi

    2006-09-01

    Full Text Available The lack of adherence to practice physical activities urges several researchers to ind answers for this matter. Among these researches, it is investigated how or what motivates people to perform any type of physical activity. Besides that, the environmental conditions are an important reason to establish a healthier lifestyle among individuals. In Brazil, the amount of validated scales about environmental barriers for physical activity in communities is restricted. The validation and the cultural adaptation of these instruments are important not only to compare with studies from other countries, but mainly for planning public politics to improve the adherence to practice physical activities. Thus, the present research aimed to analyze the validity and reliability of the Brazilian version of the Neighborhood EnvironmentWalkability Scale (NEWS. The methodological procedures were structured in three stages. The first stage had the following procedures: translation of NEWS and back-translation by bilingual specialists. The second stage was the adaptation of NEWS to the Brazilian reality through a pilot study and with reliability. The third stage, together with a professional urban panel indicating which neighborhoods had better or worse mobility, it was accomplished a application of the NEWS questionnaire to assure construct validation. The sample of this research were separated in two parts, 75persons for the reliability; and for the validity of the questionnaire 200 residents from the four neighborhoods pointed by the specialists of the city of Florianópolis (SC. Through the NEWS the subjects answered questions about the neighborhoods regarding: type of residences, stores and trade proximity, perception of access to these places, streets characteristics, facilities to walk and ride bicycle, and safety related to traffic and crimes. The statistical analysis was made in the SPSS 11.0 version for the intra-class correlation and reliability for the

  2. Modified sphygmomanometer test for the assessment of strength of the trunk, upper and lower limbs muscles in subjects with subacute stroke: reliability and validity.

    Science.gov (United States)

    Aguiar, Larissa T; Lara, Eliza M; Martins, Julia C; Teixeira-Salmela, Luci F; Quintino, Ludmylla F; Christo, Paulo P; DE Morais Fairaa, Christina

    2016-10-01

    Limitations in activities have been related to weakness of the upper limbs (UL), lower limbs (LL) and trunk muscles after stroke. Therefore, the measurement of strength after stroke becomes essential. The Modified Sphygmomanometer Test (MST) is an alternative method for the measurement of strength, since it is cheap and provides objective values. However, no studies have investigated the measurement properties of the MST in sub-acute stroke. To investigate the test-retest and inter-rater reliabilities and criterion-related validity of the MST for the measurement of strength of the UL, LL, and trunk muscles in subjects with sub-acute stroke, and verify whether the number of trials would affect the results. Diagnostic accuracy. Local community, out-patient clinics, and university laboratory. Sixty- five subjects with sub-acute stroke (62±14 years) participated of the present study. The strength of 36 muscular groups was measured with the MST and dynamometers (criterion standard). To investigate whether the number of trials would affect the results, analysis of variance was applied. For the test-retest and inter-rater reliabilities and criterion-related validity of the MST, intra-class correlation coefficients (ICC), Pearson correlation coefficients, and coefficients of determination were calculated. Similar results were found for all muscular groups and number of trials (0.01≤F≤0.14; 0.87≤p≤0.99) with significant and adequate values of test-retest (0.57≤ICC≥0.98) (exception: first trial of the non-paretic ankle dorsiflexors) and inter-rater (0.50≤ICC≥0.99) (exception: non-paretic ankle plantar flexors) reliabilities and validity (0.70≤r≥0.95; p≤0.001). The values obtained with the MST were good predictors of those obtained with the dynamometers (0.54≤r2≤0.90). In general, the MST showed adequate reliabilities and criterion-related validity for measuring strength of subjects with sub-acute stroke, and only one trial, after familiarization

  3. Assessment of Technical Skills in Young Soccer Goalkeepers: Reliability and Validity of Two Goalkeeper-Specific Tests

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    Ricardo Rebelo-Gonçalves, António J. Figueiredo, Manuel J. Coelho-e-Silva, Antonio Tessitore

    2016-09-01

    Full Text Available The purpose of this study was to evaluate the reproducibility and validity of two new tests designed to examine goalkeeper-specific technique. Twenty-six goalkeepers (14.49 ± 2.52 years old completed two trial sessions, each separated by one week, to evaluate the reproducibility of the Sprint-Keeper Test (S-Keeper and the Lateral Shuffle-Keeper Test (LS-Keeper. Construct validity was assessed among forty goalkeepers (14.49 ± 1.71 years old by competitive level (elite versus non-elite, after controlling for chronological age. All participants were examined in vertical jump (CMJ and CMJ-free arms, acceleration (5-m and 10-m sprint and goalkeeper-specific technique. The S-Keeper requires the goalkeeper to accelerate during 3 m and dive over a stationary ball after performing a change of direction in a total distance of 10 m. The LS-Keeper involves three changes of direction and a diving save over a stationary ball, in a total distance of 12.55 m. Performance was respectively measured as total time for the right and left sides in each protocol. Bivariate correlations between repeated measures were high and significant (r = 0.835 – 0.912. Test-retest results for the S-Keeper and LS-Keeper showed good reliability (reliability coefficients > 0.88, intra-class correlation coefficient > 0.908 and coefficients of variation < 4.37%, even though participants tended to improve performance when diving to their right side (p < 0.05. Both tests were able to detect significant differences between elite and non-elite goalkeepers, particularly to the left side (p < 0.05. These findings suggest that the S-Keeper and LS-Keeper are reliable and valid tests for assessing goalkeeper-specific technique. Both protocols can be used as a practical tool to provide relevant information about the influence of several components of performance in the overall execution of a diving save, particularly movement patterns, take-off movements and possible asymmetries.

  4. Validity and reliability of the semi-quantitative self-report Home Food Availability Inventory Checklist (HFAI-C) in White and South Asian populations.

    Science.gov (United States)

    Bryant, Maria; LeCroy, Madison; Sahota, Pinki; Cai, Jianwen; Stevens, June

    2016-05-04

    Despite interest in the importance of the home food environment and its potential influence on children's diets and social norms, there remain few self-report checklist methods that have been validated against the gold standard of researcher-conducted inventories. This study aimed to assess the criterion validity and reliability of the 'Home Food Availability Inventory Checklist' (HFAI-C), a 39-item checklist including categories of fruit, vegetables, snacks and drinks. The HFAI-C was completed by 97 participants of White and Pakistani origin in the UK. Validity was determined by comparing participant-reported HFAI-C responses to data from researcher observations of home food availability using PABAK and weighted kappa statistics. The validity of measuring the amount of items (in addition to presence/absence) available was also determined. Test-retest reliability compared repeated administrations of the HFAI-C using intra-class correlation coefficients. Validity and reliability was fair to moderate overall. For validity, the average category-level PABAK ranged from 0.31 (95% CI: 0.25, 0.37) for vegetables to 0.44 (95% CI: 0.40, 0.49) for fruits. Assessment of the presence/absence of items demonstrated higher validity compared to quantity measurements. Reliability was increased when the HFAI-C was repeated close to the time of the first administration. For example, ICCs for reliability of the measurement of fruits were 0.52 (95%CI: 0.47, 0.56) if re-administered within 5 months, 0.58 (95% CI: 0.51, 0.64) within 30 days and 0.97 (95%CI: 0.94, 1.00) if re-administered on the same day. Overall, the HFAI-C demonstrated fair to moderate validity and reliability in a population of White and South Asian participants. This evaluation is consistent with previous work on other checklists in less diverse, more affluent populations. Our research supports the use of the HFAI-C as a useful, albeit imperfect, representation of researcher-conducted inventories. The feasibility of

  5. Validity and Reliability of the U.S. National Cancer Institute's Patient-Reported Outcomes Version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE)

    Science.gov (United States)

    Dueck, Amylou C.; Mendoza, Tito R.; Mitchell, Sandra A.; Reeve, Bryce B.; Castro, Kathleen M.; Rogak, Lauren J.; Atkinson, Thomas M.; Bennett, Antonia V.; Denicoff, Andrea M.; O'Mara, Ann M.; Li, Yuelin; Clauser, Steven B.; Bryant, Donna M.; Bearden, James D.; Gillis, Theresa A.; Harness, Jay K.; Siegel, Robert D.; Paul, Diane B.; Cleeland, Charles S.; Schrag, Deborah; Sloan, Jeff A.; Abernethy, Amy P.; Bruner, Deborah W.; Minasian, Lori M.; Basch, Ethan

    2016-01-01

    Importance Symptomatic adverse events (AEs) in cancer trials are currently reported by clinicians using the National Cancer Institute's (NCI) Common Terminology Criteria for Adverse Events (CTCAE). To integrate the patient perspective, the NCI developed a patient-reported outcomes version of the CTCAE (PRO-CTCAE) to capture symptomatic AEs directly from patients. Objective To assess the construct validity, test-retest reliability, and responsiveness of PRO-CTCAE items. Design Participants completed PRO-CTCAE items on tablet computers in clinic waiting rooms at two visits 1-6 weeks apart. A subset completed PRO-CTCAE items during an additional visit one business day after the first visit. Setting Nine U.S. cancer centers and community oncology practices. Participants 975 adult cancer patients undergoing outpatient chemotherapy and/or radiation enrolled between January 2011 and February 2012. Eligibility required participants to read English and be without clinically significant cognitive impairment. Main Outcome(s) and Measure(s) Primary comparators were clinician-reported Eastern Cooperative Oncology Group Performance Status (ECOG PS) and the European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire (QLQ-C30). Results 940/975 (96%) and 852/940 (91%) participants completed PRO-CTCAE items at each visit. 938/940 (99.8%) participants (53% female, median age 59, 32% high school education or less, 17% ECOG PS 2-4) reported having at least one symptom. All PRO-CTCAE items had at least one correlation in the expected direction with a QLQ-C30 scale (111/124 P<.05). Stronger correlations were seen between PRO-CTCAE items and conceptually-related QLQ-C30 domains. Scores for 94/124 PRO-CTCAE items were higher in the ECOG PS 2-4 versus 0-1 group (58/124 P<.05). Overall, 119/124 items met at least one construct validity criterion. Test-retest reliability was acceptable for 36/49 pre-specified items (median intra-class correlation coefficient

  6. Reliability evaluation of I-123 ADAM SPECT imaging using SPM software and AAL ROI methods

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    Yang, Bang-Hung [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Tsai, Sung-Yi [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (China); Department of Imaging Medical, St.Martin De Porres Hospital, Chia-Yi, Taiwan (China); Wang, Shyh-Jen [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Su, Tung-Ping; Chou, Yuan-Hwa [Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan (China); Chen, Chia-Chieh [Institute of Nuclear Energy Research, Longtan, Taiwan (China); Chen, Jyh-Cheng, E-mail: jcchen@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (China)

    2011-08-21

    The level of serotonin was regulated by serotonin transporter (SERT), which is a decisive protein in regulation of serotonin neurotransmission system. Many psychiatric disorders and therapies were also related to concentration of cerebral serotonin. I-123 ADAM was the novel radiopharmaceutical to image SERT in brain. The aim of this study was to measure reliability of SERT densities of healthy volunteers by automated anatomical labeling (AAL) method. Furthermore, we also used statistic parametric mapping (SPM) on a voxel by voxel analysis to find difference of cortex between test and retest of I-123 ADAM single photon emission computed tomography (SPECT) images. Twenty-one healthy volunteers were scanned twice with SPECT at 4 h after intravenous administration of 185 MBq of {sup 123}I-ADAM. The image matrix size was 128x128 and pixel size was 3.9 mm. All images were obtained through filtered back-projection (FBP) reconstruction algorithm. Region of interest (ROI) definition was performed based on the AAL brain template in PMOD version 2.95 software package. ROI demarcations were placed on midbrain, pons, striatum, and cerebellum. All images were spatially normalized to the SPECT MNI (Montreal Neurological Institute) templates supplied with SPM2. And each image was transformed into standard stereotactic space, which was matched to the Talairach and Tournoux atlas. Then differences across scans were statistically estimated on a voxel by voxel analysis using paired t-test (population main effect: 2 cond's, 1 scan/cond.), which was applied to compare concentration of SERT between the test and retest cerebral scans. The average of specific uptake ratio (SUR: target/cerebellum-1) of {sup 123}I-ADAM binding to SERT in midbrain was 1.78{+-}0.27, pons was 1.21{+-}0.53, and striatum was 0.79{+-}0.13. The cronbach's {alpha} of intra-class correlation coefficient (ICC) was 0.92. Besides, there was also no significant statistical finding in cerebral area using SPM2

  7. Inter-Observer and Intra-Observer Reliability of Clinical Assessments in Knee Osteoarthritis

    Science.gov (United States)

    Maricar, Nasimah; Callaghan, Michael J; Parkes, Matthew J; Felson, David T; O’Neill, Terence W

    2016-01-01

    Background Clinical examination of the knee is subject to measurement error. The aim of this analysis was to determine inter- and intra-observer reliability of commonly used clinical tests in patients with knee osteoarthritis(OA). Methods We studied subjects with symptomatic knee OA who were participants in an open-label clinical trial of intra-articular steroid therapy. Following standardisation of the clinical test procedures, two clinicians assessed 25 subjects independently at the same visit, and the same clinician assessed 88 subjects over an interval period of 2–10 weeks; in both cases prior to the steroid intervention. Clinical examination included assessment of bony enlargement, crepitus, quadriceps wasting, knee effusion, joint-line and anserine tenderness and knee range of movement(ROM). Intra-class correlation coefficients(ICC), estimated kappa(κ), weighted kappa(κω) and Bland and Altman plots were used to determine inter- and intra-observer levels of agreement. Results Using Landis and Koch criteria, inter-observer kappa scores were moderate for patellofemoral joint(κ=0.53) and anserine tenderness(κ=0.48); good for bony enlargement(κ=0.66), quadriceps wasting(κ=0.78), crepitus(κ=0.78), medial tibiofemoral joint tenderness(κ=0.76), and effusion assessed by ballottement(κ=0.73) and bulge sign(κω =0.78); and excellent for lateral tibiofemoral joint tenderness(κ=1.00), flexion(ICC=0.97) and extension(ICC=0.87) ROM. Intra-observer kappa scores were moderate for lateral tibiofemoral joint tenderness(κ=0.60), good for crepitus(κ=0.78), effusion assessed by ballottement test(κ=0.77), patellofemoral joint(κ=0.66), medial tibiofemoral joint(κ=0.64) and anserine(κ=0.73) tenderness and excellent for effusion assessed by bulge sign(κω =0.83), bony enlargement(κ=0.98), quadriceps wasting(κ=0.83), flexion(ICC=0.99) and extension(ICC=0.96) ROM. Conclusion Among individuals with symptomatic knee OA, the reliability of clinical examination of the

  8. Software reliability

    CERN Document Server

    Bendell, A

    1986-01-01

    Software Reliability reviews some fundamental issues of software reliability as well as the techniques, models, and metrics used to predict the reliability of software. Topics covered include fault avoidance, fault removal, and fault tolerance, along with statistical methods for the objective assessment of predictive accuracy. Development cost models and life-cycle cost models are also discussed. This book is divided into eight sections and begins with a chapter on adaptive modeling used to predict software reliability, followed by a discussion on failure rate in software reliability growth mo

  9. Reliability and relative validity of a child nutrition questionnaire to simultaneously assess dietary patterns associated with positive energy balance and food behaviours, attitudes, knowledge and environments associated with healthy eating

    Directory of Open Access Journals (Sweden)

    Magarey Anthea M

    2008-01-01

    Full Text Available Abstract Background Food behaviours, attitudes, environments and knowledge are relevant to professionals in childhood obesity prevention, as are dietary patterns which promote positive energy balance. There is a lack of valid and reliable tools to measure these parameters. The aim of this study was to determine the reliability and relative validity of a child nutrition questionnaire assessing all of these parameters, used in the evaluation of a community-based childhood obesity prevention project. Methods The development of the 14-item questionnaire was informed by the aims of the obesity prevention project. A sub-sample of children aged 10–12 years from primary schools involved in the intervention was recruited at the project's baseline data collection (Test 1. Questionnaires were readministered (Test 2 following which students completed a 7-day food diary designed to reflect the questionnaire. Twelve scores were derived to assess consumption of fruit, vegetables, water, noncore foods and sweetened beverages plus food knowledge, behaviours, attitudes and environments. Reliability was assessed using (a the intra class correlation coefficient (ICC and 95% confidence intervals to compare scores from Tests 1 and 2 (test-retest reliability and (b Cronbach's alpha (internal consistency. Validity was assessed with Spearman correlations, bias and limits of agreement between scores from Test 1 and the 7-day diaries. The Wilcoxon signed rank test checked for significant differences between mean scores. Results One hundred and forty one students consented to the study. Test 2 (n = 134 occurred between eight and 36 days after Test 1. For 10/12 scores ICCs ranged from 0.47–0.66 (p 0.05 for 10/12 (test-retest reliability and 3/7 (validity scores. Conclusion This child nutrition questionnaire is a valid and reliable tool to simultaneously assess dietary patterns associated with positive energy balance, and food behaviours, attitudes and environments in

  10. Short-term test-retest-reliability of conditioned pain modulation using the cold-heat-pain method in healthy subjects and its correlation to parameters of standardized quantitative sensory testing.

    Science.gov (United States)

    Gehling, Julia; Mainka, Tina; Vollert, Jan; Pogatzki-Zahn, Esther M; Maier, Christoph; Enax-Krumova, Elena K

    2016-08-05

    Conditioned Pain Modulation (CPM) is often used to assess human descending pain inhibition. Nine different studies on the test-retest-reliability of different CPM paradigms have been published, but none of them has investigated the commonly used heat-cold-pain method. The results vary widely and therefore, reliability measures cannot be extrapolated from one CPM paradigm to another. Aim of the present study was to analyse the test-retest-reliability of the common heat-cold-pain method and its correlation to pain thresholds. We tested the short-term test-retest-reliability within 40 ± 19.9 h using a cold-water immersion (10 °C, left hand) as conditioning stimulus (CS) and heat pain (43-49 °C, pain intensity 60 ± 5 on the 101-point numeric rating scale, right forearm) as test stimulus (TS) in 25 healthy right-handed subjects (12females, 31.6 ± 14.1 years). The TS was applied 30s before (TSbefore), during (TSduring) and after (TSafter) the 60s CS. The difference between the pain ratings for TSbefore and TSduring represents the early CPM-effect, between TSbefore and TSafter the late CPM-effect. Quantitative sensory testing (QST, DFNS protocol) was performed on both sessions before the CPM assessment. paired t-tests, Intraclass correlation coefficient (ICC), standard error of measurement (SEM), smallest real difference (SRD), Pearson's correlation, Bland-Altman analysis, significance level p Pain ratings during CPM correlated significantly (ICC: 0.411…0.962) between both days, though ratings for TSafter were lower on day 2 (p pain thresholds. The short-term test-retest-reliability of the early CPM-effect using the heat-cold-pain method in healthy subjects achieved satisfying results in terms of the ICC. The SRD of the early CPM effect showed that an individual change of > 20 NRS can be attributed to a real change rather than chance. The late CPM-effect was weaker and not reliable.

  11. Reliability and validity of a 20-s alternative to the wingate anaerobic test in team sport male athletes.

    Directory of Open Access Journals (Sweden)

    Ahmed Attia

    Full Text Available The intent of this study was to evaluate relative and absolute reliability of the 20-s anaerobic test (WAnT20 versus the WAnT30 and to verify how far the various indices of the 30-s Wingate anaerobic test (WAnT30 could be predicted from the WAnT20 data in male athletes. The participants were Exercise Science majors (age: 21.5±1.6 yrs, stature: 0.183±0.08 m, body mass: 81.2±10.9 kg who participated regularly in team sports. In Phase I, 41 participants performed duplicate WAnT20 and WAnT30 tests to assess reliability. In Phase II, 31 participants performed one trial each of the WAnT20 and WAnT30 to determine the ability of the WAnT20 to predict components of the WAnT30. In Phase III, 31 participants were used to cross-validate the prediction equations developed in Phase II. Respective intra-class correlation coefficients (ICC for peak power output (PPO (ICC = 0.98 and 0.95 and mean power output (MPO (ICC 0.98 and 0.90 did not differ significantly between WAnT20 and WAnT30. ICCs for minimal power output (POmin and fatigue index (FI were poor for both tests (range 0.53 to 0.76. Standard errors of the means (SEM for PPO and MPO were less than their smallest worthwhile changes (SWC in both tests; however, POmin and FI values were "marginal," with SEM values greater than their respective SWCs for both tests values. Stepwise regression analysis showed that MPO had the highest coefficient of predictability (R = 0.97, with POmin and FI considerable lower (R = 0.71 and 0.41 respectively. Cross-validation showed insignificant bias with limits of agreement of 0.99±1.04, 6.5±92.7 W, and 1.6±9.8% between measured and predicted MPO, POmin, and FI, respectively. WAnT20 offers a reliable and valid test of leg anaerobic power in male athletes and could replace the classic WAnT30.

  12. Human reliability

    International Nuclear Information System (INIS)

    Embrey, D.E.

    1987-01-01

    Concepts and techniques of human reliability have been developed and are used mostly in probabilistic risk assessment. For this, the major application of human reliability assessment has been to identify the human errors which have a significant effect on the overall safety of the system and to quantify the probability of their occurrence. Some of the major issues within human reliability studies are reviewed and it is shown how these are applied to the assessment of human failures in systems. This is done under the following headings; models of human performance used in human reliability assessment, the nature of human error, classification of errors in man-machine systems, practical aspects, human reliability modelling in complex situations, quantification and examination of human reliability, judgement based approaches, holistic techniques and decision analytic approaches. (UK)

  13. Reliability Calculations

    DEFF Research Database (Denmark)

    Petersen, Kurt Erling

    1986-01-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...

  14. Smallest detectable change and test-retest reliability of a self-reported outcome measure: Results of the Center for Epidemiologic Studies Depression Scale, General Self-Efficacy Scale, and 12-item General Health Questionnaire.

    Science.gov (United States)

    Ohno, Shotaro; Takahashi, Kana; Inoue, Aimi; Takada, Koki; Ishihara, Yoshiaki; Tanigawa, Masaru; Hirao, Kazuki

    2017-12-01

    This study aims to examine the smallest detectable change (SDC) and test-retest reliability of the Center for Epidemiologic Studies Depression Scale (CES-D), General Self-Efficacy Scale (GSES), and 12-item General Health Questionnaire (GHQ-12). We tested 154 young adults at baseline and 2 weeks later. We calculated the intra-class correlation coefficients (ICCs) for test-retest reliability with a two-way random effects model for agreement. We then calculated the standard error of measurement (SEM) for agreement using the ICC formula. The SEM for agreement was used to calculate SDC values at the individual level (SDC ind ) and group level (SDC group ). The study participants included 137 young adults. The ICCs for all self-reported outcome measurement scales exceeded 0.70. The SEM of CES-D was 3.64, leading to an SDC ind of 10.10 points and SDC group of 0.86 points. The SEM of GSES was 1.56, leading to an SDC ind of 4.33 points and SDC group of 0.37 points. The SEM of GHQ-12 with bimodal scoring was 1.47, leading to an SDC ind of 4.06 points and SDC group of 0.35 points. The SEM of GHQ-12 with Likert scoring was 2.44, leading to an SDC ind of 6.76 points and SDC group of 0.58 points. To confirm that the change was not a result of measurement error, a score of self-reported outcome measurement scales would need to change by an amount greater than these SDC values. This has important implications for clinicians and epidemiologists when assessing outcomes. © 2017 John Wiley & Sons, Ltd.

  15. Measurement Error, Reliability, and Minimum Detectable Change in the Mini-Mental State Examination, Montreal Cognitive Assessment, and Color Trails Test among Community Living Middle-Aged and Older Adults.

    Science.gov (United States)

    Feeney, Joanne; Savva, George M; O'Regan, Claire; King-Kallimanis, Bellinda; Cronin, Hilary; Kenny, Rose Anne

    2016-05-31

    Knowing the reliability of cognitive tests, particularly those commonly used in clinical practice, is important in order to interpret the clinical significance of a change in performance or a low score on a single test. To report the intra-class correlation (ICC), standard error of measurement (SEM) and minimum detectable change (MDC) for the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Color Trails Test (CTT) among community dwelling older adults. 130 participants aged 55 and older without severe cognitive impairment underwent two cognitive assessments between two and four months apart. Half the group changed rater between assessments and half changed time of day. Mean (standard deviation) MMSE was 28.1 (2.1) at baseline and 28.4 (2.1) at repeat. Mean (SD) MoCA increased from 24.8 (3.6) to 25.2 (3.6). There was a rater effect on CTT, but not on the MMSE or MoCA. The SEM of the MMSE was 1.0, leading to an MDC (based on a 95% confidence interval) of 3 points. The SEM of the MoCA was 1.5, implying an MDC95 of 4 points. MoCA (ICC = 0.81) was more reliable than MMSE (ICC = 0.75), but all tests examined showed substantial within-patient variation. An individual's score would have to change by greater than or equal to 3 points on the MMSE and 4 points on the MoCA for the rater to be confident that the change was not due to measurement error. This has important implications for epidemiologists and clinicians in dementia screening and diagnosis.

  16. Structural systems reliability analysis

    International Nuclear Information System (INIS)

    Frangopol, D.

    1975-01-01

    For an exact evaluation of the reliability of a structure it appears necessary to determine the distribution densities of the loads and resistances and to calculate the correlation coefficients between loads and between resistances. These statistical characteristics can be obtained only on the basis of a long activity period. In case that such studies are missing the statistical properties formulated here give upper and lower bounds of the reliability. (orig./HP) [de

  17. Test-retest reliability of prefrontal transcranial Direct Current Stimulation (tDCS) effects on functional MRI connectivity in healthy subjects.

    Science.gov (United States)

    Wörsching, Jana; Padberg, Frank; Helbich, Konstantin; Hasan, Alkomiet; Koch, Lena; Goerigk, Stephan; Stoecklein, Sophia; Ertl-Wagner, Birgit; Keeser, Daniel

    2017-07-15

    Transcranial Direct Current Stimulation (tDCS) of the prefrontal cortex (PFC) can be used for probing functional brain connectivity and meets general interest as novel therapeutic intervention in psychiatric and neurological disorders. Along with a more extensive use, it is important to understand the interplay between neural systems and stimulation protocols requiring basic methodological work. Here, we examined the test-retest (TRT) characteristics of tDCS-induced modulations in resting-state functional-connectivity MRI (RS fcMRI). Twenty healthy subjects received 20minutes of either active or sham tDCS of the dorsolateral PFC (2mA, anode over F3 and cathode over F4, international 10-20 system), preceded and ensued by a RS fcMRI (10minutes each). All subject underwent three tDCS sessions with one-week intervals in between. Effects of tDCS on RS fcMRI were determined at an individual as well as at a group level using both ROI-based and independent-component analyses (ICA). To evaluate the TRT reliability of individual active-tDCS and sham effects on RS fcMRI, voxel-wise intra-class correlation coefficients (ICC) of post-tDCS maps between testing sessions were calculated. For both approaches, results revealed low reliability of RS fcMRI after active tDCS (ICC (2,1) = -0.09 - 0.16). Reliability of RS fcMRI (baselines only) was low to moderate for ROI-derived (ICC (2,1) = 0.13 - 0.50) and low for ICA-derived connectivity (ICC (2,1) = 0.19 - 0.34). Thus, for ROI-based analyses, the distribution of voxel-wise ICC was shifted to lower TRT reliability after active, but not after sham tDCS, for which the distribution was similar to baseline. The intra-individual variation observed here resembles variability of tDCS effects in motor regions and may be one reason why in this study robust tDCS effects at a group level were missing. The data can be used for appropriately designing large scale studies investigating methodological issues such as sources of variability and

  18. Can simple mobile phone applications provide reliable counts of respiratory rates in sick infants and children? An initial evaluation of three new applications.

    Science.gov (United States)

    Black, James; Gerdtz, Marie; Nicholson, Pat; Crellin, Dianne; Browning, Laura; Simpson, Julie; Bell, Lauren; Santamaria, Nick

    2015-05-01

    Respiratory rate is an important sign that is commonly either not recorded or recorded incorrectly. Mobile phone ownership is increasing even in resource-poor settings. Phone applications may improve the accuracy and ease of counting of respiratory rates. The study assessed the reliability and initial users' impressions of four mobile phone respiratory timer approaches, compared to a 60-second count by the same participants. Three mobile applications (applying four different counting approaches plus a standard 60-second count) were created using the Java Mobile Edition and tested on Nokia C1-01 phones. Apart from the 60-second timer application, the others included a counter based on the time for ten breaths, and three based on the time interval between breaths ('Once-per-Breath', in which the user presses for each breath and the application calculates the rate after 10 or 20 breaths, or after 60s). Nursing and physiotherapy students used the applications to count respiratory rates in a set of brief video recordings of children with different respiratory illnesses. Limits of agreement (compared to the same participant's standard 60-second count), intra-class correlation coefficients and standard errors of measurement were calculated to compare the reliability of the four approaches, and a usability questionnaire was completed by the participants. There was considerable variation in the counts, with large components of the variation related to the participants and the videos, as well as the methods. None of the methods was entirely reliable, with no limits of agreement better than -10 to +9 breaths/min. Some of the methods were superior to the others, with ICCs from 0.24 to 0.92. By ICC the Once-per-Breath 60-second count and the Once-per-Breath 20-breath count were the most consistent, better even than the 60-second count by the participants. The 10-breath approaches performed least well. Users' initial impressions were positive, with little difference between the

  19. The quadrant method measuring four points is as a reliable and accurate as the quadrant method in the evaluation after anatomical double-bundle ACL reconstruction.

    Science.gov (United States)

    Mochizuki, Yuta; Kaneko, Takao; Kawahara, Keisuke; Toyoda, Shinya; Kono, Norihiko; Hada, Masaru; Ikegami, Hiroyasu; Musha, Yoshiro

    2017-11-20

    The quadrant method was described by Bernard et al. and it has been widely used for postoperative evaluation of anterior cruciate ligament (ACL) reconstruction. The purpose of this research is to further develop the quadrant method measuring four points, which we named four-point quadrant method, and to compare with the quadrant method. Three-dimensional computed tomography (3D-CT) analyses were performed in 25 patients who underwent double-bundle ACL reconstruction using the outside-in technique. The four points in this study's quadrant method were defined as point1-highest, point2-deepest, point3-lowest, and point4-shallowest, in femoral tunnel position. Value of depth and height in each point was measured. Antero-medial (AM) tunnel is (depth1, height2) and postero-lateral (PL) tunnel is (depth3, height4) in this four-point quadrant method. The 3D-CT images were evaluated independently by 2 orthopaedic surgeons. A second measurement was performed by both observers after a 4-week interval. Intra- and inter-observer reliability was calculated by means of intra-class correlation coefficient (ICC). Also, the accuracy of the method was evaluated against the quadrant method. Intra-observer reliability was almost perfect for both AM and PL tunnel (ICC > 0.81). Inter-observer reliability of AM tunnel was substantial (ICC > 0.61) and that of PL tunnel was almost perfect (ICC > 0.81). The AM tunnel position was 0.13% deep, 0.58% high and PL tunnel position was 0.01% shallow, 0.13% low compared to quadrant method. The four-point quadrant method was found to have high intra- and inter-observer reliability and accuracy. This method can evaluate the tunnel position regardless of the shape and morphology of the bone tunnel aperture for use of comparison and can provide measurement that can be compared with various reconstruction methods. The four-point quadrant method of this study is considered to have clinical relevance in that it is a detailed and accurate tool for

  20. Reliability Engineering

    CERN Document Server

    Lazzaroni, Massimo

    2012-01-01

    This book gives a practical guide for designers and users in Information and Communication Technology context. In particular, in the first Section, the definition of the fundamental terms according to the international standards are given. Then, some theoretical concepts and reliability models are presented in Chapters 2 and 3: the aim is to evaluate performance for components and systems and reliability growth. Chapter 4, by introducing the laboratory tests, puts in evidence the reliability concept from the experimental point of view. In ICT context, the failure rate for a given system can be

  1. Reliability training

    Science.gov (United States)

    Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Dillard, Richard B.; Wong, Kam L.; Barber, Frank J.; Barina, Frank J.

    1992-01-01

    Discussed here is failure physics, the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low cost reliable products. A review of reliability for the years 1940 to 2000 is given. Next, a review of mathematics is given as well as a description of what elements contribute to product failures. Basic reliability theory and the disciplines that allow us to control and eliminate failures are elucidated.

  2. Reliability of a novel thermal imaging system for temperature assessment of healthy feet.

    Science.gov (United States)

    Petrova, N L; Whittam, A; MacDonald, A; Ainarkar, S; Donaldson, A N; Bevans, J; Allen, J; Plassmann, P; Kluwe, B; Ring, F; Rogers, L; Simpson, R; Machin, G; Edmonds, M E

    2018-01-01

    Thermal imaging is a useful modality for identifying preulcerative lesions ("hot spots") in diabetic foot patients. Despite its recognised potential, at present, there is no readily available instrument for routine podiatric assessment of patients at risk. To address this need, a novel thermal imaging system was recently developed. This paper reports the reliability of this device for temperature assessment of healthy feet. Plantar skin foot temperatures were measured with the novel thermal imaging device (Diabetic Foot Ulcer Prevention System (DFUPS), constructed by Photometrix Imaging Ltd) and also with a hand-held infrared spot thermometer (Thermofocus® 01500A3, Tecnimed, Italy) after 20 min of barefoot resting with legs supported and extended in 105 subjects (52 males and 53 females; age range 18 to 69 years) as part of a multicentre clinical trial. The temperature differences between the right and left foot at five regions of interest (ROIs), including 1st and 4th toes, 1st, 3rd and 5th metatarsal heads were calculated. The intra-instrument agreement (three repeated measures) and the inter-instrument agreement (hand-held thermometer and thermal imaging device) were quantified using intra-class correlation coefficients (ICCs) and the 95% confidence intervals (CI). Both devices showed almost perfect agreement in replication by instrument. The intra-instrument ICCs for the thermal imaging device at all five ROIs ranged from 0.95 to 0.97 and the intra-instrument ICCs for the hand-held-thermometer ranged from 0.94 to 0.97. There was substantial to perfect inter-instrument agreement between the hand-held thermometer and the thermal imaging device and the ICCs at all five ROIs ranged between 0.94 and 0.97. This study reports the performance of a novel thermal imaging device in the assessment of foot temperatures in healthy volunteers in comparison with a hand-held infrared thermometer. The newly developed thermal imaging device showed very good agreement in

  3. The Internalized Homophobia Scale for Vietnamese Sexual Minority Women (IHVN-W): Conceptualization, factor structure, reliability, and associations with hypothesized correlates

    Science.gov (United States)

    Nguyen, Trang Quynh; Poteat, Tonia; Bandeen-Roche, Karen; German, Danielle; Nguyen, Yen Hai; Vu, Loan Kieu-Chau; Nguyen, Nam Thi-Thu; Knowlton, Amy R.

    2016-01-01

    We developed the first Vietnamese internalized homophobia (IH) scale, for use with Vietnamese sexual minority women (SMW). Drawing from existing IH scales in the international literature and based on prior qualitative research about SMW in the Viet Nam context, the scale covers two domains: self-stigma (negative attitudes toward oneself as a sexual minority person) and sexual prejudice (negative attitudes toward homosexuality/same-sex relations in general). Scale items, including items borrowed from existing scales and items based on local expressions, were reviewed and confirmed by members of the target population. Quantitative evaluation used data from an anonymous web-based survey of Vietnamese SMW, including those who identified as lesbian (n=1187), or as bisexual (n=641) and those who were unsure about their sexual identity (n=353). The scale was found to consist of two highly correlated factors reflecting self-stigma (not normal/wholesome and self-reproach and wishing away same-sex sexuality) and one factor reflecting sexual prejudice, and to have excellent internal consistency. Construct validity was evidenced by subscales’ associations with a wide range of hypothesized correlates including perceived sexual stigma, outness, social support, connection to other SMW, relationship quality, psychological well-being, anticipation of heterosexual marriage and endorsement of same-sex marriage legalization. Self-stigma was more strongly associated with psychosocial correlates and sexual prejudice was more associated with endorsement of legal same-sex marriage. The variations in these associations across the hypothesized correlates and across sexual identity groups were consistent with the Minority Stress Model and the IH literature, and exhibited context-specific features, which are discussed. PMID:27007469

  4. Reliability calculations

    International Nuclear Information System (INIS)

    Petersen, K.E.

    1986-03-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested. (author)

  5. Systems reliability/structural reliability

    International Nuclear Information System (INIS)

    Green, A.E.

    1980-01-01

    The question of reliability technology using quantified techniques is considered for systems and structures. Systems reliability analysis has progressed to a viable and proven methodology whereas this has yet to be fully achieved for large scale structures. Structural loading variants over the half-time of the plant are considered to be more difficult to analyse than for systems, even though a relatively crude model may be a necessary starting point. Various reliability characteristics and environmental conditions are considered which enter this problem. The rare event situation is briefly mentioned together with aspects of proof testing and normal and upset loading conditions. (orig.)

  6. Approach to reliability assessment

    International Nuclear Information System (INIS)

    Green, A.E.; Bourne, A.J.

    1975-01-01

    Experience has shown that reliability assessments can play an important role in the early design and subsequent operation of technological systems where reliability is at a premium. The approaches to and techniques for such assessments, which have been outlined in the paper, have been successfully applied in variety of applications ranging from individual equipments to large and complex systems. The general approach involves the logical and systematic establishment of the purpose, performance requirements and reliability criteria of systems. This is followed by an appraisal of likely system achievment based on the understanding of different types of variational behavior. A fundamental reliability model emerges from the correlation between the appropriate Q and H functions for performance requirement and achievement. This model may cover the complete spectrum of performance behavior in all the system dimensions

  7. Human reliability

    International Nuclear Information System (INIS)

    Bubb, H.

    1992-01-01

    This book resulted from the activity of Task Force 4.2 - 'Human Reliability'. This group was established on February 27th, 1986, at the plenary meeting of the Technical Reliability Committee of VDI, within the framework of the joint committee of VDI on industrial systems technology - GIS. It is composed of representatives of industry, representatives of research institutes, of technical control boards and universities, whose job it is to study how man fits into the technical side of the world of work and to optimize this interaction. In a total of 17 sessions, information from the part of ergonomy dealing with human reliability in using technical systems at work was exchanged, and different methods for its evaluation were examined and analyzed. The outcome of this work was systematized and compiled in this book. (orig.) [de

  8. Microelectronics Reliability

    Science.gov (United States)

    2017-01-17

    inverters  connected in a chain. ................................................. 5  Figure 3  Typical graph showing frequency versus square root of...developing an experimental  reliability estimating methodology that could both illuminate the  lifetime  reliability of advanced devices,  circuits and...or  FIT of the device. In other words an accurate estimate of the device  lifetime  was found and thus the  reliability  that  can  be  conveniently

  9. Exploring cued and non-cued motor imagery interventions in people with multiple sclerosis: a randomised feasibility trial and reliability study.

    Science.gov (United States)

    Seebacher, Barbara; Kuisma, Raija; Glynn, Angela; Berger, Thomas

    2018-01-01

    Motor imagery (MI) is increasingly used in neurorehabilitation to facilitate motor performance. Our previous study results demonstrated significantly improved walking after rhythmic-cued MI in people with multiple sclerosis (pwMS). The present feasibility study was aimed to obtain preliminary information of changes in walking, fatigue, quality of life (QoL) and MI ability following cued and non-cued MI in pwMS. The study further investigated the feasibility of a larger study and examined the reliability of a two-dimensional gait analysis system. At the MS-Clinic, Department of Neurology, Medical University of Innsbruck, Austria, 15 adult pwMS (1.5-4.5 on the Expanded Disability Status Scale, 13 females) were randomised to one of three groups: 24 sessions of 17 min of MI with music and verbal cueing (MVMI), with music alone (MMI), or non-cued (MI). Descriptive statistics were reported for all outcomes. Primary outcomes were walking speed (Timed 25-Foot Walk) and walking distance (6-Minute Walk Test). Secondary outcomes were recruitment rate, retention, adherence, acceptability, adverse events, MI ability (Kinaesthetic and Visual Imagery Questionnaire, Time-Dependent MI test), fatigue (Modified Fatigue Impact Scale) and QoL (Multiple Sclerosis Impact Scale-29). The reliability of a gait analysis system used to assess gait synchronisation with music beat was tested. Participants showed adequate MI abilities. Post-intervention, improvements in walking speed, walking distance, fatigue, QoL and MI ability were observed in all groups. Success of the feasibility criteria was demonstrated by recruitment and retention rates of 8.6% (95% confidence interval, CI 5.2, 13.8%) and 100% (95% CI 76.4, 100%), which exceeded the target rates of 5.7% and 80%. Additionally, the 83% (95% CI 0.42, 0.99) adherence rate surpassed the 67% target rate. Intra-rater reliability analysis of the gait measurement instruments demonstrated excellent Intra-Class Correlation coefficients for step

  10. Test-retest reliability of the KINARM end-point robot for assessment of sensory, motor and neurocognitive function in young adult athletes.

    Directory of Open Access Journals (Sweden)

    Cameron S Mang

    Full Text Available Current assessment tools for sport-related concussion are limited by a reliance on subjective interpretation and patient symptom reporting. Robotic assessments may provide more objective and precise measures of neurological function than traditional clinical tests.To determine the reliability of assessments of sensory, motor and cognitive function conducted with the KINARM end-point robotic device in young adult elite athletes.Sixty-four randomly selected healthy, young adult elite athletes participated. Twenty-five individuals (25 M, mean age±SD, 20.2±2.1 years participated in a within-season study, where three assessments were conducted within a single season (assessments labeled by session: S1, S2, S3. An additional 39 individuals (28M; 22.8±6.0 years participated in a year-to-year study, where annual pre-season assessments were conducted for three consecutive seasons (assessments labeled by year: Y1, Y2, Y3. Forty-four parameters from five robotic tasks (Visually Guided Reaching, Position Matching, Object Hit, Object Hit and Avoid, and Trail Making B and overall Task Scores describing performance on each task were quantified.Test-retest reliability was determined by intra-class correlation coefficients (ICCs between the first and second, and second and third assessments. In the within-season study, ICCs were ≥0.50 for 68% of parameters between S1 and S2, 80% of parameters between S2 and S3, and for three of the five Task Scores both between S1 and S2, and S2 and S3. In the year-to-year study, ICCs were ≥0.50 for 64% of parameters between Y1 and Y2, 82% of parameters between Y2 and Y3, and for four of the five Task Scores both between Y1 and Y2, and Y2 and Y3.Overall, the results suggest moderate-to-good test-retest reliability for the majority of parameters measured by the KINARM robot in healthy young adult elite athletes. Future work will consider the potential use of this information for clinical assessment of concussion

  11. The Pooling-score (P-score): inter- and intra-rater reliability in endoscopic assessment of the severity of dysphagia.

    Science.gov (United States)

    Farneti, D; Fattori, B; Nacci, A; Mancini, V; Simonelli, M; Ruoppolo, G; Genovese, E

    2014-04-01

    This study evaluated the intra- and inter-rater reliability of the Pooling score (P-score) in clinical endoscopic evaluation of severity of swallowing disorder, considering excess residue in the pharynx and larynx. The score (minimum 4 - maximum 11) is obtained by the sum of the scores given to the site of the bolus, the amount and ability to control residue/bolus pooling, the latter assessed on the basis of cough, raclage, number of dry voluntary or reflex swallowing acts ( 5). Four judges evaluated 30 short films of pharyngeal transit of 10 solid (1/4 of a cracker), 11 creamy (1 tablespoon of jam) and 9 liquid (1 tablespoon of 5 cc of water coloured with methlyene blue, 1 ml in 100 ml) boluses in 23 subjects (10 M/13 F, age from 31 to 76 yrs, mean age 58.56±11.76 years) with different pathologies. The films were randomly distributed on two CDs, which differed in terms of the sequence of the films, and were given to judges (after an explanatory session) at time 0, 24 hours later (time 1) and after 7 days (time 2). The inter- and intra-rater reliability of the P-score was calculated using the intra-class correlation coefficient (ICC; 3,k). The possibility that consistency of boluses could affect the scoring of the films was considered. The ICC for site, amount, management and the P-score total was found to be, respectively, 0.999, 0.997, 1.00 and 0.999. Clinical evaluation of a criterion of severity of a swallowing disorder remains a crucial point in the management of patients with pathologies that predispose to complications. The P-score, derived from static and dynamic parameters, yielded a very high correlation among the scores attributed by the four judges during observations carried out at different times. Bolus consistencies did not affect the outcome of the test: the analysis of variance, performed to verify if the scores attributed by the four judges to the parameters selected, might be influenced by the different consistencies of the boluses, was not

  12. Study on weathering index for improving the reliability of terrace correlation and chronology. Based on the observation and analysis of terrace deposit distributed in the Mid Niigata region and others

    International Nuclear Information System (INIS)

    Hamada, Takaomi; Hataya, Ryuta

    2009-01-01

    We carried out field survey and laboratory analysis to investigate various weathering indexes in loam and terrace deposit at outcrops of the terraces distributed in Mid-Niigata area and other two areas, which were correlated and chronologized accurately. We also collect and analyze the data of color and hardness of eolian loam, matrix of terrace deposit, thickness of decolorated and/or browning rim of terrace gravels, color and roughness of gravel surface and effective porosity on each terrace. According to result of the analysis, thickness of weathering rind can be an useful index for terrace correlation. Weathering rind is observed frequently in mafic and fine gravels, as a result of statistical survey of occurrence of the patterns of weathering type. According to the result of our field survey, Middle terrace contains few decayed gravels and Higher terrace group, which is older than MIS8 terrace, contains large amounts of decayed gravels. We can distinguish two different age terraces according to ratio of decayed gravel concentration in terrace deposit. Combination of data of thickness of weathering rind of gravel and concentration of decayed gravel in terrace deposit, adequate terrace correlation can be obtained with increased reliability. Difference of weathering degree can be detected by a combination of several indexes that can be observed in outcrops, it is possible to distinguish between different age terraces. Color and hardness of loam, thickness of weathering rind of terrace gravel can be indexes of weathering, these can explain the facts observed in outcrops. (author)

  13. Study on weathering index for improving the reliability of terrace correlation and chronology. Part 2. Understanding weathering condition of terrace gravel and induction of application requirement for correlation index

    International Nuclear Information System (INIS)

    Hamada, Takaomi

    2012-01-01

    Geomorphographic survey of fluvial terraces, geological exploration, borehole drilling and investigation, and analysis of weathering condition of terrace gravels were carried out in Chuetsu area, Niigata prefecture, where a great deal of geomorphostratigraphic and tephrostratigraphic data are available. The results of these surveys and investigations indicate that weathering degree of terrace gravels can be considered as an index of the terrace age, and also provide points to remember for sampling and method of sampling and observation. The effective porosity and the thickness of weathering rind of gravels, which are indexes for weathering degree evaluation, in boring core, increase above the depth of about 5m from the top of the hole. Weathering doesn't reach the deep portion, therefore, investigation and evaluation for the weathering degree of terrace gravels must be carried out on the upper portion. Weathering rind thickness and effective porosity of the gravels are dispersive. Dispersion of the weathering rind thickness can be reduced by confining to andesite, and dispersion of the effective porosity can be reduced by limiting range of gravel size. Reducing dispersion, increase trend with age becomes clear in change of the weathering rind thickness and the effective porosity in many of the studied area. It shows that weathering rind thickness and effective porosity are effective for terrace correlation. Dispersion of data in an outcrop isn't small, but data from neighboring terraces with the same age are not different each other. It indicates that weathering rind thickness and effective porosity can be quantitative indexes for terrace age evaluation. In area where weathering rind is effective for terrace correlation, the rate of the weathering rind formation of andesite gravels is about 0.04mm/1000 years. Therefore, MIS6 terraces and MIS8 terraces can be distinguished each other by means of thickness of the weathering rind. This formation rate falls inside the

  14. Redefining reliability

    International Nuclear Information System (INIS)

    Paulson, S.L.

    1995-01-01

    Want to buy some reliability? The question would have been unthinkable in some markets served by the natural gas business even a few years ago, but in the new gas marketplace, industrial, commercial and even some residential customers have the opportunity to choose from among an array of options about the kind of natural gas service they need--and are willing to pay for. The complexities of this brave new world of restructuring and competition have sent the industry scrambling to find ways to educate and inform its customers about the increased responsibility they will have in determining the level of gas reliability they choose. This article discusses the new options and the new responsibilities of customers, the needed for continuous education, and MidAmerican Energy Company's experiment in direct marketing of natural gas

  15. Dependent systems reliability estimation by structural reliability approach

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard

    2014-01-01

    Estimation of system reliability by classical system reliability methods generally assumes that the components are statistically independent, thus limiting its applicability in many practical situations. A method is proposed for estimation of the system reliability with dependent components, where...... the leading failure mechanism(s) is described by physics of failure model(s). The proposed method is based on structural reliability techniques and accounts for both statistical and failure effect correlations. It is assumed that failure of any component is due to increasing damage (fatigue phenomena...... identification. Application of the proposed method can be found in many real world systems....

  16. Bony defects in chronic anterior posttraumatic dislocation of the shoulder: Is there a correlation between humeral and glenoidal lesions?

    Science.gov (United States)

    Ciais, Grégoire; Klouche, Shahnaz; Fournier, Alexandre; Rousseau, Benoit; Bauer, Thomas; Hardy, Philippe

    2016-08-01

    The prevalence of combined humeral and glenoid defects varies between 79 and 84 % in case of chronic posttraumatic anterior shoulder instability. The main goal of this study was to evaluate the relationship between humeral and glenoid defects based on quantitative radiological criteria. A retrospective study was performed between 2000 and 2011 including patients who underwent primary surgical shoulder stabilization for chronic posttraumatic anterior shoulder instability, with bone defects in both the glenoid and humerus and a healthy contralateral shoulder. The following measurements were taken: D/R ratio (Hill-Sachs lesion depth/humeral head radius) on an AP X-ray in internal rotation and the D1/D2 ratio [diameter of the involved glenoid articular surfaces (D1)/the healthy one (D2)] on a comparative Bernageau glenoid profile view. Measurements were taken by two observers. Correlations were determined by the Spearman correlation coefficients (r), Bland and Altman diagrams, and intra-class correlation coefficients (ICC). A sample size calculation was done. Thirty patients were included, 25 men/5 women, mean age 29.8 ± 11.2 years. The mean D/R was 23 ± 12 % for observer 1 and 23 ± 10 % for observer 2. The mean D1/D2 was 95 ± 4 % for observer 1 and 94 ± 6 % for observer 2. No significant correlation was found between humeral and glenoid bone defects by observer 1 (r = 0.23, p = 0.22) or observer 2 (r = 0.05, p = 0.78). Agreement of the observers for the D/R ratio was excellent (ICC = 0.89 ± 0.04, p < 0.00001) and good for the D1/D2 ratio (ICC = 0.54 ± 0.14, p = 0.006). Humeral and glenoid bone defects were not correlated. Inter-observer reliability was excellent for the D/R ratio and good for the D1/D2 ratio. Nonconsecutive Patients, Diagnostic Study, Level III.

  17. Cross-parent reliability in rating ASD markers in infants.

    Science.gov (United States)

    Ben-Sasson, Ayelet; Amit-Ben-Simhon, Hemda; Meyer, Sonya

    2015-06-01

    To investigate the congruence and discrepancies between mother and father reports of early autism spectrum disorders (ASD) markers. Mothers (n = 80) and fathers (n = 78) of 12-month-old infants (55% boys) completed the first year inventory (FYI), an ASD norm-referenced screening questionnaire. Mothers also completed the Infant Toddler Social Emotional Assessment (ITSEA). There were significant and moderate intra-class correlations between mother and father reports for most FYI factors. Fathers' median FYI social-communication domain score was almost twice that of mothers. Mann-Whitney tests indicated that fathers rated their child significantly higher than mothers on the four FYI social-communication factors and on the sensory processing factor. Linear weighted kappa analyses indicated poor agreement on gaze-related and reactivity FYI items. FYI social-communication and sensory-regulatory factors showed significant correlations with corresponding ITSEA scores. Social-communication markers pose a greater challenge for consistent report across parents than sensory-regulatory markers.

  18. Elaboração e confiabilidade da escala funcional do subir e do descer escada para Distrofia Muscular de Duchenne Elaboration and reliability of functional evaluation on going up and downstairs scale for Duchenne Muscular Dystrophy

    Directory of Open Access Journals (Sweden)

    Lilian A. Y. Fernandes

    2010-12-01

    sequence of movements assessing 120 video recordings from 30 children (from 5 to 11 years with DMD while going up and down stairs, 3 to elaborate a scale considering the degree of difficulty to execute the movements, 4 to create handbook, and 5 to submit both the scale and the handbook to be assess by 10 examiners, and review to create the final version. Both repeatability (researcher and reproducibility (two independent examiners were tested by using the IntraClass Correlation Coefficient (ICC and Weighted Kappa respectively. RESULTS: The scale encloses five phases for going up and four phases for going downstairs. Our results showed both excellent intra and intertester reliability, with values of Weighted Kappa > 0.78 in all phases and ICCs > 0.89, with p<0.05 for all scores. CONCLUSION: The proposed scale showed excellent repeatability and reproducibility, requiring continuing the studies to assess its accuracy, validity and to create digital tools to improve data collection.

  19. Test-retest reliability and longitudinal analysis of automated hippocampal subregion volumes in healthy ageing and Alzheimer's disease populations.

    Science.gov (United States)

    Worker, Amanda; Dima, Danai; Combes, Anna; Crum, William R; Streffer, Johannes; Einstein, Steven; Mehta, Mitul A; Barker, Gareth J; C R Williams, Steve; O'daly, Owen

    2018-04-01

    The hippocampal formation is a complex brain structure that is important in cognitive processes such as memory, mood, reward processing and other executive functions. Histological and neuroimaging studies have implicated the hippocampal region in neuropsychiatric disorders as well as in neurodegenerative diseases. This highly plastic limbic region is made up of several subregions that are believed to have different functional roles. Therefore, there is a growing interest in imaging the subregions of the hippocampal formation rather than modelling the hippocampus as a homogenous structure, driving the development of new automated analysis tools. Consequently, there is a pressing need to understand the stability of the measures derived from these new techniques. In this study, an automated hippocampal subregion segmentation pipeline, released as a developmental version of Freesurfer (v6.0), was applied to T1-weighted magnetic resonance imaging (MRI) scans of 22 healthy older participants, scanned on 3 separate occasions and a separate longitudinal dataset of 40 Alzheimer's disease (AD) patients. Test-retest reliability of hippocampal subregion volumes was assessed using the intra-class correlation coefficient (ICC), percentage volume difference and percentage volume overlap (Dice). Sensitivity of the regional estimates to longitudinal change was estimated using linear mixed effects (LME) modelling. The results show that out of the 24 hippocampal subregions, 20 had ICC scores of 0.9 or higher in both samples; these regions include the molecular layer, granule cell layer of the dentate gyrus, CA1, CA3 and the subiculum (ICC > 0.9), whilst the hippocampal fissure and fimbria had lower ICC scores (0.73-0.88). Furthermore, LME analysis of the independent AD dataset demonstrated sensitivity to group and individual differences in the rate of volume change over time in several hippocampal subregions (CA1, molecular layer, CA3, hippocampal tail, fissure and presubiculum

  20. Improving the Reliability of Network Metrics in Structural Brain Networks by Integrating Different Network Weighting Strategies into a Single Graph

    Directory of Open Access Journals (Sweden)

    Stavros I. Dimitriadis

    2017-12-01

    Full Text Available Structural brain networks estimated from diffusion MRI (dMRI via tractography have been widely studied in healthy controls and patients with neurological and psychiatric diseases. However, few studies have addressed the reliability of derived network metrics both node-specific and network-wide. Different network weighting strategies (NWS can be adopted to weight the strength of connection between two nodes yielding structural brain networks that are almost fully-weighted. Here, we scanned five healthy participants five times each, using a diffusion-weighted MRI protocol and computed edges between 90 regions of interest (ROI from the Automated Anatomical Labeling (AAL template. The edges were weighted according to nine different methods. We propose a linear combination of these nine NWS into a single graph using an appropriate diffusion distance metric. We refer to the resulting weighted graph as an Integrated Weighted Structural Brain Network (ISWBN. Additionally, we consider a topological filtering scheme that maximizes the information flow in the brain network under the constraint of the overall cost of the surviving connections. We compared each of the nine NWS and the ISWBN based on the improvement of: (a intra-class correlation coefficient (ICC of well-known network metrics, both node-wise and per network level; and (b the recognition accuracy of each subject compared to the remainder of the cohort, as an attempt to access the uniqueness of the structural brain network for each subject, after first applying our proposed topological filtering scheme. Based on a threshold where the network level ICC should be >0.90, our findings revealed that six out of nine NWS lead to unreliable results at the network level, while all nine NWS were unreliable at the node level. In comparison, our proposed ISWBN performed as well as the best performing individual NWS at the network level, and the ICC was higher compared to all individual NWS at the node

  1. Quantification of colour Doppler activity in the wrist in patients with rheumatoid arthritis - the reliability of different methods for image selection and evaluation

    DEFF Research Database (Denmark)

    Ellegaard, K.; Torp-Pedersen, S.; Lund, H.

    2008-01-01

    measurements in the wrist of patients with rheumatoid arthritis (RA) using different selection and quantification methods. Materials and Methods: 14 patients with RA had their wrist scanned twice by the same investigator with an interval of 30 Minutes, The images for analysis were selected either......Purpose: The amount Of colour Doppler activity in the inflamed synovium is used to quantity inflammatory activity. The measurements may vary due to image selection, quantification method, and point in cardiac cycle. This study investigated the test-retest reliability Of ultrasound colour Doppler...... was obtained when the images were selected guided by colour Doppler and the Subsequent quantification was (done in an area defined by anatomical Structures. With this method, the intra-class coefficient ICC (2.1) was 0.95 and the within-subject SD (SW) was 0.017, indicating good reliability. In contrast, poor...

  2. Fracture toughness correlations

    International Nuclear Information System (INIS)

    Wallin, Kim

    1986-09-01

    In this study existing fracture parameter correlations are reviewed. Their applicability and reliability are discussed in detail. A new K IC -CVN-correlation, based on a theoretical brittle fracture model, is presented

  3. An Introduction To Reliability

    International Nuclear Information System (INIS)

    Park, Kyoung Su

    1993-08-01

    This book introduces reliability with definition of reliability, requirement of reliability, system of life cycle and reliability, reliability and failure rate such as summary, reliability characteristic, chance failure, failure rate which changes over time, failure mode, replacement, reliability in engineering design, reliability test over assumption of failure rate, and drawing of reliability data, prediction of system reliability, conservation of system, failure such as summary and failure relay and analysis of system safety.

  4. Intra-rater reliability of hallux flexor strength measures using the Nintendo Wii Balance Board.

    Science.gov (United States)

    Quek, June; Treleaven, Julia; Brauer, Sandra G; O'Leary, Shaun; Clark, Ross A

    2015-01-01

    The purpose of this study was to investigate the intra-rater reliability of a new method in combination with the Nintendo Wii Balance Board (NWBB) to measure the strength of hallux flexor muscle. Thirty healthy individuals (age: 34.9 ± 12.9 years, height: 170.4 ± 10.5 cm, weight: 69.3 ± 15.3 kg, female = 15) participated. Repeated testing was completed within 7 days. Participants performed strength testing in sitting using a wooden platform in combination with the NWBB. This new method was set up to selectively recruit an intrinsic muscle of the foot, specifically the flexor hallucis brevis muscle. Statistical analysis was performed using intra-class coefficients and ordinary least product analysis. To estimate measurement error, standard error of measurement (SEM), minimal detectable change (MDC) and percentage error were calculated. Results indicate excellent intra-rater reliability (ICC = 0.982, CI = 0.96-0.99) with an absence of systematic bias. SEM, MDC and percentage error value were 0.5, 1.4 and 12 % respectively. This study demonstrates that a new method in combination with the NWBB application is reliable to measure hallux flexor strength and has potential to be used for future research and clinical application.

  5. Inter- and intra-rater reliability of patellofemoral kinematic and contact area quantification by fast spin echo MRI and correlation with cartilage health by quantitative T1ρ MRI.

    Science.gov (United States)

    Lau, Brian C; Thuillier, Daniel U; Pedoia, Valentina; Chen, Ellison Y; Zhang, Zhihong; Feeley, Brian T; Souza, Richard B

    2016-01-01

    Patellar maltracking is a leading cause of patellofemoral pain syndrome (PFPS). The aim of this study was to determine the inter- and intra-rater reliability of a semi-automated program for magnetic resonance imaging (MRI) based patellofemoral kinematics. Sixteen subjects (10 with PFPS [mean age 32.3; SD 5.2; eight females] and six controls without PFPS 19 [mean age 28.6; SD 2.8; three females]) participated in the study. One set of T2-weighted, fat-saturated fast spin-echo (FSE) MRIs were acquired from each subject in full extension and 30° of knee flexion. MRI including axial T1ρ relaxation time mapping sequences was also performed on each knee. Following image acquisitions, regions of interest for kinematic MRI, and patellar and trochlear cartilage were segmented and quantified with in-house designed spline- based MATLAB semi-automated software. Intraclass Correlations Coefficients (ICC) of calculated kinematic parameters were good to excellent, ICC > 0.8 in patellar flexion, rotation, tilt, and translation (anterior -posterior, medial -lateral, and superior -inferior), and contact area translation. Only patellar tilt in the flexed position and motion from extended to flexed state was significantly different between PFPS and control patients (p=0.002 and p=0.006, respectively). No significant correlations were identified between patellofemoral kinematics and contact area with T1ρ relaxation times. A semi-automated, spline-based kinematic MRI technique for patellofemoral kinematic and contact area quantification is highly reproducible with the potential to help better understand the role of patellofemoral maltracking in PFPS and other knee disorders. Level IV. Published by Elsevier B.V.

  6. Inter- and intra-rater reliability of patellofemoral kinematic and contact area quantification by fast spin echo MRI and correlation with cartilage health by quantitative T1ρ MRI☆

    Science.gov (United States)

    Lau, Brian C.; Thuillier, Daniel U.; Pedoia, Valentina; Chen, Ellison Y.; Zhang, Zhihong; Feeley, Brian T.; Souza, Richard B.

    2016-01-01

    Background Patellar maltracking is a leading cause of patellofemoral pain syndrome (PFPS). The aim of this study was to determine the inter- and intra-rater reliability of a semi-automated program for magnetic resonance imaging (MRI) based patellofemoral kinematics. Methods Sixteen subjects (10 with PFPS [mean age 32.3; SD 5.2; eight females] and six controls without PFPS 19 [mean age 28.6; SD 2.8; three females]) participated in the study. One set of T2-weighted, fat-saturated fast spin-echo (FSE) MRIs were acquired from each subject in full extension and 30° of knee flexion. MRI including axial T1ρ relaxation time mapping sequences was also performed on each knee. Following image acquisitions, regions of interest for kinematic MRI, and patellar and trochlear cartilage were segmented and quantified with in-house designed spline- based MATLAB semi-automated software. Results Intraclass Correlations Coefficients (ICC) of calculated kinematic parameters were good to excellent, ICC > 0.8 in patellar flexion, rotation, tilt, and translation (anterior -posterior, medial -lateral, and superior -inferior), and contact area translation. Only patellar tilt in the flexed position and motion from extended to flexed state was significantly different between PFPS and control patients (p = 0.002 and p = 0.006, respectively). No significant correlations were identified between patellofemoral kinematics and contact area with T1ρ relaxation times. Conclusions A semi-automated, spline-based kinematic MRI technique for patellofemoral kinematic and contact area quantification is highly reproducible with the potential to help better understand the role of patellofemoral maltracking in PFPS and other knee disorders. PMID:26746045

  7. Reliability of measuring hip abductor strength following total knee arthroplasty using a hand-held dynamometer.

    Science.gov (United States)

    Schache, Margaret B; McClelland, Jodie A; Webster, Kate E

    2016-01-01

    To investigate the test-retest reliability of measuring hip abductor strength in patients with total knee arthroplasty (TKA) using a hand-held dynamometer (HHD) with two different types of resistance: belt and manual resistance. Test-retest reliability of 30 subjects (17 female, 13 male, 71.9 ± 7.4 years old), 9.2 ± 2.7 days post TKA was measured using belt and therapist resistance. Retest reliability was calculated with intra-class coefficients (ICC3,1) and 95% confidence intervals (CI) for both the group average and the individual scores. A paired t-test assessed whether a difference existed between the belt and therapist methods of resistance. ICCs were 0.82 and 0.80 for the belt and therapist resisted methods, respectively. Hip abductor strength increases of 8 N (14%) for belt resisted and 14 N (17%) for therapist resisted measurements of the group average exceeded the 95% CI and may represent real change. For individuals, hip abductor strength increases of 33 N (72%) (belt resisted) and 57 N (79%) (therapist resisted) could be interpreted as real change. Hip abductor strength can be reliably measured using HHD in the clinical setting with the described protocol. Belt resistance demonstrated slightly higher test-retest reliability. Reliable measurement of hip abductor muscle strength in patients with TKA is important to ensure deficiencies are addressed in rehabilitation programs and function is maximized. Hip abductor strength can be reliably measured with a hand-held dynamometer in the clinical setting using manual or belt resistance.

  8. Reliability of patient-reported outcome instruments in US adults with hemophilia: the Pain, Functional Impairment and Quality of life (P-FiQ study

    Directory of Open Access Journals (Sweden)

    Kempton CL

    2017-09-01

    Full Text Available Christine L Kempton,1 Michael Wang,2 Michael Recht,3 Anne Neff,4 Amy D Shapiro,5 Amit Soni,6 Roshni Kulkarni,7 Tyler W Buckner,2 Katharine Batt,8 Neeraj N Iyer,9 David L Cooper9 1Departments of Pediatrics and Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA, USA; 2Hemophilia and Thrombosis Center, University of Colorado School of Medicine, Aurora, CO, USA; 3The Hemophilia Center, Oregon Health & Science University, Portland, OR, USA; 4Hematology and Medical Oncology, Cleveland Clinic, Cleveland, OH, USA; 5Indiana Hemophilia & Thrombosis Center, Indianapolis, IN, USA; 6Center for Inherited Blood Disorders and CHOC Children’s Hospital/UC Irvine, Orange, CA, USA; 7MSU Center for Bleeding and Clotting Disorders, Michigan State University, East Lansing, MI, USA; 8Hematology and Oncology, Wake Forest School of Medicine, Winston-Salem, NC, USA; 9Clinical, Medical and Regulatory Affairs, Novo Nordisk Inc., Plainsboro, NJ, USA Background: Hemophilia is marked by frequent joint bleeding, resulting in pain and functional impairment.Objective: This study aimed to assess the reliability of five patient-reported outcome (PRO instruments in people with hemophilia (PWH in a non-bleeding state.Methods: Adult male PWH of any severity and inhibitor status, with a history of joint pain or bleeding, completed a pain history and five PRO instruments (EQ-5D-5L, Brief Pain Inventory v2 [BPI], International Physical Activity Questionnaire [IPAQ], Short Form 36 Health Survey v2 [SF-36v2], and Hemophilia Activities List [HAL] during their routine comprehensive care visit. Patients were approached to complete the PRO instruments again at the end of their visit while in a similar non-bleeding state. Concordance of individual questionnaire items and correlation between domain scores were assessed using intra-class correlation coefficient (ICC.Results: Participants completing the retest (n=164 had a median age of 33.9 years. Median time for

  9. Frontiers of reliability

    CERN Document Server

    Basu, Asit P; Basu, Sujit K

    1998-01-01

    This volume presents recent results in reliability theory by leading experts in the world. It will prove valuable for researchers, and users of reliability theory. It consists of refereed invited papers on a broad spectrum of topics in reliability. The subjects covered include Bayesian reliability, Bayesian reliability modeling, confounding in a series system, DF tests, Edgeworth approximation to reliability, estimation under random censoring, fault tree reduction for reliability, inference about changes in hazard rates, information theory and reliability, mixture experiment, mixture of Weibul

  10. Comparison of two methods for calculating the mean vascularization index of ovarian stroma on the basis of spatio-temporal image correlation high-definition flow technology.

    Science.gov (United States)

    Kudla, Marek J; Kandzia, Tomasz; Alcázar, Juan Luis

    2013-11-01

    The aim of our study was to determine the agreement between two different methods for calculating the mean vascularization index (VI) of ovarian stroma using spatio-temporal image correlation-high definition flow (STIC-HDF) technology. Stored 4-D STIC-HDF volume data for ovaries of 34 premenopausal women were assessed retrospectively. We calculated the mean VI from the VI values derived for each 3-D volume within the STIC sequence. Then, the examiner subjectively selected the two volumes with the highest and lowest color signals, respectively. We averaged these two values. Agreement between VI measurements was estimated by calculating intra-class correlation coefficients. The intra-class correlation coefficient for the VI was 0.999 (95% confidence interval: 0.999-1.000). The mean time needed to calculate the mean VI using the entire 4-D STIC sequence was significantly longer than the mean time needed to calculate the average value from the volumes with the highest and lowest color signals determined by the operator (p < 0001). We conclude that there is significant agreement between the two methods. Calculating the average VI from the highest and lowest values is less time consuming than calculating the mean VI from the complete STIC sequence. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  11. Inter-rater reliability of the evaluation of muscular chains associated with posture alterations in scoliosis

    Directory of Open Access Journals (Sweden)

    Fortin Carole

    2012-05-01

    Full Text Available Abstract Background In the Global postural re-education (GPR evaluation, posture alterations are associated with anterior or posterior muscular chain impairments. Our goal was to assess the reliability of the GPR muscular chain evaluation. Methods Design: Inter-rater reliability study. Fifty physical therapists (PTs and two experts trained in GPR assessed the standing posture from photographs of five youths with idiopathic scoliosis using a posture analysis grid with 23 posture indices (PI. The PTs and experts indicated the muscular chain associated with posture alterations. The PTs were also divided into three groups according to their experience in GPR. Experts’ results (after consensus were used to verify agreement between PTs and experts for muscular chain and posture assessments. We used Kappa coefficients (K and the percentage of agreement (%A to assess inter-rater reliability and intra-class coefficients (ICC for determining agreement between PTs and experts. Results For the muscular chain evaluation, reliability was moderate to substantial for 12 PI for the PTs (%A: 56 to 82; K: 0.42 to 0.76 and perfect for 19 PI for the experts. For posture assessment, reliability was moderate to substantial for 12 PI for the PTs (%A > 60%; K: 0.42 to 0.75 and moderate to perfect for 18 PI for the experts (%A: 80 to 100; K: 0.55 to 1.00. The agreement between PTs and experts was good for most muscular chain evaluations (18 PI; ICC: 0.82 to 0.99 and PI (19 PI; ICC: 0.78 to 1.00. Conclusions The GPR muscular chain evaluation has good reliability for most posture indices. GPR evaluation should help guide physical therapists in targeting affected muscles for treatment of abnormal posture patterns.

  12. Development and Initial Reliability Testing of NAK-50+: A Nutrition Attitude and Knowledge Questionnaire for Adults 50+ Years of Age.

    Science.gov (United States)

    Ducak, Kate; Keller, Heather

    2016-03-01

    Few questionnaires to test nutrition knowledge and attitudes of older adults living independently in the community have been developed and tested to assess self-management tools such as Nutri-eSCREEN and other education programs. This study is a first step in the development of a questionnaire designed to evaluate the nutrition knowledge and attitudes of independent older adults (NAK-50+). The steps involved in this study were: (i) drafting initial questions based on the content of the Nutri-eSCREEN education material, (ii) using cognitive interviewing to determine if these questions were understandable and relevant (n = 9 adults ≥50 years of age), and (iii) completing test-retest reliability in a convenient community sample (n = 60 adults ≥50 years of age). Intra-class coefficients (ICC) and kappa were used to determine reliability. A 33-item questionnaire resulted from this development and analysis. ICC for the total score was 0.68 indicating good agreement and thus initial reliability. NAK-50+ is a face valid and reliable questionnaire that assesses nutrition knowledge and attitudes in independent adults aged ≥50 years. Further work to determine construct validity and to refine the questionnaire is warranted. Availability of the questionnaire for this age group will support rigorous evaluation of education and self-management interventions for this segment of the population.

  13. System Reliability Engineering

    International Nuclear Information System (INIS)

    Lim, Tae Jin

    2005-02-01

    This book tells of reliability engineering, which includes quality and reliability, reliability data, importance of reliability engineering, reliability and measure, the poisson process like goodness of fit test and the poisson arrival model, reliability estimation like exponential distribution, reliability of systems, availability, preventive maintenance such as replacement policies, minimal repair policy, shock models, spares, group maintenance and periodic inspection, analysis of common cause failure, and analysis model of repair effect.

  14. Validez y confiabilidad del cuestionario del ENASEM para la depresión en adultos mayores Validity and reliability of the screening questionnaire for geriatric depression used in the Mexican Health and Age Study

    Directory of Open Access Journals (Sweden)

    Sara Gloria Aguilar-Navarro

    2007-08-01

    for the test retest was excellent (intra-class correlation coefficient= 0.933. Finally, the Bland and Altman agreement points indicated a difference 0.22 percent points between test retest. CONCLUSION: The MHAS questionnaire is valid and trustworthy, and allows screening in the research field for the presence of depression in the elderly.

  15. Assessment of a portable device for the quantitative measurement of ankle joint stiffness in spastic individuals

    DEFF Research Database (Denmark)

    Lorentzen, Jakob; Grey, Michael J; Geertsen, Svend Sparre

    2012-01-01

    was measured with the portable device and a stationary torque motor. Inter- and intra-rater reliability was assessed with the intra-class correlation coefficient (ICC). RESULTS: Stiffness measures with the portable and stationary devices were significantly correlated for controls and MS participants (p...

  16. AMSAA Reliability Growth Guide

    National Research Council Canada - National Science Library

    Broemm, William

    2000-01-01

    ... has developed reliability growth methodology for all phases of the process, from planning to tracking to projection. The report presents this methodology and associated reliability growth concepts.

  17. What to Do With "Moderate" Reliability and Validity Coefficients?

    NARCIS (Netherlands)

    Post, Marcel W

    Clinimetric studies may use criteria for test-retest reliability and convergent validity such that correlation coefficients as low as .40 are supportive of reliability and validity. It can be argued that moderate (.40-.60) correlations should not be interpreted in this way and that reliability

  18. A reliability simulation language for reliability analysis

    International Nuclear Information System (INIS)

    Deans, N.D.; Miller, A.J.; Mann, D.P.

    1986-01-01

    The results of work being undertaken to develop a Reliability Description Language (RDL) which will enable reliability analysts to describe complex reliability problems in a simple, clear and unambiguous way are described. Component and system features can be stated in a formal manner and subsequently used, along with control statements to form a structured program. The program can be compiled and executed on a general-purpose computer or special-purpose simulator. (DG)

  19. Intraclass correlation values for adolescent health outcomes in secondary schools in 21 European countries

    Directory of Open Access Journals (Sweden)

    N. Shackleton

    2016-12-01

    Full Text Available Background: Cluster randomised controlled trials (CRCTs are increasingly used to evaluate the effectiveness of interventions for improving health. A key feature of CRCTs is that individuals in clusters are often more alike than individuals in different clusters, irrespective of treatment. This similarity within clusters needs to be taken into account when planning CRCTs to obtain adequate sample sizes, and when analysing clustered data to obtain correct estimates. Methods: Nationally representative data from 15 to 16 year olds were analysed, from 21 of the 35 countries that participated in the 2007 European School Survey Project on Alcohol and Other Drugs. Within country school level intra-class correlation coefficients (ICCs were calculated for substance use (self-reported alcohol use, regular alcohol use, binge drinking, any smoking, regular smoking, and illicit drug use and psychosocial health (depressive mood and self-esteem. Unadjusted and adjusted ICCs are presented. ICCs are adjusted for student sex and socioeconomic status. Results: ICCs ranged from 0.01 to 0.21, with the highest (0.21 reported for regular smoking. Within country school level ICCs varied substantially across health outcomes, and among countries for the same health outcomes. Estimated ICCs were consistently higher for substance use (range 0.01–0.21, than for psychosocial health (range 0.01–0.07. Within country ICCs for health outcomes varied by changes in the measurement of particular health outcomes, for example the ICCs for regular smoking (range 0.06–0.21 were higher than those for having smoked at all in the last month (range 0.03–0.17. Conclusions: For school level ICCs to be effectively utilised in informing sample size requirements for CRCTs and adjusting estimates from meta-analyses, the school level ICCs need to be both country and outcome specific. Keywords: Intra-class correlation, Schools, Adolescents, Substance use, Mental health

  20. Quantification of intervertebral displacement with a novel MRI-based modeling technique: Assessing measurement bias and reliability with a porcine spine model.

    Science.gov (United States)

    Mahato, Niladri K; Montuelle, Stephane; Goubeaux, Craig; Cotton, John; Williams, Susan; Thomas, James; Clark, Brian C

    2017-05-01

    The purpose of this study was to develop a novel magnetic resonance imaging (MRI)-based modeling technique for measuring intervertebral displacements. Here, we present the measurement bias and reliability of the developmental work using a porcine spine model. Porcine lumbar vertebral segments were fitted in a custom-built apparatus placed within an externally calibrated imaging volume of an open-MRI scanner. The apparatus allowed movement of the vertebrae through pre-assigned magnitudes of sagittal and coronal translation and rotation. The induced displacements were imaged with static (T 1 ) and fast dynamic (2D HYCE S) pulse sequences. These images were imported into animation software, in which these images formed a background 'scene'. Three-dimensional models of vertebrae were created using static axial scans from the specimen and then transferred into the animation environment. In the animation environment, the user manually moved the models (rotoscoping) to perform model-to-'scene' matching to fit the models to their image silhouettes and assigned anatomical joint axes to the motion-segments. The animation protocol quantified the experimental translation and rotation displacements between the vertebral models. Accuracy of the technique was calculated as 'bias' using a linear mixed effects model, average percentage error and root mean square errors. Between-session reliability was examined by computing intra-class correlation coefficients (ICC) and the coefficient of variations (CV). For translation trials, a constant bias (β 0 ) of 0.35 (±0.11) mm was detected for the 2D HYCE S sequence (p=0.01). The model did not demonstrate significant additional bias with each mm increase in experimental translation (β 1 Displacement=0.01mm; p=0.69). Using the T 1 sequence for the same assessments did not significantly change the bias (p>0.05). ICC values for the T 1 and 2D HYCE S pulse sequences were 0.98 and 0.97, respectively. For rotation trials, a constant bias (

  1. Reliability data banks

    International Nuclear Information System (INIS)

    Cannon, A.G.; Bendell, A.

    1991-01-01

    Following an introductory chapter on Reliability, what is it, why it is needed, how it is achieved and measured, the principles of reliability data bases and analysis methodologies are the subject of the next two chapters. Achievements due to the development of data banks are mentioned for different industries in the next chapter, FACTS, a comprehensive information system for industrial safety and reliability data collection in process plants are covered next. CREDO, the Central Reliability Data Organization is described in the next chapter and is indexed separately, as is the chapter on DANTE, the fabrication reliability Data analysis system. Reliability data banks at Electricite de France and IAEA's experience in compiling a generic component reliability data base are also separately indexed. The European reliability data system, ERDS, and the development of a large data bank come next. The last three chapters look at 'Reliability data banks, - friend foe or a waste of time'? and future developments. (UK)

  2. Suncor maintenance and reliability

    Energy Technology Data Exchange (ETDEWEB)

    Little, S. [Suncor Energy, Calgary, AB (Canada)

    2006-07-01

    Fleet maintenance and reliability at Suncor Energy was discussed in this presentation, with reference to Suncor Energy's primary and support equipment fleets. This paper also discussed Suncor Energy's maintenance and reliability standard involving people, processes and technology. An organizational maturity chart that graphed organizational learning against organizational performance was illustrated. The presentation also reviewed the maintenance and reliability framework; maintenance reliability model; the process overview of the maintenance and reliability standard; a process flow chart of maintenance strategies and programs; and an asset reliability improvement process flow chart. An example of an improvement initiative was included, with reference to a shovel reliability review; a dipper trip reliability investigation; bucket related failures by type and frequency; root cause analysis of the reliability process; and additional actions taken. Last, the presentation provided a graph of the results of the improvement initiative and presented the key lessons learned. tabs., figs.

  3. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  4. Human- and computer-accessible 2D correlation data for a more reliable structure determination of organic compounds. Future roles of researchers, software developers, spectrometer managers, journal editors, reviewers, publisher and database managers toward artificial-intelligence analysis of NMR spectra.

    Science.gov (United States)

    Jeannerat, Damien

    2017-01-01

    The introduction of a universal data format to report the correlation data of 2D NMR spectra such as COSY, HSQC and HMBC spectra will have a large impact on the reliability of structure determination of small organic molecules. These lists of assigned cross peaks will bridge signals found in NMR 1D and 2D spectra and the assigned chemical structure. The record could be very compact, human and computer readable so that it can be included in the supplementary material of publications and easily transferred into databases of scientific literature and chemical compounds. The records will allow authors, reviewers and future users to test the consistency and, in favorable situations, the uniqueness of the assignment of the correlation data to the associated chemical structures. Ideally, the data format of the correlation data should include direct links to the NMR spectra to make it possible to validate their reliability and allow direct comparison of spectra. In order to take the full benefits of their potential, the correlation data and the NMR spectra should therefore follow any manuscript in the review process and be stored in open-access database after publication. Keeping all NMR spectra, correlation data and assigned structures together at all time will allow the future development of validation tools increasing the reliability of past and future NMR data. This will facilitate the development of artificial intelligence analysis of NMR spectra by providing a source of data than can be used efficiently because they have been validated or can be validated by future users. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Reliability analysis under epistemic uncertainty

    International Nuclear Information System (INIS)

    Nannapaneni, Saideep; Mahadevan, Sankaran

    2016-01-01

    This paper proposes a probabilistic framework to include both aleatory and epistemic uncertainty within model-based reliability estimation of engineering systems for individual limit states. Epistemic uncertainty is considered due to both data and model sources. Sparse point and/or interval data regarding the input random variables leads to uncertainty regarding their distribution types, distribution parameters, and correlations; this statistical uncertainty is included in the reliability analysis through a combination of likelihood-based representation, Bayesian hypothesis testing, and Bayesian model averaging techniques. Model errors, which include numerical solution errors and model form errors, are quantified through Gaussian process models and included in the reliability analysis. The probability integral transform is used to develop an auxiliary variable approach that facilitates a single-level representation of both aleatory and epistemic uncertainty. This strategy results in an efficient single-loop implementation of Monte Carlo simulation (MCS) and FORM/SORM techniques for reliability estimation under both aleatory and epistemic uncertainty. Two engineering examples are used to demonstrate the proposed methodology. - Highlights: • Epistemic uncertainty due to data and model included in reliability analysis. • A novel FORM-based approach proposed to include aleatory and epistemic uncertainty. • A single-loop Monte Carlo approach proposed to include both types of uncertainties. • Two engineering examples used for illustration.

  6. Human Reliability Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, Michael

    2012-09-25

    This presentation covers the high points of the Human Reliability Program, including certification/decertification, critical positions, due process, organizational structure, program components, personnel security, an overview of the US DOE reliability program, retirees and academia, and security program integration.

  7. Power electronics reliability analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mark A.; Atcitty, Stanley

    2009-12-01

    This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

  8. Reliability of software

    International Nuclear Information System (INIS)

    Kopetz, H.

    1980-01-01

    Common factors and differences in the reliability of hardware and software; reliability increase by means of methods of software redundancy. Maintenance of software for long term operating behavior. (HP) [de

  9. Development and reliability of an instrument to measure psychosocial determinants of salt consumption among hypertensive patients Desarrollo y confiabilidad de un instrumento para medir los factores psicosociales determinantes en el consumo de sal entre hipertensos Desenvolvimento e confiabilidade de instrumento para mensuração dos fatores psicossociais determinantes do consumo de sal entre hipertensos

    Directory of Open Access Journals (Sweden)

    Marília Estevam Cornélio

    2009-10-01

    Full Text Available This study aimed to present the content validity and reliability analyses of an instrument to study the determinant factors of salt consumption among hypertensive subjects, based on an extension of the Theory of Planned Behavior. Content validity was assessed by 3 experts and a pre-test was carried out with 5 subjects. The final tool, comprising 3 different behaviors related to salt consumption and corresponding psychosocial variables, was applied to 32 subjects for internal consistency and temporal stability (15-day interval analysis. Cronbach's alpha coefficients > 0.70 and significant intra-class correlation coefficients were observed for most variables, indicating the temporal stability of the measured concepts. The developed instrument exhibited evidence of both content validity and reliability.Este estudio tuvo como objetivo presentar el análisis de validez de contenido y de confiabilidad de un instrumento para estudiar los factores determinantes del consumo de sodio entre hipertensos, basado en la extensión de la Teoría del Comportamiento Planificado. El instrumento fue sometido a validez de contenido por 3 jueces y a una prueba piloto con 5 sujetos. El instrumento final, compuesto por 3 comportamientos relacionados al consumo de la sal y por las variables psicosociales correspondientes, fue aplicado a 32 sujetos para evaluación de la consistencia interna y de la estabilidad temporal (intervalo de 15 días. Fueron observados coeficientes alfa de Cronbach>0,70 para la mayoría de las variables y coeficientes de correlación entra clases significativas, que apuntaron la estabilidad temporal de los conceptos mensurados. El instrumento desarrollado mostró evidencias de validez de contenido y de confiabilidad.Este estudo teve como objetivo apresentar a análise da validade de conteúdo e da confiabilidade de um instrumento para estudo dos fatores determinantes do consumo de sódio entre hipertensos, baseado na extensão da Teoria do

  10. Reliable Design Versus Trust

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth A.

    2016-01-01

    This presentation focuses on reliability and trust for the users portion of the FPGA design flow. It is assumed that the manufacturer prior to hand-off to the user tests FPGA internal components. The objective is to present the challenges of creating reliable and trusted designs. The following will be addressed: What makes a design vulnerable to functional flaws (reliability) or attackers (trust)? What are the challenges for verifying a reliable design versus a trusted design?

  11. Pocket Handbook on Reliability

    Science.gov (United States)

    1975-09-01

    exponencial distributions Weibull distribution, -xtimating reliability, confidence intervals, relia- bility growth, 0. P- curves, Bayesian analysis. 20 A S...introduction for those not familiar with reliability and a good refresher for those who are currently working in the area. LEWIS NERI, CHIEF...includes one or both of the following objectives: a) prediction of the current system reliability, b) projection on the system reliability for someI future

  12. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated......, and as an example the reliability profile and a sensitivity analyses for a corroded reinforced concrete bridge is shown....

  13. Reliability in engineering '87

    International Nuclear Information System (INIS)

    Tuma, M.

    1987-01-01

    The participants heard 51 papers dealing with the reliability of engineering products. Two of the papers were incorporated in INIS, namely ''Reliability comparison of two designs of low pressure regeneration of the 1000 MW unit at the Temelin nuclear power plant'' and ''Use of probability analysis of reliability in designing nuclear power facilities.''(J.B.)

  14. Reliable computer systems.

    Science.gov (United States)

    Wear, L L; Pinkert, J R

    1993-11-01

    In this article, we looked at some decisions that apply to the design of reliable computer systems. We began with a discussion of several terms such as testability, then described some systems that call for highly reliable hardware and software. The article concluded with a discussion of methods that can be used to achieve higher reliability in computer systems. Reliability and fault tolerance in computers probably will continue to grow in importance. As more and more systems are computerized, people will want assurances about the reliability of these systems, and their ability to work properly even when sub-systems fail.

  15. Human factor reliability program

    International Nuclear Information System (INIS)

    Knoblochova, L.

    2017-01-01

    The human factor's reliability program was at Slovenske elektrarne, a.s. (SE) nuclear power plants. introduced as one of the components Initiatives of Excellent Performance in 2011. The initiative's goal was to increase the reliability of both people and facilities, in response to 3 major areas of improvement - Need for improvement of the results, Troubleshooting support, Supporting the achievement of the company's goals. The human agent's reliability program is in practice included: - Tools to prevent human error; - Managerial observation and coaching; - Human factor analysis; -Quick information about the event with a human agent; -Human reliability timeline and performance indicators; - Basic, periodic and extraordinary training in human factor reliability(authors)

  16. The Functional Living Index-Cancer is a reliable and valid instrument in Chinese cancer patients.

    Science.gov (United States)

    Fong, Daniel Y T; Lee, Alvina H K; Tung, Stewart Y; Wong, Janet Y H; Chan, Y M; Goh, Cynthia R; Cheung, Y B

    2014-02-01

    To evaluate the linguistic and psychometric properties of the Functional Living Index-Cancer (FLIC) in assessing the quality of life of Chinese cancer patients. The English FLIC was translated into Traditional Chinese by the standard forward-backward procedure. After cognitive debriefing, a Traditional Chinese FLIC was administered to 500 cancer patients in a major public hospital in Hong Kong. Of which, 200 were invited to complete the questionnaire in 2 weeks. To identify a scale structure appropriate to Chinese, exploratory and confirmatory factor analyses were performed on two randomly split halves of the sample. We identified five scales of the Traditional Chinese FLIC which assess the physical, psychological, hardship, nausea and social aspects. These five scales and the overall scale demonstrated satisfactory fit and had the alpha coefficient ranged from 0.68 to 0.92. The intra-class correlation coefficient ranged from 0.67 to 0.88. In addition, all FLIC scales were negatively associated with the Eastern Cooperative Oncology Group performance status and, also except for the psychological scale, had lower scores in patients who were treated by chemotherapy. The Traditional Chinese FLIC is an appropriate health indicator for Chinese cancer patients.

  17. Análise da confiabilidade e da correlação de dois índices de estimativa da maturação esquelética: índice carpal e índice vertebral Reliability and correlation analysis of two skeletal maturation evaluation indexes: hand-wrist index and cervical vertebrae index

    Directory of Open Access Journals (Sweden)

    Melissa Feres Damian

    2006-10-01

    Full Text Available OBJETIVO: o objetivo deste estudo foi avaliar a confiabilidade e a correlação de dois índices de estimativa da maturação esquelética. METODOLOGIA: foi utilizada uma amostra de 210 radiografias carpais e telerradiografias laterais, de arquivo, de pacientes de ambos os gêneros, com idade entre 7 e 18 anos. As radiografias carpais foram utilizadas na determinação do Índice de Maturação Carpal (IMC e as telerradiografias laterais na determinação do Índice de Maturação Vertebral (IMV. Cada grupo de radiografias foi examinado e reexaminado por 4 avaliadores, para analisar a confiabilidade de cada índice, e ainda foi realizada a comparação entre os estágios do IMC e do IMV, para avaliar a correlação entre os índices. RESULTADOS: os resultados demonstraram que não houve diferença estatisticamente significante entre os 4 observadores nas avaliações do IMC e do IMV (pAIM: the aim of this study were to evaluate the reliability and correlation of two different skeletal maturation evaluation indexes. METHODS: two hundred and ten hand-wrist and cephalometric radiographs from files of patients with 7- 18 years old were used. The hand-wrist radiographs were used to determine the skeletal maturation index (SMI and the cephalometric radiographs to determine the cervical vertebrae maturation index (CVMI. Four independent evaluators were asked to examine twice each radiography and to verify the reliability of each index. The stages of SMI and CVMI were compared to evaluate the relationship between them. RESULTS: the results were not statisticaly different among the four evaluators on SMI and CVMI indexes (p<0.00001. The correlation average to SMI was 95% for the first evaluation and 93.5% for the second evaluation. On the CVMI, the correlation average was 84% for the first evaluation and 74% for the second evaluation. The correlation intraoperator did not showed significant difference (p<0.00001 and the average for SMI was 93.5% and for

  18. Reliability and safety engineering

    CERN Document Server

    Verma, Ajit Kumar; Karanki, Durga Rao

    2016-01-01

    Reliability and safety are core issues that must be addressed throughout the life cycle of engineering systems. Reliability and Safety Engineering presents an overview of the basic concepts, together with simple and practical illustrations. The authors present reliability terminology in various engineering fields, viz.,electronics engineering, software engineering, mechanical engineering, structural engineering and power systems engineering. The book describes the latest applications in the area of probabilistic safety assessment, such as technical specification optimization, risk monitoring and risk informed in-service inspection. Reliability and safety studies must, inevitably, deal with uncertainty, so the book includes uncertainty propagation methods: Monte Carlo simulation, fuzzy arithmetic, Dempster-Shafer theory and probability bounds. Reliability and Safety Engineering also highlights advances in system reliability and safety assessment including dynamic system modeling and uncertainty management. Cas...

  19. Human reliability analysis

    International Nuclear Information System (INIS)

    Dougherty, E.M.; Fragola, J.R.

    1988-01-01

    The authors present a treatment of human reliability analysis incorporating an introduction to probabilistic risk assessment for nuclear power generating stations. They treat the subject according to the framework established for general systems theory. Draws upon reliability analysis, psychology, human factors engineering, and statistics, integrating elements of these fields within a systems framework. Provides a history of human reliability analysis, and includes examples of the application of the systems approach

  20. Reliability of electronic systems

    International Nuclear Information System (INIS)

    Roca, Jose L.

    2001-01-01

    Reliability techniques have been developed subsequently as a need of the diverse engineering disciplines, nevertheless they are not few those that think they have been work a lot on reliability before the same word was used in the current context. Military, space and nuclear industries were the first ones that have been involved in this topic, however not only in these environments it is that it has been carried out this small great revolution in benefit of the increase of the reliability figures of the products of those industries, but rather it has extended to the whole industry. The fact of the massive production, characteristic of the current industries, drove four decades ago, to the fall of the reliability of its products, on one hand, because the massively itself and, for other, to the recently discovered and even not stabilized industrial techniques. Industry should be changed according to those two new requirements, creating products of medium complexity and assuring an enough reliability appropriated to production costs and controls. Reliability began to be integral part of the manufactured product. Facing this philosophy, the book describes reliability techniques applied to electronics systems and provides a coherent and rigorous framework for these diverse activities providing a unifying scientific basis for the entire subject. It consists of eight chapters plus a lot of statistical tables and an extensive annotated bibliography. Chapters embrace the following topics: 1- Introduction to Reliability; 2- Basic Mathematical Concepts; 3- Catastrophic Failure Models; 4-Parametric Failure Models; 5- Systems Reliability; 6- Reliability in Design and Project; 7- Reliability Tests; 8- Software Reliability. This book is in Spanish language and has a potentially diverse audience as a text book from academic to industrial courses. (author)

  1. Operational safety reliability research

    International Nuclear Information System (INIS)

    Hall, R.E.; Boccio, J.L.

    1986-01-01

    Operating reactor events such as the TMI accident and the Salem automatic-trip failures raised the concern that during a plant's operating lifetime the reliability of systems could degrade from the design level that was considered in the licensing process. To address this concern, NRC is sponsoring the Operational Safety Reliability Research project. The objectives of this project are to identify the essential tasks of a reliability program and to evaluate the effectiveness and attributes of such a reliability program applicable to maintaining an acceptable level of safety during the operating lifetime at the plant

  2. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  3. Robust D-optimal designs under correlated error, applicable invariantly for some lifetime distributions

    International Nuclear Information System (INIS)

    Das, Rabindra Nath; Kim, Jinseog; Park, Jeong-Soo

    2015-01-01

    In quality engineering, the most commonly used lifetime distributions are log-normal, exponential, gamma and Weibull. Experimental designs are useful for predicting the optimal operating conditions of the process in lifetime improvement experiments. In the present article, invariant robust first-order D-optimal designs are derived for correlated lifetime responses having the above four distributions. Robust designs are developed for some correlated error structures. It is shown that robust first-order D-optimal designs for these lifetime distributions are always robust rotatable but the converse is not true. Moreover, it is observed that these designs depend on the respective error covariance structure but are invariant to the above four lifetime distributions. This article generalizes the results of Das and Lin [7] for the above four lifetime distributions with general (intra-class, inter-class, compound symmetry, and tri-diagonal) correlated error structures. - Highlights: • This paper presents invariant robust first-order D-optimal designs under correlated lifetime responses. • The results of Das and Lin [7] are extended for the four lifetime (log-normal, exponential, gamma and Weibull) distributions. • This paper also generalizes the results of Das and Lin [7] to more general correlated error structures

  4. Hawaii Electric System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Loose, Verne William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silva Monroy, Cesar Augusto [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2012-08-01

    This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers’ views of reliability “worth” and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and for application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers’ views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.

  5. Hawaii electric system reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Silva Monroy, Cesar Augusto; Loose, Verne William

    2012-09-01

    This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers' views of reliability %E2%80%9Cworth%E2%80%9D and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and for application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers' views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.

  6. Improving machinery reliability

    CERN Document Server

    Bloch, Heinz P

    1998-01-01

    This totally revised, updated and expanded edition provides proven techniques and procedures that extend machinery life, reduce maintenance costs, and achieve optimum machinery reliability. This essential text clearly describes the reliability improvement and failure avoidance steps practiced by best-of-class process plants in the U.S. and Europe.

  7. LED system reliability

    NARCIS (Netherlands)

    Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

    2011-01-01

    This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific

  8. Integrated system reliability analysis

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard

    Specific targets: 1) The report shall describe the state of the art of reliability and risk-based assessment of wind turbine components. 2) Development of methodology for reliability and risk-based assessment of the wind turbine at system level. 3) Describe quantitative and qualitative measures...

  9. Reliability of neural encoding

    DEFF Research Database (Denmark)

    Alstrøm, Preben; Beierholm, Ulrik; Nielsen, Carsten Dahl

    2002-01-01

    The reliability with which a neuron is able to create the same firing pattern when presented with the same stimulus is of critical importance to the understanding of neuronal information processing. We show that reliability is closely related to the process of phaselocking. Experimental results f...

  10. Design reliability engineering

    International Nuclear Information System (INIS)

    Buden, D.; Hunt, R.N.M.

    1989-01-01

    Improved design techniques are needed to achieve high reliability at minimum cost. This is especially true of space systems where lifetimes of many years without maintenance are needed and severe mass limitations exist. Reliability must be designed into these systems from the start. Techniques are now being explored to structure a formal design process that will be more complete and less expensive. The intent is to integrate the best features of design, reliability analysis, and expert systems to design highly reliable systems to meet stressing needs. Taken into account are the large uncertainties that exist in materials, design models, and fabrication techniques. Expert systems are a convenient method to integrate into the design process a complete definition of all elements that should be considered and an opportunity to integrate the design process with reliability, safety, test engineering, maintenance and operator training. 1 fig

  11. Bayesian methods in reliability

    Science.gov (United States)

    Sander, P.; Badoux, R.

    1991-11-01

    The present proceedings from a course on Bayesian methods in reliability encompasses Bayesian statistical methods and their computational implementation, models for analyzing censored data from nonrepairable systems, the traits of repairable systems and growth models, the use of expert judgment, and a review of the problem of forecasting software reliability. Specific issues addressed include the use of Bayesian methods to estimate the leak rate of a gas pipeline, approximate analyses under great prior uncertainty, reliability estimation techniques, and a nonhomogeneous Poisson process. Also addressed are the calibration sets and seed variables of expert judgment systems for risk assessment, experimental illustrations of the use of expert judgment for reliability testing, and analyses of the predictive quality of software-reliability growth models such as the Weibull order statistics.

  12. Reliability of construction materials

    International Nuclear Information System (INIS)

    Merz, H.

    1976-01-01

    One can also speak of reliability with respect to materials. While for reliability of components the MTBF (mean time between failures) is regarded as the main criterium, this is replaced with regard to materials by possible failure mechanisms like physical/chemical reaction mechanisms, disturbances of physical or chemical equilibrium, or other interactions or changes of system. The main tasks of the reliability analysis of materials therefore is the prediction of the various failure reasons, the identification of interactions, and the development of nondestructive testing methods. (RW) [de

  13. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    The structural reliability methods quantitatively treat the uncertainty of predicting the behaviour and properties of a structure given the uncertain properties of its geometry, materials, and the actions it is supposed to withstand. This book addresses the probabilistic methods for evaluation...... of structural reliability, including the theoretical basis for these methods. Partial safety factor codes under current practice are briefly introduced and discussed. A probabilistic code format for obtaining a formal reliability evaluation system that catches the most essential features of the nature...... of the uncertainties and their interplay is the developed, step-by-step. The concepts presented are illustrated by numerous examples throughout the text....

  14. Reliability and mechanical design

    International Nuclear Information System (INIS)

    Lemaire, Maurice

    1997-01-01

    A lot of results in mechanical design are obtained from a modelisation of physical reality and from a numerical solution which would lead to the evaluation of needs and resources. The goal of the reliability analysis is to evaluate the confidence which it is possible to grant to the chosen design through the calculation of a probability of failure linked to the retained scenario. Two types of analysis are proposed: the sensitivity analysis and the reliability analysis. Approximate methods are applicable to problems related to reliability, availability, maintainability and safety (RAMS)

  15. RTE - 2013 Reliability Report

    International Nuclear Information System (INIS)

    Denis, Anne-Marie

    2014-01-01

    RTE publishes a yearly reliability report based on a standard model to facilitate comparisons and highlight long-term trends. The 2013 report is not only stating the facts of the Significant System Events (ESS), but it moreover underlines the main elements dealing with the reliability of the electrical power system. It highlights the various elements which contribute to present and future reliability and provides an overview of the interaction between the various stakeholders of the Electrical Power System on the scale of the European Interconnected Network. (author)

  16. The rating reliability calculator

    Directory of Open Access Journals (Sweden)

    Solomon David J

    2004-04-01

    Full Text Available Abstract Background Rating scales form an important means of gathering evaluation data. Since important decisions are often based on these evaluations, determining the reliability of rating data can be critical. Most commonly used methods of estimating reliability require a complete set of ratings i.e. every subject being rated must be rated by each judge. Over fifty years ago Ebel described an algorithm for estimating the reliability of ratings based on incomplete data. While his article has been widely cited over the years, software based on the algorithm is not readily available. This paper describes an easy-to-use Web-based utility for estimating the reliability of ratings based on incomplete data using Ebel's algorithm. Methods The program is available public use on our server and the source code is freely available under GNU General Public License. The utility is written in PHP, a common open source imbedded scripting language. The rating data can be entered in a convenient format on the user's personal computer that the program will upload to the server for calculating the reliability and other statistics describing the ratings. Results When the program is run it displays the reliability, number of subject rated, harmonic mean number of judges rating each subject, the mean and standard deviation of the averaged ratings per subject. The program also displays the mean, standard deviation and number of ratings for each subject rated. Additionally the program will estimate the reliability of an average of a number of ratings for each subject via the Spearman-Brown prophecy formula. Conclusion This simple web-based program provides a convenient means of estimating the reliability of rating data without the need to conduct special studies in order to provide complete rating data. I would welcome other researchers revising and enhancing the program.

  17. Reliability and maintainability

    International Nuclear Information System (INIS)

    1994-01-01

    Several communications in this conference are concerned with nuclear plant reliability and maintainability; their titles are: maintenance optimization of stand-by Diesels of 900 MW nuclear power plants; CLAIRE: an event-based simulation tool for software testing; reliability as one important issue within the periodic safety review of nuclear power plants; design of nuclear building ventilation by the means of functional analysis; operation characteristic analysis for a power industry plant park, as a function of influence parameters

  18. Reliability data book

    International Nuclear Information System (INIS)

    Bento, J.P.; Boerje, S.; Ericsson, G.; Hasler, A.; Lyden, C.O.; Wallin, L.; Poern, K.; Aakerlund, O.

    1985-01-01

    The main objective for the report is to improve failure data for reliability calculations as parts of safety analyses for Swedish nuclear power plants. The work is based primarily on evaluations of failure reports as well as information provided by the operation and maintenance staff of each plant. In the report are presented charts of reliability data for: pumps, valves, control rods/rod drives, electrical components, and instruments. (L.E.)

  19. Multidisciplinary System Reliability Analysis

    Science.gov (United States)

    Mahadevan, Sankaran; Han, Song; Chamis, Christos C. (Technical Monitor)

    2001-01-01

    The objective of this study is to develop a new methodology for estimating the reliability of engineering systems that encompass multiple disciplines. The methodology is formulated in the context of the NESSUS probabilistic structural analysis code, developed under the leadership of NASA Glenn Research Center. The NESSUS code has been successfully applied to the reliability estimation of a variety of structural engineering systems. This study examines whether the features of NESSUS could be used to investigate the reliability of systems in other disciplines such as heat transfer, fluid mechanics, electrical circuits etc., without considerable programming effort specific to each discipline. In this study, the mechanical equivalence between system behavior models in different disciplines are investigated to achieve this objective. A new methodology is presented for the analysis of heat transfer, fluid flow, and electrical circuit problems using the structural analysis routines within NESSUS, by utilizing the equivalence between the computational quantities in different disciplines. This technique is integrated with the fast probability integration and system reliability techniques within the NESSUS code, to successfully compute the system reliability of multidisciplinary systems. Traditional as well as progressive failure analysis methods for system reliability estimation are demonstrated, through a numerical example of a heat exchanger system involving failure modes in structural, heat transfer and fluid flow disciplines.

  20. Analysis and Application of Reliability

    International Nuclear Information System (INIS)

    Jeong, Hae Seong; Park, Dong Ho; Kim, Jae Ju

    1999-05-01

    This book tells of analysis and application of reliability, which includes definition, importance and historical background of reliability, function of reliability and failure rate, life distribution and assumption of reliability, reliability of unrepaired system, reliability of repairable system, sampling test of reliability, failure analysis like failure analysis by FEMA and FTA, and cases, accelerated life testing such as basic conception, acceleration and acceleration factor, and analysis of accelerated life testing data, maintenance policy about alternation and inspection.

  1. Correlation and agreement between eplet mismatches calculated using serological, low-intermediate and high resolution molecular human leukocyte antigen typing methods.

    Science.gov (United States)

    Fidler, Samantha; D'Orsogna, Lloyd; Irish, Ashley B; Lewis, Joshua R; Wong, Germaine; Lim, Wai H

    2018-03-02

    Structural human leukocyte antigen (HLA) matching at the eplet level can be identified by HLAMatchmaker, which requires the entry of four-digit alleles. The aim of this study was to evaluate the agreement between eplet mismatches calculated by serological and two-digit typing methods compared to high-resolution four-digit typing. In a cohort of 264 donor/recipient pairs, the evaluation of measurement error was assessed using intra-class correlation to confirm the absolute agreement between the number of eplet mismatches at class I (HLA-A, -B, C) and II loci (HLA-DQ and -DR) calculated using serological or two-digit molecular typing compared to four-digit molecular typing methods. The proportion of donor/recipient pairs with a difference of >5 eplet mismatches between the HLA typing methods was also determined. Intra-class correlation coefficients between serological and four-digit molecular typing methods were 0.969 (95% confidence intervals [95% CI] 0.960-0.975) and 0.926 (95% CI 0.899-0.944), respectively; and 0.995 (95% CI 0.994-0.996) and 0.993 (95% CI 0.991-0.995), respectively between two-digit and four-digit molecular typing methods. The proportion of donor/recipient pairs with a difference of >5 eplet mismatches at class I and II loci was 4% and 16% for serological versus four-digit molecular typing methods, and 0% and 2% for two-digit versus four-digit molecular typing methods, respectively. In this small predominantly Caucasian population, compared with serology, there is a high level of agreement in the number of eplet mismatches calculated using two-compared to four-digit molecular HLA-typing methods, suggesting that two-digit typing may be sufficient in determining eplet mismatch load in kidney transplantation.

  2. A study of the validity and reliability of the Brazilian version of the Body Shape Questionnaire (BSQ among adolescents Estudo de validade e confiabilidade da versão brasileira do Body Shape Questionnaire (BSQ para adolescentes

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Conti

    2009-09-01

    Full Text Available OBJECTIVES: to produce evidence of the validity and reliability of the Body Shape Questionnaire (BSQ - a tool for measuring an individual's attitude towards his or her body image. METHODS: the study covered 386 young people of both sexes aged between 10 and 18 from a private school and used self-applied questionnaires and anthropometric evaluation. It evaluated the internal consistency, the discriminant validity for differences from the means, according to nutritional status (underweight, eutrophic, overweight and obese, the concurrent validity by way of Spearman's correlation coefficient between the scale and the Body Mass Index (BMI, the waist-hip circumference ratio (WHR and the waist circumference (WC. Reliability was tested using Wilcoxon's Test, the intraclass correlation coefficient and the Bland-Altman figures. RESULTS: the BSQ displayed good internal consistency (±=0.96 and was capable of discriminating among the total population, boys and girls, according to nutritional status (pOBJETIVOS: verificar evidência de validade e confiabilidade do Body Shape Questionnaire (BSQ - instrumento que mensura o aspecto atitudinal da imagem corporal. MÉTODOS: PArticiparam 386 jovens, de ambos os sexos, na faixa etária de 10-18 anos de uma escola particular de ensino, por meio de questionários auto-aplicáveis e avaliação antropométrica. Avaliou-se a consistência interna, a validade discriminante pelas diferenças das médias, segundo estado nutricional (baixo peso, eutrófico, sobrepeso e obesidade, a validade concorrente por meio do coeficiente de correlação de Spearman entre a escala e o Índice de Massa Corporal (IMC, a razão circunferência quadril (RCQ e a circunferência da cintura (CC. Para confiabilidade, utilizou-se o teste de Wilcoxon, o coeficiente de correlação intraclasse e as Figuras de Bland-Altman. RESULTADOS: o BSQ apresentou boa consistência interna (±=0,96 e foi capaz de discriminar população total, meninos e

  3. An approach for assessing human decision reliability

    International Nuclear Information System (INIS)

    Pyy, P.

    2000-01-01

    This paper presents a method to study human reliability in decision situations related to nuclear power plant disturbances. Decisions often play a significant role in handling of emergency situations. The method may be applied to probabilistic safety assessments (PSAs) in cases where decision making is an important dimension of an accident sequence. Such situations are frequent e.g. in accident management. In this paper, a modelling approach for decision reliability studies is first proposed. Then, a case study with two decision situations with relatively different characteristics is presented. Qualitative and quantitative findings of the study are discussed. In very simple decision cases with time pressure, time reliability correlation proved out to be a feasible reliability modelling method. In all other decision situations, more advanced probabilistic decision models have to be used. Finally, decision probability assessment by using simulator run results and expert judgement is presented

  4. Confiabilidade da versão em Português do Inventário de Fobia Social (SPIN entre adolescentes estudantes do Município do Rio de Janeiro Reliability of the Portuguese-language version of the Social Phobia Inventory (SPIN among adolescent students in the city of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Liliane Maria Pereira Vilete

    2004-02-01

    Full Text Available Acredita-se que a fobia social teria início na adolescência e que precederia outros transtornos mentais, sendo importante a sua investigação nos jovens. Até o momento, não há nenhuma escala de fobia social validada para a nossa população. Neste estudo investigou-se a confiabilidade da versão em Português do Social Phobia Inventory (SPIN entre escolares adolescentes da rede pública do Município do Rio de Janeiro. Após a versão do SPIN para o Português, conduziu-se um estudo de confiabilidade teste-reteste com 190 adolescentes de duas escolas, estimando-se os coeficientes de correlação intraclasse (CCIC, kappa ponderado (kw² e ajuste de modelos log-lineares. Foram ainda construídos gráficos Bland & Altman. Observou-se uma boa consistência interna (a de Cronbach = 0,88 e boa confiabilidade da pontuação total do instrumento (CCIC = 0,78. A confiabilidade das perguntas isoladas não foi tão boa (kw² variando de 0,32 a 0,65. O modelo log-linear de melhor ajuste aos dados na maior parte dos itens foi o de "semi-associação". Esses achados nos permitiram concluir que a versão em português do SPIN exibiu resultados de boa confiabilidade, semelhantes aos da versão original em Inglês.It is believed that social phobia has its onset during adolescence and precedes other mental disorders; it is thus important to investigate the condition among young people. To date there is no self-reported scale validated for the Brazilian population. The present study investigated the reliability of the Portuguese-language version of the Social Phobia Inventory (SPIN among adolescent students from public schools in the city of Rio de Janeiro. After SPIN was translated into Portuguese, a test-retest reliability study was carried out with 190 students. Intra-class correlation coefficient (ICC and weighted kappa (kw² were estimated, log-linear models were fitted, and Bland & Altman graphs were built. The Portuguese version showed good internal

  5. Safety and reliability criteria

    International Nuclear Information System (INIS)

    O'Neil, R.

    1978-01-01

    Nuclear power plants and, in particular, reactor pressure boundary components have unique reliability requirements, in that usually no significant redundancy is possible, and a single failure can give rise to possible widespread core damage and fission product release. Reliability may be required for availability or safety reasons, but in the case of the pressure boundary and certain other systems safety may dominate. Possible Safety and Reliability (S and R) criteria are proposed which would produce acceptable reactor design. Without some S and R requirement the designer has no way of knowing how far he must go in analysing his system or component, or whether his proposed solution is likely to gain acceptance. The paper shows how reliability targets for given components and systems can be individually considered against the derived S and R criteria at the design and construction stage. Since in the case of nuclear pressure boundary components there is often very little direct experience on which to base reliability studies, relevant non-nuclear experience is examined. (author)

  6. Proposed reliability cost model

    Science.gov (United States)

    Delionback, L. M.

    1973-01-01

    The research investigations which were involved in the study include: cost analysis/allocation, reliability and product assurance, forecasting methodology, systems analysis, and model-building. This is a classic example of an interdisciplinary problem, since the model-building requirements include the need for understanding and communication between technical disciplines on one hand, and the financial/accounting skill categories on the other. The systems approach is utilized within this context to establish a clearer and more objective relationship between reliability assurance and the subcategories (or subelements) that provide, or reenforce, the reliability assurance for a system. Subcategories are further subdivided as illustrated by a tree diagram. The reliability assurance elements can be seen to be potential alternative strategies, or approaches, depending on the specific goals/objectives of the trade studies. The scope was limited to the establishment of a proposed reliability cost-model format. The model format/approach is dependent upon the use of a series of subsystem-oriented CER's and sometimes possible CTR's, in devising a suitable cost-effective policy.

  7. Reliability Centered Maintenance - Methodologies

    Science.gov (United States)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  8. Issues in cognitive reliability

    International Nuclear Information System (INIS)

    Woods, D.D.; Hitchler, M.J.; Rumancik, J.A.

    1984-01-01

    This chapter examines some problems in current methods to assess reactor operator reliability at cognitive tasks and discusses new approaches to solve these problems. The two types of human failures are errors in the execution of an intention and errors in the formation/selection of an intention. Topics considered include the types of description, error correction, cognitive performance and response time, the speed-accuracy tradeoff function, function based task analysis, and cognitive task analysis. One problem of human reliability analysis (HRA) techniques in general is the question of what are the units of behavior whose reliability are to be determined. A second problem for HRA is that people often detect and correct their errors. The use of function based analysis, which maps the problem space for plant control, is recommended

  9. Reliability issues in PACS

    Science.gov (United States)

    Taira, Ricky K.; Chan, Kelby K.; Stewart, Brent K.; Weinberg, Wolfram S.

    1991-07-01

    Reliability is an increasing concern when moving PACS from the experimental laboratory to the clinical environment. Any system downtime may seriously affect patient care. The authors report on the several classes of errors encountered during the pre-clinical release of the PACS during the past several months and present the solutions implemented to handle them. The reliability issues discussed include: (1) environmental precautions, (2) database backups, (3) monitor routines of critical resources and processes, (4) hardware redundancy (networks, archives), and (5) development of a PACS quality control program.

  10. Reliability Parts Derating Guidelines

    Science.gov (United States)

    1982-06-01

    226-30, October 1974. 66 I, 26. "Reliability of GAAS Injection Lasers", De Loach , B. C., Jr., 1973 IEEE/OSA Conference on Laser Engineering and...Vol. R-23, No. 4, 226-30, October 1974. 28. "Reliability of GAAS Injection Lasers", De Loach , B. C., Jr., 1973 IEEE/OSA Conference on Laser...opnatien ot 󈨊 deg C, mounted on a 4-inach square 0.250~ inch thick al~loy alum~nusi panel.. This mounting technique should be L~ ken into cunoidur~tiou

  11. Columbus safety and reliability

    Science.gov (United States)

    Longhurst, F.; Wessels, H.

    1988-10-01

    Analyses carried out to ensure Columbus reliability, availability, and maintainability, and operational and design safety are summarized. Failure modes/effects/criticality is the main qualitative tool used. The main aspects studied are fault tolerance, hazard consequence control, risk minimization, human error effects, restorability, and safe-life design.

  12. Reliability versus reproducibility

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.

    1976-01-01

    Defect detection and reproducibility of results are two separate but closely related subjects. It is axiomatic that a defect must be detected from examination to examination or reproducibility of results is very poor. On the other hand, a defect can be detected on each of subsequent examinations for higher reliability and still have poor reproducibility of results

  13. Power transformer reliability modelling

    NARCIS (Netherlands)

    Schijndel, van A.

    2010-01-01

    Problem description Electrical power grids serve to transport and distribute electrical power with high reliability and availability at acceptable costs and risks. These grids play a crucial though preferably invisible role in supplying sufficient power in a convenient form. Today’s society has

  14. Designing reliability into accelerators

    International Nuclear Information System (INIS)

    Hutton, A.

    1992-08-01

    For the next generation of high performance, high average luminosity colliders, the ''factories,'' reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis

  15. Proof tests on reliability

    International Nuclear Information System (INIS)

    Mishima, Yoshitsugu

    1983-01-01

    In order to obtain public understanding on nuclear power plants, tests should be carried out to prove the reliability and safety of present LWR plants. For example, the aseismicity of nuclear power plants must be verified by using a large scale earthquake simulator. Reliability test began in fiscal 1975, and the proof tests on steam generators and on PWR support and flexure pins against stress corrosion cracking have already been completed, and the results have been internationally highly appreciated. The capacity factor of the nuclear power plant operation in Japan rose to 80% in the summer of 1983, and considering the period of regular inspection, it means the operation of almost full capacity. Japanese LWR technology has now risen to the top place in the world after having overcome the defects. The significance of the reliability test is to secure the functioning till the age limit is reached, to confirm the correct forecast of deteriorating process, to confirm the effectiveness of the remedy to defects and to confirm the accuracy of predicting the behavior of facilities. The reliability of nuclear valves, fuel assemblies, the heat affected zones in welding, reactor cooling pumps and electric instruments has been tested or is being tested. (Kako, I.)

  16. Reliability and code level

    NARCIS (Netherlands)

    Kasperski, M.; Geurts, C.P.W.

    2005-01-01

    The paper describes the work of the IAWE Working Group WBG - Reliability and Code Level, one of the International Codification Working Groups set up at ICWE10 in Copenhagen. The following topics are covered: sources of uncertainties in the design wind load, appropriate design target values for the

  17. Reliability of Plastic Slabs

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    1989-01-01

    In the paper it is shown how upper and lower bounds for the reliability of plastic slabs can be determined. For the fundamental case it is shown that optimal bounds of a deterministic and a stochastic analysis are obtained on the basis of the same failure mechanisms and the same stress fields....

  18. Reliability based structural design

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2014-01-01

    According to ISO 2394, structures shall be designed, constructed and maintained in such a way that they are suited for their use during the design working life in an economic way. To fulfil this requirement one needs insight into the risk and reliability under expected and non-expected actions. A

  19. Travel time reliability modeling.

    Science.gov (United States)

    2011-07-01

    This report includes three papers as follows: : 1. Guo F., Rakha H., and Park S. (2010), "A Multi-state Travel Time Reliability Model," : Transportation Research Record: Journal of the Transportation Research Board, n 2188, : pp. 46-54. : 2. Park S.,...

  20. Reliability and Model Fit

    Science.gov (United States)

    Stanley, Leanne M.; Edwards, Michael C.

    2016-01-01

    The purpose of this article is to highlight the distinction between the reliability of test scores and the fit of psychometric measurement models, reminding readers why it is important to consider both when evaluating whether test scores are valid for a proposed interpretation and/or use. It is often the case that an investigator judges both the…

  1. Parametric Mass Reliability Study

    Science.gov (United States)

    Holt, James P.

    2014-01-01

    The International Space Station (ISS) systems are designed based upon having redundant systems with replaceable orbital replacement units (ORUs). These ORUs are designed to be swapped out fairly quickly, but some are very large, and some are made up of many components. When an ORU fails, it is replaced on orbit with a spare; the failed unit is sometimes returned to Earth to be serviced and re-launched. Such a system is not feasible for a 500+ day long-duration mission beyond low Earth orbit. The components that make up these ORUs have mixed reliabilities. Components that make up the most mass-such as computer housings, pump casings, and the silicon board of PCBs-typically are the most reliable. Meanwhile components that tend to fail the earliest-such as seals or gaskets-typically have a small mass. To better understand the problem, my project is to create a parametric model that relates both the mass of ORUs to reliability, as well as the mass of ORU subcomponents to reliability.

  2. Reliability Approach of a Compressor System using Reliability Block ...

    African Journals Online (AJOL)

    pc

    2018-03-05

    Mar 5, 2018 ... This paper presents a reliability analysis of such a system using reliability ... Keywords-compressor system, reliability, reliability block diagram, RBD .... the same structure has been kept with the three subsystems: air flow, oil flow and .... and Safety in Engineering Design", Springer, 2009. [3] P. O'Connor ...

  3. The City of Hope-Quality of Life-Ostomy Questionnaire: Persian Translation and Validation

    OpenAIRE

    Anaraki, F; Vafaie, M; Behboo, R; Esmaeilpour, S; Maghsoodi, N; Safaee, A; Grant, M

    2014-01-01

    Background: Since there is no disease-specific instrument for measuring quality-of-life (QOL) in Ostomy patients in Persian language. Aim: This study was designed to translate and evaluate the validity and reliability of City of Hope-quality of life-Ostomy questionnaire (COH-QOL-Ostomy questionnaire). Subjects and Methods: This study was designed as cross-sectional study. Reliability of the subscales and the summary scores were demonstrated by intra-class correlation coefficients. Pearson's c...

  4. Reliability in the utility computing era: Towards reliable Fog computing

    DEFF Research Database (Denmark)

    Madsen, Henrik; Burtschy, Bernard; Albeanu, G.

    2013-01-01

    This paper considers current paradigms in computing and outlines the most important aspects concerning their reliability. The Fog computing paradigm as a non-trivial extension of the Cloud is considered and the reliability of the networks of smart devices are discussed. Combining the reliability...... requirements of grid and cloud paradigms with the reliability requirements of networks of sensor and actuators it follows that designing a reliable Fog computing platform is feasible....

  5. System reliability developments in structural engineering

    International Nuclear Information System (INIS)

    Moses, F.

    1982-01-01

    Two major limitations occur in present structural design code developments utilizing reliability theory. The notional system reliabilities may differ significantly from calibrated component reliabilities. Secondly, actual failures are often due to gross errors not reflected in most present code formats. A review is presented of system reliability methods and further new concepts are developed. The incremental load approach for identifying and expressing collapse modes is expanded by employing a strategy to identify and enumerate the significant structural collapse modes. It further isolates the importance of critical components in the system performance. Ductile and brittle component behavior and strength correlation is reflected in the system model and illustrated in several examples. Modal combinations for the system reliability are also reviewed. From these developments a system factor can be addended to component safety checking equations. Values may be derived from system behavior by substituting in a damage model which accounts for the response range from component failure to collapse. Other strategies are discussed which emphasize quality assurance during design and in-service inspection for components whose behavior is critical to the system reliability. (Auth.)

  6. Test-retest reliability of cognitive EEG

    Science.gov (United States)

    McEvoy, L. K.; Smith, M. E.; Gevins, A.

    2000-01-01

    OBJECTIVE: Task-related EEG is sensitive to changes in cognitive state produced by increased task difficulty and by transient impairment. If task-related EEG has high test-retest reliability, it could be used as part of a clinical test to assess changes in cognitive function. The aim of this study was to determine the reliability of the EEG recorded during the performance of a working memory (WM) task and a psychomotor vigilance task (PVT). METHODS: EEG was recorded while subjects rested quietly and while they performed the tasks. Within session (test-retest interval of approximately 1 h) and between session (test-retest interval of approximately 7 days) reliability was calculated for four EEG components: frontal midline theta at Fz, posterior theta at Pz, and slow and fast alpha at Pz. RESULTS: Task-related EEG was highly reliable within and between sessions (r0.9 for all components in WM task, and r0.8 for all components in the PVT). Resting EEG also showed high reliability, although the magnitude of the correlation was somewhat smaller than that of the task-related EEG (r0.7 for all 4 components). CONCLUSIONS: These results suggest that under appropriate conditions, task-related EEG has sufficient retest reliability for use in assessing clinical changes in cognitive status.

  7. RTE - Reliability report 2016

    International Nuclear Information System (INIS)

    2017-06-01

    Every year, RTE produces a reliability report for the past year. This document lays out the main factors that affected the electrical power system's operational reliability in 2016 and the initiatives currently under way intended to ensure its reliability in the future. Within a context of the energy transition, changes to the European interconnected network mean that RTE has to adapt on an on-going basis. These changes include the increase in the share of renewables injecting an intermittent power supply into networks, resulting in a need for flexibility, and a diversification in the numbers of stakeholders operating in the energy sector and changes in the ways in which they behave. These changes are dramatically changing the structure of the power system of tomorrow and the way in which it will operate - particularly the way in which voltage and frequency are controlled, as well as the distribution of flows, the power system's stability, the level of reserves needed to ensure supply-demand balance, network studies, assets' operating and control rules, the tools used and the expertise of operators. The results obtained in 2016 are evidence of a globally satisfactory level of reliability for RTE's operations in somewhat demanding circumstances: more complex supply-demand balance management, cross-border schedules at interconnections indicating operation that is closer to its limits and - most noteworthy - having to manage a cold spell just as several nuclear power plants had been shut down. In a drive to keep pace with the changes expected to occur in these circumstances, RTE implemented numerous initiatives to ensure high levels of reliability: - maintaining investment levels of euro 1.5 billion per year; - increasing cross-zonal capacity at borders with our neighbouring countries, thus bolstering the security of our electricity supply; - implementing new mechanisms (demand response, capacity mechanism, interruptibility, etc.); - involvement in tests or projects

  8. Waste package reliability analysis

    International Nuclear Information System (INIS)

    Pescatore, C.; Sastre, C.

    1983-01-01

    Proof of future performance of a complex system such as a high-level nuclear waste package over a period of hundreds to thousands of years cannot be had in the ordinary sense of the word. The general method of probabilistic reliability analysis could provide an acceptable framework to identify, organize, and convey the information necessary to satisfy the criterion of reasonable assurance of waste package performance according to the regulatory requirements set forth in 10 CFR 60. General principles which may be used to evaluate the qualitative and quantitative reliability of a waste package design are indicated and illustrated with a sample calculation of a repository concept in basalt. 8 references, 1 table

  9. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L; Duru, Ph; Koch, J M; Revol, J L; Van Vaerenbergh, P; Volpe, A M; Clugnet, K; Dely, A; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  10. Human Reliability Program Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Landers, John; Rogers, Erin; Gerke, Gretchen

    2014-05-18

    A Human Reliability Program (HRP) is designed to protect national security as well as worker and public safety by continuously evaluating the reliability of those who have access to sensitive materials, facilities, and programs. Some elements of a site HRP include systematic (1) supervisory reviews, (2) medical and psychological assessments, (3) management evaluations, (4) personnel security reviews, and (4) training of HRP staff and critical positions. Over the years of implementing an HRP, the Department of Energy (DOE) has faced various challenges and overcome obstacles. During this 4-day activity, participants will examine programs that mitigate threats to nuclear security and the insider threat to include HRP, Nuclear Security Culture (NSC) Enhancement, and Employee Assistance Programs. The focus will be to develop an understanding of the need for a systematic HRP and to discuss challenges and best practices associated with mitigating the insider threat.

  11. Reliability and construction control

    Directory of Open Access Journals (Sweden)

    Sherif S. AbdelSalam

    2016-06-01

    Full Text Available The goal of this study was to determine the most reliable and efficient combination of design and construction methods required for vibro piles. For a wide range of static and dynamic formulas, the reliability-based resistance factors were calculated using EGYPT database, which houses load test results for 318 piles. The analysis was extended to introduce a construction control factor that determines the variation between the pile nominal capacities calculated using static versus dynamic formulae. From the major outcomes, the lowest coefficient of variation is associated with Davisson’s criterion, and the resistance factors calculated for the AASHTO method are relatively high compared with other methods. Additionally, the CPT-Nottingham and Schmertmann method provided the most economic design. Recommendations related to a pile construction control factor were also presented, and it was found that utilizing the factor can significantly reduce variations between calculated and actual capacities.

  12. Scyllac equipment reliability analysis

    International Nuclear Information System (INIS)

    Gutscher, W.D.; Johnson, K.J.

    1975-01-01

    Most of the failures in Scyllac can be related to crowbar trigger cable faults. A new cable has been designed, procured, and is currently undergoing evaluation. When the new cable has been proven, it will be worked into the system as quickly as possible without causing too much additional down time. The cable-tip problem may not be easy or even desirable to solve. A tightly fastened permanent connection that maximizes contact area would be more reliable than the plug-in type of connection in use now, but it would make system changes and repairs much more difficult. The balance of the failures have such a low occurrence rate that they do not cause much down time and no major effort is underway to eliminate them. Even though Scyllac was built as an experimental system and has many thousands of components, its reliability is very good. Because of this the experiment has been able to progress at a reasonable pace

  13. Improving Power Converter Reliability

    DEFF Research Database (Denmark)

    Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon

    2014-01-01

    of a high-power IGBT module during converter operation, which may play a vital role in improving the reliability of the power converters. The measured voltage is used to estimate the module average junction temperature of the high and low-voltage side of a half-bridge IGBT separately in every fundamental......The real-time junction temperature monitoring of a high-power insulated-gate bipolar transistor (IGBT) module is important to increase the overall reliability of power converters for industrial applications. This article proposes a new method to measure the on-state collector?emitter voltage...... is measured in a wind power converter at a low fundamental frequency. To illustrate more, the test method as well as the performance of the measurement circuit are also presented. This measurement is also useful to indicate failure mechanisms such as bond wire lift-off and solder layer degradation...

  14. Accelerator reliability workshop

    International Nuclear Information System (INIS)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D.

    2002-01-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop

  15. Safety and reliability assessment

    International Nuclear Information System (INIS)

    1979-01-01

    This report contains the papers delivered at the course on safety and reliability assessment held at the CSIR Conference Centre, Scientia, Pretoria. The following topics were discussed: safety standards; licensing; biological effects of radiation; what is a PWR; safety principles in the design of a nuclear reactor; radio-release analysis; quality assurance; the staffing, organisation and training for a nuclear power plant project; event trees, fault trees and probability; Automatic Protective Systems; sources of failure-rate data; interpretation of failure data; synthesis and reliability; quantification of human error in man-machine systems; dispersion of noxious substances through the atmosphere; criticality aspects of enrichment and recovery plants; and risk and hazard analysis. Extensive examples are given as well as case studies

  16. Reliability of Circumplex Axes

    Directory of Open Access Journals (Sweden)

    Micha Strack

    2013-06-01

    Full Text Available We present a confirmatory factor analysis (CFA procedure for computing the reliability of circumplex axes. The tau-equivalent CFA variance decomposition model estimates five variance components: general factor, axes, scale-specificity, block-specificity, and item-specificity. Only the axes variance component is used for reliability estimation. We apply the model to six circumplex types and 13 instruments assessing interpersonal and motivational constructs—Interpersonal Adjective List (IAL, Interpersonal Adjective Scales (revised; IAS-R, Inventory of Interpersonal Problems (IIP, Impact Messages Inventory (IMI, Circumplex Scales of Interpersonal Values (CSIV, Support Action Scale Circumplex (SAS-C, Interaction Problems With Animals (IPI-A, Team Role Circle (TRC, Competing Values Leadership Instrument (CV-LI, Love Styles, Organizational Culture Assessment Instrument (OCAI, Customer Orientation Circle (COC, and System for Multi-Level Observation of Groups (behavioral adjectives; SYMLOG—in 17 German-speaking samples (29 subsamples, grouped by self-report, other report, and metaperception assessments. The general factor accounted for a proportion ranging from 1% to 48% of the item variance, the axes component for 2% to 30%; and scale specificity for 1% to 28%, respectively. Reliability estimates varied considerably from .13 to .92. An application of the Nunnally and Bernstein formula proposed by Markey, Markey, and Tinsley overestimated axes reliabilities in cases of large-scale specificities but otherwise works effectively. Contemporary circumplex evaluations such as Tracey’s RANDALL are sensitive to the ratio of the axes and scale-specificity components. In contrast, the proposed model isolates both components.

  17. The cost of reliability

    International Nuclear Information System (INIS)

    Ilic, M.

    1998-01-01

    In this article the restructuring process under way in the US power industry is being revisited from the point of view of transmission system provision and reliability was rolled into the average cost of electricity to all, it is not so obvious how is this cost managed in the new industry. A new MIT approach to transmission pricing is here suggested as a possible solution [it

  18. The Attenuation of Correlation Coefficients: A Statistical Literacy Issue

    Science.gov (United States)

    Trafimow, David

    2016-01-01

    Much of the science reported in the media depends on correlation coefficients. But the size of correlation coefficients depends, in part, on the reliability with which the correlated variables are measured. Understanding this is a statistical literacy issue.

  19. Software reliability studies

    Science.gov (United States)

    Hoppa, Mary Ann; Wilson, Larry W.

    1994-01-01

    There are many software reliability models which try to predict future performance of software based on data generated by the debugging process. Our research has shown that by improving the quality of the data one can greatly improve the predictions. We are working on methodologies which control some of the randomness inherent in the standard data generation processes in order to improve the accuracy of predictions. Our contribution is twofold in that we describe an experimental methodology using a data structure called the debugging graph and apply this methodology to assess the robustness of existing models. The debugging graph is used to analyze the effects of various fault recovery orders on the predictive accuracy of several well-known software reliability algorithms. We found that, along a particular debugging path in the graph, the predictive performance of different models can vary greatly. Similarly, just because a model 'fits' a given path's data well does not guarantee that the model would perform well on a different path. Further we observed bug interactions and noted their potential effects on the predictive process. We saw that not only do different faults fail at different rates, but that those rates can be affected by the particular debugging stage at which the rates are evaluated. Based on our experiment, we conjecture that the accuracy of a reliability prediction is affected by the fault recovery order as well as by fault interaction.

  20. Investment in new product reliability

    International Nuclear Information System (INIS)

    Murthy, D.N.P.; Rausand, M.; Virtanen, S.

    2009-01-01

    Product reliability is of great importance to both manufacturers and customers. Building reliability into a new product is costly, but the consequences of inadequate product reliability can be costlier. This implies that manufacturers need to decide on the optimal investment in new product reliability by achieving a suitable trade-off between the two costs. This paper develops a framework and proposes an approach to help manufacturers decide on the investment in new product reliability.

  1. Training benefits of research on operator reliability

    International Nuclear Information System (INIS)

    Worledge, D.H.

    1989-01-01

    The purpose of the EPRI Operator Reliability Experiments (ORE) Program is to collect data for use in reliability and safety studies of nuclear power plant operation which more realistically take credit for operator performance in preventing core damage. The three objectives in fulfilling this purpose are: to obtain quantitative/qualitative performance data on operating crew responses in the control room for potential accident sequences by using plant simulators; to test the human cognitive reliability (HCR) correlation; and to develop a data collection analysis procedure. This paper discusses the background to this program, data collection and analysis, and the results of quantitative/qualitative insights stemming from initial work. Special attention is paid to how this program impacts upon simulator use and assessment of simulator fidelity. Attention is also paid to the use of data collection procedures to assist training departments in assessing the quality of their training programs

  2. Nuclear performance and reliability

    International Nuclear Information System (INIS)

    Rothwell, G.

    1993-01-01

    If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive. There has been a significant improvement in nuclear power plant performance, due largely to a decline in the forced outage rate and a dramatic drop in the average number of forced outages per fuel cycle. If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive over time. To encourage further increases in performance, regulatory incentive schemes should reward reactor operators for improved reliability and safety, as well as for improved performance

  3. [How Reliable is Neuronavigation?].

    Science.gov (United States)

    Stieglitz, Lennart Henning

    2016-02-17

    Neuronavigation plays a central role in modern neurosurgery. It allows visualizing instruments and three-dimensional image data intraoperatively and supports spatial orientation. Thus it allows to reduce surgical risks and speed up complex surgical procedures. The growing availability and importance of neuronavigation makes clear how relevant it is to know about its reliability and accuracy. Different factors may influence the accuracy during the surgery unnoticed, misleading the surgeon. Besides the best possible optimization of the systems themselves, a good knowledge about its weaknesses is mandatory for every neurosurgeon.

  4. The value of reliability

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Karlström, Anders

    2010-01-01

    We derive the value of reliability in the scheduling of an activity of random duration, such as travel under congested conditions. Using a simple formulation of scheduling utility, we show that the maximal expected utility is linear in the mean and standard deviation of trip duration, regardless...... of the form of the standardised distribution of trip durations. This insight provides a unification of the scheduling model and models that include the standard deviation of trip duration directly as an argument in the cost or utility function. The results generalise approximately to the case where the mean...

  5. Reliability of lifeline networks under seismic hazard

    International Nuclear Information System (INIS)

    Selcuk, A. Sevtap; Yuecemen, M. Semih

    1999-01-01

    Lifelines, such as pipelines, transportation, communication and power transmission systems, are networks which extend spatially over large geographical regions. The quantification of the reliability (survival probability) of a lifeline under seismic threat requires attention, as the proper functioning of these systems during or after a destructive earthquake is vital. In this study, a lifeline is idealized as an equivalent network with the capacity of its elements being random and spatially correlated and a comprehensive probabilistic model for the assessment of the reliability of lifelines under earthquake loads is developed. The seismic hazard that the network is exposed to is described by a probability distribution derived by using the past earthquake occurrence data. The seismic hazard analysis is based on the 'classical' seismic hazard analysis model with some modifications. An efficient algorithm developed by Yoo and Deo (Yoo YB, Deo N. A comparison of algorithms for terminal pair reliability. IEEE Transactions on Reliability 1988; 37: 210-215) is utilized for the evaluation of the network reliability. This algorithm eliminates the CPU time and memory capacity problems for large networks. A comprehensive computer program, called LIFEPACK is coded in Fortran language in order to carry out the numerical computations. Two detailed case studies are presented to show the implementation of the proposed model

  6. Interactive reliability assessment using an integrated reliability data bank

    International Nuclear Information System (INIS)

    Allan, R.N.; Whitehead, A.M.

    1986-01-01

    The logical structure, techniques and practical application of a computer-aided technique based on a microcomputer using floppy disc Random Access Files is described. This interactive computational technique is efficient if the reliability prediction program is coupled directly to a relevant source of data to create an integrated reliability assessment/reliability data bank system. (DG)

  7. Reliability metrics extraction for power electronics converter stressed by thermal cycles

    DEFF Research Database (Denmark)

    Ma, Ke; Choi, Uimin; Blaabjerg, Frede

    2017-01-01

    Due to the continuous demands for highly reliable and cost-effective power conversion, the quantified reliability performances of the power electronics converter are becoming emerging needs. The existing reliability modelling approaches for the power electronics converter mainly focuses on the pr...... performance of power electronics system. The final predicted results showed good accuracy with much more reliability information compared to the existing approaches, and the quantified reliability correlation to the mission profiles of converter is mathematically established....

  8. Load Control System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Trudnowski, Daniel [Montana Tech of the Univ. of Montana, Butte, MT (United States)

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  9. Microprocessor hardware reliability

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R I

    1982-01-01

    Microprocessor-based technology has had an impact in nearly every area of industrial electronics and many applications have important safety implications. Microprocessors are being used for the monitoring and control of hazardous processes in the chemical, oil and power generation industries, for the control and instrumentation of aircraft and other transport systems and for the control of industrial machinery. Even in the field of nuclear reactor protection, where designers are particularly conservative, microprocessors are used to implement certain safety functions and may play increasingly important roles in protection systems in the future. Where microprocessors are simply replacing conventional hard-wired control and instrumentation systems no new hazards are created by their use. In the field of robotics, however, the microprocessor has opened up a totally new technology and with it has created possible new and as yet unknown hazards. The paper discusses some of the design and manufacturing techniques which may be used to enhance the reliability of microprocessor based systems and examines the available reliability data on lsi/vlsi microcircuits. 12 references.

  10. Supply chain reliability modelling

    Directory of Open Access Journals (Sweden)

    Eugen Zaitsev

    2012-03-01

    Full Text Available Background: Today it is virtually impossible to operate alone on the international level in the logistics business. This promotes the establishment and development of new integrated business entities - logistic operators. However, such cooperation within a supply chain creates also many problems related to the supply chain reliability as well as the optimization of the supplies planning. The aim of this paper was to develop and formulate the mathematical model and algorithms to find the optimum plan of supplies by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Methods: The mathematical model and algorithms to find the optimum plan of supplies were developed and formulated by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Results and conclusions: The problem of ensuring failure-free performance of goods supply channel analyzed in the paper is characteristic of distributed network systems that make active use of business process outsourcing technologies. The complex planning problem occurring in such systems that requires taking into account the consumer's requirements for failure-free performance in terms of supply volumes and correctness can be reduced to a relatively simple linear programming problem through logical analysis of the structures. The sequence of the operations, which should be taken into account during the process of the supply planning with the supplier's functional reliability, was presented.

  11. Superadditive correlation

    International Nuclear Information System (INIS)

    Giraud, B.G.; Heumann, J.M.; Lapedes, A.S.

    1999-01-01

    The fact that correlation does not imply causation is well known. Correlation between variables at two sites does not imply that the two sites directly interact, because, e.g., correlation between distant sites may be induced by chaining of correlation between a set of intervening, directly interacting sites. Such 'noncausal correlation' is well understood in statistical physics: an example is long-range order in spin systems, where spins which have only short-range direct interactions, e.g., the Ising model, display correlation at a distance. It is less well recognized that such long-range 'noncausal' correlations can in fact be stronger than the magnitude of any causal correlation induced by direct interactions. We call this phenomenon superadditive correlation (SAC). We demonstrate this counterintuitive phenomenon by explicit examples in (i) a model spin system and (ii) a model continuous variable system, where both models are such that two variables have multiple intervening pathways of indirect interaction. We apply the technique known as decimation to explain SAC as an additive, constructive interference phenomenon between the multiple pathways of indirect interaction. We also explain the effect using a definition of the collective mode describing the intervening spin variables. Finally, we show that the SAC effect is mirrored in information theory, and is true for mutual information measures in addition to correlation measures. Generic complex systems typically exhibit multiple pathways of indirect interaction, making SAC a potentially widespread phenomenon. This affects, e.g., attempts to deduce interactions by examination of correlations, as well as, e.g., hierarchical approximation methods for multivariate probability distributions, which introduce parameters based on successive orders of correlation. copyright 1999 The American Physical Society

  12. Pair Correlation Function Integrals

    DEFF Research Database (Denmark)

    Wedberg, Nils Hejle Rasmus Ingemar; O'Connell, John P.; Peters, Günther H.J.

    2011-01-01

    We describe a method for extending radial distribution functions obtained from molecular simulations of pure and mixed molecular fluids to arbitrary distances. The method allows total correlation function integrals to be reliably calculated from simulations of relatively small systems. The long......-distance behavior of radial distribution functions is determined by requiring that the corresponding direct correlation functions follow certain approximations at long distances. We have briefly described the method and tested its performance in previous communications [R. Wedberg, J. P. O’Connell, G. H. Peters......, and J. Abildskov, Mol. Simul. 36, 1243 (2010); Fluid Phase Equilib. 302, 32 (2011)], but describe here its theoretical basis more thoroughly and derive long-distance approximations for the direct correlation functions. We describe the numerical implementation of the method in detail, and report...

  13. OSS reliability measurement and assessment

    CERN Document Server

    Yamada, Shigeru

    2016-01-01

    This book analyses quantitative open source software (OSS) reliability assessment and its applications, focusing on three major topic areas: the Fundamentals of OSS Quality/Reliability Measurement and Assessment; the Practical Applications of OSS Reliability Modelling; and Recent Developments in OSS Reliability Modelling. Offering an ideal reference guide for graduate students and researchers in reliability for open source software (OSS) and modelling, the book introduces several methods of reliability assessment for OSS including component-oriented reliability analysis based on analytic hierarchy process (AHP), analytic network process (ANP), and non-homogeneous Poisson process (NHPP) models, the stochastic differential equation models and hazard rate models. These measurement and management technologies are essential to producing and maintaining quality/reliable systems using OSS.

  14. Transit ridership, reliability, and retention.

    Science.gov (United States)

    2008-10-01

    This project explores two major components that affect transit ridership: travel time reliability and rider : retention. It has been recognized that transit travel time reliability may have a significant impact on : attractiveness of transit to many ...

  15. Travel reliability inventory for Chicago.

    Science.gov (United States)

    2013-04-01

    The overarching goal of this research project is to enable state DOTs to document and monitor the reliability performance : of their highway networks. To this end, a computer tool, TRIC, was developed to produce travel reliability inventories from : ...

  16. Distribution-level electricity reliability: Temporal trends using statistical analysis

    International Nuclear Information System (INIS)

    Eto, Joseph H.; LaCommare, Kristina H.; Larsen, Peter; Todd, Annika; Fisher, Emily

    2012-01-01

    This paper helps to address the lack of comprehensive, national-scale information on the reliability of the U.S. electric power system by assessing trends in U.S. electricity reliability based on the information reported by the electric utilities on power interruptions experienced by their customers. The research analyzes up to 10 years of electricity reliability information collected from 155 U.S. electric utilities, which together account for roughly 50% of total U.S. electricity sales. We find that reported annual average duration and annual average frequency of power interruptions have been increasing over time at a rate of approximately 2% annually. We find that, independent of this trend, installation or upgrade of an automated outage management system is correlated with an increase in the reported annual average duration of power interruptions. We also find that reliance on IEEE Standard 1366-2003 is correlated with higher reported reliability compared to reported reliability not using the IEEE standard. However, we caution that we cannot attribute reliance on the IEEE standard as having caused or led to higher reported reliability because we could not separate the effect of reliance on the IEEE standard from other utility-specific factors that may be correlated with reliance on the IEEE standard. - Highlights: ► We assess trends in electricity reliability based on the information reported by the electric utilities. ► We use rigorous statistical techniques to account for utility-specific differences. ► We find modest declines in reliability analyzing interruption duration and frequency experienced by utility customers. ► Installation or upgrade of an OMS is correlated to an increase in reported duration of power interruptions. ► We find reliance in IEEE Standard 1366 is correlated with higher reported reliability.

  17. Exponential smoothing weighted correlations

    Science.gov (United States)

    Pozzi, F.; Di Matteo, T.; Aste, T.

    2012-06-01

    In many practical applications, correlation matrices might be affected by the "curse of dimensionality" and by an excessive sensitiveness to outliers and remote observations. These shortcomings can cause problems of statistical robustness especially accentuated when a system of dynamic correlations over a running window is concerned. These drawbacks can be partially mitigated by assigning a structure of weights to observational events. In this paper, we discuss Pearson's ρ and Kendall's τ correlation matrices, weighted with an exponential smoothing, computed on moving windows using a data-set of daily returns for 300 NYSE highly capitalized companies in the period between 2001 and 2003. Criteria for jointly determining optimal weights together with the optimal length of the running window are proposed. We find that the exponential smoothing can provide more robust and reliable dynamic measures and we discuss that a careful choice of the parameters can reduce the autocorrelation of dynamic correlations whilst keeping significance and robustness of the measure. Weighted correlations are found to be smoother and recovering faster from market turbulence than their unweighted counterparts, helping also to discriminate more effectively genuine from spurious correlations.

  18. 2017 NREL Photovoltaic Reliability Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-15

    NREL's Photovoltaic (PV) Reliability Workshop (PVRW) brings together PV reliability experts to share information, leading to the improvement of PV module reliability. Such improvement reduces the cost of solar electricity and promotes investor confidence in the technology -- both critical goals for moving PV technologies deeper into the electricity marketplace.

  19. AECL's reliability and maintainability program

    International Nuclear Information System (INIS)

    Wolfe, W.A.; Nieuwhof, G.W.E.

    1976-05-01

    AECL's reliability and maintainability program for nuclear generating stations is described. How the various resources of the company are organized to design and construct stations that operate reliably and safely is shown. Reliability and maintainability includes not only special mathematically oriented techniques, but also the technical skills and organizational abilities of the company. (author)

  20. Reliable and Valid Assessment of Clinical Bronchoscopy Performance

    DEFF Research Database (Denmark)

    Konge, Lars; Larsen, Klaus Richter; Clementsen, Paul

    2012-01-01

    : The interrater reliability was high, with Cronbach's a = 0.86. Assessment of 3 bronchoscopies by a single rater had a generalizability coefficient of 0.84. The correlation between experience and performance was good (Pearson correlation = 0.76). There were significant differences between the groups for all...

  1. Business of reliability

    Science.gov (United States)

    Engel, Pierre

    1999-12-01

    The presentation is organized around three themes: (1) The decrease of reception equipment costs allows non-Remote Sensing organization to access a technology until recently reserved to scientific elite. What this means is the rise of 'operational' executive agencies considering space-based technology and operations as a viable input to their daily tasks. This is possible thanks to totally dedicated ground receiving entities focusing on one application for themselves, rather than serving a vast community of users. (2) The multiplication of earth observation platforms will form the base for reliable technical and financial solutions. One obstacle to the growth of the earth observation industry is the variety of policies (commercial versus non-commercial) ruling the distribution of the data and value-added products. In particular, the high volume of data sales required for the return on investment does conflict with traditional low-volume data use for most applications. Constant access to data sources supposes monitoring needs as well as technical proficiency. (3) Large volume use of data coupled with low- cost equipment costs is only possible when the technology has proven reliable, in terms of application results, financial risks and data supply. Each of these factors is reviewed. The expectation is that international cooperation between agencies and private ventures will pave the way for future business models. As an illustration, the presentation proposes to use some recent non-traditional monitoring applications, that may lead to significant use of earth observation data, value added products and services: flood monitoring, ship detection, marine oil pollution deterrent systems and rice acreage monitoring.

  2. Electronics reliability calculation and design

    CERN Document Server

    Dummer, Geoffrey W A; Hiller, N

    1966-01-01

    Electronics Reliability-Calculation and Design provides an introduction to the fundamental concepts of reliability. The increasing complexity of electronic equipment has made problems in designing and manufacturing a reliable product more and more difficult. Specific techniques have been developed that enable designers to integrate reliability into their products, and reliability has become a science in its own right. The book begins with a discussion of basic mathematical and statistical concepts, including arithmetic mean, frequency distribution, median and mode, scatter or dispersion of mea

  3. Reliability Correction for Functional Connectivity: Theory and Implementation

    Science.gov (United States)

    Mueller, Sophia; Wang, Danhong; Fox, Michael D.; Pan, Ruiqi; Lu, Jie; Li, Kuncheng; Sun, Wei; Buckner, Randy L.; Liu, Hesheng

    2016-01-01

    Network properties can be estimated using functional connectivity MRI (fcMRI). However, regional variation of the fMRI signal causes systematic biases in network estimates including correlation attenuation in regions of low measurement reliability. Here we computed the spatial distribution of fcMRI reliability using longitudinal fcMRI datasets and demonstrated how pre-estimated reliability maps can correct for correlation attenuation. As a test case of reliability-based attenuation correction we estimated properties of the default network, where reliability was significantly lower than average in the medial temporal lobe and higher in the posterior medial cortex, heterogeneity that impacts estimation of the network. Accounting for this bias using attenuation correction revealed that the medial temporal lobe’s contribution to the default network is typically underestimated. To render this approach useful to a greater number of datasets, we demonstrate that test-retest reliability maps derived from repeated runs within a single scanning session can be used as a surrogate for multi-session reliability mapping. Using data segments with different scan lengths between 1 and 30 min, we found that test-retest reliability of connectivity estimates increases with scan length while the spatial distribution of reliability is relatively stable even at short scan lengths. Finally, analyses of tertiary data revealed that reliability distribution is influenced by age, neuropsychiatric status and scanner type, suggesting that reliability correction may be especially important when studying between-group differences. Collectively, these results illustrate that reliability-based attenuation correction is an easily implemented strategy that mitigates certain features of fMRI signal nonuniformity. PMID:26493163

  4. The validation of the visual analogue scale for patient satisfaction after total hip arthroplasty.

    Science.gov (United States)

    Brokelman, Roy B G; Haverkamp, Daniel; van Loon, Corné; Hol, Annemiek; van Kampen, Albert; Veth, Rene

    2012-06-01

    INTRODUCTION: Patient satisfaction becomes more important in our modern health care system. The assessment of satisfaction is difficult because it is a multifactorial item for which no golden standard exists. One of the potential methods of measuring satisfaction is by using the well-known visual analogue scale (VAS). In this study, we validated VAS for satisfaction. PATIENT AND METHODS: In this prospective study, we studied 147 patients (153 hips). The construct validity was measured using the Spearman correlation test that compares the satisfaction VAS with the Harris hip score, pain VAS at rest and during activity, Oxford hip score, Short Form 36 and Western Ontario McMaster Universities Osteoarthritis Index. The reliability was tested using the intra-class coefficient. RESULTS: The Pearson correlation test showed correlations in the range of 0.40-0.80. The satisfaction VAS had a high correlation between the pain VAS and Oxford hip score, which could mean that pain is one of the most important factors in patient satisfaction. The intra-class coefficient was 0.95. CONCLUSIONS: There is a moderate to mark degree of correlation between the satisfaction VAS and the currently available subjective and objective scoring systems. The intra-class coefficient of 0.95 indicates an excellent test-retest reliability. The VAS satisfaction is a simple instrument to quantify the satisfaction of a patient after total hip arthroplasty. In this study, we showed that the satisfaction VAS has a good validity and reliability.

  5. The Assumption of a Reliable Instrument and Other Pitfalls to Avoid When Considering the Reliability of Data

    Science.gov (United States)

    Nimon, Kim; Zientek, Linda Reichwein; Henson, Robin K.

    2012-01-01

    The purpose of this article is to help researchers avoid common pitfalls associated with reliability including incorrectly assuming that (a) measurement error always attenuates observed score correlations, (b) different sources of measurement error originate from the same source, and (c) reliability is a function of instrumentation. To accomplish our purpose, we first describe what reliability is and why researchers should care about it with focus on its impact on effect sizes. Second, we review how reliability is assessed with comment on the consequences of cumulative measurement error. Third, we consider how researchers can use reliability generalization as a prescriptive method when designing their research studies to form hypotheses about whether or not reliability estimates will be acceptable given their sample and testing conditions. Finally, we discuss options that researchers may consider when faced with analyzing unreliable data. PMID:22518107

  6. Mathematical reliability an expository perspective

    CERN Document Server

    Mazzuchi, Thomas; Singpurwalla, Nozer

    2004-01-01

    In this volume consideration was given to more advanced theoretical approaches and novel applications of reliability to ensure that topics having a futuristic impact were specifically included. Topics like finance, forensics, information, and orthopedics, as well as the more traditional reliability topics were purposefully undertaken to make this collection different from the existing books in reliability. The entries have been categorized into seven parts, each emphasizing a theme that seems poised for the future development of reliability as an academic discipline with relevance. The seven parts are networks and systems; recurrent events; information and design; failure rate function and burn-in; software reliability and random environments; reliability in composites and orthopedics, and reliability in finance and forensics. Embedded within the above are some of the other currently active topics such as causality, cascading, exchangeability, expert testimony, hierarchical modeling, optimization and survival...

  7. Of plants and reliability

    International Nuclear Information System (INIS)

    Schneider Horst

    2009-01-01

    Behind the political statements made about the transformer event at the Kruemmel nuclear power station (KKK) in the summer of 2009 there are fundamental issues of atomic law. Pursuant to Articles 20 and 28 of its Basic Law, Germany is a state in which the rule of law applies. Consequently, the aspects of atomic law associated with the incident merit a closer look, all the more so as the items concerned have been known for many years. Important aspects in the debate about the Kruemmel nuclear power plant are the fact that the transformer is considered part of the nuclear power station under atomic law and thus a ''plant'' subject to surveillance by the nuclear regulatory agencies, on the one hand, and the reliability under atomic law of the operator and the executive personnel responsible, on the other hand. Both ''plant'' and ''reliability'' are terms focusing on nuclear safety. Hence the question to what extent safety was affected in the Kruemmel incident. The classification of the event as 0 = no or only a very slight safety impact on the INES scale (INES = International Nuclear Event Scale) should not be used to put aside the safety issue once and for all. Points of fact and their technical significance must be considered prior to any legal assessment. Legal assessments and regulations are associated with facts and circumstances. Any legal examination is based on the facts as determined and elucidated. Any other procedure would be tantamount to an inadmissible legal advance conviction. Now, what is the position of political statements, i.e. political assessments and political responsibility? If everything is done the correct way, they come at the end, after exploration of the facts and evaluation under applicable law. Sometimes things are handled differently, with consequences which are not very helpful. In the light of the provisions about the rule of law as laid down in the Basic Law, the new federal government should be made to observe the proper sequence of

  8. Multinomial-exponential reliability function: a software reliability model

    International Nuclear Information System (INIS)

    Saiz de Bustamante, Amalio; Saiz de Bustamante, Barbara

    2003-01-01

    The multinomial-exponential reliability function (MERF) was developed during a detailed study of the software failure/correction processes. Later on MERF was approximated by a much simpler exponential reliability function (EARF), which keeps most of MERF mathematical properties, so the two functions together makes up a single reliability model. The reliability model MERF/EARF considers the software failure process as a non-homogeneous Poisson process (NHPP), and the repair (correction) process, a multinomial distribution. The model supposes that both processes are statistically independent. The paper discusses the model's theoretical basis, its mathematical properties and its application to software reliability. Nevertheless it is foreseen model applications to inspection and maintenance of physical systems. The paper includes a complete numerical example of the model application to a software reliability analysis

  9. Quality assurance and reliability

    International Nuclear Information System (INIS)

    Normand, J.; Charon, M.

    1975-01-01

    Concern for obtaining high-quality products which will function properly when required to do so is nothing new - it is one manifestation of a conscientious attitude to work. However, the complexity and cost of equipment and the consequences of even temporary immobilization are such that it has become necessary to make special arrangements for obtaining high-quality products and examining what one has obtained. Each unit within an enterprise must examine its own work or arrange for it to be examined; a unit whose specific task is quality assurance is responsible for overall checking, but does not relieve other units of their responsibility. Quality assurance is a form of mutual assistance within an enterprise, designed to remove the causes of faults as far as possible. It begins very early in a project and continues through the ordering stage, construction, start-up trials and operation. Quality and hence reliability are the direct result of what is done at all stages of a project. They depend on constant attention to detail, for even a minor piece of poor workmanship can, in the case of an essential item of equipment, give rise to serious operational difficulties

  10. Reliability of Oronasal Fistula Classification.

    Science.gov (United States)

    Sitzman, Thomas J; Allori, Alexander C; Matic, Damir B; Beals, Stephen P; Fisher, David M; Samson, Thomas D; Marcus, Jeffrey R; Tse, Raymond W

    2018-01-01

    Objective Oronasal fistula is an important complication of cleft palate repair that is frequently used to evaluate surgical quality, yet reliability of fistula classification has never been examined. The objective of this study was to determine the reliability of oronasal fistula classification both within individual surgeons and between multiple surgeons. Design Using intraoral photographs of children with repaired cleft palate, surgeons rated the location of palatal fistulae using the Pittsburgh Fistula Classification System. Intrarater and interrater reliability scores were calculated for each region of the palate. Participants Eight cleft surgeons rated photographs obtained from 29 children. Results Within individual surgeons reliability for each region of the Pittsburgh classification ranged from moderate to almost perfect (κ = .60-.96). By contrast, reliability between surgeons was lower, ranging from fair to substantial (κ = .23-.70). Between-surgeon reliability was lowest for the junction of the soft and hard palates (κ = .23). Within-surgeon and between-surgeon reliability were almost perfect for the more general classification of fistula in the secondary palate (κ = .95 and κ = .83, respectively). Conclusions This is the first reliability study of fistula classification. We show that the Pittsburgh Fistula Classification System is reliable when used by an individual surgeon, but less reliable when used among multiple surgeons. Comparisons of fistula occurrence among surgeons may be subject to less bias if they use the more general classification of "presence or absence of fistula of the secondary palate" rather than the Pittsburgh Fistula Classification System.

  11. Methodology for reliability based condition assessment

    International Nuclear Information System (INIS)

    Mori, Y.; Ellingwood, B.

    1993-08-01

    Structures in nuclear power plants may be exposed to aggressive environmental effects that cause their strength to decrease over an extended period of service. A major concern in evaluating the continued service for such structures is to ensure that in their current condition they are able to withstand future extreme load events during the intended service life with a level of reliability sufficient for public safety. This report describes a methodology to facilitate quantitative assessments of current and future structural reliability and performance of structures in nuclear power plants. This methodology takes into account the nature of past and future loads, and randomness in strength and in degradation resulting from environmental factors. An adaptive Monte Carlo simulation procedure is used to evaluate time-dependent system reliability. The time-dependent reliability is sensitive to the time-varying load characteristics and to the choice of initial strength and strength degradation models but not to correlation in component strengths within a system. Inspection/maintenance strategies are identified that minimize the expected future costs of keeping the failure probability of a structure at or below an established target failure probability during its anticipated service period

  12. Measurement of portal blood flow in healthy individuals: a comparison between magnetic resonance imaging and Doppler ultrasound

    International Nuclear Information System (INIS)

    Costa, Juliana Dantas da; Sebastiane, Patricia Moreno; Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; D'Ippolito, Giuseppe

    2008-01-01

    Objective: To evaluate the inter-observer agreement between Doppler ultrasonography and magnetic resonance imaging in the quantification of portal blood flow in healthy individuals, as well as evaluating the reproducibility of both methods. Materials and methods: A prospective, transverse, observational and self-paired study was developed evaluating 20 healthy volunteers whose portal blood flow was measured by means of Doppler ultrasonography and magnetic resonance imaging performed by two independent observers. Interobserver and inter method agreements were calculated using the intra class and Pearson's correlation coefficients. Results: The agreement between Doppler ultrasonography and magnetic resonance imaging was low (intra class coefficient: 1.9%-18.2%; Pearson's coefficient: 0.1%-13.7%; p=0.565). Mean values for the portal blood flow measured by Doppler ultrasonography and magnetic resonance imaging were respectively 0.768 l/min and 0.742 l/min. Interobserver agreement for quantification of the portal blood flow by Doppler ultrasonography and magnetic resonance imaging was respectively reasonable (intra class coefficient: 43.3%; Pearson's coefficient: 43.0%) and excellent (intra class coefficient: 91.4%; Pearson's coefficient: 93.4%). Conclusion: In the present study, magnetic resonance imaging demonstrated to be a reliable method for quantifying the portal blood flow, with a higher interobserver agreement than Doppler ultrasonography. The inter method agreement was low. (author)

  13. Deep Correlated Holistic Metric Learning for Sketch-Based 3D Shape Retrieval.

    Science.gov (United States)

    Dai, Guoxian; Xie, Jin; Fang, Yi

    2018-07-01

    How to effectively retrieve desired 3D models with simple queries is a long-standing problem in computer vision community. The model-based approach is quite straightforward but nontrivial, since people could not always have the desired 3D query model available by side. Recently, large amounts of wide-screen electronic devices are prevail in our daily lives, which makes the sketch-based 3D shape retrieval a promising candidate due to its simpleness and efficiency. The main challenge of sketch-based approach is the huge modality gap between sketch and 3D shape. In this paper, we proposed a novel deep correlated holistic metric learning (DCHML) method to mitigate the discrepancy between sketch and 3D shape domains. The proposed DCHML trains two distinct deep neural networks (one for each domain) jointly, which learns two deep nonlinear transformations to map features from both domains into a new feature space. The proposed loss, including discriminative loss and correlation loss, aims to increase the discrimination of features within each domain as well as the correlation between different domains. In the new feature space, the discriminative loss minimizes the intra-class distance of the deep transformed features and maximizes the inter-class distance of the deep transformed features to a large margin within each domain, while the correlation loss focused on mitigating the distribution discrepancy across different domains. Different from existing deep metric learning methods only with loss at the output layer, our proposed DCHML is trained with loss at both hidden layer and output layer to further improve the performance by encouraging features in the hidden layer also with desired properties. Our proposed method is evaluated on three benchmarks, including 3D Shape Retrieval Contest 2013, 2014, and 2016 benchmarks, and the experimental results demonstrate the superiority of our proposed method over the state-of-the-art methods.

  14. Correlation between RUST assessments of fracture healing to structural and biomechanical properties.

    Science.gov (United States)

    Cooke, Margaret E; Hussein, Amira I; Lybrand, Kyle E; Wulff, Alexander; Simmons, Erin; Choi, Jeffrey H; Litrenta, Jody; Ricci, William M; Nascone, Jason W; O'Toole, Robert V; Morgan, Elise F; Gerstenfeld, Louis C; Tornetta, Paul

    2018-03-01

    Radiographic Union Score for Tibia (RUST) and modified RUST (mRUST) are radiographic tools for quantitatively evaluating fracture healing using a cortical scoring system. This tool has high intra-class correlation coefficients (ICCs); however, little evidence has evaluated the scores against the physical properties of bone healing. Closed, stabilized fractures were made in the femora of C3H/HeJ male mice (8-12 week-old) of two dietary groups: A control and a phosphate restricted diet group. Micro-computed tomography (µCT) and torsion testing were carried out at post-operative days (POD) 14, 21, 35, and 42 (n = 10-16) per group time-point. Anteroposterior and lateral radiographic views were constructed from the µCT scans and scored by five raters. The raters also indicated if the fracture were healed. ICCs were 0.71 (mRUST) and 0.63 (RUST). Both RUST scores were positively correlated with callus bone mineral density (BMD) (r = 0.85 and 0.80, p RUST scores positively correlated with callus strength (r = 0.35 and 0.26, p RUST ≥10 and had excellent relationship to structural and biomechanical metrics. Effect of delayed healing due to phosphate dietary restrictions was found at later time points with all mechanical properties (p RUST scores (p > 0.318). Clinical relevance of this study is both RUST scores showed high correlation to physical properties of healing and generally distinguished healed vs. non-healed fractures. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:945-953, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  15. Reliability of reactor materials

    International Nuclear Information System (INIS)

    Toerroenen, K.; Aho-Mantila, I.

    1986-05-01

    This report is the final technical report of the fracture mechanics part of the Reliability of Reactor Materials Programme, which was carried out at the Technical Research Centre of Finland (VTT) through the years 1981 to 1983. Research and development work was carried out in five major areas, viz. statistical treatment and modelling of cleavage fracture, crack arrest, ductile fracture, instrumented impact testing as well as comparison of numerical and experimental elastic-plastic fracture mechanics. In the area of cleavage fracture the critical variables affecting the fracture of steels are considered in the frames of a statistical model, so called WST-model. Comparison of fracture toughness values predicted by the model and corresponding experimental values shows excellent agreement for a variety of microstructures. different posibilities for using the model are discussed. The development work in the area of crack arrest testing was concentrated in the crack starter properties, test arrangement and computer control. A computerized elastic-plastic fracture testing method with a variety of test specimen geometries in a large temperature range was developed for a routine stage. Ductile fracture characteristics of reactor pressure vessel steel A533B and comparable weld material are given. The features of a new, patented instrumented impact tester are described. Experimental and theoretical comparisons between the new and conventional testers indicated clearly the improvements achieved with the new tester. A comparison of numerical and experimental elastic-plastic fracture mechanics capabilities at VTT was carried out. The comparison consisted of two-dimensional linear elastic as well as elastic-plastic finite element analysis of four specimen geometries and equivalent experimental tests. (author)

  16. Field reliability of electronic systems

    International Nuclear Information System (INIS)

    Elm, T.

    1984-02-01

    This report investigates, through several examples from the field, the reliability of electronic units in a broader sense. That is, it treats not just random parts failure, but also inadequate reliability design and (externally and internally) induced failures. The report is not meant to be merely an indication of the state of the art for the reliability prediction methods we know, but also as a contribution to the investigation of man-machine interplay in the operation and repair of electronic equipment. The report firmly links electronics reliability to safety and risk analyses approaches with a broader, system oriented view of reliability prediction and with postfailure stress analysis. It is intended to reveal, in a qualitative manner, the existence of symptom and cause patterns. It provides a background for further investigations to identify the detailed mechanisms of the faults and the remedical actions and precautions for achieving cost effective reliability. (author)

  17. Reliability Assessment Of Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2014-01-01

    Reduction of cost of energy for wind turbines are very important in order to make wind energy competitive compared to other energy sources. Therefore the turbine components should be designed to have sufficient reliability but also not be too costly (and safe). This paper presents models...... for uncertainty modeling and reliability assessment of especially the structural components such as tower, blades, substructure and foundation. But since the function of a wind turbine is highly dependent on many electrical and mechanical components as well as a control system also reliability aspects...... of these components are discussed and it is described how there reliability influences the reliability of the structural components. Two illustrative examples are presented considering uncertainty modeling, reliability assessment and calibration of partial safety factors for structural wind turbine components exposed...

  18. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2014-01-01

    This book shows how to build in, evaluate, and demonstrate reliability and availability of components, equipment, systems. It presents the state-of-theart of reliability engineering, both in theory and practice, and is based on the author's more than 30 years experience in this field, half in industry and half as Professor of Reliability Engineering at the ETH, Zurich. The structure of the book allows rapid access to practical results. This final edition extend and replace all previous editions. New are, in particular, a strategy to mitigate incomplete coverage, a comprehensive introduction to human reliability with design guidelines and new models, and a refinement of reliability allocation, design guidelines for maintainability, and concepts related to regenerative stochastic processes. The set of problems for homework has been extended. Methods & tools are given in a way that they can be tailored to cover different reliability requirement levels and be used for safety analysis. Because of the Appendice...

  19. Reliability of Wireless Sensor Networks

    Science.gov (United States)

    Dâmaso, Antônio; Rosa, Nelson; Maciel, Paulo

    2014-01-01

    Wireless Sensor Networks (WSNs) consist of hundreds or thousands of sensor nodes with limited processing, storage, and battery capabilities. There are several strategies to reduce the power consumption of WSN nodes (by increasing the network lifetime) and increase the reliability of the network (by improving the WSN Quality of Service). However, there is an inherent conflict between power consumption and reliability: an increase in reliability usually leads to an increase in power consumption. For example, routing algorithms can send the same packet though different paths (multipath strategy), which it is important for reliability, but they significantly increase the WSN power consumption. In this context, this paper proposes a model for evaluating the reliability of WSNs considering the battery level as a key factor. Moreover, this model is based on routing algorithms used by WSNs. In order to evaluate the proposed models, three scenarios were considered to show the impact of the power consumption on the reliability of WSNs. PMID:25157553

  20. The value of service reliability

    OpenAIRE

    Benezech , Vincent; Coulombel , Nicolas

    2013-01-01

    International audience; This paper studies the impact of service frequency and reliability on the choice of departure time and the travel cost of transit users. When the user has (α, β, γ) scheduling preferences, we show that the optimal head start decreases with service reliability, as expected. It does not necessarily decrease with service frequency, however. We derive the value of service headway (VoSH) and the value of service reliability (VoSR), which measure the marginal effect on the e...

  1. Distribution-Independent Reliable Learning

    OpenAIRE

    Kanade, Varun; Thaler, Justin

    2014-01-01

    We study several questions in the reliable agnostic learning framework of Kalai et al. (2009), wh