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Sample records for prevalences confidence intervals

  1. Using the confidence interval confidently.

    Science.gov (United States)

    Hazra, Avijit

    2017-10-01

    Biomedical research is seldom done with entire populations but rather with samples drawn from a population. Although we work with samples, our goal is to describe and draw inferences regarding the underlying population. It is possible to use a sample statistic and estimates of error in the sample to get a fair idea of the population parameter, not as a single value, but as a range of values. This range is the confidence interval (CI) which is estimated on the basis of a desired confidence level. Calculation of the CI of a sample statistic takes the general form: CI = Point estimate ± Margin of error, where the margin of error is given by the product of a critical value (z) derived from the standard normal curve and the standard error of point estimate. Calculation of the standard error varies depending on whether the sample statistic of interest is a mean, proportion, odds ratio (OR), and so on. The factors affecting the width of the CI include the desired confidence level, the sample size and the variability in the sample. Although the 95% CI is most often used in biomedical research, a CI can be calculated for any level of confidence. A 99% CI will be wider than 95% CI for the same sample. Conflict between clinical importance and statistical significance is an important issue in biomedical research. Clinical importance is best inferred by looking at the effect size, that is how much is the actual change or difference. However, statistical significance in terms of P only suggests whether there is any difference in probability terms. Use of the CI supplements the P value by providing an estimate of actual clinical effect. Of late, clinical trials are being designed specifically as superiority, non-inferiority or equivalence studies. The conclusions from these alternative trial designs are based on CI values rather than the P value from intergroup comparison.

  2. Robust misinterpretation of confidence intervals

    NARCIS (Netherlands)

    Hoekstra, Rink; Morey, Richard; Rouder, Jeffrey N.; Wagenmakers, Eric-Jan

    2014-01-01

    Null hypothesis significance testing (NHST) is undoubtedly the most common inferential technique used to justify claims in the social sciences. However, even staunch defenders of NHST agree that its outcomes are often misinterpreted. Confidence intervals (CIs) have frequently been proposed as a more

  3. Robust misinterpretation of confidence intervals.

    Science.gov (United States)

    Hoekstra, Rink; Morey, Richard D; Rouder, Jeffrey N; Wagenmakers, Eric-Jan

    2014-10-01

    Null hypothesis significance testing (NHST) is undoubtedly the most common inferential technique used to justify claims in the social sciences. However, even staunch defenders of NHST agree that its outcomes are often misinterpreted. Confidence intervals (CIs) have frequently been proposed as a more useful alternative to NHST, and their use is strongly encouraged in the APA Manual. Nevertheless, little is known about how researchers interpret CIs. In this study, 120 researchers and 442 students-all in the field of psychology-were asked to assess the truth value of six particular statements involving different interpretations of a CI. Although all six statements were false, both researchers and students endorsed, on average, more than three statements, indicating a gross misunderstanding of CIs. Self-declared experience with statistics was not related to researchers' performance, and, even more surprisingly, researchers hardly outperformed the students, even though the students had not received any education on statistical inference whatsoever. Our findings suggest that many researchers do not know the correct interpretation of a CI. The misunderstandings surrounding p-values and CIs are particularly unfortunate because they constitute the main tools by which psychologists draw conclusions from data.

  4. Generalized Confidence Intervals and Fiducial Intervals for Some Epidemiological Measures

    Directory of Open Access Journals (Sweden)

    Ionut Bebu

    2016-06-01

    Full Text Available For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR from several studies, the number needed to treat (NNT, and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities even when the sample sizes are not large. An appealing feature of the proposed solutions is that they are not based on maximization of the likelihood, and hence are free from convergence issues associated with the numerical calculation of the maximum likelihood estimators, especially in the context of the log-binomial model. The results are illustrated with a number of examples. The overall conclusion is that the proposed methodologies based on generalized pivotal quantities and fiducial quantities provide an accurate and unified approach for the interval estimation of the various epidemiological measures in the context of binary outcome data with or without covariates.

  5. Interpretation of Confidence Interval Facing the Conflict

    Science.gov (United States)

    Andrade, Luisa; Fernández, Felipe

    2016-01-01

    As literature has reported, it is usual that university students in statistics courses, and even statistics teachers, interpret the confidence level associated with a confidence interval as the probability that the parameter value will be between the lower and upper interval limits. To confront this misconception, class activities have been…

  6. Confidence Interval Approximation For Treatment Variance In ...

    African Journals Online (AJOL)

    In a random effects model with a single factor, variation is partitioned into two as residual error variance and treatment variance. While a confidence interval can be imposed on the residual error variance, it is not possible to construct an exact confidence interval for the treatment variance. This is because the treatment ...

  7. Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions

    Science.gov (United States)

    Padilla, Miguel A.; Divers, Jasmin

    2013-01-01

    The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…

  8. Understanding Confidence Intervals With Visual Representations

    OpenAIRE

    Navruz, Bilgin; Delen, Erhan

    2014-01-01

    In the present paper, we showed how confidence intervals (CIs) are valuable and useful in research studies when they are used in the correct form with correct interpretations. The sixth edition of the APA (2010) Publication Manual strongly recommended reporting CIs in research studies, and it was described as “the best reporting strategy” (p. 34). Misconceptions and correct interpretations of CIs were presented from several textbooks. In addition, limitations of the null hypothesis statistica...

  9. Confidence intervals for the lognormal probability distribution

    International Nuclear Information System (INIS)

    Smith, D.L.; Naberejnev, D.G.

    2004-01-01

    The present communication addresses the topic of symmetric confidence intervals for the lognormal probability distribution. This distribution is frequently utilized to characterize inherently positive, continuous random variables that are selected to represent many physical quantities in applied nuclear science and technology. The basic formalism is outlined herein and a conjured numerical example is provided for illustration. It is demonstrated that when the uncertainty reflected in a lognormal probability distribution is large, the use of a confidence interval provides much more useful information about the variable used to represent a particular physical quantity than can be had by adhering to the notion that the mean value and standard deviation of the distribution ought to be interpreted as best value and corresponding error, respectively. Furthermore, it is shown that if the uncertainty is very large a disturbing anomaly can arise when one insists on interpreting the mean value and standard deviation as the best value and corresponding error, respectively. Reliance on using the mode and median as alternative parameters to represent the best available knowledge of a variable with large uncertainties is also shown to entail limitations. Finally, a realistic physical example involving the decay of radioactivity over a time period that spans many half-lives is presented and analyzed to further illustrate the concepts discussed in this communication

  10. Confidence Intervals from Normalized Data: A correction to Cousineau (2005

    Directory of Open Access Journals (Sweden)

    Richard D. Morey

    2008-09-01

    Full Text Available Presenting confidence intervals around means is a common method of expressing uncertainty in data. Loftus and Masson (1994 describe confidence intervals for means in within-subjects designs. These confidence intervals are based on the ANOVA mean squared error. Cousineau (2005 presents an alternative to the Loftus and Masson method, but his method produces confidence intervals that are smaller than those of Loftus and Masson. I show why this is the case and offer a simple correction that makes the expected size of Cousineau confidence intervals the same as that of Loftus and Masson confidence intervals.

  11. Learning about confidence intervals with software R

    Directory of Open Access Journals (Sweden)

    Gariela Gonçalves

    2013-08-01

    Full Text Available 0 0 1 202 1111 USAL 9 2 1311 14.0 Normal 0 21 false false false ES JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-ansi-language:ES; mso-fareast-language:EN-US;} This work was to study the feasibility of implementing a teaching method that employs software, in a Computational Mathematics course, involving students and teachers through the use of the statistical software R in carrying out practical work, such as strengthening the traditional teaching. The statistical inference, namely the determination of confidence intervals, was the content selected for this experience. It was intended show, first of all, that it is possible to promote, through the proposal methodology, the acquisition of basic skills in statistical inference and to promote the positive relationships between teachers and students. It presents also a comparative study between the methodologies used and their quantitative and qualitative results on two consecutive school years, in several indicators. The data used in the study were obtained from the students to the exam questions in the years 2010/2011 and 2011/2012, from the achievement of a working group in 2011/2012 and via the responses to a questionnaire (optional and anonymous also applied in 2011 / 2012. In terms of results, we emphasize a better performance of students in the examination questions in 2011/2012, the year that students used the software R, and a very favorable student’s perspective about

  12. Confidence Intervals: From tests of statistical significance to confidence intervals, range hypotheses and substantial effects

    Directory of Open Access Journals (Sweden)

    Dominic Beaulieu-Prévost

    2006-03-01

    Full Text Available For the last 50 years of research in quantitative social sciences, the empirical evaluation of scientific hypotheses has been based on the rejection or not of the null hypothesis. However, more than 300 articles demonstrated that this method was problematic. In summary, null hypothesis testing (NHT is unfalsifiable, its results depend directly on sample size and the null hypothesis is both improbable and not plausible. Consequently, alternatives to NHT such as confidence intervals (CI and measures of effect size are starting to be used in scientific publications. The purpose of this article is, first, to provide the conceptual tools necessary to implement an approach based on confidence intervals, and second, to briefly demonstrate why such an approach is an interesting alternative to an approach based on NHT. As demonstrated in the article, the proposed CI approach avoids most problems related to a NHT approach and can often improve the scientific and contextual relevance of the statistical interpretations by testing range hypotheses instead of a point hypothesis and by defining the minimal value of a substantial effect. The main advantage of such a CI approach is that it replaces the notion of statistical power by an easily interpretable three-value logic (probable presence of a substantial effect, probable absence of a substantial effect and probabilistic undetermination. The demonstration includes a complete example.

  13. Differentially Private Confidence Intervals for Empirical Risk Minimization

    OpenAIRE

    Wang, Yue; Kifer, Daniel; Lee, Jaewoo

    2018-01-01

    The process of data mining with differential privacy produces results that are affected by two types of noise: sampling noise due to data collection and privacy noise that is designed to prevent the reconstruction of sensitive information. In this paper, we consider the problem of designing confidence intervals for the parameters of a variety of differentially private machine learning models. The algorithms can provide confidence intervals that satisfy differential privacy (as well as the mor...

  14. Confidence intervals for correlations when data are not normal.

    Science.gov (United States)

    Bishara, Anthony J; Hittner, James B

    2017-02-01

    With nonnormal data, the typical confidence interval of the correlation (Fisher z') may be inaccurate. The literature has been unclear as to which of several alternative methods should be used instead, and how extreme a violation of normality is needed to justify an alternative. Through Monte Carlo simulation, 11 confidence interval methods were compared, including Fisher z', two Spearman rank-order methods, the Box-Cox transformation, rank-based inverse normal (RIN) transformation, and various bootstrap methods. Nonnormality often distorted the Fisher z' confidence interval-for example, leading to a 95 % confidence interval that had actual coverage as low as 68 %. Increasing the sample size sometimes worsened this problem. Inaccurate Fisher z' intervals could be predicted by a sample kurtosis of at least 2, an absolute sample skewness of at least 1, or significant violations of normality hypothesis tests. Only the Spearman rank-order and RIN transformation methods were universally robust to nonnormality. Among the bootstrap methods, an observed imposed bootstrap came closest to accurate coverage, though it often resulted in an overly long interval. The results suggest that sample nonnormality can justify avoidance of the Fisher z' interval in favor of a more robust alternative. R code for the relevant methods is provided in supplementary materials.

  15. Estimation and interpretation of keff confidence intervals in MCNP

    International Nuclear Information System (INIS)

    Urbatsch, T.J.

    1995-11-01

    MCNP's criticality methodology and some basic statistics are reviewed. Confidence intervals are discussed, as well as how to build them and their importance in the presentation of a Monte Carlo result. The combination of MCNP's three k eff estimators is shown, theoretically and empirically, by statistical studies and examples, to be the best k eff estimator. The method of combining estimators is based on a solid theoretical foundation, namely, the Gauss-Markov Theorem in regard to the least squares method. The confidence intervals of the combined estimator are also shown to have correct coverage rates for the examples considered

  16. Robust Confidence Interval for a Ratio of Standard Deviations

    Science.gov (United States)

    Bonett, Douglas G.

    2006-01-01

    Comparing variability of test scores across alternate forms, test conditions, or subpopulations is a fundamental problem in psychometrics. A confidence interval for a ratio of standard deviations is proposed that performs as well as the classic method with normal distributions and performs dramatically better with nonnormal distributions. A simple…

  17. Comparing confidence intervals for Goodman and Kruskal's gamma coefficient

    NARCIS (Netherlands)

    van der Ark, L.A.; van Aert, R.C.M.

    2015-01-01

    This study was motivated by the question which type of confidence interval (CI) one should use to summarize sample variance of Goodman and Kruskal's coefficient gamma. In a Monte-Carlo study, we investigated the coverage and computation time of the Goodman-Kruskal CI, the Cliff-consistent CI, the

  18. Confidence Intervals for Assessing Heterogeneity in Generalized Linear Mixed Models

    Science.gov (United States)

    Wagler, Amy E.

    2014-01-01

    Generalized linear mixed models are frequently applied to data with clustered categorical outcomes. The effect of clustering on the response is often difficult to practically assess partly because it is reported on a scale on which comparisons with regression parameters are difficult to make. This article proposes confidence intervals for…

  19. Parametric change point estimation, testing and confidence interval ...

    African Journals Online (AJOL)

    In many applications like finance, industry and medicine, it is important to consider that the model parameters may undergo changes at unknown moment in time. This paper deals with estimation, testing and confidence interval of a change point for a univariate variable which is assumed to be normally distributed. To detect ...

  20. On Bayesian treatment of systematic uncertainties in confidence interval calculation

    CERN Document Server

    Tegenfeldt, Fredrik

    2005-01-01

    In high energy physics, a widely used method to treat systematic uncertainties in confidence interval calculations is based on combining a frequentist construction of confidence belts with a Bayesian treatment of systematic uncertainties. In this note we present a study of the coverage of this method for the standard Likelihood Ratio (aka Feldman & Cousins) construction for a Poisson process with known background and Gaussian or log-Normal distributed uncertainties in the background or signal efficiency. For uncertainties in the signal efficiency of upto 40 % we find over-coverage on the level of 2 to 4 % depending on the size of uncertainties and the region in signal space. Uncertainties in the background generally have smaller effect on the coverage. A considerable smoothing of the coverage curves is observed. A software package is presented which allows fast calculation of the confidence intervals for a variety of assumptions on shape and size of systematic uncertainties for different nuisance paramete...

  1. Quantifying uncertainty on sediment loads using bootstrap confidence intervals

    Science.gov (United States)

    Slaets, Johanna I. F.; Piepho, Hans-Peter; Schmitter, Petra; Hilger, Thomas; Cadisch, Georg

    2017-01-01

    Load estimates are more informative than constituent concentrations alone, as they allow quantification of on- and off-site impacts of environmental processes concerning pollutants, nutrients and sediment, such as soil fertility loss, reservoir sedimentation and irrigation channel siltation. While statistical models used to predict constituent concentrations have been developed considerably over the last few years, measures of uncertainty on constituent loads are rarely reported. Loads are the product of two predictions, constituent concentration and discharge, integrated over a time period, which does not make it straightforward to produce a standard error or a confidence interval. In this paper, a linear mixed model is used to estimate sediment concentrations. A bootstrap method is then developed that accounts for the uncertainty in the concentration and discharge predictions, allowing temporal correlation in the constituent data, and can be used when data transformations are required. The method was tested for a small watershed in Northwest Vietnam for the period 2010-2011. The results showed that confidence intervals were asymmetric, with the highest uncertainty in the upper limit, and that a load of 6262 Mg year-1 had a 95 % confidence interval of (4331, 12 267) in 2010 and a load of 5543 Mg an interval of (3593, 8975) in 2011. Additionally, the approach demonstrated that direct estimates from the data were biased downwards compared to bootstrap median estimates. These results imply that constituent loads predicted from regression-type water quality models could frequently be underestimating sediment yields and their environmental impact.

  2. Confidence Intervals from Realizations of Simulated Nuclear Data

    Energy Technology Data Exchange (ETDEWEB)

    Younes, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ratkiewicz, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ressler, J. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-28

    Various statistical techniques are discussed that can be used to assign a level of confidence in the prediction of models that depend on input data with known uncertainties and correlations. The particular techniques reviewed in this paper are: 1) random realizations of the input data using Monte-Carlo methods, 2) the construction of confidence intervals to assess the reliability of model predictions, and 3) resampling techniques to impose statistical constraints on the input data based on additional information. These techniques are illustrated with a calculation of the keff value, based on the 235U(n, f) and 239Pu (n, f) cross sections.

  3. Profile-likelihood Confidence Intervals in Item Response Theory Models.

    Science.gov (United States)

    Chalmers, R Philip; Pek, Jolynn; Liu, Yang

    2017-01-01

    Confidence intervals (CIs) are fundamental inferential devices which quantify the sampling variability of parameter estimates. In item response theory, CIs have been primarily obtained from large-sample Wald-type approaches based on standard error estimates, derived from the observed or expected information matrix, after parameters have been estimated via maximum likelihood. An alternative approach to constructing CIs is to quantify sampling variability directly from the likelihood function with a technique known as profile-likelihood confidence intervals (PL CIs). In this article, we introduce PL CIs for item response theory models, compare PL CIs to classical large-sample Wald-type CIs, and demonstrate important distinctions among these CIs. CIs are then constructed for parameters directly estimated in the specified model and for transformed parameters which are often obtained post-estimation. Monte Carlo simulation results suggest that PL CIs perform consistently better than Wald-type CIs for both non-transformed and transformed parameters.

  4. Effect size, confidence intervals and statistical power in psychological research.

    Directory of Open Access Journals (Sweden)

    Téllez A.

    2015-07-01

    Full Text Available Quantitative psychological research is focused on detecting the occurrence of certain population phenomena by analyzing data from a sample, and statistics is a particularly helpful mathematical tool that is used by researchers to evaluate hypotheses and make decisions to accept or reject such hypotheses. In this paper, the various statistical tools in psychological research are reviewed. The limitations of null hypothesis significance testing (NHST and the advantages of using effect size and its respective confidence intervals are explained, as the latter two measurements can provide important information about the results of a study. These measurements also can facilitate data interpretation and easily detect trivial effects, enabling researchers to make decisions in a more clinically relevant fashion. Moreover, it is recommended to establish an appropriate sample size by calculating the optimum statistical power at the moment that the research is designed. Psychological journal editors are encouraged to follow APA recommendations strictly and ask authors of original research studies to report the effect size, its confidence intervals, statistical power and, when required, any measure of clinical significance. Additionally, we must account for the teaching of statistics at the graduate level. At that level, students do not receive sufficient information concerning the importance of using different types of effect sizes and their confidence intervals according to the different types of research designs; instead, most of the information is focused on the various tools of NHST.

  5. On a linear method in bootstrap confidence intervals

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    Andrea Pallini

    2007-10-01

    Full Text Available A linear method for the construction of asymptotic bootstrap confidence intervals is proposed. We approximate asymptotically pivotal and non-pivotal quantities, which are smooth functions of means of n independent and identically distributed random variables, by using a sum of n independent smooth functions of the same analytical form. Errors are of order Op(n-3/2 and Op(n-2, respectively. The linear method allows a straightforward approximation of bootstrap cumulants, by considering the set of n independent smooth functions as an original random sample to be resampled with replacement.

  6. Comparison of Bootstrap Confidence Intervals Using Monte Carlo Simulations

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    Roberto S. Flowers-Cano

    2018-02-01

    Full Text Available Design of hydraulic works requires the estimation of design hydrological events by statistical inference from a probability distribution. Using Monte Carlo simulations, we compared coverage of confidence intervals constructed with four bootstrap techniques: percentile bootstrap (BP, bias-corrected bootstrap (BC, accelerated bias-corrected bootstrap (BCA and a modified version of the standard bootstrap (MSB. Different simulation scenarios were analyzed. In some cases, the mother distribution function was fit to the random samples that were generated. In other cases, a distribution function different to the mother distribution was fit to the samples. When the fitted distribution had three parameters, and was the same as the mother distribution, the intervals constructed with the four techniques had acceptable coverage. However, the bootstrap techniques failed in several of the cases in which the fitted distribution had two parameters.

  7. Confidence interval procedures for Monte Carlo transport simulations

    International Nuclear Information System (INIS)

    Pederson, S.P.

    1997-01-01

    The problem of obtaining valid confidence intervals based on estimates from sampled distributions using Monte Carlo particle transport simulation codes such as MCNP is examined. Such intervals can cover the true parameter of interest at a lower than nominal rate if the sampled distribution is extremely right-skewed by large tallies. Modifications to the standard theory of confidence intervals are discussed and compared with some existing heuristics, including batched means normality tests. Two new types of diagnostics are introduced to assess whether the conditions of central limit theorem-type results are satisfied: the relative variance of the variance determines whether the sample size is sufficiently large, and estimators of the slope of the right tail of the distribution are used to indicate the number of moments that exist. A simulation study is conducted to quantify the relationship between various diagnostics and coverage rates and to find sample-based quantities useful in indicating when intervals are expected to be valid. Simulated tally distributions are chosen to emulate behavior seen in difficult particle transport problems. Measures of variation in the sample variance s 2 are found to be much more effective than existing methods in predicting when coverage will be near nominal rates. Batched means tests are found to be overly conservative in this regard. A simple but pathological MCNP problem is presented as an example of false convergence using existing heuristics. The new methods readily detect the false convergence and show that the results of the problem, which are a factor of 4 too small, should not be used. Recommendations are made for applying these techniques in practice, using the statistical output currently produced by MCNP

  8. Estimation and interpretation of keff confidence intervals in MCNP

    International Nuclear Information System (INIS)

    Urbatsch, T.J.

    1995-01-01

    MCNP has three different, but correlated, estimators for Calculating k eff in nuclear criticality calculations: collision, absorption, and track length estimators. The combination of these three estimators, the three-combined k eff estimator, is shown to be the best k eff estimator available in MCNP for estimating k eff confidence intervals. Theoretically, the Gauss-Markov Theorem provides a solid foundation for MCNP's three-combined estimator. Analytically, a statistical study, where the estimates are drawn using a known covariance matrix, shows that the three-combined estimator is superior to the individual estimator with the smallest variance. The importance of MCNP's batch statistics is demonstrated by an investigation of the effects of individual estimator variance bias on the combination of estimators, both heuristically with the analytical study and emprically with MCNP

  9. The 95% confidence intervals of error rates and discriminant coefficients

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    Shuichi Shinmura

    2015-02-01

    Full Text Available Fisher proposed a linear discriminant function (Fisher’s LDF. From 1971, we analysed electrocardiogram (ECG data in order to develop the diagnostic logic between normal and abnormal symptoms by Fisher’s LDF and a quadratic discriminant function (QDF. Our four years research was inferior to the decision tree logic developed by the medical doctor. After this experience, we discriminated many data and found four problems of the discriminant analysis. A revised Optimal LDF by Integer Programming (Revised IP-OLDF based on the minimum number of misclassification (minimum NM criterion resolves three problems entirely [13, 18]. In this research, we discuss fourth problem of the discriminant analysis. There are no standard errors (SEs of the error rate and discriminant coefficient. We propose a k-fold crossvalidation method. This method offers a model selection technique and a 95% confidence intervals (C.I. of error rates and discriminant coefficients.

  10. GENERALISED MODEL BASED CONFIDENCE INTERVALS IN TWO STAGE CLUSTER SAMPLING

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    Christopher Ouma Onyango

    2010-09-01

    Full Text Available Chambers and Dorfman (2002 constructed bootstrap confidence intervals in model based estimation for finite population totals assuming that auxiliary values are available throughout a target population and that the auxiliary values are independent. They also assumed that the cluster sizes are known throughout the target population. We now extend to two stage sampling in which the cluster sizes are known only for the sampled clusters, and we therefore predict the unobserved part of the population total. Jan and Elinor (2008 have done similar work, but unlike them, we use a general model, in which the auxiliary values are not necessarily independent. We demonstrate that the asymptotic properties of our proposed estimator and its coverage rates are better than those constructed under the model assisted local polynomial regression model.

  11. Estimation and interpretation of keff confidence intervals in MCNP

    International Nuclear Information System (INIS)

    Urbatsch, T.J.

    1995-01-01

    The Monte Carlo code MCNP has three different, but correlated, estimators for calculating k eff in nuclear criticality calculations: collision, absorption, and track length estimators. The combination of these three estimators, the three-combined k eff estimator, is shown to be the best k eff estimator available in MCNP for estimating k eff confidence intervals. Theoretically, the Gauss-Markov theorem provides a solid foundation for MCNP's three-combined estimator. Analytically, a statistical study, where the estimates are drawn using a known covariance matrix, shows that the three-combined estimator is superior to the estimator with the smallest variance. Empirically, MCNP examples for several physical systems demonstrate the three-combined estimator's superiority over each of the three individual estimators and its correct coverage rates. Additionally, the importance of MCNP's statistical checks is demonstrated

  12. Secure and Usable Bio-Passwords based on Confidence Interval

    Directory of Open Access Journals (Sweden)

    Aeyoung Kim

    2017-02-01

    Full Text Available The most popular user-authentication method is the password. Many authentication systems try to enhance their security by enforcing a strong password policy, and by using the password as the first factor, something you know, with the second factor being something you have. However, a strong password policy and a multi-factor authentication system can make it harder for a user to remember the password and login in. In this paper a bio-password-based scheme is proposed as a unique authentication method, which uses biometrics and confidence interval sets to enhance the security of the log-in process and make it easier as well. The method offers a user-friendly solution for creating and registering strong passwords without the user having to memorize them. Here we also show the results of our experiments which demonstrate the efficiency of this method and how it can be used to protect against a variety of malicious attacks.

  13. Confidence Intervals for Asbestos Fiber Counts: Approximate Negative Binomial Distribution.

    Science.gov (United States)

    Bartley, David; Slaven, James; Harper, Martin

    2017-03-01

    The negative binomial distribution is adopted for analyzing asbestos fiber counts so as to account for both the sampling errors in capturing only a finite number of fibers and the inevitable human variation in identifying and counting sampled fibers. A simple approximation to this distribution is developed for the derivation of quantiles and approximate confidence limits. The success of the approximation depends critically on the use of Stirling's expansion to sufficient order, on exact normalization of the approximating distribution, on reasonable perturbation of quantities from the normal distribution, and on accurately approximating sums by inverse-trapezoidal integration. Accuracy of the approximation developed is checked through simulation and also by comparison to traditional approximate confidence intervals in the specific case that the negative binomial distribution approaches the Poisson distribution. The resulting statistics are shown to relate directly to early research into the accuracy of asbestos sampling and analysis. Uncertainty in estimating mean asbestos fiber concentrations given only a single count is derived. Decision limits (limits of detection) and detection limits are considered for controlling false-positive and false-negative detection assertions and are compared to traditional limits computed assuming normal distributions. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2017.

  14. Number of core samples: Mean concentrations and confidence intervals

    International Nuclear Information System (INIS)

    Jensen, L.; Cromar, R.D.; Wilmarth, S.R.; Heasler, P.G.

    1995-01-01

    This document provides estimates of how well the mean concentration of analytes are known as a function of the number of core samples, composite samples, and replicate analyses. The estimates are based upon core composite data from nine recently sampled single-shell tanks. The results can be used when determining the number of core samples needed to ''characterize'' the waste from similar single-shell tanks. A standard way of expressing uncertainty in the estimate of a mean is with a 95% confidence interval (CI). The authors investigate how the width of a 95% CI on the mean concentration decreases as the number of observations increase. Specifically, the tables and figures show how the relative half-width (RHW) of a 95% CI decreases as the number of core samples increases. The RHW of a CI is a unit-less measure of uncertainty. The general conclusions are as follows: (1) the RHW decreases dramatically as the number of core samples is increased, the decrease is much smaller when the number of composited samples or the number of replicate analyses are increase; (2) if the mean concentration of an analyte needs to be estimated with a small RHW, then a large number of core samples is required. The estimated number of core samples given in the tables and figures were determined by specifying different sizes of the RHW. Four nominal sizes were examined: 10%, 25%, 50%, and 100% of the observed mean concentration. For a majority of analytes the number of core samples required to achieve an accuracy within 10% of the mean concentration is extremely large. In many cases, however, two or three core samples is sufficient to achieve a RHW of approximately 50 to 100%. Because many of the analytes in the data have small concentrations, this level of accuracy may be satisfactory for some applications

  15. Confidence intervals for experiments with background and small numbers of events

    International Nuclear Information System (INIS)

    Bruechle, W.

    2003-01-01

    Methods to find a confidence interval for Poisson distributed variables are illuminated, especially for the case of poor statistics. The application of 'central' and 'highest probability density' confidence intervals is compared for the case of low count-rates. A method to determine realistic estimates of the confidence intervals for Poisson distributed variables affected with background, and their ratios, is given. (orig.)

  16. Confidence intervals for experiments with background and small numbers of events

    International Nuclear Information System (INIS)

    Bruechle, W.

    2002-07-01

    Methods to find a confidence interval for Poisson distributed variables are illuminated, especially for the case of poor statistics. The application of 'central' and 'highest probability density' confidence intervals is compared for the case of low count-rates. A method to determine realistic estimates of the confidence intervals for Poisson distributed variables affected with background, and their ratios, is given. (orig.)

  17. An Introduction to Confidence Intervals for Both Statistical Estimates and Effect Sizes.

    Science.gov (United States)

    Capraro, Mary Margaret

    This paper summarizes methods of estimating confidence intervals, including classical intervals and intervals for effect sizes. The recent American Psychological Association (APA) Task Force on Statistical Inference report suggested that confidence intervals should always be reported, and the fifth edition of the APA "Publication Manual"…

  18. How to Avoid Errors in Error Propagation: Prediction Intervals and Confidence Intervals in Forest Biomass

    Science.gov (United States)

    Lilly, P.; Yanai, R. D.; Buckley, H. L.; Case, B. S.; Woollons, R. C.; Holdaway, R. J.; Johnson, J.

    2016-12-01

    Calculations of forest biomass and elemental content require many measurements and models, each contributing uncertainty to the final estimates. While sampling error is commonly reported, based on replicate plots, error due to uncertainty in the regression used to estimate biomass from tree diameter is usually not quantified. Some published estimates of uncertainty due to the regression models have used the uncertainty in the prediction of individuals, ignoring uncertainty in the mean, while others have propagated uncertainty in the mean while ignoring individual variation. Using the simple case of the calcium concentration of sugar maple leaves, we compare the variation among individuals (the standard deviation) to the uncertainty in the mean (the standard error) and illustrate the declining importance in the prediction of individual concentrations as the number of individuals increases. For allometric models, the analogous statistics are the prediction interval (or the residual variation in the model fit) and the confidence interval (describing the uncertainty in the best fit model). The effect of propagating these two sources of error is illustrated using the mass of sugar maple foliage. The uncertainty in individual tree predictions was large for plots with few trees; for plots with 30 trees or more, the uncertainty in individuals was less important than the uncertainty in the mean. Authors of previously published analyses have reanalyzed their data to show the magnitude of these two sources of uncertainty in scales ranging from experimental plots to entire countries. The most correct analysis will take both sources of uncertainty into account, but for practical purposes, country-level reports of uncertainty in carbon stocks, as required by the IPCC, can ignore the uncertainty in individuals. Ignoring the uncertainty in the mean will lead to exaggerated estimates of confidence in estimates of forest biomass and carbon and nutrient contents.

  19. A note on Nonparametric Confidence Interval for a Shift Parameter ...

    African Journals Online (AJOL)

    The method is illustrated using the Cauchy distribution as a location model. The kernel-based method is found to have a shorter interval for the shift parameter between two Cauchy distributions than the one based on the Mann-Whitney test statistic. Keywords: Best Asymptotic Normal; Cauchy distribution; Kernel estimates; ...

  20. Bootstrap confidence intervals for three-way methods

    NARCIS (Netherlands)

    Kiers, Henk A.L.

    Results from exploratory three-way analysis techniques such as CANDECOMP/PARAFAC and Tucker3 analysis are usually presented without giving insight into uncertainties due to sampling. Here a bootstrap procedure is proposed that produces percentile intervals for all output parameters. Special

  1. Using an R Shiny to Enhance the Learning Experience of Confidence Intervals

    Science.gov (United States)

    Williams, Immanuel James; Williams, Kelley Kim

    2018-01-01

    Many students find understanding confidence intervals difficult, especially because of the amalgamation of concepts such as confidence levels, standard error, point estimates and sample sizes. An R Shiny application was created to assist the learning process of confidence intervals using graphics and data from the US National Basketball…

  2. Estimating confidence intervals in predicted responses for oscillatory biological models.

    Science.gov (United States)

    St John, Peter C; Doyle, Francis J

    2013-07-29

    The dynamics of gene regulation play a crucial role in a cellular control: allowing the cell to express the right proteins to meet changing needs. Some needs, such as correctly anticipating the day-night cycle, require complicated oscillatory features. In the analysis of gene regulatory networks, mathematical models are frequently used to understand how a network's structure enables it to respond appropriately to external inputs. These models typically consist of a set of ordinary differential equations, describing a network of biochemical reactions, and unknown kinetic parameters, chosen such that the model best captures experimental data. However, since a model's parameter values are uncertain, and since dynamic responses to inputs are highly parameter-dependent, it is difficult to assess the confidence associated with these in silico predictions. In particular, models with complex dynamics - such as oscillations - must be fit with computationally expensive global optimization routines, and cannot take advantage of existing measures of identifiability. Despite their difficulty to model mathematically, limit cycle oscillations play a key role in many biological processes, including cell cycling, metabolism, neuron firing, and circadian rhythms. In this study, we employ an efficient parameter estimation technique to enable a bootstrap uncertainty analysis for limit cycle models. Since the primary role of systems biology models is the insight they provide on responses to rate perturbations, we extend our uncertainty analysis to include first order sensitivity coefficients. Using a literature model of circadian rhythms, we show how predictive precision is degraded with decreasing sample points and increasing relative error. Additionally, we show how this method can be used for model discrimination by comparing the output identifiability of two candidate model structures to published literature data. Our method permits modellers of oscillatory systems to confidently

  3. The P Value Problem in Otolaryngology: Shifting to Effect Sizes and Confidence Intervals.

    Science.gov (United States)

    Vila, Peter M; Townsend, Melanie Elizabeth; Bhatt, Neel K; Kao, W Katherine; Sinha, Parul; Neely, J Gail

    2017-06-01

    There is a lack of reporting effect sizes and confidence intervals in the current biomedical literature. The objective of this article is to present a discussion of the recent paradigm shift encouraging the use of reporting effect sizes and confidence intervals. Although P values help to inform us about whether an effect exists due to chance, effect sizes inform us about the magnitude of the effect (clinical significance), and confidence intervals inform us about the range of plausible estimates for the general population mean (precision). Reporting effect sizes and confidence intervals is a necessary addition to the biomedical literature, and these concepts are reviewed in this article.

  4. Graphing within-subjects confidence intervals using SPSS and S-Plus.

    Science.gov (United States)

    Wright, Daniel B

    2007-02-01

    Within-subjects confidence intervals are often appropriate to report and to display. Loftus and Masson (1994) have reported methods to calculate these, and their use is becoming common. In the present article, procedures for calculating within-subjects confidence intervals in SPSS and S-Plus are presented (an R version is on the accompanying Web site). The procedure in S-Plus allows the user to report the bias corrected and adjusted bootstrap confidence intervals as well as the standard confidence intervals based on traditional methods. The presented code can be easily altered to fit the individual user's needs.

  5. Confidence intervals for distinguishing ordinal and disordinal interactions in multiple regression.

    Science.gov (United States)

    Lee, Sunbok; Lei, Man-Kit; Brody, Gene H

    2015-06-01

    Distinguishing between ordinal and disordinal interaction in multiple regression is useful in testing many interesting theoretical hypotheses. Because the distinction is made based on the location of a crossover point of 2 simple regression lines, confidence intervals of the crossover point can be used to distinguish ordinal and disordinal interactions. This study examined 2 factors that need to be considered in constructing confidence intervals of the crossover point: (a) the assumption about the sampling distribution of the crossover point, and (b) the possibility of abnormally wide confidence intervals for the crossover point. A Monte Carlo simulation study was conducted to compare 6 different methods for constructing confidence intervals of the crossover point in terms of the coverage rate, the proportion of true values that fall to the left or right of the confidence intervals, and the average width of the confidence intervals. The methods include the reparameterization, delta, Fieller, basic bootstrap, percentile bootstrap, and bias-corrected accelerated bootstrap methods. The results of our Monte Carlo simulation study suggest that statistical inference using confidence intervals to distinguish ordinal and disordinal interaction requires sample sizes more than 500 to be able to provide sufficiently narrow confidence intervals to identify the location of the crossover point. (c) 2015 APA, all rights reserved).

  6. Sample size planning for composite reliability coefficients: accuracy in parameter estimation via narrow confidence intervals.

    Science.gov (United States)

    Terry, Leann; Kelley, Ken

    2012-11-01

    Composite measures play an important role in psychology and related disciplines. Composite measures almost always have error. Correspondingly, it is important to understand the reliability of the scores from any particular composite measure. However, the point estimates of the reliability of composite measures are fallible and thus all such point estimates should be accompanied by a confidence interval. When confidence intervals are wide, there is much uncertainty in the population value of the reliability coefficient. Given the importance of reporting confidence intervals for estimates of reliability, coupled with the undesirability of wide confidence intervals, we develop methods that allow researchers to plan sample size in order to obtain narrow confidence intervals for population reliability coefficients. We first discuss composite reliability coefficients and then provide a discussion on confidence interval formation for the corresponding population value. Using the accuracy in parameter estimation approach, we develop two methods to obtain accurate estimates of reliability by planning sample size. The first method provides a way to plan sample size so that the expected confidence interval width for the population reliability coefficient is sufficiently narrow. The second method ensures that the confidence interval width will be sufficiently narrow with some desired degree of assurance (e.g., 99% assurance that the 95% confidence interval for the population reliability coefficient will be less than W units wide). The effectiveness of our methods was verified with Monte Carlo simulation studies. We demonstrate how to easily implement the methods with easy-to-use and freely available software. ©2011 The British Psychological Society.

  7. Confidence Intervals for True Scores Using the Skew-Normal Distribution

    Science.gov (United States)

    Garcia-Perez, Miguel A.

    2010-01-01

    A recent comparative analysis of alternative interval estimation approaches and procedures has shown that confidence intervals (CIs) for true raw scores determined with the Score method--which uses the normal approximation to the binomial distribution--have actual coverage probabilities that are closest to their nominal level. It has also recently…

  8. Confidence Intervals for Weighted Composite Scores under the Compound Binomial Error Model

    Science.gov (United States)

    Kim, Kyung Yong; Lee, Won-Chan

    2018-01-01

    Reporting confidence intervals with test scores helps test users make important decisions about examinees by providing information about the precision of test scores. Although a variety of estimation procedures based on the binomial error model are available for computing intervals for test scores, these procedures assume that items are randomly…

  9. Binomial confidence intervals for testing non-inferiority or superiority: a practitioner's dilemma.

    Science.gov (United States)

    Pradhan, Vivek; Evans, John C; Banerjee, Tathagata

    2016-08-01

    In testing for non-inferiority or superiority in a single arm study, the confidence interval of a single binomial proportion is frequently used. A number of such intervals are proposed in the literature and implemented in standard software packages. Unfortunately, use of different intervals leads to conflicting conclusions. Practitioners thus face a serious dilemma in deciding which one to depend on. Is there a way to resolve this dilemma? We address this question by investigating the performances of ten commonly used intervals of a single binomial proportion, in the light of two criteria, viz., coverage and expected length of the interval. © The Author(s) 2013.

  10. Closed-form confidence intervals for functions of the normal mean and standard deviation.

    Science.gov (United States)

    Donner, Allan; Zou, G Y

    2012-08-01

    Confidence interval methods for a normal mean and standard deviation are well known and simple to apply. However, the same cannot be said for important functions of these parameters. These functions include the normal distribution percentiles, the Bland-Altman limits of agreement, the coefficient of variation and Cohen's effect size. We present a simple approach to this problem by using variance estimates recovered from confidence limits computed for the mean and standard deviation separately. All resulting confidence intervals have closed forms. Simulation results demonstrate that this approach performs very well for limits of agreement, coefficients of variation and their differences.

  11. Binomial Distribution Sample Confidence Intervals Estimation 1. Sampling and Medical Key Parameters Calculation

    Directory of Open Access Journals (Sweden)

    Tudor DRUGAN

    2003-08-01

    Full Text Available The aim of the paper was to present the usefulness of the binomial distribution in studying of the contingency tables and the problems of approximation to normality of binomial distribution (the limits, advantages, and disadvantages. The classification of the medical keys parameters reported in medical literature and expressing them using the contingency table units based on their mathematical expressions restrict the discussion of the confidence intervals from 34 parameters to 9 mathematical expressions. The problem of obtaining different information starting with the computed confidence interval for a specified method, information like confidence intervals boundaries, percentages of the experimental errors, the standard deviation of the experimental errors and the deviation relative to significance level was solves through implementation in PHP programming language of original algorithms. The cases of expression, which contain two binomial variables, were separately treated. An original method of computing the confidence interval for the case of two-variable expression was proposed and implemented. The graphical representation of the expression of two binomial variables for which the variation domain of one of the variable depend on the other variable was a real problem because the most of the software used interpolation in graphical representation and the surface maps were quadratic instead of triangular. Based on an original algorithm, a module was implements in PHP in order to represent graphically the triangular surface plots. All the implementation described above was uses in computing the confidence intervals and estimating their performance for binomial distributions sample sizes and variable.

  12. The Applicability of Confidence Intervals of Quantiles for the Generalized Logistic Distribution

    Science.gov (United States)

    Shin, H.; Heo, J.; Kim, T.; Jung, Y.

    2007-12-01

    The generalized logistic (GL) distribution has been widely used for frequency analysis. However, there is a little study related to the confidence intervals that indicate the prediction accuracy of distribution for the GL distribution. In this paper, the estimation of the confidence intervals of quantiles for the GL distribution is presented based on the method of moments (MOM), maximum likelihood (ML), and probability weighted moments (PWM) and the asymptotic variances of each quantile estimator are derived as functions of the sample sizes, return periods, and parameters. Monte Carlo simulation experiments are also performed to verify the applicability of the derived confidence intervals of quantile. As the results, the relative bias (RBIAS) and relative root mean square error (RRMSE) of the confidence intervals generally increase as return period increases and reverse as sample size increases. And PWM for estimating the confidence intervals performs better than the other methods in terms of RRMSE when the data is almost symmetric while ML shows the smallest RBIAS and RRMSE when the data is more skewed and sample size is moderately large. The GL model was applied to fit the distribution of annual maximum rainfall data. The results show that there are little differences in the estimated quantiles between ML and PWM while distinct differences in MOM.

  13. Tests and Confidence Intervals for an Extended Variance Component Using the Modified Likelihood Ratio Statistic

    DEFF Research Database (Denmark)

    Christensen, Ole Fredslund; Frydenberg, Morten; Jensen, Jens Ledet

    2005-01-01

    The large deviation modified likelihood ratio statistic is studied for testing a variance component equal to a specified value. Formulas are presented in the general balanced case, whereas in the unbalanced case only the one-way random effects model is studied. Simulation studies are presented......, showing that the normal approximation to the large deviation modified likelihood ratio statistic gives confidence intervals for variance components with coverage probabilities very close to the nominal confidence coefficient....

  14. The Optimal Confidence Intervals for Agricultural Products’ Price Forecasts Based on Hierarchical Historical Errors

    Directory of Open Access Journals (Sweden)

    Yi Wang

    2016-12-01

    Full Text Available With the levels of confidence and system complexity, interval forecasts and entropy analysis can deliver more information than point forecasts. In this paper, we take receivers’ demands as our starting point, use the trade-off model between accuracy and informativeness as the criterion to construct the optimal confidence interval, derive the theoretical formula of the optimal confidence interval and propose a practical and efficient algorithm based on entropy theory and complexity theory. In order to improve the estimation precision of the error distribution, the point prediction errors are STRATIFIED according to prices and the complexity of the system; the corresponding prediction error samples are obtained by the prices stratification; and the error distributions are estimated by the kernel function method and the stability of the system. In a stable and orderly environment for price forecasting, we obtain point prediction error samples by the weighted local region and RBF (Radial basis function neural network methods, forecast the intervals of the soybean meal and non-GMO (Genetically Modified Organism soybean continuous futures closing prices and implement unconditional coverage, independence and conditional coverage tests for the simulation results. The empirical results are compared from various interval evaluation indicators, different levels of noise, several target confidence levels and different point prediction methods. The analysis shows that the optimal interval construction method is better than the equal probability method and the shortest interval method and has good anti-noise ability with the reduction of system entropy; the hierarchical estimation error method can obtain higher accuracy and better interval estimation than the non-hierarchical method in a stable system.

  15. Binomial Distribution Sample Confidence Intervals Estimation 7. Absolute Risk Reduction and ARR-like Expressions

    Directory of Open Access Journals (Sweden)

    Andrei ACHIMAŞ CADARIU

    2004-08-01

    Full Text Available Assessments of a controlled clinical trial suppose to interpret some key parameters as the controlled event rate, experimental event date, relative risk, absolute risk reduction, relative risk reduction, number needed to treat when the effect of the treatment are dichotomous variables. Defined as the difference in the event rate between treatment and control groups, the absolute risk reduction is the parameter that allowed computing the number needed to treat. The absolute risk reduction is compute when the experimental treatment reduces the risk for an undesirable outcome/event. In medical literature when the absolute risk reduction is report with its confidence intervals, the method used is the asymptotic one, even if it is well know that may be inadequate. The aim of this paper is to introduce and assess nine methods of computing confidence intervals for absolute risk reduction and absolute risk reduction – like function.Computer implementations of the methods use the PHP language. Methods comparison uses the experimental errors, the standard deviations, and the deviation relative to the imposed significance level for specified sample sizes. Six methods of computing confidence intervals for absolute risk reduction and absolute risk reduction-like functions were assessed using random binomial variables and random sample sizes.The experiments shows that the ADAC, and ADAC1 methods obtains the best overall performance of computing confidence intervals for absolute risk reduction.

  16. Comparing confidence intervals for Goodman and Kruskal’s gamma coefficient

    NARCIS (Netherlands)

    van der Ark, L.A.; van Aert, R.C.M.

    2015-01-01

    This study was motivated by the question which type of confidence interval (CI) one should use to summarize sample variance of Goodman and Kruskal's coefficient gamma. In a Monte-Carlo study, we investigated the coverage and computation time of the Goodman–Kruskal CI, the Cliff-consistent CI, the

  17. The Distribution of the Product Explains Normal Theory Mediation Confidence Interval Estimation.

    Science.gov (United States)

    Kisbu-Sakarya, Yasemin; MacKinnon, David P; Miočević, Milica

    2014-05-01

    The distribution of the product has several useful applications. One of these applications is its use to form confidence intervals for the indirect effect as the product of 2 regression coefficients. The purpose of this article is to investigate how the moments of the distribution of the product explain normal theory mediation confidence interval coverage and imbalance. Values of the critical ratio for each random variable are used to demonstrate how the moments of the distribution of the product change across values of the critical ratio observed in research studies. Results of the simulation study showed that as skewness in absolute value increases, coverage decreases. And as skewness in absolute value and kurtosis increases, imbalance increases. The difference between testing the significance of the indirect effect using the normal theory versus the asymmetric distribution of the product is further illustrated with a real data example. This article is the first study to show the direct link between the distribution of the product and indirect effect confidence intervals and clarifies the results of previous simulation studies by showing why normal theory confidence intervals for indirect effects are often less accurate than those obtained from the asymmetric distribution of the product or from resampling methods.

  18. Optimal and Most Exact Confidence Intervals for Person Parameters in Item Response Theory Models

    Science.gov (United States)

    Doebler, Anna; Doebler, Philipp; Holling, Heinz

    2013-01-01

    The common way to calculate confidence intervals for item response theory models is to assume that the standardized maximum likelihood estimator for the person parameter [theta] is normally distributed. However, this approximation is often inadequate for short and medium test lengths. As a result, the coverage probabilities fall below the given…

  19. WASP (Write a Scientific Paper) using Excel - 6: Standard error and confidence interval.

    Science.gov (United States)

    Grech, Victor

    2018-03-01

    The calculation of descriptive statistics includes the calculation of standard error and confidence interval, an inevitable component of data analysis in inferential statistics. This paper provides pointers as to how to do this in Microsoft Excel™. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Methods for confidence interval estimation of a ratio parameter with application to location quotients

    Directory of Open Access Journals (Sweden)

    Beyene Joseph

    2005-10-01

    Full Text Available Abstract Background The location quotient (LQ ratio, a measure designed to quantify and benchmark the degree of relative concentration of an activity in the analysis of area localization, has received considerable attention in the geographic and economics literature. This index can also naturally be applied in the context of population health to quantify and compare health outcomes across spatial domains. However, one commonly observed limitation of LQ is its widespread use as only a point estimate without an accompanying confidence interval. Methods In this paper we present statistical methods that can be used to construct confidence intervals for location quotients. The delta and Fieller's methods are generic approaches for a ratio parameter and the generalized linear modelling framework is a useful re-parameterization particularly helpful for generating profile-likelihood based confidence intervals for the location quotient. A simulation experiment is carried out to assess the performance of each of the analytic approaches and a health utilization data set is used for illustration. Results Both the simulation results as well as the findings from the empirical data show that the different analytical methods produce very similar confidence limits for location quotients. When incidence of outcome is not rare and sample sizes are large, the confidence limits are almost indistinguishable. The confidence limits from the generalized linear model approach might be preferable in small sample situations. Conclusion LQ is a useful measure which allows quantification and comparison of health and other outcomes across defined geographical regions. It is a very simple index to compute and has a straightforward interpretation. Reporting this estimate with appropriate confidence limits using methods presented in this paper will make the measure particularly attractive for policy and decision makers.

  1. Confidence Intervals Verification for Simulated Error Rate Performance of Wireless Communication System

    KAUST Repository

    Smadi, Mahmoud A.

    2012-12-06

    In this paper, we derived an efficient simulation method to evaluate the error rate of wireless communication system. Coherent binary phase-shift keying system is considered with imperfect channel phase recovery. The results presented demonstrate the system performance under very realistic Nakagami-m fading and additive white Gaussian noise channel. On the other hand, the accuracy of the obtained results is verified through running the simulation under a good confidence interval reliability of 95 %. We see that as the number of simulation runs N increases, the simulated error rate becomes closer to the actual one and the confidence interval difference reduces. Hence our results are expected to be of significant practical use for such scenarios. © 2012 Springer Science+Business Media New York.

  2. Energy Performance Certificate of building and confidence interval in assessment: An Italian case study

    International Nuclear Information System (INIS)

    Tronchin, Lamberto; Fabbri, Kristian

    2012-01-01

    The Directive 2002/91/CE introduced the Energy Performance Certificate (EPC), an energy policy tool. The aim of the EPC is to inform building buyers about the energy performance and energy costs of buildings. The EPCs represent a specific energy policy tool to orient the building sector and real-estate markets toward higher energy efficiency buildings. The effectiveness of the EPC depends on two factors: •The accuracy of energy performance evaluation made by independent experts. •The capability of the energy classification and of the scale of energy performance to control the energy index fluctuations. In this paper, the results of a case study located in Italy are shown. In this example, 162 independent technicians on energy performance of building evaluation have studied the same building. The results reveal which part of confidence intervals is dependent on software misunderstanding and that the energy classification ranges are able to tolerate the fluctuation of energy indices. The example was chosen in accordance with the legislation of the Emilia-Romagna Region on Energy Efficiency of Buildings. Following these results, some thermo-economic evaluation related to building and energy labelling are illustrated, as the EPC, which is an energy policy tool for the real-estate market and building sector to find a way to build or retrofit an energy efficiency building. - Highlights: ► Evaluation of the accuracy of energy performance of buildings in relation with the knowledge of independent experts. ► Round robin test based on 162 case studies on the confidence intervals expressed by independent experts. ► Statistical considerations between the confidence intervals expressed by independent experts and energy simulation software. ► Relation between “proper class” in energy classification of buildings and confidence intervals of independent experts.

  3. Growth Estimators and Confidence Intervals for the Mean of Negative Binomial Random Variables with Unknown Dispersion

    Directory of Open Access Journals (Sweden)

    David Shilane

    2013-01-01

    Full Text Available The negative binomial distribution becomes highly skewed under extreme dispersion. Even at moderately large sample sizes, the sample mean exhibits a heavy right tail. The standard normal approximation often does not provide adequate inferences about the data's expected value in this setting. In previous work, we have examined alternative methods of generating confidence intervals for the expected value. These methods were based upon Gamma and Chi Square approximations or tail probability bounds such as Bernstein's inequality. We now propose growth estimators of the negative binomial mean. Under high dispersion, zero values are likely to be overrepresented in the data. A growth estimator constructs a normal-style confidence interval by effectively removing a small, predetermined number of zeros from the data. We propose growth estimators based upon multiplicative adjustments of the sample mean and direct removal of zeros from the sample. These methods do not require estimating the nuisance dispersion parameter. We will demonstrate that the growth estimators' confidence intervals provide improved coverage over a wide range of parameter values and asymptotically converge to the sample mean. Interestingly, the proposed methods succeed despite adding both bias and variance to the normal approximation.

  4. Bootstrap resampling: a powerful method of assessing confidence intervals for doses from experimental data

    International Nuclear Information System (INIS)

    Iwi, G.; Millard, R.K.; Palmer, A.M.; Preece, A.W.; Saunders, M.

    1999-01-01

    Bootstrap resampling provides a versatile and reliable statistical method for estimating the accuracy of quantities which are calculated from experimental data. It is an empirically based method, in which large numbers of simulated datasets are generated by computer from existing measurements, so that approximate confidence intervals of the derived quantities may be obtained by direct numerical evaluation. A simple introduction to the method is given via a detailed example of estimating 95% confidence intervals for cumulated activity in the thyroid following injection of 99m Tc-sodium pertechnetate using activity-time data from 23 subjects. The application of the approach to estimating confidence limits for the self-dose to the kidney following injection of 99m Tc-DTPA organ imaging agent based on uptake data from 19 subjects is also illustrated. Results are then given for estimates of doses to the foetus following administration of 99m Tc-sodium pertechnetate for clinical reasons during pregnancy, averaged over 25 subjects. The bootstrap method is well suited for applications in radiation dosimetry including uncertainty, reliability and sensitivity analysis of dose coefficients in biokinetic models, but it can also be applied in a wide range of other biomedical situations. (author)

  5. A Note on Confidence Interval for the Power of the One Sample Test

    OpenAIRE

    A. Wong

    2010-01-01

    In introductory statistics texts, the power of the test of a one-sample mean when the variance is known is widely discussed. However, when the variance is unknown, the power of the Student's -test is seldom mentioned. In this note, a general methodology for obtaining inference concerning a scalar parameter of interest of any exponential family model is proposed. The method is then applied to the one-sample mean problem with unknown variance to obtain a ( 1 − ) 100% confidence interval for...

  6. Rescaled Range Analysis and Detrended Fluctuation Analysis: Finite Sample Properties and Confidence Intervals

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    4/2010, č. 3 (2010), s. 236-250 ISSN 1802-4696 R&D Projects: GA ČR GD402/09/H045; GA ČR GA402/09/0965 Grant - others:GA UK(CZ) 118310 Institutional research plan: CEZ:AV0Z10750506 Keywords : rescaled range analysis * detrended fluctuation analysis * Hurst exponent * long-range dependence Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/kristoufek-rescaled range analysis and detrended fluctuation analysis finite sample properties and confidence intervals.pdf

  7. A NEW METHOD FOR CONSTRUCTING CONFIDENCE INTERVAL FOR CPM BASED ON FUZZY DATA

    Directory of Open Access Journals (Sweden)

    Bahram Sadeghpour Gildeh

    2011-06-01

    Full Text Available A measurement control system ensures that measuring equipment and measurement processes are fit for their intended use and its importance in achieving product quality objectives. In most real life applications, the observations are fuzzy. In some cases specification limits (SLs are not precise numbers and they are expressed in fuzzy terms, s o that the classical capability indices could not be applied. In this paper we obtain 100(1 - α% fuzzy confidence interval for C pm fuzzy process capability index, where instead of precise quality we have two membership functions for specification limits.

  8. Confidence intervals for the first crossing point of two hazard functions.

    Science.gov (United States)

    Cheng, Ming-Yen; Qiu, Peihua; Tan, Xianming; Tu, Dongsheng

    2009-12-01

    The phenomenon of crossing hazard rates is common in clinical trials with time to event endpoints. Many methods have been proposed for testing equality of hazard functions against a crossing hazards alternative. However, there has been relatively few approaches available in the literature for point or interval estimation of the crossing time point. The problem of constructing confidence intervals for the first crossing time point of two hazard functions is considered in this paper. After reviewing a recent procedure based on Cox proportional hazard modeling with Box-Cox transformation of the time to event, a nonparametric procedure using the kernel smoothing estimate of the hazard ratio is proposed. The proposed procedure and the one based on Cox proportional hazard modeling with Box-Cox transformation of the time to event are both evaluated by Monte-Carlo simulations and applied to two clinical trial datasets.

  9. Generalized additive models and Lucilia sericata growth: assessing confidence intervals and error rates in forensic entomology.

    Science.gov (United States)

    Tarone, Aaron M; Foran, David R

    2008-07-01

    Forensic entomologists use blow fly development to estimate a postmortem interval. Although accurate, fly age estimates can be imprecise for older developmental stages and no standard means of assigning confidence intervals exists. Presented here is a method for modeling growth of the forensically important blow fly Lucilia sericata, using generalized additive models (GAMs). Eighteen GAMs were created to predict the extent of juvenile fly development, encompassing developmental stage, length, weight, strain, and temperature data, collected from 2559 individuals. All measures were informative, explaining up to 92.6% of the deviance in the data, though strain and temperature exerted negligible influences. Predictions made with an independent data set allowed for a subsequent examination of error. Estimates using length and developmental stage were within 5% of true development percent during the feeding portion of the larval life cycle, while predictions for postfeeding third instars were less precise, but within expected error.

  10. Confidence interval of intrinsic optimum temperature estimated using thermodynamic SSI model

    Institute of Scientific and Technical Information of China (English)

    Takaya Ikemoto; Issei Kurahashi; Pei-Jian Shi

    2013-01-01

    The intrinsic optimum temperature for the development of ectotherms is one of the most important factors not only for their physiological processes but also for ecological and evolutional processes.The Sharpe-Schoolfield-Ikemoto (SSI) model succeeded in defining the temperature that can thermodynamically meet the condition that at a particular temperature the probability of an active enzyme reaching its maximum activity is realized.Previously,an algorithm was developed by Ikemoto (Tropical malaria does not mean hot environments.Journal of Medical Entomology,45,963-969) to estimate model parameters,but that program was computationally very time consuming.Now,investigators can use the SSI model more easily because a full automatic computer program was designed by Shi et al.(A modified program for estimating the parameters of the SSI model.Environmental Entomology,40,462-469).However,the statistical significance of the point estimate of the intrinsic optimum temperature for each ectotherm has not yet been determined.Here,we provided a new method for calculating the confidence interval of the estimated intrinsic optimum temperature by modifying the approximate bootstrap confidence intervals method.For this purpose,it was necessary to develop a new program for a faster estimation of the parameters in the SSI model,which we have also done.

  11. Confidence intervals for modeling anthocyanin retention in grape pomace during nonisothermal heating.

    Science.gov (United States)

    Mishra, D K; Dolan, K D; Yang, L

    2008-01-01

    Degradation of nutraceuticals in low- and intermediate-moisture foods heated at high temperature (>100 degrees C) is difficult to model because of the nonisothermal condition. Isothermal experiments above 100 degrees C are difficult to design because they require high pressure and small sample size in sealed containers. Therefore, a nonisothermal method was developed to estimate the thermal degradation kinetic parameter of nutraceuticals and determine the confidence intervals for the parameters and the predicted Y (concentration). Grape pomace at 42% moisture content (wb) was heated in sealed 202 x 214 steel cans in a steam retort at 126.7 degrees C for > 30 min. Can center temperature was measured by thermocouple and predicted using Comsol software. Thermal conductivity (k) and specific heat (C(p)) were estimated as quadratic functions of temperature using Comsol and nonlinear regression. The k and C(p) functions were then used to predict temperature inside the grape pomace during retorting. Similar heating experiments were run at different time-temperature treatments from 8 to 25 min for kinetic parameter estimation. Anthocyanin concentration in the grape pomace was measured using HPLC. Degradation rate constant (k(110 degrees C)) and activation energy (E(a)) were estimated using nonlinear regression. The thermophysical properties estimates at 100 degrees C were k = 0.501 W/m degrees C, Cp= 3600 J/kg and the kinetic parameters were k(110 degrees C)= 0.0607/min and E(a)= 65.32 kJ/mol. The 95% confidence intervals for the parameters and the confidence bands and prediction bands for anthocyanin retention were plotted. These methods are useful for thermal processing design for nutraceutical products.

  12. Statistical variability and confidence intervals for planar dose QA pass rates

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Daniel W.; Nelms, Benjamin E.; Attwood, Kristopher; Kumaraswamy, Lalith; Podgorsak, Matthew B. [Department of Physics, State University of New York at Buffalo, Buffalo, New York 14260 (United States) and Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Department of Biostatistics, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Molecular and Cellular Biophysics and Biochemistry, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States) and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States)

    2011-11-15

    Purpose: The most common metric for comparing measured to calculated dose, such as for pretreatment quality assurance of intensity-modulated photon fields, is a pass rate (%) generated using percent difference (%Diff), distance-to-agreement (DTA), or some combination of the two (e.g., gamma evaluation). For many dosimeters, the grid of analyzed points corresponds to an array with a low areal density of point detectors. In these cases, the pass rates for any given comparison criteria are not absolute but exhibit statistical variability that is a function, in part, on the detector sampling geometry. In this work, the authors analyze the statistics of various methods commonly used to calculate pass rates and propose methods for establishing confidence intervals for pass rates obtained with low-density arrays. Methods: Dose planes were acquired for 25 prostate and 79 head and neck intensity-modulated fields via diode array and electronic portal imaging device (EPID), and matching calculated dose planes were created via a commercial treatment planning system. Pass rates for each dose plane pair (both centered to the beam central axis) were calculated with several common comparison methods: %Diff/DTA composite analysis and gamma evaluation, using absolute dose comparison with both local and global normalization. Specialized software was designed to selectively sample the measured EPID response (very high data density) down to discrete points to simulate low-density measurements. The software was used to realign the simulated detector grid at many simulated positions with respect to the beam central axis, thereby altering the low-density sampled grid. Simulations were repeated with 100 positional iterations using a 1 detector/cm{sup 2} uniform grid, a 2 detector/cm{sup 2} uniform grid, and similar random detector grids. For each simulation, %/DTA composite pass rates were calculated with various %Diff/DTA criteria and for both local and global %Diff normalization

  13. The Precision of Effect Size Estimation From Published Psychological Research: Surveying Confidence Intervals.

    Science.gov (United States)

    Brand, Andrew; Bradley, Michael T

    2016-02-01

    Confidence interval ( CI) widths were calculated for reported Cohen's d standardized effect sizes and examined in two automated surveys of published psychological literature. The first survey reviewed 1,902 articles from Psychological Science. The second survey reviewed a total of 5,169 articles from across the following four APA journals: Journal of Abnormal Psychology, Journal of Applied Psychology, Journal of Experimental Psychology: Human Perception and Performance, and Developmental Psychology. The median CI width for d was greater than 1 in both surveys. Hence, CI widths were, as Cohen (1994) speculated, embarrassingly large. Additional exploratory analyses revealed that CI widths varied across psychological research areas and that CI widths were not discernably decreasing over time. The theoretical implications of these findings are discussed along with ways of reducing the CI widths and thus improving precision of effect size estimation.

  14. A Note on Confidence Interval for the Power of the One Sample Test

    Directory of Open Access Journals (Sweden)

    A. Wong

    2010-01-01

    Full Text Available In introductory statistics texts, the power of the test of a one-sample mean when the variance is known is widely discussed. However, when the variance is unknown, the power of the Student's -test is seldom mentioned. In this note, a general methodology for obtaining inference concerning a scalar parameter of interest of any exponential family model is proposed. The method is then applied to the one-sample mean problem with unknown variance to obtain a (1−100% confidence interval for the power of the Student's -test that detects the difference (−0. The calculations require only the density and the cumulative distribution functions of the standard normal distribution. In addition, the methodology presented can also be applied to determine the required sample size when the effect size and the power of a size test of mean are given.

  15. Assessing a disaggregated energy input: using confidence intervals around translog elasticity estimates

    International Nuclear Information System (INIS)

    Hisnanick, J.J.; Kyer, B.L.

    1995-01-01

    The role of energy in the production of manufacturing output has been debated extensively in the literature, particularly its relationship with capital and labor. In an attempt to provide some clarification in this debate, a two-step methodology was used. First under the assumption of a five-factor production function specification, we distinguished between electric and non-electric energy and assessed each component's relationship with capital and labor. Second, we calculated both the Allen and price elasticities and constructed 95% confidence intervals around these values. Our approach led to the following conclusions: that the disaggregation of the energy input into electric and non-electric energy is justified; that capital and electric energy and capital and non-electric energy are substitutes, while labor and electric energy and labor and non-electric energy are complements in production; and that capital and energy are substitutes, while labor and energy are complements. (author)

  16. Test Statistics and Confidence Intervals to Establish Noninferiority between Treatments with Ordinal Categorical Data.

    Science.gov (United States)

    Zhang, Fanghong; Miyaoka, Etsuo; Huang, Fuping; Tanaka, Yutaka

    2015-01-01

    The problem for establishing noninferiority is discussed between a new treatment and a standard (control) treatment with ordinal categorical data. A measure of treatment effect is used and a method of specifying noninferiority margin for the measure is provided. Two Z-type test statistics are proposed where the estimation of variance is constructed under the shifted null hypothesis using U-statistics. Furthermore, the confidence interval and the sample size formula are given based on the proposed test statistics. The proposed procedure is applied to a dataset from a clinical trial. A simulation study is conducted to compare the performance of the proposed test statistics with that of the existing ones, and the results show that the proposed test statistics are better in terms of the deviation from nominal level and the power.

  17. An SPSS Macro to Compute Confidence Intervals for Pearson’s Correlation

    Directory of Open Access Journals (Sweden)

    Bruce Weaver

    2014-04-01

    Full Text Available In many disciplines, including psychology, medical research, epidemiology and public health, authors are required, or at least encouraged to report confidence intervals (CIs along with effect size estimates. Many students and researchers in these areas use IBM-SPSS for statistical analysis. Unfortunately, the CORRELATIONS procedure in SPSS does not provide CIs in the output. Various work-around solutions have been suggested for obtaining CIs for rhowith SPSS, but most of them have been sub-optimal. Since release 18, it has been possible to compute bootstrap CIs, but only if users have the optional bootstrap module. The !rhoCI macro described in this article is accessible to all SPSS users with release 14 or later. It directs output from the CORRELATIONS procedure to another dataset, restructures that dataset to have one row per correlation, computes a CI for each correlation, and displays the results in a single table. Because the macro uses the CORRELATIONS procedure, it allows users to specify a list of two or more variables to include in the correlation matrix, to choose a confidence level, and to select either listwise or pairwise deletion. Thus, it offers substantial improvements over previous solutions to theproblem of how to compute CIs for rho with SPSS.

  18. Computing confidence and prediction intervals of industrial equipment degradation by bootstrapped support vector regression

    International Nuclear Information System (INIS)

    Lins, Isis Didier; Droguett, Enrique López; Moura, Márcio das Chagas; Zio, Enrico; Jacinto, Carlos Magno

    2015-01-01

    Data-driven learning methods for predicting the evolution of the degradation processes affecting equipment are becoming increasingly attractive in reliability and prognostics applications. Among these, we consider here Support Vector Regression (SVR), which has provided promising results in various applications. Nevertheless, the predictions provided by SVR are point estimates whereas in order to take better informed decisions, an uncertainty assessment should be also carried out. For this, we apply bootstrap to SVR so as to obtain confidence and prediction intervals, without having to make any assumption about probability distributions and with good performance even when only a small data set is available. The bootstrapped SVR is first verified on Monte Carlo experiments and then is applied to a real case study concerning the prediction of degradation of a component from the offshore oil industry. The results obtained indicate that the bootstrapped SVR is a promising tool for providing reliable point and interval estimates, which can inform maintenance-related decisions on degrading components. - Highlights: • Bootstrap (pairs/residuals) and SVR are used as an uncertainty analysis framework. • Numerical experiments are performed to assess accuracy and coverage properties. • More bootstrap replications does not significantly improve performance. • Degradation of equipment of offshore oil wells is estimated by bootstrapped SVR. • Estimates about the scale growth rate can support maintenance-related decisions

  19. Uncertainty in population growth rates: determining confidence intervals from point estimates of parameters.

    Directory of Open Access Journals (Sweden)

    Eleanor S Devenish Nelson

    Full Text Available BACKGROUND: Demographic models are widely used in conservation and management, and their parameterisation often relies on data collected for other purposes. When underlying data lack clear indications of associated uncertainty, modellers often fail to account for that uncertainty in model outputs, such as estimates of population growth. METHODOLOGY/PRINCIPAL FINDINGS: We applied a likelihood approach to infer uncertainty retrospectively from point estimates of vital rates. Combining this with resampling techniques and projection modelling, we show that confidence intervals for population growth estimates are easy to derive. We used similar techniques to examine the effects of sample size on uncertainty. Our approach is illustrated using data on the red fox, Vulpes vulpes, a predator of ecological and cultural importance, and the most widespread extant terrestrial mammal. We show that uncertainty surrounding estimated population growth rates can be high, even for relatively well-studied populations. Halving that uncertainty typically requires a quadrupling of sampling effort. CONCLUSIONS/SIGNIFICANCE: Our results compel caution when comparing demographic trends between populations without accounting for uncertainty. Our methods will be widely applicable to demographic studies of many species.

  20. Bayesian-statistical decision threshold, detection limit, and confidence interval in nuclear radiation measurement

    International Nuclear Information System (INIS)

    Weise, K.

    1998-01-01

    When a contribution of a particular nuclear radiation is to be detected, for instance, a spectral line of interest for some purpose of radiation protection, and quantities and their uncertainties must be taken into account which, such as influence quantities, cannot be determined by repeated measurements or by counting nuclear radiation events, then conventional statistics of event frequencies is not sufficient for defining the decision threshold, the detection limit, and the limits of a confidence interval. These characteristic limits are therefore redefined on the basis of Bayesian statistics for a wider applicability and in such a way that the usual practice remains as far as possible unaffected. The principle of maximum entropy is applied to establish probability distributions from available information. Quantiles of these distributions are used for defining the characteristic limits. But such a distribution must not be interpreted as a distribution of event frequencies such as the Poisson distribution. It rather expresses the actual state of incomplete knowledge of a physical quantity. The different definitions and interpretations and their quantitative consequences are presented and discussed with two examples. The new approach provides a theoretical basis for the DIN 25482-10 standard presently in preparation for general applications of the characteristic limits. (orig.) [de

  1. Confidence interval estimation of the difference between two sensitivities to the early disease stage.

    Science.gov (United States)

    Dong, Tuochuan; Kang, Le; Hutson, Alan; Xiong, Chengjie; Tian, Lili

    2014-03-01

    Although most of the statistical methods for diagnostic studies focus on disease processes with binary disease status, many diseases can be naturally classified into three ordinal diagnostic categories, that is normal, early stage, and fully diseased. For such diseases, the volume under the ROC surface (VUS) is the most commonly used index of diagnostic accuracy. Because the early disease stage is most likely the optimal time window for therapeutic intervention, the sensitivity to the early diseased stage has been suggested as another diagnostic measure. For the purpose of comparing the diagnostic abilities on early disease detection between two markers, it is of interest to estimate the confidence interval of the difference between sensitivities to the early diseased stage. In this paper, we present both parametric and non-parametric methods for this purpose. An extensive simulation study is carried out for a variety of settings for the purpose of evaluating and comparing the performance of the proposed methods. A real example of Alzheimer's disease (AD) is analyzed using the proposed approaches. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Confidence intervals permit, but don't guarantee, better inference than statistical significance testing

    Directory of Open Access Journals (Sweden)

    Melissa Coulson

    2010-07-01

    Full Text Available A statistically significant result, and a non-significant result may differ little, although significance status may tempt an interpretation of difference. Two studies are reported that compared interpretation of such results presented using null hypothesis significance testing (NHST, or confidence intervals (CIs. Authors of articles published in psychology, behavioural neuroscience, and medical journals were asked, via email, to interpret two fictitious studies that found similar results, one statistically significant, and the other non-significant. Responses from 330 authors varied greatly, but interpretation was generally poor, whether results were presented as CIs or using NHST. However, when interpreting CIs respondents who mentioned NHST were 60% likely to conclude, unjustifiably, the two results conflicted, whereas those who interpreted CIs without reference to NHST were 95% likely to conclude, justifiably, the two results were consistent. Findings were generally similar for all three disciplines. An email survey of academic psychologists confirmed that CIs elicit better interpretations if NHST is not invoked. Improved statistical inference can result from encouragement of meta-analytic thinking and use of CIs but, for full benefit, such highly desirable statistical reform requires also that researchers interpret CIs without recourse to NHST.

  3. PCA-based bootstrap confidence interval tests for gene-disease association involving multiple SNPs

    Directory of Open Access Journals (Sweden)

    Xue Fuzhong

    2010-01-01

    Full Text Available Abstract Background Genetic association study is currently the primary vehicle for identification and characterization of disease-predisposing variant(s which usually involves multiple single-nucleotide polymorphisms (SNPs available. However, SNP-wise association tests raise concerns over multiple testing. Haplotype-based methods have the advantage of being able to account for correlations between neighbouring SNPs, yet assuming Hardy-Weinberg equilibrium (HWE and potentially large number degrees of freedom can harm its statistical power and robustness. Approaches based on principal component analysis (PCA are preferable in this regard but their performance varies with methods of extracting principal components (PCs. Results PCA-based bootstrap confidence interval test (PCA-BCIT, which directly uses the PC scores to assess gene-disease association, was developed and evaluated for three ways of extracting PCs, i.e., cases only(CAES, controls only(COES and cases and controls combined(CES. Extraction of PCs with COES is preferred to that with CAES and CES. Performance of the test was examined via simulations as well as analyses on data of rheumatoid arthritis and heroin addiction, which maintains nominal level under null hypothesis and showed comparable performance with permutation test. Conclusions PCA-BCIT is a valid and powerful method for assessing gene-disease association involving multiple SNPs.

  4. R package to estimate intracluster correlation coefficient with confidence interval for binary data.

    Science.gov (United States)

    Chakraborty, Hrishikesh; Hossain, Akhtar

    2018-03-01

    The Intracluster Correlation Coefficient (ICC) is a major parameter of interest in cluster randomized trials that measures the degree to which responses within the same cluster are correlated. There are several types of ICC estimators and its confidence intervals (CI) suggested in the literature for binary data. Studies have compared relative weaknesses and advantages of ICC estimators as well as its CI for binary data and suggested situations where one is advantageous in practical research. The commonly used statistical computing systems currently facilitate estimation of only a very few variants of ICC and its CI. To address the limitations of current statistical packages, we developed an R package, ICCbin, to facilitate estimating ICC and its CI for binary responses using different methods. The ICCbin package is designed to provide estimates of ICC in 16 different ways including analysis of variance methods, moments based estimation, direct probabilistic methods, correlation based estimation, and resampling method. CI of ICC is estimated using 5 different methods. It also generates cluster binary data using exchangeable correlation structure. ICCbin package provides two functions for users. The function rcbin() generates cluster binary data and the function iccbin() estimates ICC and it's CI. The users can choose appropriate ICC and its CI estimate from the wide selection of estimates from the outputs. The R package ICCbin presents very flexible and easy to use ways to generate cluster binary data and to estimate ICC and it's CI for binary response using different methods. The package ICCbin is freely available for use with R from the CRAN repository (https://cran.r-project.org/package=ICCbin). We believe that this package can be a very useful tool for researchers to design cluster randomized trials with binary outcome. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Adjusted Wald Confidence Interval for a Difference of Binomial Proportions Based on Paired Data

    Science.gov (United States)

    Bonett, Douglas G.; Price, Robert M.

    2012-01-01

    Adjusted Wald intervals for binomial proportions in one-sample and two-sample designs have been shown to perform about as well as the best available methods. The adjusted Wald intervals are easy to compute and have been incorporated into introductory statistics courses. An adjusted Wald interval for paired binomial proportions is proposed here and…

  6. Simulation data for an estimation of the maximum theoretical value and confidence interval for the correlation coefficient.

    Science.gov (United States)

    Rocco, Paolo; Cilurzo, Francesco; Minghetti, Paola; Vistoli, Giulio; Pedretti, Alessandro

    2017-10-01

    The data presented in this article are related to the article titled "Molecular Dynamics as a tool for in silico screening of skin permeability" (Rocco et al., 2017) [1]. Knowledge of the confidence interval and maximum theoretical value of the correlation coefficient r can prove useful to estimate the reliability of developed predictive models, in particular when there is great variability in compiled experimental datasets. In this Data in Brief article, data from purposely designed numerical simulations are presented to show how much the maximum r value is worsened by increasing the data uncertainty. The corresponding confidence interval of r is determined by using the Fisher r → Z transform.

  7. Confidence Intervals for Effect Sizes: Compliance and Clinical Significance in the "Journal of Consulting and Clinical Psychology"

    Science.gov (United States)

    Odgaard, Eric C.; Fowler, Robert L.

    2010-01-01

    Objective: In 2005, the "Journal of Consulting and Clinical Psychology" ("JCCP") became the first American Psychological Association (APA) journal to require statistical measures of clinical significance, plus effect sizes (ESs) and associated confidence intervals (CIs), for primary outcomes (La Greca, 2005). As this represents the single largest…

  8. Coverage probability of bootstrap confidence intervals in heavy-tailed frequency models, with application to precipitation data

    Czech Academy of Sciences Publication Activity Database

    Kyselý, Jan

    2010-01-01

    Roč. 101, 3-4 (2010), s. 345-361 ISSN 0177-798X R&D Projects: GA AV ČR KJB300420801 Institutional research plan: CEZ:AV0Z30420517 Keywords : bootstrap * extreme value analysis * confidence intervals * heavy-tailed distributions * precipitation amounts Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.684, year: 2010

  9. A computer program (COSTUM) to calculate confidence intervals for in situ stress measurements. V. 1

    International Nuclear Information System (INIS)

    Dzik, E.J.; Walker, J.R.; Martin, C.D.

    1989-03-01

    The state of in situ stress is one of the parameters required both for the design and analysis of underground excavations and for the evaluation of numerical models used to simulate underground conditions. To account for the variability and uncertainty of in situ stress measurements, it is desirable to apply confidence limits to measured stresses. Several measurements of the state of stress along a borehole are often made to estimate the average state of stress at a point. Since stress is a tensor, calculating the mean stress and confidence limits using scalar techniques is inappropriate as well as incorrect. A computer program has been written to calculate and present the mean principle stresses and the confidence limits for the magnitudes and directions of the mean principle stresses. This report describes the computer program, COSTUM

  10. Confidence intervals for population allele frequencies: the general case of sampling from a finite diploid population of any size.

    Science.gov (United States)

    Fung, Tak; Keenan, Kevin

    2014-01-01

    The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%), a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L.), occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.

  11. Confidence intervals for population allele frequencies: the general case of sampling from a finite diploid population of any size.

    Directory of Open Access Journals (Sweden)

    Tak Fung

    Full Text Available The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%, a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L., occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.

  12. Common pitfalls in statistical analysis: "P" values, statistical significance and confidence intervals

    Directory of Open Access Journals (Sweden)

    Priya Ranganathan

    2015-01-01

    Full Text Available In the second part of a series on pitfalls in statistical analysis, we look at various ways in which a statistically significant study result can be expressed. We debunk some of the myths regarding the ′P′ value, explain the importance of ′confidence intervals′ and clarify the importance of including both values in a paper

  13. Common pitfalls in statistical analysis: “P” values, statistical significance and confidence intervals

    Science.gov (United States)

    Ranganathan, Priya; Pramesh, C. S.; Buyse, Marc

    2015-01-01

    In the second part of a series on pitfalls in statistical analysis, we look at various ways in which a statistically significant study result can be expressed. We debunk some of the myths regarding the ‘P’ value, explain the importance of ‘confidence intervals’ and clarify the importance of including both values in a paper PMID:25878958

  14. The confidence-accuracy relationship for eyewitness identification decisions: Effects of exposure duration, retention interval, and divided attention.

    Science.gov (United States)

    Palmer, Matthew A; Brewer, Neil; Weber, Nathan; Nagesh, Ambika

    2013-03-01

    Prior research points to a meaningful confidence-accuracy (CA) relationship for positive identification decisions. However, there are theoretical grounds for expecting that different aspects of the CA relationship (calibration, resolution, and over/underconfidence) might be undermined in some circumstances. This research investigated whether the CA relationship for eyewitness identification decisions is affected by three, forensically relevant variables: exposure duration, retention interval, and divided attention at encoding. In Study 1 (N = 986), a field experiment, we examined the effects of exposure duration (5 s vs. 90 s) and retention interval (immediate testing vs. a 1-week delay) on the CA relationship. In Study 2 (N = 502), we examined the effects of attention during encoding on the CA relationship by reanalyzing data from a laboratory experiment in which participants viewed a stimulus video under full or divided attention conditions and then attempted to identify two targets from separate lineups. Across both studies, all three manipulations affected identification accuracy. The central analyses concerned the CA relation for positive identification decisions. For the manipulations of exposure duration and retention interval, overconfidence was greater in the more difficult conditions (shorter exposure; delayed testing) than the easier conditions. Only the exposure duration manipulation influenced resolution (which was better for 5 s than 90 s), and only the retention interval manipulation affected calibration (which was better for immediate testing than delayed testing). In all experimental conditions, accuracy and diagnosticity increased with confidence, particularly at the upper end of the confidence scale. Implications for theory and forensic settings are discussed.

  15. The best confidence interval of the failure rate and unavailability per demand when few experimental data are available

    International Nuclear Information System (INIS)

    Goodman, J.

    1985-01-01

    Using a few available data the likelihood functions for the failure rate and unavailability per demand are constructed. These likelihood functions are used to obtain likelihood density functions for the failure rate and unavailability per demand. The best (or shortest) confidence intervals for these functions are provided. The failure rate and unavailability per demand are important characteristics needed for reliability and availability analysis. The methods of estimation of these characteristics when plenty of observed data are available are well known. However, on many occasions when we deal with rare failure modes or with new equipment or components for which sufficient experience has not accumulated, we have scarce data where few or zero failures have occurred. In these cases, a technique which reflects exactly our state of knowledge is required. This technique is based on likelihood density function or Bayesian methods depending on the available prior distribution. To extract the maximum amount of information from the data the best confidence interval is determined

  16. Bootstrap confidence intervals and bias correction in the estimation of HIV incidence from surveillance data with testing for recent infection.

    Science.gov (United States)

    Carnegie, Nicole Bohme

    2011-04-15

    The incidence of new infections is a key measure of the status of the HIV epidemic, but accurate measurement of incidence is often constrained by limited data. Karon et al. (Statist. Med. 2008; 27:4617–4633) developed a model to estimate the incidence of HIV infection from surveillance data with biologic testing for recent infection for newly diagnosed cases. This method has been implemented by public health departments across the United States and is behind the new national incidence estimates, which are about 40 per cent higher than previous estimates. We show that the delta method approximation given for the variance of the estimator is incomplete, leading to an inflated variance estimate. This contributes to the generation of overly conservative confidence intervals, potentially obscuring important differences between populations. We demonstrate via simulation that an innovative model-based bootstrap method using the specified model for the infection and surveillance process improves confidence interval coverage and adjusts for the bias in the point estimate. Confidence interval coverage is about 94–97 per cent after correction, compared with 96–99 per cent before. The simulated bias in the estimate of incidence ranges from −6.3 to +14.6 per cent under the original model but is consistently under 1 per cent after correction by the model-based bootstrap. In an application to data from King County, Washington in 2007 we observe correction of 7.2 per cent relative bias in the incidence estimate and a 66 per cent reduction in the width of the 95 per cent confidence interval using this method. We provide open-source software to implement the method that can also be extended for alternate models.

  17. [Confidence interval or p-value--similarities and differences between two important methods of statistical inference of quantitative studies].

    Science.gov (United States)

    Harari, Gil

    2014-01-01

    Statistic significance, also known as p-value, and CI (Confidence Interval) are common statistics measures and are essential for the statistical analysis of studies in medicine and life sciences. These measures provide complementary information about the statistical probability and conclusions regarding the clinical significance of study findings. This article is intended to describe the methodologies, compare between the methods, assert their suitability for the different needs of study results analysis and to explain situations in which each method should be used.

  18. Monte Carlo simulation of parameter confidence intervals for non-linear regression analysis of biological data using Microsoft Excel.

    Science.gov (United States)

    Lambert, Ronald J W; Mytilinaios, Ioannis; Maitland, Luke; Brown, Angus M

    2012-08-01

    This study describes a method to obtain parameter confidence intervals from the fitting of non-linear functions to experimental data, using the SOLVER and Analysis ToolPaK Add-In of the Microsoft Excel spreadsheet. Previously we have shown that Excel can fit complex multiple functions to biological data, obtaining values equivalent to those returned by more specialized statistical or mathematical software. However, a disadvantage of using the Excel method was the inability to return confidence intervals for the computed parameters or the correlations between them. Using a simple Monte-Carlo procedure within the Excel spreadsheet (without recourse to programming), SOLVER can provide parameter estimates (up to 200 at a time) for multiple 'virtual' data sets, from which the required confidence intervals and correlation coefficients can be obtained. The general utility of the method is exemplified by applying it to the analysis of the growth of Listeria monocytogenes, the growth inhibition of Pseudomonas aeruginosa by chlorhexidine and the further analysis of the electrophysiological data from the compound action potential of the rodent optic nerve. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  19. Characterizing the Prevalence of Chromosome Instability in Interval Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    A.L. Cisyk

    2015-03-01

    Full Text Available A substantial proportion of colorectal cancers (CRCs are interval CRCs (I-CRCs; i.e., CRCs diagnosed soon after a colonoscopy. Chromosomal instability (CIN is defined as an increase in the rate of which whole chromosomes/large chromosomal fragments are gained or lost and is observed in 85% of non-hereditary CRCs. The contribution of CIN to the etiology of I-CRCs remains unknown. We established a fluorescence in situ hybridization (FISH approach to characterize CIN by enumerating specific chromosomes and determined the prevalence of numerical CIN in a population-based cohort of I-CRCs and control (sporadic CRCs. Using the population-based Manitoba Health administrative databases and Manitoba Cancer Registry, we identified an age, sex, and colonic site of CRC matched cohort of I-CRCs and controls and retrieved their archived paraffin-embedded tumor samples. FISH chromosome enumeration probes specifically recognizing the pericentric regions of chromosomes 8, 11, and 17 were first used on cell lines and then CRC tissue microarrays to detect aneusomy, which was then used to calculate a CIN score (CS. The 15th percentile CS for control CRC was used to define CIN phenotype. Mean CSs were similar in the control CRCs and I-CRCs; 82% of I-CRCs exhibited a CIN phenotype, which was similar to that in the control CRCs. This study suggests that CIN is the most prevalent contributor to genomic instability in I-CRCs. Further studies should evaluate CIN and microsatellite instability (MSI in the same cohort of I-CRCs to corroborate our findings and to further assess concomitant contribution of CIN and MSI to I-CRCs.

  20. Technical Report: Algorithm and Implementation for Quasispecies Abundance Inference with Confidence Intervals from Metagenomic Sequence Data

    Energy Technology Data Exchange (ETDEWEB)

    McLoughlin, Kevin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-11

    This report describes the design and implementation of an algorithm for estimating relative microbial abundances, together with confidence limits, using data from metagenomic DNA sequencing. For the background behind this project and a detailed discussion of our modeling approach for metagenomic data, we refer the reader to our earlier technical report, dated March 4, 2014. Briefly, we described a fully Bayesian generative model for paired-end sequence read data, incorporating the effects of the relative abundances, the distribution of sequence fragment lengths, fragment position bias, sequencing errors and variations between the sampled genomes and the nearest reference genomes. A distinctive feature of our modeling approach is the use of a Chinese restaurant process (CRP) to describe the selection of genomes to be sampled, and thus the relative abundances. The CRP component is desirable for fitting abundances to reads that may map ambiguously to multiple targets, because it naturally leads to sparse solutions that select the best representative from each set of nearly equivalent genomes.

  1. Tablet potency of Tianeptine in coated tablets by near infrared spectroscopy: model optimisation, calibration transfer and confidence intervals.

    Science.gov (United States)

    Boiret, Mathieu; Meunier, Loïc; Ginot, Yves-Michel

    2011-02-20

    A near infrared (NIR) method was developed for determination of tablet potency of active pharmaceutical ingredient (API) in a complex coated tablet matrix. The calibration set contained samples from laboratory and production scale batches. The reference values were obtained by high performance liquid chromatography (HPLC) and partial least squares (PLS) regression was used to establish a model. The model was challenged by calculating tablet potency of two external test sets. Root mean square errors of prediction were respectively equal to 2.0% and 2.7%. To use this model with a second spectrometer from the production field, a calibration transfer method called piecewise direct standardisation (PDS) was used. After the transfer, the root mean square error of prediction of the first test set was 2.4% compared to 4.0% without transferring the spectra. A statistical technique using bootstrap of PLS residuals was used to estimate confidence intervals of tablet potency calculations. This method requires an optimised PLS model, selection of the bootstrap number and determination of the risk. In the case of a chemical analysis, the tablet potency value will be included within the confidence interval calculated by the bootstrap method. An easy to use graphical interface was developed to easily determine if the predictions, surrounded by minimum and maximum values, are within the specifications defined by the regulatory organisation. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Weighted profile likelihood-based confidence interval for the difference between two proportions with paired binomial data.

    Science.gov (United States)

    Pradhan, Vivek; Saha, Krishna K; Banerjee, Tathagata; Evans, John C

    2014-07-30

    Inference on the difference between two binomial proportions in the paired binomial setting is often an important problem in many biomedical investigations. Tang et al. (2010, Statistics in Medicine) discussed six methods to construct confidence intervals (henceforth, we abbreviate it as CI) for the difference between two proportions in paired binomial setting using method of variance estimates recovery. In this article, we propose weighted profile likelihood-based CIs for the difference between proportions of a paired binomial distribution. However, instead of the usual likelihood, we use weighted likelihood that is essentially making adjustments to the cell frequencies of a 2 × 2 table in the spirit of Agresti and Min (2005, Statistics in Medicine). We then conduct numerical studies to compare the performances of the proposed CIs with that of Tang et al. and Agresti and Min in terms of coverage probabilities and expected lengths. Our numerical study clearly indicates that the weighted profile likelihood-based intervals and Jeffreys interval (cf. Tang et al.) are superior in terms of achieving the nominal level, and in terms of expected lengths, they are competitive. Finally, we illustrate the use of the proposed CIs with real-life examples. Copyright © 2014 John Wiley & Sons, Ltd.

  3. A comparison of confidence interval methods for the concordance correlation coefficient and intraclass correlation coefficient with small number of raters.

    Science.gov (United States)

    Feng, Dai; Svetnik, Vladimir; Coimbra, Alexandre; Baumgartner, Richard

    2014-01-01

    The intraclass correlation coefficient (ICC) with fixed raters or, equivalently, the concordance correlation coefficient (CCC) for continuous outcomes is a widely accepted aggregate index of agreement in settings with small number of raters. Quantifying the precision of the CCC by constructing its confidence interval (CI) is important in early drug development applications, in particular in qualification of biomarker platforms. In recent years, there have been several new methods proposed for construction of CIs for the CCC, but their comprehensive comparison has not been attempted. The methods consisted of the delta method and jackknifing with and without Fisher's Z-transformation, respectively, and Bayesian methods with vague priors. In this study, we carried out a simulation study, with data simulated from multivariate normal as well as heavier tailed distribution (t-distribution with 5 degrees of freedom), to compare the state-of-the-art methods for assigning CI to the CCC. When the data are normally distributed, the jackknifing with Fisher's Z-transformation (JZ) tended to provide superior coverage and the difference between it and the closest competitor, the Bayesian method with the Jeffreys prior was in general minimal. For the nonnormal data, the jackknife methods, especially the JZ method, provided the coverage probabilities closest to the nominal in contrast to the others which yielded overly liberal coverage. Approaches based upon the delta method and Bayesian method with conjugate prior generally provided slightly narrower intervals and larger lower bounds than others, though this was offset by their poor coverage. Finally, we illustrated the utility of the CIs for the CCC in an example of a wake after sleep onset (WASO) biomarker, which is frequently used in clinical sleep studies of drugs for treatment of insomnia.

  4. User guide to the UNC1NLI1 package and three utility programs for computation of nonlinear confidence and prediction intervals using MODFLOW-2000

    DEFF Research Database (Denmark)

    Christensen, Steen; Cooley, R.L.

    a model (for example when using the Parameter-Estimation Process of MODFLOW-2000) it is advantageous to also use regression-based methods to quantify uncertainty. For this reason the UNC Process computes (1) confidence intervals for parameters of the Parameter-Estimation Process and (2) confidence...

  5. Determination and Interpretation of Characteristic Limits for Radioactivity Measurements: Decision Threshhold, Detection Limit and Limits of the Confidence Interval

    International Nuclear Information System (INIS)

    2017-01-01

    Since 2004, the environment programme of the IAEA has included activities aimed at developing a set of procedures for analytical measurements of radionuclides in food and the environment. Reliable, comparable and fit for purpose results are essential for any analytical measurement. Guidelines and national and international standards for laboratory practices to fulfil quality assurance requirements are extremely important when performing such measurements. The guidelines and standards should be comprehensive, clearly formulated and readily available to both the analyst and the customer. ISO 11929:2010 is the international standard on the determination of the characteristic limits (decision threshold, detection limit and limits of the confidence interval) for measuring ionizing radiation. For nuclear analytical laboratories involved in the measurement of radioactivity in food and the environment, robust determination of the characteristic limits of radioanalytical techniques is essential with regard to national and international regulations on permitted levels of radioactivity. However, characteristic limits defined in ISO 11929:2010 are complex, and the correct application of the standard in laboratories requires a full understanding of various concepts. This publication provides additional information to Member States in the understanding of the terminology, definitions and concepts in ISO 11929:2010, thus facilitating its implementation in Member State laboratories.

  6. Confidence intervals for effect sizes: compliance and clinical significance in the Journal of Consulting and clinical Psychology.

    Science.gov (United States)

    Odgaard, Eric C; Fowler, Robert L

    2010-06-01

    In 2005, the Journal of Consulting and Clinical Psychology (JCCP) became the first American Psychological Association (APA) journal to require statistical measures of clinical significance, plus effect sizes (ESs) and associated confidence intervals (CIs), for primary outcomes (La Greca, 2005). As this represents the single largest editorial effort to improve statistical reporting practices in any APA journal in at least a decade, in this article we investigate the efficacy of that change. All intervention studies published in JCCP in 2003, 2004, 2007, and 2008 were reviewed. Each article was coded for method of clinical significance, type of ES, and type of associated CI, broken down by statistical test (F, t, chi-square, r/R(2), and multivariate modeling). By 2008, clinical significance compliance was 75% (up from 31%), with 94% of studies reporting some measure of ES (reporting improved for individual statistical tests ranging from eta(2) = .05 to .17, with reasonable CIs). Reporting of CIs for ESs also improved, although only to 40%. Also, the vast majority of reported CIs used approximations, which become progressively less accurate for smaller sample sizes and larger ESs (cf. Algina & Kessleman, 2003). Changes are near asymptote for ESs and clinical significance, but CIs lag behind. As CIs for ESs are required for primary outcomes, we show how to compute CIs for the vast majority of ESs reported in JCCP, with an example of how to use CIs for ESs as a method to assess clinical significance.

  7. Bootstrap Signal-to-Noise Confidence Intervals: An Objective Method for Subject Exclusion and Quality Control in ERP Studies

    Science.gov (United States)

    Parks, Nathan A.; Gannon, Matthew A.; Long, Stephanie M.; Young, Madeleine E.

    2016-01-01

    Analysis of event-related potential (ERP) data includes several steps to ensure that ERPs meet an appropriate level of signal quality. One such step, subject exclusion, rejects subject data if ERP waveforms fail to meet an appropriate level of signal quality. Subject exclusion is an important quality control step in the ERP analysis pipeline as it ensures that statistical inference is based only upon those subjects exhibiting clear evoked brain responses. This critical quality control step is most often performed simply through visual inspection of subject-level ERPs by investigators. Such an approach is qualitative, subjective, and susceptible to investigator bias, as there are no standards as to what constitutes an ERP of sufficient signal quality. Here, we describe a standardized and objective method for quantifying waveform quality in individual subjects and establishing criteria for subject exclusion. The approach uses bootstrap resampling of ERP waveforms (from a pool of all available trials) to compute a signal-to-noise ratio confidence interval (SNR-CI) for individual subject waveforms. The lower bound of this SNR-CI (SNRLB) yields an effective and objective measure of signal quality as it ensures that ERP waveforms statistically exceed a desired signal-to-noise criterion. SNRLB provides a quantifiable metric of individual subject ERP quality and eliminates the need for subjective evaluation of waveform quality by the investigator. We detail the SNR-CI methodology, establish the efficacy of employing this approach with Monte Carlo simulations, and demonstrate its utility in practice when applied to ERP datasets. PMID:26903849

  8. Using Confidence Interval-Based Estimation of Relevance to Select Social-Cognitive Determinants for Behavior Change Interventions

    Directory of Open Access Journals (Sweden)

    Rik Crutzen

    2017-07-01

    Full Text Available When developing an intervention aimed at behavior change, one of the crucial steps in the development process is to select the most relevant social-cognitive determinants. These determinants can be seen as the buttons one needs to push to establish behavior change. Insight into these determinants is needed to select behavior change methods (i.e., general behavior change techniques that are applied in an intervention in the development process. Therefore, a study on determinants is often conducted as formative research in the intervention development process. Ideally, all relevant determinants identified in such a study are addressed by an intervention. However, when developing a behavior change intervention, there are limits in terms of, for example, resources available for intervention development and the amount of content that participants of an intervention can be exposed to. Hence, it is important to select those determinants that are most relevant to the target behavior as these determinants should be addressed in an intervention. The aim of the current paper is to introduce a novel approach to select the most relevant social-cognitive determinants and use them in intervention development. This approach is based on visualization of confidence intervals for the means and correlation coefficients for all determinants simultaneously. This visualization facilitates comparison, which is necessary when making selections. By means of a case study on the determinants of using a high dose of 3,4-methylenedioxymethamphetamine (commonly known as ecstasy, we illustrate this approach. We provide a freely available tool to facilitate the analyses needed in this approach.

  9. Using Confidence Interval-Based Estimation of Relevance to Select Social-Cognitive Determinants for Behavior Change Interventions.

    Science.gov (United States)

    Crutzen, Rik; Peters, Gjalt-Jorn Ygram; Noijen, Judith

    2017-01-01

    When developing an intervention aimed at behavior change, one of the crucial steps in the development process is to select the most relevant social-cognitive determinants. These determinants can be seen as the buttons one needs to push to establish behavior change. Insight into these determinants is needed to select behavior change methods (i.e., general behavior change techniques that are applied in an intervention) in the development process. Therefore, a study on determinants is often conducted as formative research in the intervention development process. Ideally, all relevant determinants identified in such a study are addressed by an intervention. However, when developing a behavior change intervention, there are limits in terms of, for example, resources available for intervention development and the amount of content that participants of an intervention can be exposed to. Hence, it is important to select those determinants that are most relevant to the target behavior as these determinants should be addressed in an intervention. The aim of the current paper is to introduce a novel approach to select the most relevant social-cognitive determinants and use them in intervention development. This approach is based on visualization of confidence intervals for the means and correlation coefficients for all determinants simultaneously. This visualization facilitates comparison, which is necessary when making selections. By means of a case study on the determinants of using a high dose of 3,4-methylenedioxymethamphetamine (commonly known as ecstasy), we illustrate this approach. We provide a freely available tool to facilitate the analyses needed in this approach.

  10. Five-band microwave radiometer system for noninvasive brain temperature measurement in newborn babies: Phantom experiment and confidence interval

    Science.gov (United States)

    Sugiura, T.; Hirata, H.; Hand, J. W.; van Leeuwen, J. M. J.; Mizushina, S.

    2011-10-01

    Clinical trials of hypothermic brain treatment for newborn babies are currently hindered by the difficulty in measuring deep brain temperatures. As one of the possible methods for noninvasive and continuous temperature monitoring that is completely passive and inherently safe is passive microwave radiometry (MWR). We have developed a five-band microwave radiometer system with a single dual-polarized, rectangular waveguide antenna operating within the 1-4 GHz range and a method for retrieving the temperature profile from five radiometric brightness temperatures. This paper addresses (1) the temperature calibration for five microwave receivers, (2) the measurement experiment using a phantom model that mimics the temperature profile in a newborn baby, and (3) the feasibility for noninvasive monitoring of deep brain temperatures. Temperature resolutions were 0.103, 0.129, 0.138, 0.105 and 0.111 K for 1.2, 1.65, 2.3, 3.0 and 3.6 GHz receivers, respectively. The precision of temperature estimation (2σ confidence interval) was about 0.7°C at a 5-cm depth from the phantom surface. Accuracy, which is the difference between the estimated temperature using this system and the measured temperature by a thermocouple at a depth of 5 cm, was about 2°C. The current result is not satisfactory for clinical application because the clinical requirement for accuracy must be better than 1°C for both precision and accuracy at a depth of 5 cm. Since a couple of possible causes for this inaccuracy have been identified, we believe that the system can take a step closer to the clinical application of MWR for hypothermic rescue treatment.

  11. A comparison of confidence interval methods for the intraclass correlation coefficient in community-based cluster randomization trials with a binary outcome.

    Science.gov (United States)

    Braschel, Melissa C; Svec, Ivana; Darlington, Gerarda A; Donner, Allan

    2016-04-01

    Many investigators rely on previously published point estimates of the intraclass correlation coefficient rather than on their associated confidence intervals to determine the required size of a newly planned cluster randomized trial. Although confidence interval methods for the intraclass correlation coefficient that can be applied to community-based trials have been developed for a continuous outcome variable, fewer methods exist for a binary outcome variable. The aim of this study is to evaluate confidence interval methods for the intraclass correlation coefficient applied to binary outcomes in community intervention trials enrolling a small number of large clusters. Existing methods for confidence interval construction are examined and compared to a new ad hoc approach based on dividing clusters into a large number of smaller sub-clusters and subsequently applying existing methods to the resulting data. Monte Carlo simulation is used to assess the width and coverage of confidence intervals for the intraclass correlation coefficient based on Smith's large sample approximation of the standard error of the one-way analysis of variance estimator, an inverted modified Wald test for the Fleiss-Cuzick estimator, and intervals constructed using a bootstrap-t applied to a variance-stabilizing transformation of the intraclass correlation coefficient estimate. In addition, a new approach is applied in which clusters are randomly divided into a large number of smaller sub-clusters with the same methods applied to these data (with the exception of the bootstrap-t interval, which assumes large cluster sizes). These methods are also applied to a cluster randomized trial on adolescent tobacco use for illustration. When applied to a binary outcome variable in a small number of large clusters, existing confidence interval methods for the intraclass correlation coefficient provide poor coverage. However, confidence intervals constructed using the new approach combined with Smith

  12. A nonparametric statistical method for determination of a confidence interval for the mean of a set of results obtained in a laboratory intercomparison

    International Nuclear Information System (INIS)

    Veglia, A.

    1981-08-01

    In cases where sets of data are obviously not normally distributed, the application of a nonparametric method for the estimation of a confidence interval for the mean seems to be more suitable than some other methods because such a method requires few assumptions about the population of data. A two-step statistical method is proposed which can be applied to any set of analytical results: elimination of outliers by a nonparametric method based on Tchebycheff's inequality, and determination of a confidence interval for the mean by a non-parametric method based on binominal distribution. The method is appropriate only for samples of size n>=10

  13. The Confidence-Accuracy Relationship for Eyewitness Identification Decisions: Effects of Exposure Duration, Retention Interval, and Divided Attention

    Science.gov (United States)

    Palmer, Matthew A.; Brewer, Neil; Weber, Nathan; Nagesh, Ambika

    2013-01-01

    Prior research points to a meaningful confidence-accuracy (CA) relationship for positive identification decisions. However, there are theoretical grounds for expecting that different aspects of the CA relationship (calibration, resolution, and over/underconfidence) might be undermined in some circumstances. This research investigated whether the…

  14. Perpetrator admissions and earwitness renditions: the effects of retention interval and rehearsal on accuracy of and confidence in memory for criminal accounts

    OpenAIRE

    Boydell, Carroll

    2008-01-01

    While much research has explored how well earwitnesses can identify the voice of a perpetrator, little research has examined how well they can recall details from a perpetrator’s confession. This study examines the accuracy-confidence correlation for memory for details from a perpetrator’s verbal account of a crime, as well as the effects of two variables commonly encountered in a criminal investigation (rehearsal and length of retention interval) on that correlation. Results suggest that con...

  15. Long QT interval in Turner syndrome: a high prevalence of LQTS gene mutations

    DEFF Research Database (Denmark)

    Trolle, Christian

    Objective: QT interval prolongation of unknown aetiology is common in Turner syndrome (TS). This study set out to explore the presence of known pathogenic long QT (LQT) mutations in TS and to examine the corrected QT interval (QTc) over time and relate the findings to the TS phenotype. Methods......QTc). The prevalence of mutations in genes related to Long QT syndrome (LQTS) was determined in females with TS and a QTc >432.0 milliseconds (ms). Echocardiographic assessment of aortic valve morphology, 24-hour blood pressures and blood samples were done. Results: The mean hQTc in females with TS (414.0±25.5 ms...

  16. Empirical likelihood-based confidence intervals for the sensitivity of a continuous-scale diagnostic test at a fixed level of specificity.

    Science.gov (United States)

    Gengsheng Qin; Davis, Angela E; Jing, Bing-Yi

    2011-06-01

    For a continuous-scale diagnostic test, it is often of interest to find the range of the sensitivity of the test at the cut-off that yields a desired specificity. In this article, we first define a profile empirical likelihood ratio for the sensitivity of a continuous-scale diagnostic test and show that its limiting distribution is a scaled chi-square distribution. We then propose two new empirical likelihood-based confidence intervals for the sensitivity of the test at a fixed level of specificity by using the scaled chi-square distribution. Simulation studies are conducted to compare the finite sample performance of the newly proposed intervals with the existing intervals for the sensitivity in terms of coverage probability. A real example is used to illustrate the application of the recommended methods.

  17. Prediction of the distillation temperatures of crude oils using ¹H NMR and support vector regression with estimated confidence intervals.

    Science.gov (United States)

    Filgueiras, Paulo R; Terra, Luciana A; Castro, Eustáquio V R; Oliveira, Lize M S L; Dias, Júlio C M; Poppi, Ronei J

    2015-09-01

    This paper aims to estimate the temperature equivalent to 10% (T10%), 50% (T50%) and 90% (T90%) of distilled volume in crude oils using (1)H NMR and support vector regression (SVR). Confidence intervals for the predicted values were calculated using a boosting-type ensemble method in a procedure called ensemble support vector regression (eSVR). The estimated confidence intervals obtained by eSVR were compared with previously accepted calculations from partial least squares (PLS) models and a boosting-type ensemble applied in the PLS method (ePLS). By using the proposed boosting strategy, it was possible to identify outliers in the T10% property dataset. The eSVR procedure improved the accuracy of the distillation temperature predictions in relation to standard PLS, ePLS and SVR. For T10%, a root mean square error of prediction (RMSEP) of 11.6°C was obtained in comparison with 15.6°C for PLS, 15.1°C for ePLS and 28.4°C for SVR. The RMSEPs for T50% were 24.2°C, 23.4°C, 22.8°C and 14.4°C for PLS, ePLS, SVR and eSVR, respectively. For T90%, the values of RMSEP were 39.0°C, 39.9°C and 39.9°C for PLS, ePLS, SVR and eSVR, respectively. The confidence intervals calculated by the proposed boosting methodology presented acceptable values for the three properties analyzed; however, they were lower than those calculated by the standard methodology for PLS. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. A spreadsheet template compatible with Microsoft Excel and iWork Numbers that returns the simultaneous confidence intervals for all pairwise differences between multiple sample means.

    Science.gov (United States)

    Brown, Angus M

    2010-04-01

    The objective of the method described in this paper is to develop a spreadsheet template for the purpose of comparing multiple sample means. An initial analysis of variance (ANOVA) test on the data returns F--the test statistic. If F is larger than the critical F value drawn from the F distribution at the appropriate degrees of freedom, convention dictates rejection of the null hypothesis and allows subsequent multiple comparison testing to determine where the inequalities between the sample means lie. A variety of multiple comparison methods are described that return the 95% confidence intervals for differences between means using an inclusive pairwise comparison of the sample means. 2009 Elsevier Ireland Ltd. All rights reserved.

  19. Long QT interval in Turner syndrome--a high prevalence of LQTS gene mutations.

    Science.gov (United States)

    Trolle, Christian; Mortensen, Kristian H; Pedersen, Lisbeth N; Berglund, Agnethe; Jensen, Henrik K; Andersen, Niels H; Gravholt, Claus H

    2013-01-01

    QT-interval prolongation of unknown aetiology is common in Turner syndrome. This study set out to explore the presence of known long QT mutations in Turner syndrome and to examine the corrected QT-interval (QTc) over time and relate the findings to the Turner syndrome phenotype. Adult women with Turner syndrome (n = 88) were examined thrice and 68 age-matched healthy controls were examined once. QTc was measured by one blinded reader (intra-reader variability: 0.7%), and adjusted for influence of heart rate by Bazett's (bQTc) and Hodges's formula (hQTc). The prevalence of mutations in genes related to Long QT syndrome was determined in women with Turner syndrome and a QTc >432.0 milliseconds (ms). Echocardiographic assessment of aortic valve morphology, 24-hour blood pressures and blood samples were done. The mean hQTc in women with Turner syndrome (414.0 ± 25.5 ms) compared to controls (390.4 ± 17.8 ms) was prolonged (pTurner syndrome karyotypes (418.2 ± 24.8 vs. 407.6 ± 25.5 ms; p = 0.055). In women with Turner syndrome and a bQTc >432 ms, 7 had mutations in major Long QT syndrome genes (SCN5A and KCNH2) and one in a minor Long QT syndrome gene (KCNE2). There is a high prevalence of mutations in the major LQTS genes in women with TS and prolonged QTc. It remains to be settled, whether these findings are related to the unexplained excess mortality in Turner women. NCT00624949. https://register.clinicaltrials.gov/prs/app/action/SelectProtocol/sid/S0001FLI/selectaction/View/ts/3/uid/U000099E.

  20. Long QT interval in Turner syndrome--a high prevalence of LQTS gene mutations.

    Directory of Open Access Journals (Sweden)

    Christian Trolle

    Full Text Available QT-interval prolongation of unknown aetiology is common in Turner syndrome. This study set out to explore the presence of known long QT mutations in Turner syndrome and to examine the corrected QT-interval (QTc over time and relate the findings to the Turner syndrome phenotype.Adult women with Turner syndrome (n = 88 were examined thrice and 68 age-matched healthy controls were examined once. QTc was measured by one blinded reader (intra-reader variability: 0.7%, and adjusted for influence of heart rate by Bazett's (bQTc and Hodges's formula (hQTc. The prevalence of mutations in genes related to Long QT syndrome was determined in women with Turner syndrome and a QTc >432.0 milliseconds (ms. Echocardiographic assessment of aortic valve morphology, 24-hour blood pressures and blood samples were done.The mean hQTc in women with Turner syndrome (414.0 ± 25.5 ms compared to controls (390.4 ± 17.8 ms was prolonged (p432 ms, 7 had mutations in major Long QT syndrome genes (SCN5A and KCNH2 and one in a minor Long QT syndrome gene (KCNE2.There is a high prevalence of mutations in the major LQTS genes in women with TS and prolonged QTc. It remains to be settled, whether these findings are related to the unexplained excess mortality in Turner women.NCT00624949. https://register.clinicaltrials.gov/prs/app/action/SelectProtocol/sid/S0001FLI/selectaction/View/ts/3/uid/U000099E.

  1. Factorial-based response-surface modeling with confidence intervals for optimizing thermal-optical transmission analysis of atmospheric black carbon

    International Nuclear Information System (INIS)

    Conny, J.M.; Norris, G.A.; Gould, T.R.

    2009-01-01

    Thermal-optical transmission (TOT) analysis measures black carbon (BC) in atmospheric aerosol on a fibrous filter. The method pyrolyzes organic carbon (OC) and employs laser light absorption to distinguish BC from the pyrolyzed OC; however, the instrument does not necessarily separate the two physically. In addition, a comprehensive temperature protocol for the analysis based on the Beer-Lambert Law remains elusive. Here, empirical response-surface modeling was used to show how the temperature protocol in TOT analysis can be modified to distinguish pyrolyzed OC from BC based on the Beer-Lambert Law. We determined the apparent specific absorption cross sections for pyrolyzed OC (σ Char ) and BC (σ BC ), which accounted for individual absorption enhancement effects within the filter. Response-surface models of these cross sections were derived from a three-factor central-composite factorial experimental design: temperature and duration of the high-temperature step in the helium phase, and the heating increase in the helium-oxygen phase. The response surface for σ BC , which varied with instrument conditions, revealed a ridge indicating the correct conditions for OC pyrolysis in helium. The intersection of the σ BC and σ Char surfaces indicated the conditions where the cross sections were equivalent, satisfying an important assumption upon which the method relies. 95% confidence interval surfaces defined a confidence region for a range of pyrolysis conditions. Analyses of wintertime samples from Seattle, WA revealed a temperature between 830 deg. C and 850 deg. C as most suitable for the helium high-temperature step lasting 150 s. However, a temperature as low as 750 deg. C could not be rejected statistically

  2. "Normality of Residuals Is a Continuous Variable, and Does Seem to Influence the Trustworthiness of Confidence Intervals: A Response to, and Appreciation of, Williams, Grajales, and Kurkiewicz (2013"

    Directory of Open Access Journals (Sweden)

    Jason W. Osborne

    2013-09-01

    Full Text Available Osborne and Waters (2002 focused on checking some of the assumptions of multiple linear.regression. In a critique of that paper, Williams, Grajales, and Kurkiewicz correctly clarify that.regression models estimated using ordinary least squares require the assumption of normally.distributed errors, but not the assumption of normally distributed response or predictor variables..They go on to discuss estimate bias and provide a helpful summary of the assumptions of multiple.regression when using ordinary least squares. While we were not as precise as we could have been.when discussing assumptions of normality, the critical issue of the 2002 paper remains -' researchers.often do not check on or report on the assumptions of their statistical methods. This response.expands on the points made by Williams, advocates a thorough examination of data prior to.reporting results, and provides an example of how incremental improvements in meeting the.assumption of normality of residuals incrementally improves the accuracy of confidence intervals.

  3. The prevalence and significance of a short QT interval in 18,825 low-risk individuals including athletes.

    Science.gov (United States)

    Dhutia, Harshil; Malhotra, Aneil; Parpia, Sameer; Gabus, Vincent; Finocchiaro, Gherardo; Mellor, Greg; Merghani, Ahmed; Millar, Lynne; Narain, Rajay; Sheikh, Nabeel; Behr, Elijah R; Papadakis, Michael; Sharma, Sanjay

    2016-01-01

    The short QT syndrome is a cardiac channelopathy characterised by accelerated repolarisation which manifests as a short QT interval on the ECG. The definition of a short QT interval is debated, ranging from <390 to ≤320 ms, and its clinical significance in healthy young individuals is unknown. We assessed the prevalence and medium-term significance of an isolated short QT interval in a diverse young British population. Between 2005 and 2013, 18 825 apparently healthy people aged 14-35 years underwent cardiovascular evaluation with history, physical examination and ECG. QT intervals were measured by cardiologists using 4 recommended guidelines (Seattle 2013, Heart Rhythm Society 2013, European Society of Cardiology 2010 and American Heart Association 2009). The prevalence of a short QT interval was 0.1% (26 patients, ≤320 ms), 0.2% (44 patients, ≤330 ms), 7.9% (1478 patients, <380 ms), 15.8% (2973 patients, <390 ms). Male gender and Afro-Caribbean ethnicity had the strongest association with short QT intervals. Athletes had shorter QT intervals than non-athletes but athletic status did not predict short QT intervals. Individuals with short QT intervals ≤320 ms did not report syncope or a sinister family history, and during a follow-up period of 5.3±1.2 years, there were no deaths in this group. The prevalence of a short QT interval depends on the recommended cut-off value. Even at values ≤320 ms, there was an excellent medium-term prognosis among 14 people followed. We conclude that a definition of ≤320 ms is realistic to prevent overdiagnosis and excessive investigations. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  4. Zero- vs. one-dimensional, parametric vs. non-parametric, and confidence interval vs. hypothesis testing procedures in one-dimensional biomechanical trajectory analysis.

    Science.gov (United States)

    Pataky, Todd C; Vanrenterghem, Jos; Robinson, Mark A

    2015-05-01

    Biomechanical processes are often manifested as one-dimensional (1D) trajectories. It has been shown that 1D confidence intervals (CIs) are biased when based on 0D statistical procedures, and the non-parametric 1D bootstrap CI has emerged in the Biomechanics literature as a viable solution. The primary purpose of this paper was to clarify that, for 1D biomechanics datasets, the distinction between 0D and 1D methods is much more important than the distinction between parametric and non-parametric procedures. A secondary purpose was to demonstrate that a parametric equivalent to the 1D bootstrap exists in the form of a random field theory (RFT) correction for multiple comparisons. To emphasize these points we analyzed six datasets consisting of force and kinematic trajectories in one-sample, paired, two-sample and regression designs. Results showed, first, that the 1D bootstrap and other 1D non-parametric CIs were qualitatively identical to RFT CIs, and all were very different from 0D CIs. Second, 1D parametric and 1D non-parametric hypothesis testing results were qualitatively identical for all six datasets. Last, we highlight the limitations of 1D CIs by demonstrating that they are complex, design-dependent, and thus non-generalizable. These results suggest that (i) analyses of 1D data based on 0D models of randomness are generally biased unless one explicitly identifies 0D variables before the experiment, and (ii) parametric and non-parametric 1D hypothesis testing provide an unambiguous framework for analysis when one׳s hypothesis explicitly or implicitly pertains to whole 1D trajectories. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. A comparison of confidence/credible interval methods for the area under the ROC curve for continuous diagnostic tests with small sample size.

    Science.gov (United States)

    Feng, Dai; Cortese, Giuliana; Baumgartner, Richard

    2017-12-01

    The receiver operating characteristic (ROC) curve is frequently used as a measure of accuracy of continuous markers in diagnostic tests. The area under the ROC curve (AUC) is arguably the most widely used summary index for the ROC curve. Although the small sample size scenario is common in medical tests, a comprehensive study of small sample size properties of various methods for the construction of the confidence/credible interval (CI) for the AUC has been by and large missing in the literature. In this paper, we describe and compare 29 non-parametric and parametric methods for the construction of the CI for the AUC when the number of available observations is small. The methods considered include not only those that have been widely adopted, but also those that have been less frequently mentioned or, to our knowledge, never applied to the AUC context. To compare different methods, we carried out a simulation study with data generated from binormal models with equal and unequal variances and from exponential models with various parameters and with equal and unequal small sample sizes. We found that the larger the true AUC value and the smaller the sample size, the larger the discrepancy among the results of different approaches. When the model is correctly specified, the parametric approaches tend to outperform the non-parametric ones. Moreover, in the non-parametric domain, we found that a method based on the Mann-Whitney statistic is in general superior to the others. We further elucidate potential issues and provide possible solutions to along with general guidance on the CI construction for the AUC when the sample size is small. Finally, we illustrate the utility of different methods through real life examples.

  6. Prevalence of E/A wave fusion and A wave truncation in DDD pacemaker patients with complete AV block under nominal AV intervals.

    Directory of Open Access Journals (Sweden)

    Wolfram C Poller

    Full Text Available Optimization of the AV-interval (AVI in DDD pacemakers improves cardiac hemodynamics and reduces pacemaker syndromes. Manual optimization is typically not performed in clinical routine. In the present study we analyze the prevalence of E/A wave fusion and A wave truncation under resting conditions in 160 patients with complete AV block (AVB under the pre-programmed AVI. We manually optimized sub-optimal AVI.We analyzed 160 pacemaker patients with complete AVB, both in sinus rhythm (AV-sense; n = 129 and under atrial pacing (AV-pace; n = 31. Using Doppler analyses of the transmitral inflow we classified the nominal AVI as: a normal, b too long (E/A wave fusion or c too short (A wave truncation. In patients with a sub-optimal AVI, we performed manual optimization according to the recommendations of the American Society of Echocardiography.All AVB patients with atrial pacing exhibited a normal transmitral inflow under the nominal AV-pace intervals (100%. In contrast, 25 AVB patients in sinus rhythm showed E/A wave fusion under the pre-programmed AV-sense intervals (19.4%; 95% confidence interval (CI: 12.6-26.2%. A wave truncations were not observed in any patient. All patients with a complete E/A wave fusion achieved a normal transmitral inflow after AV-sense interval reduction (mean optimized AVI: 79.4 ± 13.6 ms.Given the rate of 19.4% (CI 12.6-26.2% of patients with a too long nominal AV-sense interval, automatic algorithms may prove useful in improving cardiac hemodynamics, especially in the subgroup of atrially triggered pacemaker patients with AV node diseases.

  7. The impact of change in albumin assay on reference intervals, prevalence of 'hypoalbuminaemia' and albumin prescriptions.

    Science.gov (United States)

    Coley-Grant, Deon; Herbert, Mike; Cornes, Michael P; Barlow, Ian M; Ford, Clare; Gama, Rousseau

    2016-01-01

    We studied the impact on reference intervals, classification of patients with hypoalbuminaemia and albumin infusion prescriptions on changing from a bromocresol green (BCG) to a bromocresol purple (BCP) serum albumin assay. Passing-Bablok regression analysis and Bland-Altman plot were used to compare Abbott BCP and Roche BCG methods. Linear regression analysis was used to compare in-house and an external laboratory Abbott BCP serum albumin results. Reference intervals for Abbott BCP serum albumin were derived in two different laboratories using pathology data from adult patients in primary care. Prescriptions for 20% albumin infusions were compared one year before and one year after changing the albumin method. Abbott BCP assay had a negative bias of approximately 6 g/L compared with Roche BCG method.There was good agreement (y = 1.04 x - 1.03; R(2 )= 0.9933) between in-house and external laboratory Abbott BCP results. Reference intervals for the serum albumin Abbott BCP assay were 31-45 g/L, different to those recommended by Pathology Harmony and the manufacturers (35-50 g/L). Following the change in method there was a large increase in the number of patients classified as hypoalbuminaemic using Pathology Harmony references intervals (32%) but not when retrospectively compared to locally derived reference intervals (16%) compared with the previous year (12%). The method change was associated with a 44.6% increase in albumin prescriptions. This equated to an annual increase in expenditure of £35,234. We suggest that serum albumin reference intervals be method specific to prevent misclassification of albumin status in patients. Change in albumin methodology may have significant impact on hospital resources. © The Author(s) 2015.

  8. 用Delta法估计多维测验合成信度的置信区间%Estimating the Confidence Interval of Composite Reliability of a Multidimensional Test With the Delta Method

    Institute of Scientific and Technical Information of China (English)

    叶宝娟; 温忠麟

    2012-01-01

    Reliability is very important in evaluating the quality of a test. Based on the confirmatory factor analysis, composite reliabili- ty is a good index to estimate the test reliability for general applications. As is well known, point estimate contains limited information a- bout a population parameter and cannot indicate how far it can be from the population parameter. The confidence interval of the parame- ter can provide more information. In evaluating the quality of a test, the confidence interval of composite reliability has received atten- tion in recent years. There are three approaches to estimating the confidence interval of composite reliability of an unidimensional test: the Bootstrap method, the Delta method, and the direct use of the standard error of a software output (e. g. , LISREL). The Bootstrap method pro- vides empirical results of the standard error, and is the most credible method. But it needs data simulation techniques, and its computa- tion process is rather complex. The Delta method computes the standard error of composite reliability by approximate calculation. It is simpler than the Bootstrap method. The LISREL software can directly prompt the standard error, and it is the easiest among the three methods. By simulation study, it had been found that the interval estimates obtained by the Delta method and the Bootstrap method were almost identical, whereas the results obtained by LISREL and by the Bootstrap method were substantially different ( Ye & Wen, 2011 ). The Delta method is recommended when the confidence interval of composite reliability of a unidimensional test is estimated, because the Delta method is simpler than the Bootstrap method. There was little research about how to compute the confidence interval of composite reliability of a multidimensional test. We de- duced a formula by using the Delta method for computing the standard error of composite reliability of a multidimensional test. Based on the standard error, the

  9. AlphaCI: un programa de cálculo de intervalos de confianza para el coeficiente alfa de Cronbach AlphaCI: a computer program for computing confidence intervals around Cronbach's alfa coefficient

    Directory of Open Access Journals (Sweden)

    Rubén Ledesma

    2004-06-01

    Full Text Available El coeficiente alfa de Cronbach es el modo más habitual de estimar la fiabilidad de pruebas basadas en Teoría Clásica de los Test. En dicha estimación, los investigadores usualmente omiten informar intervalos de confianza para el coeficiente, un aspecto no solo recomendado por los especialistas, sino también requerido explícitamente en las normas editoriales de algunas revistas especializadas. Esta situación puede atribuirse a que los métodos de estimación de intervalos de confianza son poco conocidos, además de no estar disponibles al usuario en los programas estadísticos más populares. Así, en este trabajo se presenta un programa desarrollado dentro del sistema estadístico ViSta que permite calcular intervalos de confianza basados en el enfoque clásico y mediante la técnica bootstrap. Se espera promover la inclusión de intervalos de confianza para medidas de fiabilidad, facilitando el acceso a las herramientas necesarias para su aplicación. El programa es gratuito y puede obtenerse enviando un mail de solicitud al autor del trabajo.Cronbach's alpha coefficient is the most popular way of estimating reliability in measurement scales based on Classic Test Theory. When estimating it, researchers usually omit to report confidence intervals of this coefficient, as it is not only recommended by experts, but also required by some journal's guidelines. This situation is because the different methods of estimating confidence intervals are not well-known by researchers, as well as they are not being available among the most popular statistical packages. Therefore, this paper describes a computer program integrated into the ViSta statistical system, which allows computing confidence intervals based on the classical approach and using bootstrap technique. It is hoped that this work promotes the inclusion of confidence intervals of reliability measures, by increasing the availability of the required computer tools. The program is free and

  10. Bootstrap confidence intervals for principal response curves

    NARCIS (Netherlands)

    Timmerman, Marieke E.; Ter Braak, Cajo J. F.

    2008-01-01

    The principal response curve (PRC) model is of use to analyse multivariate data resulting from experiments involving repeated sampling in time. The time-dependent treatment effects are represented by PRCs, which are functional in nature. The sample PRCs can be estimated using a raw approach, or the

  11. Bootstrap Confidence Intervals for Principal Response Curves

    NARCIS (Netherlands)

    Timmerman, M.E.; Braak, ter C.J.F.

    2008-01-01

    The principal response curve (PRC) model is of use to analyse multivariate data resulting from experiments involving repeated sampling in time. The time-dependent treatment effects are represented by PRCs, which are functional in nature. The sample PRCs can be estimated using a raw approach, or the

  12. Interpretando correctamente en salud pública estimaciones puntuales, intervalos de confianza y contrastes de hipótesis Accurate interpretation of point estimates, confidence intervals, and hypothesis tests in public health

    Directory of Open Access Journals (Sweden)

    Manuel G Scotto

    2003-12-01

    Full Text Available El presente ensayo trata de aclarar algunos conceptos utilizados habitualmente en el campo de investigación de la salud pública, que en numerosas situaciones son interpretados de manera incorrecta. Entre ellos encontramos la estimación puntual, los intervalos de confianza, y los contrastes de hipótesis. Estableciendo un paralelismo entre estos tres conceptos, podemos observar cuáles son sus diferencias más importantes a la hora de ser interpretados, tanto desde el punto de vista del enfoque clásico como desde la óptica bayesiana.This essay reviews some statistical concepts frequently used in public health research that are commonly misinterpreted. These include point estimates, confidence intervals, and hypothesis tests. By comparing them using the classical and the Bayesian perspectives, their interpretation becomes clearer.

  13. Reference intervals for serum lipids and prevalence of dyslipidaemia in 6-12-year-old children: The Health Oriented Pedagogical Project (HOPP).

    Science.gov (United States)

    Strand, Martin Frank; Fredriksen, Per Morten; Hjelle, Ole Petter; Lindberg, Morten

    2018-05-01

    Elevated serum lipid concentrations in childhood are thought to be risk factors for the development of cardiovascular disease later in life. The present study aims to provide age- and gender-related reference intervals for total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol in healthy school children. We also investigated the prevalence of dyslipidaemia using the published criteria for these biomarkers. Venous blood and anthropometric data were collected from 1340 children in the HOPP study, aged between 6 and 12 years. Age- and gender-related reference intervals (2.5th and 97.5th percentiles) were established according to the IFCC recommendations, using the software RefVal 4.10. Gender differences were observed for total cholesterol and non-HDL cholesterol, but not for HDL cholesterol. Age differences were observed for total cholesterol. The reference intervals were in the range of 3.1-5.9 mmol/L for total cholesterol, 1.0-2.4 mmol/L for HDL cholesterol and 1.4-4.2 mmol/L for non-HDL cholesterol. Dyslipidaemia prevalence was as follows: increased TC 9.6%, decreased HDL 1.6%, and increased non-HDL 5.6%. Age- and gender-related reference intervals in a Norwegian population are similar to those reported in other countries. The prevalence of dyslipidaemia among Norwegian children is significant, emphasising the importance of appropriate reference intervals in clinical practice.

  14. Mixture models for undiagnosed prevalent disease and interval-censored incident disease: applications to a cohort assembled from electronic health records.

    Science.gov (United States)

    Cheung, Li C; Pan, Qing; Hyun, Noorie; Schiffman, Mark; Fetterman, Barbara; Castle, Philip E; Lorey, Thomas; Katki, Hormuzd A

    2017-09-30

    For cost-effectiveness and efficiency, many large-scale general-purpose cohort studies are being assembled within large health-care providers who use electronic health records. Two key features of such data are that incident disease is interval-censored between irregular visits and there can be pre-existing (prevalent) disease. Because prevalent disease is not always immediately diagnosed, some disease diagnosed at later visits are actually undiagnosed prevalent disease. We consider prevalent disease as a point mass at time zero for clinical applications where there is no interest in time of prevalent disease onset. We demonstrate that the naive Kaplan-Meier cumulative risk estimator underestimates risks at early time points and overestimates later risks. We propose a general family of mixture models for undiagnosed prevalent disease and interval-censored incident disease that we call prevalence-incidence models. Parameters for parametric prevalence-incidence models, such as the logistic regression and Weibull survival (logistic-Weibull) model, are estimated by direct likelihood maximization or by EM algorithm. Non-parametric methods are proposed to calculate cumulative risks for cases without covariates. We compare naive Kaplan-Meier, logistic-Weibull, and non-parametric estimates of cumulative risk in the cervical cancer screening program at Kaiser Permanente Northern California. Kaplan-Meier provided poor estimates while the logistic-Weibull model was a close fit to the non-parametric. Our findings support our use of logistic-Weibull models to develop the risk estimates that underlie current US risk-based cervical cancer screening guidelines. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  15. The Model Confidence Set

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Nason, James M.

    The paper introduces the model confidence set (MCS) and applies it to the selection of models. A MCS is a set of models that is constructed such that it will contain the best model with a given level of confidence. The MCS is in this sense analogous to a confidence interval for a parameter. The MCS......, beyond the comparison of models. We apply the MCS procedure to two empirical problems. First, we revisit the inflation forecasting problem posed by Stock and Watson (1999), and compute the MCS for their set of inflation forecasts. Second, we compare a number of Taylor rule regressions and determine...... the MCS of the best in terms of in-sample likelihood criteria....

  16. Effects and prevalence of nonresponders after 12 weeks of high-intensity interval or resistance training in women with insulin resistance: a randomized trial.

    Science.gov (United States)

    Álvarez, Cristian; Ramírez-Campillo, Rodrigo; Ramírez-Vélez, Robinson; Izquierdo, Mikel

    2017-04-01

    Our aim was to investigate the effects and prevalence of nonresponders (NR) to high-intensity interval training (HIIT) and resistance training (RT) in women with insulin resistance on cardiometabolic health parameters. Sedentary overweight/obese insulin-resistant women (age = 33.5 ± 6.5 yr; body mass index = 29.9 ± 3.7 kg/m 2 ) were randomly assigned to a triweekly HIIT program (HIIT; n = 18) or resistance training (RT; n = 17). Anthropometry (body mass, fat mass, muscle mass, waist circumference, and skinfold thickness), cardiovascular (blood pressure), metabolic [fasting glucose, fasting insulin, and homeostatic model of insulin resistance (HOMA-IR)], as well as muscle strength, and endurance performance covariables were measured before and after 12 wk in both intervention groups. The interindividual variability to exercise training of the subjects was categorized as responders and NR using as cut points two times the typical error of measurement in mean outcomes. After intervention, significant reduction in waist circumference, skinfold thicknesses, fat mass, blood pressure, fasting glucose, insulin, and HOMA-IR ( P HIIT and RT group, respectively. Both HIIT and RT groups exhibited a significant decrease in the endurance performance, whereas only RT exhibited increased muscle strength. Significant differences in the NR prevalence between the HIIT and RT groups were identified for a decrease in fat mass (HIIT 33.3% vs. RT 70.5%; P = 0.028), muscle mass (HIIT 100% vs. RT 52.9%; P = 0.001), and tricipital skinfold (HIIT 5.5% vs. RT 29.4%; P HIIT and RT groups (55.5% vs. 94.1; P = 0.009). However, there were no differences in the NR prevalence between HIIT and RT for decreasing fasting glucose. Twelve weeks of HIIT and RT have similar effects and NR prevalence to improve glucose control variables; however, there is different NR prevalence in other anthropometric, cardiovascular, strength, and endurance performance measurements in insulin-resistant women. These

  17. Prevalence

    Directory of Open Access Journals (Sweden)

    Mohammed Al-Darwish

    2014-07-01

    Conclusion: Results indicated that dental caries prevalence among school children in Qatar has reached critical levels, and is influenced by socio-demographic factors. The mean decayed, missing, and filled teeth values obtained in this study were the second highest detected in the Eastern Mediterranean region.

  18. Prevalence of Non-responders for Glucose Control Markers after 10 Weeks of High-Intensity Interval Training in Adult Women with Higher and Lower Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Cristian Álvarez

    2017-07-01

    Full Text Available Background: Exercise training improves performance and biochemical parameters on average, but wide interindividual variability exists, with individuals classified as responders (R or non-responders (NRs, especially between populations with higher or lower levels of insulin resistance. This study assessed the effects of high-intensity interval training (HIIT and the prevalence of NRs in adult women with higher and lower levels of insulin resistance.Methods: Forty adult women were assigned to a HIIT program, and after training were analyzed in two groups; a group with higher insulin resistance (H-IR, 40 ± 6 years; BMI: 29.5 ± 3.7 kg/m2; n = 20 and a group with lower insulin resistance (L-IR, 35 ± 9 years; 27.8 ± 2.8 kg/m2; n = 20. Anthropometric, cardiovascular, metabolic, and performance variables were measured at baseline and after 10 weeks of training.Results: There were significant training-induced changes [delta percent (Δ%] in fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance (HOMA-IR scores in the H-IR group (−8.8, −26.5, −32.1%, p < 0.0001, whereas no significant changes were observed in the L-IR. Both groups showed significant pre-post changes in other anthropometric variables [waist circumference (−5.2, p < 0.010, and −3.8%, p = 0.046 and tricipital (−13.3, p < 0.010, and −13.6%, p < 0.0001, supra-iliac (−19.4, p < 0.0001, and −13.6%, p < 0.0001, and abdominal (−18.2, p < 0.0001, and −15.6%, p < 0.010 skinfold measurements]. Systolic blood pressure decreased significantly only in the L-IR group (−3.2%, p < 0.010. Both groups showed significant increases in 1RMLE (+12.9, p < 0.010, and +14.7%, p = 0.045. There were significant differences in the prevalence of NRs between the H-IR and L-IR groups for fasting glucose (25 vs. 95%, p < 0.0001 and fasting insulin (p = 0.025 but not for HOMA-IR (25 vs. 45%, p = 0.185.Conclusion: Independent of the “magnitude” of the

  19. Confidant Relations in Italy

    Directory of Open Access Journals (Sweden)

    Jenny Isaacs

    2015-02-01

    Full Text Available Confidants are often described as the individuals with whom we choose to disclose personal, intimate matters. The presence of a confidant is associated with both mental and physical health benefits. In this study, 135 Italian adults responded to a structured questionnaire that asked if they had a confidant, and if so, to describe various features of the relationship. The vast majority of participants (91% reported the presence of a confidant and regarded this relationship as personally important, high in mutuality and trust, and involving minimal lying. Confidants were significantly more likely to be of the opposite sex. Participants overall were significantly more likely to choose a spouse or other family member as their confidant, rather than someone outside of the family network. Familial confidants were generally seen as closer, and of greater value, than non-familial confidants. These findings are discussed within the context of Italian culture.

  20. Statistical intervals a guide for practitioners

    CERN Document Server

    Hahn, Gerald J

    2011-01-01

    Presents a detailed exposition of statistical intervals and emphasizes applications in industry. The discussion differentiates at an elementary level among different kinds of statistical intervals and gives instruction with numerous examples and simple math on how to construct such intervals from sample data. This includes confidence intervals to contain a population percentile, confidence intervals on probability of meeting specified threshold value, and prediction intervals to include observation in a future sample. Also has an appendix containing computer subroutines for nonparametric stati

  1. Confidence Intervals for Omega Coefficient: Proposal for Calculus.

    Science.gov (United States)

    Ventura-León, José Luis

    2018-01-01

    La confiabilidad es entendida como una propiedad métrica de las puntuaciones de un instrumento de medida. Recientemente se viene utilizando el coeficiente omega (ω) para la estimación de la confiabilidad. No obstante, la medición nunca es exacta por la influencia del error aleatorio, por esa razón es necesario calcular y reportar el intervalo de confianza (IC) que permite encontrar en valor verdadero en un rango de medida. En ese contexto, el artículo plantea una forma de estimar el IC mediante el método de bootstrap para facilitar este procedimiento se brindan códigos de R (un software de acceso libre) para que puedan realizarse los cálculos de una forma amigable. Se espera que el artículo sirva de ayuda a los investigadores de ámbito de salud.

  2. Secure and Usable Bio-Passwords based on Confidence Interval

    OpenAIRE

    Aeyoung Kim; Geunshik Han; Seung-Hyun Seo

    2017-01-01

    The most popular user-authentication method is the password. Many authentication systems try to enhance their security by enforcing a strong password policy, and by using the password as the first factor, something you know, with the second factor being something you have. However, a strong password policy and a multi-factor authentication system can make it harder for a user to remember the password and login in. In this paper a bio-password-based scheme is proposed as a unique authenticatio...

  3. Intervals of confidence: Uncertain accounts of global hunger

    NARCIS (Netherlands)

    Yates-Doerr, E.

    2015-01-01

    Global health policy experts tend to organize hunger through scales of ‘the individual’, ‘the community’ and ‘the global’. This organization configures hunger as a discrete, measurable object to be scaled up or down with mathematical certainty. This article offers a counter to this approach, using

  4. A quick method to calculate QTL confidence interval

    Indian Academy of Sciences (India)

    2011-08-19

    Aug 19, 2011 ... experimental design and analysis to reveal the real molecular nature of the ... strap sample form the bootstrap distribution of QTL location. The 2.5 and ..... ative probability to harbour a true QTL, hence x-LOD rule is not stable ... Darvasi A. and Soller M. 1997 A simple method to calculate resolv- ing power ...

  5. Large Sample Confidence Intervals for Item Response Theory Reliability Coefficients

    Science.gov (United States)

    Andersson, Björn; Xin, Tao

    2018-01-01

    In applications of item response theory (IRT), an estimate of the reliability of the ability estimates or sum scores is often reported. However, analytical expressions for the standard errors of the estimators of the reliability coefficients are not available in the literature and therefore the variability associated with the estimated reliability…

  6. An approximate confidence interval for recombination fraction in ...

    African Journals Online (AJOL)

    user

    2011-02-14

    Feb 14, 2011 ... whose parents are not in the pedigree) and θ be the recombination fraction. ( )|. P x g is the penetrance probability, that is, the probability that an individual with genotype g has phenotype x . Let (. ) | , k k k f m. P g g g be the transmission probability, that is, the probability that an individual having genotype k.

  7. Raising Confident Kids

    Science.gov (United States)

    ... First Aid & Safety Doctors & Hospitals Videos Recipes for Kids Kids site Sitio para niños How the Body ... Videos for Educators Search English Español Raising Confident Kids KidsHealth / For Parents / Raising Confident Kids What's in ...

  8. nigerian students' self-confidence in responding to statements

    African Journals Online (AJOL)

    Temechegn

    Altogether the test is made up of 40 items covering students' ability to recall definition ... confidence interval within which student have confidence in their choice of the .... is mentioned these equilibrium systems come to memory of the learner.

  9. Human Papillomavirus - Prevalence of High-Risk and Low-Risk Types among Females Aged 14-59 Years, National Health and ...

    Science.gov (United States)

    ... Archive Data & Statistics Sexually Transmitted Diseases Figure 45. Human Papillomavirus — Prevalence of High-risk and Low-risk ... on the STD Data and Statistics page . * HPV = human papillomavirus. NOTE: Error bars indicate 95% confidence interval. ...

  10. Hepatitis B prevalence in Denmark

    DEFF Research Database (Denmark)

    Hansen, N; Hay, G; Cowan, S

    2013-01-01

    The prevalence of chronic hepatitis B virus (HBV) infection in Denmark is not clear. The primary aim of this study was to estimate the prevalence of chronic HBV infection in Denmark. The capture–recapture method was used to estimate the total population diagnosed with chronic HBV infection......, and the capture–recapture estimate of the total population diagnosed with chronic hepatitis B was 7,112 (95% confidence interval (CI): 6,953–10,747). Only 17% of the identified patients attended recommended clinical care according to national guidelines. Including undiagnosed patients, the current population...

  11. Comparing the Prevalence of Handedness between Normal and Congenitally Deaf Students in Age Intervals of 12 to 18 Years in Tehran

    Directory of Open Access Journals (Sweden)

    Zahra Jafari

    2007-04-01

    Full Text Available Objective: Handedness is the most prominent behavioral asymmetry in human. The term of hand preference points to prefer hand or functional asymmetry in manual tasks. The items were considered in this study were: the comparison of handedness between normal and congenitally deaf students the effects of age, sex, and pressure on using right hand for unimanual tasks on handedness the frequency of left-handers among student’s families, the influence of hand preference on English language capabilities, and the point of view of people rather to left-handers have been investigated. Materials & Methods: This cross-sectional comparative study was conducted on 760 students including 380 normal students and 380 deaf students with congenital severe or profound sensory-neural hearing loss from 12 to 18 years of age by that were selected purposefully, completing Edinburg handedness inventory in Tehran. The students didn’t have any confirmed diseases or neurological disorders, except hearing loss in deaf student. Data were gathered through the completion of the Edinburg Handedness Inventory by the students. The student’s aural records and also the confirmation of the audiologist in the deaf schools were considered in order to determine the kind and degree of hearing loss. Results: The prevalence of left-handedness among normal (9.7% and deaf (10.3% students were near to each other, and there was no significant difference between them (P=0.901, z=-1.24. The prevalence of left-handedness was higher in boys rather than girls, but there was no significant influence of sex and age on results (P>0.05. The family and/or teacher pressure for using right hand was 16.0% in normal students and 5.0% in deaf students, and they didn’t report any strict pressure or severity regard this mater. The frequency of left-handers was higher among family of normal students (22.6% than deaf students (13.2%, and the difference between them was significant statistically (P=0

  12. Prevalence of Chlamydophila psittaci in fecal droppings from feral pigeons in Amsterdam, The Netherlands

    NARCIS (Netherlands)

    Heddema, Edou R.; ter Sluis, Sietske; Buys, Jan A.; Vandenbroucke-Grauls, Christina M. J. E.; van Wijnen, Joop H.; Visser, Caroline E.

    2006-01-01

    In many cities, the feral rock dove is an abundant bird species that can harbor Chlamydophila psittaci. We determined the prevalence and genotype of C. psittaci in fresh fecal samples from feral pigeons in Amsterdam, The Netherlands. The prevalence was 7.9% overall (26/331; 95% confidence interval,

  13. Prevalence of childhood disability in rural KwaZulu Natal | Couper ...

    African Journals Online (AJOL)

    1 000 (95% confidence interval (CI): 71 - 95). The overall confirmed prevalence rate for children with disabilities under 10years was 60/1 000 (95% CI: 50- 71). The most prevalent disabilities were mild perceptual or learning disability (17/1 000) ...

  14. Reclaim your creative confidence.

    Science.gov (United States)

    Kelley, Tom; Kelley, David

    2012-12-01

    Most people are born creative. But over time, a lot of us learn to stifle those impulses. We become warier of judgment, more cautious more analytical. The world seems to divide into "creatives" and "noncreatives," and too many people resign themselves to the latter category. And yet we know that creativity is essential to success in any discipline or industry. The good news, according to authors Tom Kelley and David Kelley of IDEO, is that we all can rediscover our creative confidence. The trick is to overcome the four big fears that hold most of us back: fear of the messy unknown, fear of judgment, fear of the first step, and fear of losing control. The authors use an approach based on the work of psychologist Albert Bandura in helping patients get over their snake phobias: You break challenges down into small steps and then build confidence by succeeding on one after another. Creativity is something you practice, say the authors, not just a talent you are born with.

  15. Confidence in Numerical Simulations

    International Nuclear Information System (INIS)

    Hemez, Francois M.

    2015-01-01

    This PowerPoint presentation offers a high-level discussion of uncertainty, confidence and credibility in scientific Modeling and Simulation (M&S). It begins by briefly evoking M&S trends in computational physics and engineering. The first thrust of the discussion is to emphasize that the role of M&S in decision-making is either to support reasoning by similarity or to ''forecast,'' that is, make predictions about the future or extrapolate to settings or environments that cannot be tested experimentally. The second thrust is to explain that M&S-aided decision-making is an exercise in uncertainty management. The three broad classes of uncertainty in computational physics and engineering are variability and randomness, numerical uncertainty and model-form uncertainty. The last part of the discussion addresses how scientists ''think.'' This thought process parallels the scientific method where by a hypothesis is formulated, often accompanied by simplifying assumptions, then, physical experiments and numerical simulations are performed to confirm or reject the hypothesis. ''Confidence'' derives, not just from the levels of training and experience of analysts, but also from the rigor with which these assessments are performed, documented and peer-reviewed.

  16. Confidence bands for inverse regression models

    International Nuclear Information System (INIS)

    Birke, Melanie; Bissantz, Nicolai; Holzmann, Hajo

    2010-01-01

    We construct uniform confidence bands for the regression function in inverse, homoscedastic regression models with convolution-type operators. Here, the convolution is between two non-periodic functions on the whole real line rather than between two periodic functions on a compact interval, since the former situation arguably arises more often in applications. First, following Bickel and Rosenblatt (1973 Ann. Stat. 1 1071–95) we construct asymptotic confidence bands which are based on strong approximations and on a limit theorem for the supremum of a stationary Gaussian process. Further, we propose bootstrap confidence bands based on the residual bootstrap and prove consistency of the bootstrap procedure. A simulation study shows that the bootstrap confidence bands perform reasonably well for moderate sample sizes. Finally, we apply our method to data from a gel electrophoresis experiment with genetically engineered neuronal receptor subunits incubated with rat brain extract

  17. Globalization of consumer confidence

    Directory of Open Access Journals (Sweden)

    Çelik Sadullah

    2017-01-01

    Full Text Available The globalization of world economies and the importance of nowcasting analysis have been at the core of the recent literature. Nevertheless, these two strands of research are hardly coupled. This study aims to fill this gap through examining the globalization of the consumer confidence index (CCI by applying conventional and unconventional econometric methods. The US CCI is used as the benchmark in tests of comovement among the CCIs of several developing and developed countries, with the data sets divided into three sub-periods: global liquidity abundance, the Great Recession, and postcrisis. The existence and/or degree of globalization of the CCIs vary according to the period, whereas globalization in the form of coherence and similar paths is observed only during the Great Recession and, surprisingly, stronger in developing/emerging countries.

  18. Prevalence and predictors of institutional delivery among pregnant ...

    African Journals Online (AJOL)

    ebutamanya

    2015-05-25

    May 25, 2015 ... in a year with contraceptive use coverage of 15% in 2012 (Regional. Annual Reproductive and Child Health Report). Sampling and data collection. Using the formula Z2p(100-p)/e2, the marginal error (e) of 5%, z at. 95% confidence interval of 1.96, and prevalence (p) of institution delivery of 46%, we ...

  19. Prevalence of multiple sclerosis in Denmark 1950-2005

    DEFF Research Database (Denmark)

    Bentzen, Joan; Meulengracht Flachs, Esben; Stenager, Egon

    2010-01-01

    Multiple sclerosis is an inflammatory disease of the central nervous system of unknown aetiology. Its prevalence varies by ethnicity and place: persons of northern European descent are at increased risk while persons living at lower latitudes appear to be protected against the disease. The Danish...... Multiple Sclerosis Registry is a national registry established in 1956 after a population-based survey which receives information from numerous sources. It is considered to be more than 90% complete, with a validity of 94%. Using data from the Registry, we calculated prevalences per 100,000 inhabitants....... The standardized prevalence of multiple sclerosis increased from 58.8 (95% confidence interval: 54.9-62.7) in 1950 to 154.5 per 100,000 (95% confidence interval: 148.8-160.2) in 2005, and the female to male ratio increased from 1.31 in 1950 to 2.02 in 2005. The increase in prevalence is due to both increased...

  20. Confidence in Numerical Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Hemez, Francois M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    This PowerPoint presentation offers a high-level discussion of uncertainty, confidence and credibility in scientific Modeling and Simulation (M&S). It begins by briefly evoking M&S trends in computational physics and engineering. The first thrust of the discussion is to emphasize that the role of M&S in decision-making is either to support reasoning by similarity or to “forecast,” that is, make predictions about the future or extrapolate to settings or environments that cannot be tested experimentally. The second thrust is to explain that M&S-aided decision-making is an exercise in uncertainty management. The three broad classes of uncertainty in computational physics and engineering are variability and randomness, numerical uncertainty and model-form uncertainty. The last part of the discussion addresses how scientists “think.” This thought process parallels the scientific method where by a hypothesis is formulated, often accompanied by simplifying assumptions, then, physical experiments and numerical simulations are performed to confirm or reject the hypothesis. “Confidence” derives, not just from the levels of training and experience of analysts, but also from the rigor with which these assessments are performed, documented and peer-reviewed.

  1. Confidence bounds for normal and lognormal distribution coefficients of variation

    Science.gov (United States)

    Steve Verrill

    2003-01-01

    This paper compares the so-called exact approach for obtaining confidence intervals on normal distribution coefficients of variation to approximate methods. Approximate approaches were found to perform less well than the exact approach for large coefficients of variation and small sample sizes. Web-based computer programs are described for calculating confidence...

  2. The idiosyncratic nature of confidence.

    Science.gov (United States)

    Navajas, Joaquin; Hindocha, Chandni; Foda, Hebah; Keramati, Mehdi; Latham, Peter E; Bahrami, Bahador

    2017-11-01

    Confidence is the 'feeling of knowing' that accompanies decision making. Bayesian theory proposes that confidence is a function solely of the perceived probability of being correct. Empirical research has suggested, however, that different individuals may perform different computations to estimate confidence from uncertain evidence. To test this hypothesis, we collected confidence reports in a task where subjects made categorical decisions about the mean of a sequence. We found that for most individuals, confidence did indeed reflect the perceived probability of being correct. However, in approximately half of them, confidence also reflected a different probabilistic quantity: the perceived uncertainty in the estimated variable. We found that the contribution of both quantities was stable over weeks. We also observed that the influence of the perceived probability of being correct was stable across two tasks, one perceptual and one cognitive. Overall, our findings provide a computational interpretation of individual differences in human confidence.

  3. Diverse interpretations of confidence building

    International Nuclear Information System (INIS)

    Macintosh, J.

    1998-01-01

    This paper explores the variety of operational understandings associated with the term 'confidence building'. Collectively, these understandings constitute what should be thought of as a 'family' of confidence building approaches. This unacknowledged and generally unappreciated proliferation of operational understandings that function under the rubric of confidence building appears to be an impediment to effective policy. The paper's objective is to analyze these different understandings, stressing the important differences in their underlying assumptions. In the process, the paper underlines the need for the international community to clarify its collective thinking about what it means when it speaks of 'confidence building'. Without enhanced clarity, it will be unnecessarily difficult to employ the confidence building approach effectively due to the lack of consistent objectives and common operating assumptions. Although it is not the intention of this paper to promote a particular account of confidence building, dissecting existing operational understandings should help to identify whether there are fundamental elements that define what might be termed 'authentic' confidence building. Implicit here is the view that some operational understandings of confidence building may diverge too far from consensus models to count as meaningful members of the confidence building family. (author)

  4. Correct Bayesian and frequentist intervals are similar

    International Nuclear Information System (INIS)

    Atwood, C.L.

    1986-01-01

    This paper argues that Bayesians and frequentists will normally reach numerically similar conclusions, when dealing with vague data or sparse data. It is shown that both statistical methodologies can deal reasonably with vague data. With sparse data, in many important practical cases Bayesian interval estimates and frequentist confidence intervals are approximately equal, although with discrete data the frequentist intervals are somewhat longer. This is not to say that the two methodologies are equally easy to use: The construction of a frequentist confidence interval may require new theoretical development. Bayesians methods typically require numerical integration, perhaps over many variables. Also, Bayesian can easily fall into the trap of over-optimism about their amount of prior knowledge. But in cases where both intervals are found correctly, the two intervals are usually not very different. (orig.)

  5. Interval selection with machine-dependent intervals

    OpenAIRE

    Bohmova K.; Disser Y.; Mihalak M.; Widmayer P.

    2013-01-01

    We study an offline interval scheduling problem where every job has exactly one associated interval on every machine. To schedule a set of jobs, exactly one of the intervals associated with each job must be selected, and the intervals selected on the same machine must not intersect.We show that deciding whether all jobs can be scheduled is NP-complete already in various simple cases. In particular, by showing the NP-completeness for the case when all the intervals associated with the same job...

  6. Nuclear power: restoring public confidence

    International Nuclear Information System (INIS)

    Arnold, L.

    1986-01-01

    The paper concerns a one day conference on nuclear power organised by the Centre for Science Studies and Science Policy, Lancaster, April 1986. Following the Chernobyl reactor accident, the conference concentrated on public confidence in nuclear power. Causes of lack of public confidence, public perceptions of risk, and the effect of Chernobyl in the United Kingdom, were all discussed. A Select Committee on the Environment examined the problems of radioactive waste disposal. (U.K.)

  7. The prevalence of diagnosed tourette syndrome in Canada: A national population-based study.

    Science.gov (United States)

    Yang, Jaeun; Hirsch, Lauren; Martino, Davide; Jette, Nathalie; Roberts, Jodie; Pringsheim, Tamara

    2016-11-01

    The objective of this study was to examine: (1) the prevalence of diagnosed Tourette syndrome in Canada by sex in youth (aged 12-17) and adults and (2) socioeconomic factors in this population. The majority of epidemiological studies of tics have focused on children and youth, with few studies describing the prevalence of tics in adult populations. Canadian data on Tourette syndrome prevalence were derived from the Canadian Community Health Survey 2010 and 2011 cycles, a Statistics Canada population-based cross-sectional survey that collects information related to health status. We determined the prevalence of diagnosed Tourette syndrome and examined sociodemographic factors, including age, sex, education, income, employment, and birthplace. Overall, 122,884 Canadians participated in the surveys, with 122 participants diagnosed with Tourette syndrome. The prevalence of Tourette syndrome was higher in males in youth: 6.03 per 1000 (95% confidence interval: 3.24-8.81) in males versus 0.48 per 1,000 (95% confidence interval: 0.05-0.91) in females, with a prevalence risk ratio of 5.31 (95% confidence interval: 2.38-11.81). In adults, the prevalence of Tourette syndrome was 0.89 per 1,000 (95% confidence interval: 0.48-1.29) in males versus 0.44 (95% confidence interval: 0.16.0-0.71) in females, with a prevalence risk ratio of 1.93 (95% confidence interval: 1.21-3.08). After adjusting for age and sex, adults with Tourette syndrome had lower odds of receiving postsecondary education or being employed and higher odds of having income lower than the median and receiving governmental support. Data on the prevalence of Tourette syndrome in adults are scarce because most studies focus on children. Our data demonstrate a decreasing prevalence risk ratio for sex in adults compared to children. A diagnosis of Tourette syndrome is associated with lower education, income, and employment in adulthood. © 2016 International Parkinson and Movement Disorder Society. © 2016

  8. Prevalence and Determinants of Corneal Blindness in a Semi-Urban ...

    African Journals Online (AJOL)

    2017-07-26

    Jul 26, 2017 ... blindness with a prevalence of 1.1% (95% confidence interval: 0.5–1.7). Corneal blindness .... Power Holding Company of Nigeria. The local ... trauma, the redness of the eye with or without pain, history suggestive of measles,.

  9. Prevalence of dry eye syndrome in an adult population.

    Science.gov (United States)

    Hashemi, Hassan; Khabazkhoob, Mehdi; Kheirkhah, Ahmad; Emamian, Mohammad Hassan; Mehravaran, Shiva; Shariati, Mohammad; Fotouhi, Akbar

    2014-04-01

    To determine the prevalence of dry eye syndrome in the general 40- to 64-year-old population of Shahroud, Iran. Population-based cross-sectional study. Through cluster sampling, 6311 people were selected and 5190 participated. Assessment of dry eye was done in a random subsample of 1008 people. Subjective assessment for dry eye syndrome was performed using Ocular Surface Disease Index questionnaire. In addition, the following objective tests of dry eye syndrome were employed: Schirmer test, tear break-up time, and fluorescein and Rose Bengal staining using the Oxford grading scheme. Those with an Ocular Surface Disease Index score ≥23 were considered symptomatic, and dry eye syndrome was defined as having symptoms and at least one positive objective sign. The prevalence of dry eye syndrome was 8.7% (95% confidence interval 6.9-10.6). Assessment of signs showed an abnormal Schirmer score in 17.8% (95% confidence interval 15.5-20.0), tear break-up time in 34.2% (95% confidence interval 29.5-38.8), corneal fluorescein staining (≥1) in 11.3% (95% confidence interval 8.5-14.1) and Rose Bengal staining (≥3 for cornea and/or conjunctiva) in 4.9% (95% confidence interval 3.4-6.5). According to the Ocular Surface Disease Index scores, 18.3% (95% confidence interval 15.9-20.6) had dry eye syndrome symptoms. The prevalence of dry eye syndrome was significantly higher in women (P = 0.010) and not significantly associated with age (P = 0.291). The objective dry eye syndrome signs significantly increased with age. Based on the findings, the prevalence of dry eye syndrome in the studied population is in the mid-range. The prevalence is higher in women. Also, objective tests tend to turn abnormal at higher age. Pterygium is associated with dry eye syndrome and increased its symptoms. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

  10. Confidence in critical care nursing.

    Science.gov (United States)

    Evans, Jeanne; Bell, Jennifer L; Sweeney, Annemarie E; Morgan, Jennifer I; Kelly, Helen M

    2010-10-01

    The purpose of the study was to gain an understanding of the nursing phenomenon, confidence, from the experience of nurses in the nursing subculture of critical care. Leininger's theory of cultural care diversity and universality guided this qualitative descriptive study. Questions derived from the sunrise model were used to elicit nurses' perspectives about cultural and social structures that exist within the critical care nursing subculture and the influence that these factors have on confidence. Twenty-eight critical care nurses from a large Canadian healthcare organization participated in semistructured interviews about confidence. Five themes arose from the descriptions provided by the participants. The three themes, tenuously navigating initiation rituals, deliberately developing holistic supportive relationships, and assimilating clinical decision-making rules were identified as social and cultural factors related to confidence. The remaining two themes, preserving a sense of security despite barriers and accommodating to diverse challenges, were identified as environmental factors related to confidence. Practice and research implications within the culture of critical care nursing are discussed in relation to each of the themes.

  11. Professional confidence: a concept analysis.

    Science.gov (United States)

    Holland, Kathlyn; Middleton, Lyn; Uys, Leana

    2012-03-01

    Professional confidence is a concept that is frequently used and or implied in occupational therapy literature, but often without specifying its meaning. Rodgers's Model of Concept Analysis was used to analyse the term "professional confidence". Published research obtained from a federated search in four health sciences databases was used to inform the concept analysis. The definitions, attributes, antecedents, and consequences of professional confidence as evidenced in the literature are discussed. Surrogate terms and related concepts are identified, and a model case of the concept provided. Based on the analysis, professional confidence can be described as a dynamic, maturing personal belief held by a professional or student. This includes an understanding of and a belief in the role, scope of practice, and significance of the profession, and is based on their capacity to competently fulfil these expectations, fostered through a process of affirming experiences. Developing and fostering professional confidence should be nurtured and valued to the same extent as professional competence, as the former underpins the latter, and both are linked to professional identity.

  12. Targeting Low Career Confidence Using the Career Planning Confidence Scale

    Science.gov (United States)

    McAuliffe, Garrett; Jurgens, Jill C.; Pickering, Worth; Calliotte, James; Macera, Anthony; Zerwas, Steven

    2006-01-01

    The authors describe the development and validation of a test of career planning confidence that makes possible the targeting of specific problem issues in employment counseling. The scale, developed using a rational process and the authors' experience with clients, was tested for criterion-related validity against 2 other measures. The scale…

  13. Convex Interval Games

    NARCIS (Netherlands)

    Alparslan-Gok, S.Z.; Brânzei, R.; Tijs, S.H.

    2008-01-01

    In this paper, convex interval games are introduced and some characterizations are given. Some economic situations leading to convex interval games are discussed. The Weber set and the Shapley value are defined for a suitable class of interval games and their relations with the interval core for

  14. Prevalence and incidence of peptic ulcer disease in a Danish County--a prospective cohort study.

    OpenAIRE

    Rosenstock, S J; Jørgensen, T

    1995-01-01

    Peptic ulcer prevalence and five year incidence were assessed in a sex and age stratified population sample of 3608 Danish subjects aged 30-60 years. Statements of peptic ulcer disease obtained from questionnaires were scrutinised by reviewing medical records. Life time ulcer prevalence (95% confidence intervals) was 5.6 (4.9-6.4) per cent. Male to female prevalence ratio was 2.2:1, and duodenal to gastric ulcer prevalence ratio was 3.8:1. Thirty two participants with no previous history of p...

  15. Increasing autism prevalence in metropolitan New Jersey.

    Science.gov (United States)

    Zahorodny, Walter; Shenouda, Josephine; Howell, Sandra; Rosato, Nancy Scotto; Peng, Bo; Mehta, Uday

    2014-02-01

    High baseline autism spectrum disorder prevalence estimates in New Jersey led to a follow-up surveillance. The objectives were to determine autism spectrum disorder prevalence in the year 2006 in New Jersey and to identify changes in the prevalence of autism spectrum disorder or in the characteristics of the children with autism spectrum disorder, between 2002 and 2006. The cohorts included 30,570 children, born in 1998 and 28,936 children, born in 1994, residing in Hudson, Union, and Ocean counties, New Jersey. Point prevalence estimates by sex, ethnicity, autism spectrum disorder subtype, and previous autism spectrum disorder diagnosis were determined. For 2006, a total of 533 children with autism spectrum disorder were identified, consistent with prevalence of 17.4 per 1000 (95% confidence interval = 15.9-18.9), indicating a significant increase in the autism spectrum disorder prevalence (p autism spectrum disorder was broad, affecting major demographic groups and subtypes. Boys with autism spectrum disorder outnumbered girls by nearly 5:1. Autism spectrum disorder prevalence was higher among White children than children of other ethnicities. Additional studies are needed to specify the influence of better awareness of autism spectrum disorder prevalence estimates and to identify possible autism spectrum disorder risk factors. More resources are necessary to address the needs of individuals affected by autism spectrum disorder.

  16. Normal probability plots with confidence.

    Science.gov (United States)

    Chantarangsi, Wanpen; Liu, Wei; Bretz, Frank; Kiatsupaibul, Seksan; Hayter, Anthony J; Wan, Fang

    2015-01-01

    Normal probability plots are widely used as a statistical tool for assessing whether an observed simple random sample is drawn from a normally distributed population. The users, however, have to judge subjectively, if no objective rule is provided, whether the plotted points fall close to a straight line. In this paper, we focus on how a normal probability plot can be augmented by intervals for all the points so that, if the population distribution is normal, then all the points should fall into the corresponding intervals simultaneously with probability 1-α. These simultaneous 1-α probability intervals provide therefore an objective mean to judge whether the plotted points fall close to the straight line: the plotted points fall close to the straight line if and only if all the points fall into the corresponding intervals. The powers of several normal probability plot based (graphical) tests and the most popular nongraphical Anderson-Darling and Shapiro-Wilk tests are compared by simulation. Based on this comparison, recommendations are given in Section 3 on which graphical tests should be used in what circumstances. An example is provided to illustrate the methods. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Methodology for building confidence measures

    Science.gov (United States)

    Bramson, Aaron L.

    2004-04-01

    This paper presents a generalized methodology for propagating known or estimated levels of individual source document truth reliability to determine the confidence level of a combined output. Initial document certainty levels are augmented by (i) combining the reliability measures of multiply sources, (ii) incorporating the truth reinforcement of related elements, and (iii) incorporating the importance of the individual elements for determining the probability of truth for the whole. The result is a measure of confidence in system output based on the establishing of links among the truth values of inputs. This methodology was developed for application to a multi-component situation awareness tool under development at the Air Force Research Laboratory in Rome, New York. Determining how improvements in data quality and the variety of documents collected affect the probability of a correct situational detection helps optimize the performance of the tool overall.

  18. Alan Greenspan, the confidence strategy

    Directory of Open Access Journals (Sweden)

    Edwin Le Heron

    2006-12-01

    Full Text Available To evaluate the Greenspan era, we nevertheless need to address three questions: Is his success due to talent or just luck? Does he have a system of monetary policy or is he himself the system? What will be his legacy? Greenspan was certainly lucky, but he was also clairvoyant. Above all, he has developed a profoundly original monetary policy. His confidence strategy is clearly opposed to the credibility strategy developed in central banks and the academic milieu after 1980, but also inflation targeting, which today constitutes the mainstream monetary policy regime. The question of his legacy seems more nuanced. However, Greenspan will remain 'for a considerable period of time' a highly heterodox and original central banker. His political vision, his perception of an uncertain world, his pragmatism and his openness form the structure of a powerful alternative system, the confidence strategy, which will leave its mark on the history of monetary policy.

  19. Graphical interpretation of confidence curves in rankit plots

    DEFF Research Database (Denmark)

    Hyltoft Petersen, Per; Blaabjerg, Ole; Andersen, Marianne

    2004-01-01

    A well-known transformation from the bell-shaped Gaussian (normal) curve to a straight line in the rankit plot is investigated, and a tool for evaluation of the distribution of reference groups is presented. It is based on the confidence intervals for percentiles of the calculated Gaussian distri...

  20. The prevalence of stroke and associated disability.

    Science.gov (United States)

    O'Mahony, P G; Thomson, R G; Dobson, R; Rodgers, H; James, O F

    1999-06-01

    There are limited data available on the prevalence of stroke in the United Kingdom. Such data are important for the assessment of the health needs of the population. This study aimed to determine the prevalence of stroke and the prevalence of associated dependence in a district of northern England. This was a two-stage point prevalence study. A valid screening questionnaire was used to identify stroke survivors from an age- and sex-stratified sample of the population aged 45 years and over in a family health services authority district. This was followed by assessment of stroke patients with scales of disability and handicap. The overall prevalence of stroke was found to be 17.5/1000 (95 per cent confidence interval (CI) 17.0, 18.0). The prevalence of stroke-associated dependence was 11.7/1000 (95 per cent CI 11.3, 12.1). Self-reported comorbidity was most commonly due to circulatory and musculoskeletal disorders. The prevalence of stroke in this district is considerably higher than current guidelines and previous results suggest. Nevertheless, the result from this study combined with that from a previous study in another district in the United Kingdom should allow those interested in epidemiologically based health needs assessment to make reasonable estimates of the burden of stroke in their area.

  1. Leadership by Confidence in Teams

    OpenAIRE

    Kobayashi, Hajime; Suehiro, Hideo

    2008-01-01

    We study endogenous signaling by analyzing a team production problem with endogenous timing. Each agent of the team is privately endowed with some level of confidence about team productivity. Each of them must then commit a level of effort in one of two periods. At the end of each period, each agent observes his partner' s move in this period. Both agents are rewarded by a team output determined by team productivity and total invested effort. Each agent must personally incur the cost of effor...

  2. Towards confidence in transport safety

    International Nuclear Information System (INIS)

    Robison, R.W.

    1992-01-01

    The U.S. Department of Energy (US DOE) plans to demonstrate to the public that high-level waste can be transported safely to the proposed repository. The author argues US DOE should begin now to demonstrate its commitment to safety by developing an extraordinary safety program for nuclear cargo it is now shipping. The program for current shipments should be developed with State, Tribal, and local officials. Social scientists should be involved in evaluating the effect of the safety program on public confidence. The safety program developed in cooperation with western states for shipments to the Waste Isolation Pilot plant is a good basis for designing that extraordinary safety program

  3. Prevalence of Hypertension in Children with Early-Stage ADPKD.

    Science.gov (United States)

    Massella, Laura; Mekahli, Djalila; Paripović, Dušan; Prikhodina, Larisa; Godefroid, Nathalie; Niemirska, Anna; Ağbaş, Ayşe; Kalicka, Karolina; Jankauskiene, Augustina; Mizerska-Wasiak, Malgorzata; Afonso, Alberto Caldas; Salomon, Rémi; Deschênes, Georges; Ariceta, Gema; Özçakar, Z Birsin; Teixeira, Ana; Duzova, Ali; Harambat, Jérôme; Seeman, Tomáš; Hrčková, Gabriela; Lungu, Adrian Catalin; Papizh, Svetlana; Peco-Antic, Amira; De Rechter, Stéphanie; Giordano, Ugo; Kirchner, Marietta; Lutz, Teresa; Schaefer, Franz; Devuyst, Olivier; Wühl, Elke; Emma, Francesco

    2018-04-19

    Autosomal dominant polycystic kidney disease is the most common inheritable kidney disease, frequently thought to become symptomatic in adulthood. However, patients with autosomal dominant polycystic kidney disease may develop signs or symptoms during childhood, in particular hypertension. Although ambulatory BP monitoring is the preferred method to diagnose hypertension in pediatrics, data in children with autosomal dominant polycystic kidney disease are limited. Our retrospective multicenter study was conducted to collect ambulatory BP monitoring recordings from patients with autosomal dominant polycystic kidney disease age 1 cm per kidney and daytime hypertension (odds ratio, 1.70; 95% confidence interval, 1.21 to 2.4; P =0.002), nighttime hypertension (odds ratio, 1.31; 95% confidence interval, 1.05 to 1.63; P =0.02), or 24-hour hypertension (odds ratio, 1.39; 95% confidence interval, 1.08 to 1.81; P =0.01). Kidney length, expressed as SD score, was also significantly associated with nighttime hypertension (odds ratio, 1.23; 95% confidence interval, 1.06 to 1.42; P =0.10). These data indicate high prevalence of hypertension in children with autosomal dominant polycystic kidney disease starting at young ages. Copyright © 2018 by the American Society of Nephrology.

  4. Workshop on confidence limits. Proceedings

    International Nuclear Information System (INIS)

    James, F.; Lyons, L.; Perrin, Y.

    2000-01-01

    The First Workshop on Confidence Limits was held at CERN on 17-18 January 2000. It was devoted to the problem of setting confidence limits in difficult cases: number of observed events is small or zero, background is larger than signal, background not well known, and measurements near a physical boundary. Among the many examples in high-energy physics are searches for the Higgs, searches for neutrino oscillations, B s mixing, SUSY, compositeness, neutrino masses, and dark matter. Several different methods are on the market: the CL s methods used by the LEP Higgs searches; Bayesian methods; Feldman-Cousins and modifications thereof; empirical and combined methods. The Workshop generated considerable interest, and attendance was finally limited by the seating capacity of the CERN Council Chamber where all the sessions took place. These proceedings contain all the papers presented, as well as the full text of the discussions after each paper and of course the last session which was a discussion session. The list of participants and the 'required reading', which was expected to be part of the prior knowledge of all participants, are also included. (orig.)

  5. The Great Recession and confidence in homeownership

    OpenAIRE

    Anat Bracha; Julian Jamison

    2013-01-01

    Confidence in homeownership shifts for those who personally experienced real estate loss during the Great Recession. Older Americans are confident in the value of homeownership. Younger Americans are less confident.

  6. Reviewing interval cancers: Time well spent?

    International Nuclear Information System (INIS)

    Gower-Thomas, Kate; Fielder, Hilary M.P.; Branston, Lucy; Greening, Sarah; Beer, Helen; Rogers, Cerilan

    2002-01-01

    OBJECTIVES: To categorize interval cancers, and thus identify false-negatives, following prevalent and incident screens in the Welsh breast screening programme. SETTING: Breast Test Wales (BTW) Llandudno, Cardiff and Swansea breast screening units. METHODS: Five hundred and sixty interval breast cancers identified following negative mammographic screening between 1989 and 1997 were reviewed by eight screening radiologists. The blind review was achieved by mixing the screening films of women who subsequently developed an interval cancer with screen negative films of women who did not develop cancer, in a ratio of 4:1. Another radiologist used patients' symptomatic films to record a reference against which the reviewers' reports of the screening films were compared. Interval cancers were categorized as 'true', 'occult', 'false-negative' or 'unclassified' interval cancers or interval cancers with minimal signs, based on the National Health Service breast screening programme (NHSBSP) guidelines. RESULTS: Of the classifiable interval films, 32% were false-negatives, 55% were true intervals and 12% occult. The proportion of false-negatives following incident screens was half that following prevalent screens (P = 0.004). Forty percent of the seed films were recalled by the panel. CONCLUSIONS: Low false-negative interval cancer rates following incident screens (18%) versus prevalent screens (36%) suggest that lower cancer detection rates at incident screens may have resulted from fewer cancers than expected being present, rather than from a failure to detect tumours. The panel method for categorizing interval cancers has significant flaws as the results vary markedly with different protocol and is no more accurate than other, quicker and more timely methods. Gower-Thomas, K. et al. (2002)

  7. Programming with Intervals

    Science.gov (United States)

    Matsakis, Nicholas D.; Gross, Thomas R.

    Intervals are a new, higher-level primitive for parallel programming with which programmers directly construct the program schedule. Programs using intervals can be statically analyzed to ensure that they do not deadlock or contain data races. In this paper, we demonstrate the flexibility of intervals by showing how to use them to emulate common parallel control-flow constructs like barriers and signals, as well as higher-level patterns such as bounded-buffer producer-consumer. We have implemented intervals as a publicly available library for Java and Scala.

  8. Public confidence and nuclear energy

    International Nuclear Information System (INIS)

    Chaussade, J.P.

    1990-01-01

    Today in France there are 54 nuclear power units in operation at 18 sites. They supply 75% of all electricity produced, 12% of which is exported to neighbouring countries, and play an important role in the French economy. For the French, nuclear power is a fact of life, and most accept it. However, the accident of Chernobyl has made public opinion more sensitive, and the public relations work has had to be reconsidered carefully with a view to increase the confidence of the French public in nuclear power, anticipating media crises and being equipped to deal with such crises. The three main approaches are the following: keeping the public better informed, providing clear information at time of crisis and international activities

  9. Knowledge, Self Confidence and Courage

    DEFF Research Database (Denmark)

    Selberg, Hanne; Steenberg Holtzmann, Jette; Hovedskov, Jette

    . Results The students identified their major learning outcomes as transfer of operational skills, experiencing self-efficacy and enhanced understanding of the patients' perspective.Involving simulated patients in the training of technical skills contributed to the development of the students' communication......Knowledge, self confidence and courage – long lasting learning outcomes through simulation in a clinical context. Hanne Selberg1, Jette Hovedskov2, Jette Steenberg Holtzmann2 The significance and methodology of the researchThe study focuses on simulation alongside the clinical practice and linked...... Development, Clinical Lecturer, Metropolitan University College, Faculty of Nursing, Email: hase@phoe.dk, phone: +45-72282830. 2. Jette Hovedskov, RN, Development Consultant, Glostrup University Hospital, Department of Development Email : jeho@glo.regionh.dk ,phone: +45- 43232090 3. Jette Holtzmann Steenberg...

  10. Doubly Bayesian Analysis of Confidence in Perceptual Decision-Making.

    Science.gov (United States)

    Aitchison, Laurence; Bang, Dan; Bahrami, Bahador; Latham, Peter E

    2015-10-01

    Humans stand out from other animals in that they are able to explicitly report on the reliability of their internal operations. This ability, which is known as metacognition, is typically studied by asking people to report their confidence in the correctness of some decision. However, the computations underlying confidence reports remain unclear. In this paper, we present a fully Bayesian method for directly comparing models of confidence. Using a visual two-interval forced-choice task, we tested whether confidence reports reflect heuristic computations (e.g. the magnitude of sensory data) or Bayes optimal ones (i.e. how likely a decision is to be correct given the sensory data). In a standard design in which subjects were first asked to make a decision, and only then gave their confidence, subjects were mostly Bayes optimal. In contrast, in a less-commonly used design in which subjects indicated their confidence and decision simultaneously, they were roughly equally likely to use the Bayes optimal strategy or to use a heuristic but suboptimal strategy. Our results suggest that, while people's confidence reports can reflect Bayes optimal computations, even a small unusual twist or additional element of complexity can prevent optimality.

  11. Confidence limits for parameters of Poisson and binomial distributions

    International Nuclear Information System (INIS)

    Arnett, L.M.

    1976-04-01

    The confidence limits for the frequency in a Poisson process and for the proportion of successes in a binomial process were calculated and tabulated for the situations in which the observed values of the frequency or proportion and an a priori distribution of these parameters are available. Methods are used that produce limits with exactly the stated confidence levels. The confidence interval [a,b] is calculated so that Pr [a less than or equal to lambda less than or equal to b c,μ], where c is the observed value of the parameter, and μ is the a priori hypothesis of the distribution of this parameter. A Bayesian type analysis is used. The intervals calculated are narrower and appreciably different from results, known to be conservative, that are often used in problems of this type. Pearson and Hartley recognized the characteristics of their methods and contemplated that exact methods could someday be used. The calculation of the exact intervals requires involved numerical analyses readily implemented only on digital computers not available to Pearson and Hartley. A Monte Carlo experiment was conducted to verify a selected interval from those calculated. This numerical experiment confirmed the results of the analytical methods and the prediction of Pearson and Hartley that their published tables give conservative results

  12. Confidence building in safety assessments

    International Nuclear Information System (INIS)

    Grundfelt, Bertil

    1999-01-01

    Future generations should be adequately protected from damage caused by the present disposal of radioactive waste. This presentation discusses the core of safety and performance assessment: The demonstration and building of confidence that the disposal system meets the safety requirements stipulated by society. The major difficulty is to deal with risks in the very long time perspective of the thousands of years during which the waste is hazardous. Concern about these problems has stimulated the development of the safety assessment discipline. The presentation concentrates on two of the elements of safety assessment: (1) Uncertainty and sensitivity analysis, and (2) validation and review. Uncertainty is associated both with respect to what is the proper conceptual model and with respect to parameter values for a given model. A special kind of uncertainty derives from the variation of a property in space. Geostatistics is one approach to handling spatial variability. The simplest way of doing a sensitivity analysis is to offset the model parameters one by one and observe how the model output changes. The validity of the models and data used to make predictions is central to the credibility of safety assessments for radioactive waste repositories. There are several definitions of model validation. The presentation discusses it as a process and highlights some aspects of validation methodologies

  13. Prevalence of orofacial clefts and risks for nonsyndromic cleft lip with or without cleft palate in newborns at a university hospital from West Mexico.

    Science.gov (United States)

    Corona-Rivera, Jorge Román; Bobadilla-Morales, Lucina; Corona-Rivera, Alfredo; Peña-Padilla, Christian; Olvera-Molina, Sandra; Orozco-Martín, Miriam A; García-Cruz, Diana; Ríos-Flores, Izabel M; Gómez-Rodríguez, Brian Gabriel; Rivas-Soto, Gemma; Pérez-Molina, J Jesús

    2018-02-19

    We determined the overall prevalence of typical orofacial clefts and the potential risks for nonsyndromic cleft lip with or without cleft palate in a university hospital from West México. For the prevalence, 227 liveborn infants with typical orofacial clefts were included from a total of 81,193 births occurred during the period 2009-2016 at the "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara (Guadalajara, Jalisco, Mexico). To evaluate potential risks, a case-control study was conducted among 420 newborns, including only those 105 patients with nonsyndromic cleft lip with or without cleft palate (cases), and 315 infants without birth defects (controls). Data were analyzed using multivariable logistic regression analysis expressed as adjusted odds ratio with 95% confidence intervals . The overall prevalence for typical orofacial clefts was 28 per 10,000 (95% confidence interval: 24.3-31.6), or 1 per 358 live births. The mean values for the prepregnancy weight, antepartum weight, and pre-pregnancy body mass index were statistically higher among the mothers of cases. Infants with nonsyndromic cleft lip with or without cleft palate had a significantly higher risk for previous history of any type of congenital anomaly (adjusted odds ratio: 2.7; 95% confidence interval: 1.4-5.1), history of a relative with cleft lip with or without cleft palate (adjusted odds ratio: 19.6; 95% confidence interval: 8.2-47.1), and first-trimester exposures to progestogens (adjusted odds ratio: 6.8; 95% CI 1.8-25.3), hyperthermia (adjusted odds ratio: 3.4; 95% confidence interval: 1.1-10.6), and common cold (adjusted odds ratio: 3.6; 95% confidence interval: 1.1-11.9). These risks could have contributed to explain the high prevalence of orofacial clefts in our region of Mexico, emphasizing that except for history of relatives with cleft lip with or without cleft palate, most are susceptible of modification. © 2018 Japanese Teratology Society.

  14. Confidence bounds for nonlinear dose-response relationships

    DEFF Research Database (Denmark)

    Baayen, C; Hougaard, P

    2015-01-01

    An important aim of drug trials is to characterize the dose-response relationship of a new compound. Such a relationship can often be described by a parametric (nonlinear) function that is monotone in dose. If such a model is fitted, it is useful to know the uncertainty of the fitted curve...... intervals for the dose-response curve. These confidence bounds have better coverage than Wald intervals and are more precise and generally faster than bootstrap methods. Moreover, if monotonicity is assumed, the profile likelihood approach takes this automatically into account. The approach is illustrated...

  15. Prevalence of tics in schoolchildren in central Spain: a population-based study.

    Science.gov (United States)

    Cubo, Esther; Gabriel y Galán, José María Trejo; Villaverde, Vanesa Ausín; Velasco, Sara Sáez; Benito, Vanesa Delgado; Macarrón, Jesús Vicente; Guevara, José Cordero; Louis, Elan D; Benito-León, Julián

    2011-08-01

    Tic disorders constitute a neurodevelopmental disorder of childhood. This study sought to determine the prevalence of tic disorders in a school-based sample. A randomized sample of 1158 schoolchildren, based on clusters (classrooms) in the province of Burgos (Spain), was identified on a stratified sampling frame combining types of educational center and setting (mainstream schools and special education), using a two-phase approach (screening and diagnosis ascertainment by a neurologist). Tics with/without impairment criterion were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders criteria. In mainstream schools, tics were observed in 125/741 students (16.86%; 95% confidence interval, 14.10-19.63), and were more frequent in boys (87/448, 19.42%; 95% confidence interval, 15.64-23.19) compared with girls (38/293, 12.96%; 95% confidence interval, 8.95-16.98; P = 0.03). In special education centers, tics disorders were observed in 11/54 of children (20.37%; 95% confidence interval, 8.70-32.03). Overall, tics with impairment criteria were less frequent than tics without impairment criteria (4.65% vs 11.85%, P tics (6.07%) and Tourette syndrome (5.26%). Tic disorders are common in childhood, and the use or nonuse of impairment criteria exerts a significant impact on tic prevalence estimates. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Confidence Intervals Verification for Simulated Error Rate Performance of Wireless Communication System

    KAUST Repository

    Smadi, Mahmoud A.; Ghaeb, Jasim A.; Jazzar, Saleh; Saraereh, Omar A.

    2012-01-01

    In this paper, we derived an efficient simulation method to evaluate the error rate of wireless communication system. Coherent binary phase-shift keying system is considered with imperfect channel phase recovery. The results presented demonstrate

  17. Optimizing lengths of confidence intervals: fourth-order efficiency in location models

    NARCIS (Netherlands)

    Klaassen, C.; Venetiaan, S.

    2010-01-01

    Under regularity conditions the maximum likelihood estimator of the location parameter in a location model is asymptotically efficient among translation equivariant estimators. Additional regularity conditions warrant third- and even fourth-order efficiency, in the sense that no translation

  18. Confidence Intervals for System Reliability and Availability of Maintained Systems Using Monte Carlo Techniques

    Science.gov (United States)

    1981-12-01

    DTIC _JUN ,I 51982 UNITED STATES AIR FORCE AIR UNIVERSITY E AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air-force Base,Ohio S 2 B 14 Best...t’re Air F:or- e -ns"it’.,, e of Technclogy Air Uv-ýerz.tyj in Partial 𔄁ulfilIThent Reýquirements fol- ,-hth D,ýýr.e c4" MastLer of’ OperaZ-ins...iesearc- VeTA 3 MohamedO ’’’’Jo SpD’ Fas.abal-la Lt. C ol. Egyplt.’.an Army Gradua~’p ( ler ons Research December 1981 Approcved fL~r pu>ý’ rclea.se

  19. Confidence intervals and hypothesis testing for the Permutation Entropy with an application to epilepsy

    Science.gov (United States)

    Traversaro, Francisco; O. Redelico, Francisco

    2018-04-01

    In nonlinear dynamics, and to a lesser extent in other fields, a widely used measure of complexity is the Permutation Entropy. But there is still no known method to determine the accuracy of this measure. There has been little research on the statistical properties of this quantity that characterize time series. The literature describes some resampling methods of quantities used in nonlinear dynamics - as the largest Lyapunov exponent - but these seems to fail. In this contribution, we propose a parametric bootstrap methodology using a symbolic representation of the time series to obtain the distribution of the Permutation Entropy estimator. We perform several time series simulations given by well-known stochastic processes: the 1/fα noise family, and show in each case that the proposed accuracy measure is as efficient as the one obtained by the frequentist approach of repeating the experiment. The complexity of brain electrical activity, measured by the Permutation Entropy, has been extensively used in epilepsy research for detection in dynamical changes in electroencephalogram (EEG) signal with no consideration of the variability of this complexity measure. An application of the parametric bootstrap methodology is used to compare normal and pre-ictal EEG signals.

  20. Confidence Intervals for a Semiparametric Approach to Modeling Nonlinear Relations among Latent Variables

    Science.gov (United States)

    Pek, Jolynn; Losardo, Diane; Bauer, Daniel J.

    2011-01-01

    Compared to parametric models, nonparametric and semiparametric approaches to modeling nonlinearity between latent variables have the advantage of recovering global relationships of unknown functional form. Bauer (2005) proposed an indirect application of finite mixtures of structural equation models where latent components are estimated in the…

  1. Technical Report: Benchmarking for Quasispecies Abundance Inference with Confidence Intervals from Metagenomic Sequence Data

    Energy Technology Data Exchange (ETDEWEB)

    McLoughlin, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-22

    The software application “MetaQuant” was developed by our group at Lawrence Livermore National Laboratory (LLNL). It is designed to profile microbial populations in a sample using data from whole-genome shotgun (WGS) metagenomic DNA sequencing. Several other metagenomic profiling applications have been described in the literature. We ran a series of benchmark tests to compare the performance of MetaQuant against that of a few existing profiling tools, using real and simulated sequence datasets. This report describes our benchmarking procedure and results.

  2. Bayesian Methods and Confidence Intervals for Automatic Target Recognition of SAR Canonical Shapes

    Science.gov (United States)

    2014-03-27

    and DirectX [22]. The CUDA platform was developed by the NVIDIA Corporation to allow programmers access to the computational capabilities of the...were used for the intense repetitive computations. Developing CUDA software requires writing code for specialized compilers provided by NVIDIA and

  3. Statistical Significance, Effect Size Reporting, and Confidence Intervals: Best Reporting Strategies

    Science.gov (United States)

    Capraro, Robert M.

    2004-01-01

    With great interest the author read the May 2002 editorial in the "Journal for Research in Mathematics Education (JRME)" (King, 2002) regarding changes to the 5th edition of the "Publication Manual of the American Psychological Association" (APA, 2001). Of special note to him, and of great import to the field of mathematics education research, are…

  4. Technical Report on Modeling for Quasispecies Abundance Inference with Confidence Intervals from Metagenomic Sequence Data

    Energy Technology Data Exchange (ETDEWEB)

    McLoughlin, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-11

    The overall aim of this project is to develop a software package, called MetaQuant, that can determine the constituents of a complex microbial sample and estimate their relative abundances by analysis of metagenomic sequencing data. The goal for Task 1 is to create a generative model describing the stochastic process underlying the creation of sequence read pairs in the data set. The stages in this generative process include the selection of a source genome sequence for each read pair, with probability dependent on its abundance in the sample. The other stages describe the evolution of the source genome from its nearest common ancestor with a reference genome, breakage of the source DNA into short fragments, and the errors in sequencing the ends of the fragments to produce read pairs.

  5. High Confidence Software and Systems Research Needs

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — This White Paper presents a survey of high confidence software and systems research needs. It has been prepared by the High Confidence Software and Systems...

  6. Confidence Building Strategies in the Public Schools.

    Science.gov (United States)

    Achilles, C. M.; And Others

    1985-01-01

    Data from the Phi Delta Kappa Commission on Public Confidence in Education indicate that "high-confidence" schools make greater use of marketing and public relations strategies. Teacher attitudes were ranked first and administrator attitudes second by 409 respondents for both gain and loss of confidence in schools. (MLF)

  7. The prevalence and determinants of hypothyroidism in hospitalized patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Song, Fei; Bao, Cuiping; Deng, Meiyu; Xu, Hui; Fan, Meijuan; Paillard-Borg, Stéphanie; Xu, Weili; Qi, Xiuying

    2017-01-01

    The purpose of this study was to investigate the prevalence of hypothyroidism among hospitalized patients with type 2 diabetes mellitus and its related factors, and to assess the prevalence of macrovascular and microvascular diseases among type 2 diabetes mellitus inpatients with hypothyroidism and euthyroidism. A total of 1662 type 2 diabetes mellitus inpatients hospitalized at the Metabolic Diseases Hospital, Tianjin Medical University from 1 January 2008 to 1 March 2013 were included in this study. Information on demographic and anthropometric factors and additional variables related to hypothyroidism were collected from medical records. Prevalence rates were calculated and standardized using direct method based on the age-specific and sex-specific structure of all participants. Data were analyzed using binary logistic regression with adjustment for potential confounders. The prevalence of hypothyroidism among type 2 diabetes mellitus inpatients was 6.8 %, and 77.0 % of the patients with hypothyroidism had subclinical hypothyroidism. The prevalence of hypothyroidism increased with age, and was higher in women (10.8 %) than in men (3.4 %). Older age (odds ratio, 1.74; 95 % confidence interval, 1. 05 to 2.89), female gender (odds ratio, 2.02; 95 % confidence interval, 1.05 to 3.87), and positive thyroid peroxidase antibody (odds ratio, 4.99; 95 % confidence interval, 2.83 to 8.79) were associated with higher odds of hypothyroidism among type 2 diabetes mellitus inpatients. The type 2 diabetes mellitus inpatients with hypothyroidism had higher prevalence of cerebrovascular diseases than those with euthyroidism after adjustment for age and gender. The prevalence of hypothyroidism among type 2 diabetes mellitus inpatients was 6.8 %, and most patients had subclinical hypothyroidism. Older age, female gender, and positive thyroid peroxidase antibody could be indicators for detecting hypothyroidism in type 2 diabetes mellitus inpatients.

  8. Overconfidence in Interval Estimates

    Science.gov (United States)

    Soll, Jack B.; Klayman, Joshua

    2004-01-01

    Judges were asked to make numerical estimates (e.g., "In what year was the first flight of a hot air balloon?"). Judges provided high and low estimates such that they were X% sure that the correct answer lay between them. They exhibited substantial overconfidence: The correct answer fell inside their intervals much less than X% of the time. This…

  9. Quality of Vitamin K Antagonist Anticoagulation in Spain: Prevalence of Poor Control and Associated Factors.

    Science.gov (United States)

    Anguita Sánchez, Manuel; Bertomeu Martínez, Vicente; Cequier Fillat, Ángel

    2015-09-01

    To study the prevalence of poorly controlled vitamin K antagonist anticoagulation in Spain in patients with nonvalvular atrial fibrillation, and to identify associated factors. We studied 1056 consecutive patients seen at 120 cardiology clinics in Spain between November 2013 and March 2014. We analyzed the international normalized ratio from the 6 months prior to the patient's visit, calculating the prevalence of poorly controlled anticoagulation, defined as < 65% time in therapeutic range using the Rosendaal method. Mean age was 73.6 years (standard deviation, 9.8 years); women accounted for 42% of patients. The prevalence of poorly controlled anticoagulation was 47.3%. Mean time in therapeutic range was 63.8% (25.9%). The following factors were independently associated with poorly controlled anticoagulation: kidney disease (odds ratio = 1.53; 95% confidence interval, 1.08-2.18; P = .018), routine nonsteroidal anti-inflammatory drugs (odds ratio = 1.79; 95% confidence interval, 1.20-2.79; P = .004), antiplatelet therapy (odds ratio = 2.16; 95% confidence interval, 1.49-3.12; P < .0001) and absence of angiotensin receptor blockers (odds ratio = 1.39; 95% confidence interval, 1.08-1.79; P = .011). There is a high prevalence of poorly controlled vitamin K antagonist anticoagulation in Spain. Factors associated with poor control are kidney disease, routine nonsteroidal anti-inflammatory drugs, antiplatelet use, and absence of angiotensin receptor blockers. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  10. Periodontal Bacteria and Prediabetes Prevalence in ORIGINS

    Science.gov (United States)

    Demmer, R.T.; Jacobs, D.R.; Singh, R.; Zuk, A.; Rosenbaum, M.; Papapanou, P.N.; Desvarieux, M.

    2015-01-01

    Periodontitis and type 2 diabetes mellitus are known to be associated. The relationship between periodontal microbiota and early diabetes risk has not been studied. We investigated the association between periodontal bacteria and prediabetes prevalence among diabetes-free adults. ORIGINS (the Oral Infections, Glucose Intolerance and Insulin Resistance Study) cross sectionally enrolled 300 diabetes-free adults aged 20 to 55 y (mean ± SD, 34 ± 10 y; 77% female). Prediabetes was defined as follows: 1) hemoglobin A1c values ranging from 5.7% to 6.4% or 2) fasting plasma glucose ranging from 100 to 125 mg/dL. In 1,188 subgingival plaque samples, 11 bacterial species were assessed at baseline, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Actinomyces naeslundii. Full-mouth clinical periodontal examinations were performed, and participants were defined as having no/mild periodontitis vs. moderate/severe periodontitis per the definition of the Centers for Disease Control and Prevention / American Academy of Periodontology. Modified Poisson regression evaluated prediabetes prevalence across bacterial tertiles. Prevalence ratios and 95% confidence intervals for third vs. first tertiles are presented. All analyses were adjusted for cardiometabolic risk factors. All results presented currently arise from the baseline cross section. Prediabetes prevalence was 18%, and 58% of participants had moderate/severe periodontitis. Prevalence ratios (95% confidence intervals) summarizing associations between bacterial levels and prediabetes were as follows: A. actinomycetemcomitans, 2.48 (1.34, 4.58), P = 0.004; P. gingivalis, 3.41 (1.78, 6.58), P = 0.0003; T. denticola, 1.99 (0.992, 4.00), P = 0.052; T. forsythia, 1.95 (1.0, 3.84), P = 0.05; A. naeslundii, 0.46 (0.25, 0.85), P = 0.01. The prevalence ratio for prediabetes among participants with moderate/severe vs. no/mild periodontitis was 1.47 (0.78, 2.74), P

  11. Global Prevalence of Elder Abuse: A Meta-analysis and Meta-regression.

    Science.gov (United States)

    Ho, C Sh; Wong, S Y; Chiu, M M; Ho, R Cm

    2017-06-01

    Elder abuse is increasingly recognised as a global public health and social problem. There has been limited inter-study comparison of the prevalence and risk factors for elder abuse. This study aimed to estimate the pooled and subtype prevalence of elder abuse worldwide and identify significant associated risk factors. We conducted a meta-analysis and meta-regression of 34 population-based and 17 non-population-based studies. The pooled prevalences of elder abuse were 10.0% (95% confidence interval, 5.2%-18.6%) and 34.3% (95% confidence interval, 22.9%-47.8%) in population-based studies and third party- or caregiver-reported studies, respectively. Being in a marital relationship was found to be a significant moderator using random-effects model. This meta-analysis revealed that third parties or caregivers were more likely to report abuse than older abused adults. Subgroup analyses showed that females and those resident in non-western countries were more likely to be abused. Emotional abuse was the most prevalent elder abuse subtype and financial abuse was less commonly reported by third parties or caregivers. Heterogeneity in the prevalence was due to the high proportion of married older adults in the sample. Subgroup analysis showed that cultural factors, subtypes of abuse, and gender also contributed to heterogeneity in the pooled prevalence of elder abuse.

  12. Regional Competition for Confidence: Features of Formation

    Directory of Open Access Journals (Sweden)

    Irina Svyatoslavovna Vazhenina

    2016-09-01

    Full Text Available The increase in economic independence of the regions inevitably leads to an increase in the quality requirements of the regional economic policy. The key to successful regional policy, both during its development and implementation, is the understanding of the necessity of gaining confidence (at all levels, and the inevitable participation in the competition for confidence. The importance of confidence in the region is determined by its value as a competitive advantage in the struggle for partners, resources and tourists, and attracting investments. In today’s environment the focus of governments, regions and companies on long-term cooperation is clearly expressed, which is impossible without a high level of confidence between partners. Therefore, the most important competitive advantages of territories are intangible assets such as an attractive image and a good reputation, which builds up confidence of the population and partners. The higher the confidence in the region is, the broader is the range of potential partners, the larger is the planning horizon of long-term concerted action, the better are the chances of acquiring investment, the higher is the level of competitive immunity of the territories. The article defines competition for confidence as purposeful behavior of a market participant in economic environment, aimed at acquiring specific intangible competitive advantage – the confidence of the largest possible number of other market actors. The article also highlights the specifics of confidence as a competitive goal, presents factors contributing to the destruction of confidence, proposes a strategy to fight for confidence as a program of four steps, considers the factors which integrate regional confidence and offers several recommendations for the establishment of effective regional competition for confidence

  13. Applications of interval computations

    CERN Document Server

    Kreinovich, Vladik

    1996-01-01

    Primary Audience for the Book • Specialists in numerical computations who are interested in algorithms with automatic result verification. • Engineers, scientists, and practitioners who desire results with automatic verification and who would therefore benefit from the experience of suc­ cessful applications. • Students in applied mathematics and computer science who want to learn these methods. Goal Of the Book This book contains surveys of applications of interval computations, i. e. , appli­ cations of numerical methods with automatic result verification, that were pre­ sented at an international workshop on the subject in EI Paso, Texas, February 23-25, 1995. The purpose of this book is to disseminate detailed and surveyed information about existing and potential applications of this new growing field. Brief Description of the Papers At the most fundamental level, interval arithmetic operations work with sets: The result of a single arithmetic operation is the set of all possible results as the o...

  14. Small area variation in diabetes prevalence in Puerto Rico.

    Science.gov (United States)

    Tierney, Edward F; Burrows, Nilka R; Barker, Lawrence E; Beckles, Gloria L; Boyle, James P; Cadwell, Betsy L; Kirtland, Karen A; Thompson, Theodore J

    2013-06-01

    To estimate the 2009 prevalence of diagnosed diabetes in Puerto Rico among adults ≥ 20 years of age in order to gain a better understanding of its geographic distribution so that policymakers can more efficiently target prevention and control programs. A Bayesian multilevel model was fitted to the combined 2008-2010 Behavioral Risk Factor Surveillance System and 2009 United States Census data to estimate diabetes prevalence for each of the 78 municipios (counties) in Puerto Rico. The mean unadjusted estimate for all counties was 14.3% (range by county, 9.9%-18.0%). The average width of the confidence intervals was 6.2%. Adjusted and unadjusted estimates differed little. These 78 county estimates are higher on average and showed less variability (i.e., had a smaller range) than the previously published estimates of the 2008 diabetes prevalence for all United States counties (mean, 9.9%; range, 3.0%-18.2%).

  15. Non-alcoholic fatty liver disease is associated with high prevalence of gastro-oesophageal reflux symptoms.

    Science.gov (United States)

    Miele, Luca; Cammarota, Giovanni; Vero, Vittoria; Racco, Simona; Cefalo, Consuelo; Marrone, Giuseppe; Pompili, Maurizio; Rapaccini, Gianlodovico; Bianco, Alessandro; Landolfi, Raffaele; Gasbarrini, Antonio; Grieco, Antonio

    2012-12-01

    Gastro-oesophageal reflux symptoms are usually reported by patients with obesity and metabolic syndrome. Aim of this study was to assess the prevalence and clinical characteristics of gastro-oesophageal reflux symptoms in subjects with non-alcoholic fatty liver disease. Cross-sectional, case-control study of 185 consecutive patients with non-alcoholic fatty liver disease and an age- and sex-matched control group of 112 healthy volunteers. Participants were interviewed with the aid of a previously validated questionnaire to assess lifestyle and reflux symptoms in the 3 months preceding enrolment. Odds ratios were determined before and after adjustment for body mass index, increased waist circumference, physical activity, metabolic syndrome and proton pump inhibitors and/or antiacid medication. The prevalence of heartburn and/or regurgitation and of at least one of gastro-oesophageal reflux symptoms was significantly higher in the non-alcoholic fatty liver disease group. Non-alcoholic fatty liver disease subjects were associated to higher prevalence of heartburn (adjusted odds ratios: 2.17, 95% confidence intervals: 1.16-4.04), regurgitation (adjusted odds ratios: 2.61, 95% confidence intervals: 1.24-5.48) and belching (adjusted odds ratios: 2.01, 95% confidence intervals: 1.12-3.59) and had higher prevalence of at least one GER symptom (adjusted odds ratios: 3.34, 95% confidence intervals: 1.76-6.36). Non-alcoholic fatty liver disease is associated with a higher prevalence of gastro-oesophageal reflux symptoms. Copyright © 2012 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  16. The integrated model of sport confidence: a canonical correlation and mediational analysis.

    Science.gov (United States)

    Koehn, Stefan; Pearce, Alan J; Morris, Tony

    2013-12-01

    The main purpose of the study was to examine crucial parts of Vealey's (2001) integrated framework hypothesizing that sport confidence is a mediating variable between sources of sport confidence (including achievement, self-regulation, and social climate) and athletes' affect in competition. The sample consisted of 386 athletes, who completed the Sources of Sport Confidence Questionnaire, Trait Sport Confidence Inventory, and Dispositional Flow Scale-2. Canonical correlation analysis revealed a confidence-achievement dimension underlying flow. Bias-corrected bootstrap confidence intervals in AMOS 20.0 were used in examining mediation effects between source domains and dispositional flow. Results showed that sport confidence partially mediated the relationship between achievement and self-regulation domains and flow, whereas no significant mediation was found for social climate. On a subscale level, full mediation models emerged for achievement and flow dimensions of challenge-skills balance, clear goals, and concentration on the task at hand.

  17. Prevalence of corporal punishment among students in Washington State schools.

    Science.gov (United States)

    Grossman, D C; Rauh, M J; Rivara, F P

    1995-05-01

    To determine the prevalence of corporal punishment in Washington State and the factors associated with its use in Washington elementary and secondary schools. Cross-sectional mail survey performed during the summer of 1992. All elementary and secondary schools in the state of Washington. One thousand eighteen schools (47%) responded to the survey, of which 80% were publicly funded and 63% were located in urban areas. The study sample closely resembled the profile of all schools in the state. Almost 11% of participating schools permitted corporal punishment at the time of the survey and 3.2% reported its actual use during the 1991-1992 school year, resulting in an estimated prevalence of 7.2 incidents per 1000 students per year. Sixteen percent of corporal punishment actions occurred in schools not permitting its use. Ninety percent of public schools relied on district policy regarding corporal punishment. School characteristics associated with the use of corporal punishment included rural location (crude odds ratio, 2.2; 95% confidence interval, 1.5 to 3.4), enrollment of less than 500 students (crude odds ratio, 1.7; 95% confidence interval, 1.1 to 2.7), and kindergarten to eighth-grade or kindergarten to 12th-grade enrollment (crude odds ratio, 2.5; 95% confidence interval, 1.6 to 3.9). The lack of a statewide ban on school corporal punishment at the time of this survey was associated with the continued use of corporal punishment against children in districts that continued to permit it. School policies against corporal punishment were associated with much lower prevalence. Continued efforts are needed to enact and enforce laws in the remaining states that have not yet banned corporal punishment.

  18. Prevalence and characteristics of orofacial pain in university students.

    Science.gov (United States)

    Smiljic, Sonja; Savic, Sladjana; Stevanovic, Jasmina; Kostic, Mirjana

    2016-01-01

    This cross-sectional study investigated the characteristics and prevalence of orofacial pain, and its associations with sociodemographic characteristics, in 319 university students: 188 second-year students in the Medical Faculty and 131 students in the Faculty of Technical Sciences at the University of Kosovska Mitrovica. A specially designed questionnaire was used to assess the prevalence and characteristics of pain. Among the 319 students, 101 (32%) reported previous orofacial pain, and pain was more frequent among women (P pain and that the risk for pain development among women was 1.8 times that among men. Place of residence and relationship status were not associated with frequency of orofacial pain. The regions with the highest pain prevalences were the temporal region (7%; 95% confidence interval, 4-10%) and the region around the eye (6%; 95% confidence interval, 4-9%). The first episode of orofacial pain was less than 3 months previously in 59% of the participants, and 39% of students had sought professional medical help. (J Oral Sci 58, 7-13, 2016).

  19. Prevalence, determinants and prognosis of pulmonary hypertension among hemodialysis patients

    Science.gov (United States)

    Agarwal, Rajiv

    2012-01-01

    Background The prevalence, determinants and prognosis of pulmonary hypertension among long-term hemodialysis patients in the USA are poorly understood. Methods A cross-sectional survey of prevalence and determinants of pulmonary hypertension was performed, followed by longitudinal follow-up for all-cause mortality. Pulmonary hypertension was defined as an estimated systolic pulmonary artery pressure of >35 mmHg using echocardiograms performed within an hour after the end of dialysis. Results Prevalent in 110/288 patients (38%), the independent determinants of pulmonary hypertension were the following: left atrial diameter (odds ratio 10.1 per cm/m2, P pulmonary hypertension (53%, CMR 168.9/1000 patient-years) and 39 among 178 without pulmonary hypertension (22%, CMR 52.5/1000 patient-years) [unadjusted hazard ratio (HR) for death 2.12 (95% confidence interval 1.41–3.19), P pulmonary hypertension remained an independent predictor for all-cause mortality [HR 2.17 (95% confidence interval 1.31–3.61), P pulmonary hypertension is common and is strongly associated with an enlarged left atrium and poor long-term survival. Reducing left atrial size such as through volume control may be an attractive target to improve pulmonary hypertension. Improving pulmonary hypertension in this group of patients may improve the dismal outcomes. PMID:22290987

  20. Surveillance test interval optimization

    International Nuclear Information System (INIS)

    Cepin, M.; Mavko, B.

    1995-01-01

    Technical specifications have been developed on the bases of deterministic analyses, engineering judgment, and expert opinion. This paper introduces our risk-based approach to surveillance test interval (STI) optimization. This approach consists of three main levels. The first level is the component level, which serves as a rough estimation of the optimal STI and can be calculated analytically by a differentiating equation for mean unavailability. The second and third levels give more representative results. They take into account the results of probabilistic risk assessment (PRA) calculated by a personal computer (PC) based code and are based on system unavailability at the system level and on core damage frequency at the plant level

  1. Smoking prevalence: a comparison of two American surveys.

    Science.gov (United States)

    Rodu, B; Cole, P

    2009-09-01

    To compare smoking prevalence estimates from two nationally representative surveys in the USA. Smoking prevalence estimates derived from the National Health Interview Survey (NHIS) and the National Survey on Drug Use and Health (NSDUH) for the period 1998-2005. Comparisons according to age (18-34 or 35+ years) and according to smoking frequency (every day or some days). In 1998, the prevalence of smoking in both surveys was nearly identical at 24%. From 1999 to 2005, a divergence occurred in smoking prevalence found by the NSDUH and the NHIS. By 2005, NHIS prevalence had declined to 20.9% [95% confidence interval (CI) 20.3-21.5], but the NSDUH estimate was 25.4% (95%CI 24.6-26.2), amounting to 9.1 million more smokers. In 1999, prevalence among 18-34 year olds in the NSDUH was only 18% (95%CI 13-22) higher than that in the NHIS, but that difference had doubled by 2005, when smoking prevalence among 18-34 year olds was 36% (95%CI 30-41) higher in the NSDUH than in the NHIS. NSDUH and NHIS prevalence among 35+ year olds were similar in 1999 and 2001, but the difference was 13% (95%CI 9-18) in 2005. Higher smoking prevalence estimates in the NSDUH were largely due to much higher estimates for some-day smoking in that survey, although every-day smoking prevalence among 18-34 year-olds was also higher in the NSDUH than in the NHIS. These results raise doubt about the recent decline in smoking prevalence described by the NHIS. Further investigation of the NSDUH/NHIS discrepancy may lead to better surveys and to a clearer picture of smoking trends in the USA.

  2. Prevalence of common food allergies in Europe

    DEFF Research Database (Denmark)

    Nwaru, B I; Hickstein, L; Panesar, S S

    2014-01-01

    Allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish constitutes the majority of food allergy reactions, but reliable estimates of their prevalence are lacking. This systematic review aimed to provide up-to-date estimates of their prevalence in Europe.Studies published...... synthesis and 42 studies in the meta-analyses. Although there were significant heterogeneity between the studies, the overall pooled estimates for all age groups of self-reported lifetime prevalence of allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish were 6.0% (95% confidence...... interval: 5.7-6.4), 2.5% (2.3-2.7), 3.6% (3.0-4.2), 0.4% (0.3-0.6), 1.3% (1.2-1.5), 2.2% (1.8-2.5), and 1.3% (0.9-1.7), respectively. The prevalence of food-challenge-defined allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish was 0.6% (0.5-0.8), 0.2% (0.2-0.3), 0.1% (0...

  3. The prognostic value of the QT interval and QT interval dispersion in all-cause and cardiac mortality and morbidity in a population of Danish citizens.

    Science.gov (United States)

    Elming, H; Holm, E; Jun, L; Torp-Pedersen, C; Køber, L; Kircshoff, M; Malik, M; Camm, J

    1998-09-01

    To evaluate the prognostic value of the QT interval and QT interval dispersion in total and in cardiovascular mortality, as well as in cardiac morbidity, in a general population. The QT interval was measured in all leads from a standard 12-lead ECG in a random sample of 1658 women and 1797 men aged 30-60 years. QT interval dispersion was calculated from the maximal difference between QT intervals in any two leads. All cause mortality over 13 years, and cardiovascular mortality as well as cardiac morbidity over 11 years, were the main outcome parameters. Subjects with a prolonged QT interval (430 ms or more) or prolonged QT interval dispersion (80 ms or more) were at higher risk of cardiovascular death and cardiac morbidity than subjects whose QT interval was less than 360 ms, or whose QT interval dispersion was less than 30 ms. Cardiovascular death relative risk ratios, adjusted for age, gender, myocardial infarct, angina pectoris, diabetes mellitus, arterial hypertension, smoking habits, serum cholesterol level, and heart rate were 2.9 for the QT interval (95% confidence interval 1.1-7.8) and 4.4 for QT interval dispersion (95% confidence interval 1.0-19-1). Fatal and non-fatal cardiac morbidity relative risk ratios were similar, at 2.7 (95% confidence interval 1.4-5.5) for the QT interval and 2.2 (95% confidence interval 1.1-4.0) for QT interval dispersion. Prolongation of the QT interval and QT interval dispersion independently affected the prognosis of cardiovascular mortality and cardiac fatal and non-fatal morbidity in a general population over 11 years.

  4. Chaos on the interval

    CERN Document Server

    Ruette, Sylvie

    2017-01-01

    The aim of this book is to survey the relations between the various kinds of chaos and related notions for continuous interval maps from a topological point of view. The papers on this topic are numerous and widely scattered in the literature; some of them are little known, difficult to find, or originally published in Russian, Ukrainian, or Chinese. Dynamical systems given by the iteration of a continuous map on an interval have been broadly studied because they are simple but nevertheless exhibit complex behaviors. They also allow numerical simulations, which enabled the discovery of some chaotic phenomena. Moreover, the "most interesting" part of some higher-dimensional systems can be of lower dimension, which allows, in some cases, boiling it down to systems in dimension one. Some of the more recent developments such as distributional chaos, the relation between entropy and Li-Yorke chaos, sequence entropy, and maps with infinitely many branches are presented in book form for the first time. The author gi...

  5. Self-Confidence in the Hospitality Industry

    Directory of Open Access Journals (Sweden)

    Michael Oshins

    2014-02-01

    Full Text Available Few industries rely on self-confidence to the extent that the hospitality industry does because guests must feel welcome and that they are in capable hands. This article examines the results of hundreds of student interviews with industry professionals at all levels to determine where the majority of the hospitality industry gets their self-confidence.

  6. Consumer confidence or the business cycle

    DEFF Research Database (Denmark)

    Møller, Stig Vinther; Nørholm, Henrik; Rangvid, Jesper

    2014-01-01

    Answer: The business cycle. We show that consumer confidence and the output gap both excess returns on stocks in many European countries: When the output gap is positive (the economy is doing well), expected returns are low, and when consumer confidence is high, expected returns are also low...

  7. Financial Literacy, Confidence and Financial Advice Seeking

    NARCIS (Netherlands)

    Kramer, Marc M.

    2016-01-01

    We find that people with higher confidence in their own financial literacy are less likely to seek financial advice, but no relation between objective measures of literacy and advice seeking. The negative association between confidence and advice seeking is more pronounced among wealthy households.

  8. Aging and Confidence Judgments in Item Recognition

    Science.gov (United States)

    Voskuilen, Chelsea; Ratcliff, Roger; McKoon, Gail

    2018-01-01

    We examined the effects of aging on performance in an item-recognition experiment with confidence judgments. A model for confidence judgments and response time (RTs; Ratcliff & Starns, 2013) was used to fit a large amount of data from a new sample of older adults and a previously reported sample of younger adults. This model of confidence…

  9. Organic labbeling systems and consumer confidence

    OpenAIRE

    Sønderskov, Kim Mannemar; Daugbjerg, Carsten

    2009-01-01

    A research analysis suggests that a state certification and labelling system creates confidence in organic labelling systems and consequently green consumerism. Danish consumers have higher levels of confidence in the labelling system than consumers in countries where the state plays a minor role in labelling and certification.

  10. Self-confidence and metacognitive processes

    Directory of Open Access Journals (Sweden)

    Kleitman Sabina

    2005-01-01

    Full Text Available This paper examines the status of Self-confidence trait. Two studies strongly suggest that Self-confidence is a component of metacognition. In the first study, participants (N=132 were administered measures of Self-concept, a newly devised Memory and Reasoning Competence Inventory (MARCI, and a Verbal Reasoning Test (VRT. The results indicate a significant relationship between confidence ratings on the VRT and the Reasoning component of MARCI. The second study (N=296 employed an extensive battery of cognitive tests and several metacognitive measures. Results indicate the presence of robust Self-confidence and Metacognitive Awareness factors, and a significant correlation between them. Self-confidence taps not only processes linked to performance on items that have correct answers, but also beliefs about events that may never occur.

  11. Interval methods: An introduction

    DEFF Research Database (Denmark)

    Achenie, L.E.K.; Kreinovich, V.; Madsen, Kaj

    2006-01-01

    This chapter contains selected papers presented at the Minisymposium on Interval Methods of the PARA'04 Workshop '' State-of-the-Art in Scientific Computing ''. The emphasis of the workshop was on high-performance computing (HPC). The ongoing development of ever more advanced computers provides...... the potential for solving increasingly difficult computational problems. However, given the complexity of modern computer architectures, the task of realizing this potential needs careful attention. A main concern of HPC is the development of software that optimizes the performance of a given computer....... An important characteristic of the computer performance in scientific computing is the accuracy of the Computation results. Often, we can estimate this accuracy by using traditional statistical techniques. However, in many practical situations, we do not know the probability distributions of different...

  12. Multichannel interval timer

    International Nuclear Information System (INIS)

    Turko, B.T.

    1983-10-01

    A CAMAC based modular multichannel interval timer is described. The timer comprises twelve high resolution time digitizers with a common start enabling twelve independent stop inputs. Ten time ranges from 2.5 μs to 1.3 μs can be preset. Time can be read out in twelve 24-bit words either via CAMAC Crate Controller or an external FIFO register. LSB time calibration is 78.125 ps. An additional word reads out the operational status of twelve stop channels. The system consists of two modules. The analog module contains a reference clock and 13 analog time stretchers. The digital module contains counters, logic and interface circuits. The timer has an excellent differential linearity, thermal stability and crosstalk free performance

  13. Experimenting with musical intervals

    Science.gov (United States)

    Lo Presto, Michael C.

    2003-07-01

    When two tuning forks of different frequency are sounded simultaneously the result is a complex wave with a repetition frequency that is the fundamental of the harmonic series to which both frequencies belong. The ear perceives this 'musical interval' as a single musical pitch with a sound quality produced by the harmonic spectrum responsible for the waveform. This waveform can be captured and displayed with data collection hardware and software. The fundamental frequency can then be calculated and compared with what would be expected from the frequencies of the tuning forks. Also, graphing software can be used to determine equations for the waveforms and predict their shapes. This experiment could be used in an introductory physics or musical acoustics course as a practical lesson in superposition of waves, basic Fourier series and the relationship between some of the ear's subjective perceptions of sound and the physical properties of the waves that cause them.

  14. Interpregnancy interval and risk of autistic disorder.

    Science.gov (United States)

    Gunnes, Nina; Surén, Pål; Bresnahan, Michaeline; Hornig, Mady; Lie, Kari Kveim; Lipkin, W Ian; Magnus, Per; Nilsen, Roy Miodini; Reichborn-Kjennerud, Ted; Schjølberg, Synnve; Susser, Ezra Saul; Øyen, Anne-Siri; Stoltenberg, Camilla

    2013-11-01

    A recent California study reported increased risk of autistic disorder in children conceived within a year after the birth of a sibling. We assessed the association between interpregnancy interval and risk of autistic disorder using nationwide registry data on pairs of singleton full siblings born in Norway. We defined interpregnancy interval as the time from birth of the first-born child to conception of the second-born child in a sibship. The outcome of interest was autistic disorder in the second-born child. Analyses were restricted to sibships in which the second-born child was born in 1990-2004. Odds ratios (ORs) were estimated by fitting ordinary logistic models and logistic generalized additive models. The study sample included 223,476 singleton full-sibling pairs. In sibships with interpregnancy intervals autistic disorder, compared with 0.13% in the reference category (≥ 36 months). For interpregnancy intervals shorter than 9 months, the adjusted OR of autistic disorder in the second-born child was 2.18 (95% confidence interval 1.42-3.26). The risk of autistic disorder in the second-born child was also increased for interpregnancy intervals of 9-11 months in the adjusted analysis (OR = 1.71 [95% CI = 1.07-2.64]). Consistent with a previous report from California, interpregnancy intervals shorter than 1 year were associated with increased risk of autistic disorder in the second-born child. A possible explanation is depletion of micronutrients in mothers with closely spaced pregnancies.

  15. Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Benjamin E Smith

    Full Text Available Patellofemoral pain is considered one of the most common forms of knee pain, affecting adults, adolescents, and physically active populations. Inconsistencies in reported incidence and prevalence exist and in relation to the allocation of healthcare and research funding, there is a clear need to accurately understand the epidemiology of patellofemoral pain.An electronic database search was conducted, as well as grey literature databases, from inception to June 2017. Two authors independently selected studies, extracted data and appraised methodological quality. If heterogeneous, data were analysed descriptively. Where studies were homogeneous, data were pooled through a meta-analysis.23 studies were included. Annual prevalence for patellofemoral pain in the general population was reported as 22.7%, and adolescents as 28.9%. Incidence rates in military recruits ranged from 9.7-571.4/1,000 person-years, amateur runners in the general population at 1080.5/1,000 person-years and adolescents amateur athletes 5.1%-14.9% over 1 season. One study reported point prevalence within military populations as 13.5%. The pooled estimate for point prevalence in adolescents was 7.2% (95% Confidence Interval: 6.3%-8.3%, and in female only adolescent athletes was 22.7% (95% Confidence Interval 17.4%-28.0%.This review demonstrates high incidence and prevalence levels for patellofemoral pain. Within the context of this, and poor long term prognosis and high disability levels, PFP should be an urgent research priority.CRD42016038870.

  16. We will be champions: Leaders' confidence in 'us' inspires team members' team confidence and performance.

    Science.gov (United States)

    Fransen, K; Steffens, N K; Haslam, S A; Vanbeselaere, N; Vande Broek, G; Boen, F

    2016-12-01

    The present research examines the impact of leaders' confidence in their team on the team confidence and performance of their teammates. In an experiment involving newly assembled soccer teams, we manipulated the team confidence expressed by the team leader (high vs neutral vs low) and assessed team members' responses and performance as they unfolded during a competition (i.e., in a first baseline session and a second test session). Our findings pointed to team confidence contagion such that when the leader had expressed high (rather than neutral or low) team confidence, team members perceived their team to be more efficacious and were more confident in the team's ability to win. Moreover, leaders' team confidence affected individual and team performance such that teams led by a highly confident leader performed better than those led by a less confident leader. Finally, the results supported a hypothesized mediational model in showing that the effect of leaders' confidence on team members' team confidence and performance was mediated by the leader's perceived identity leadership and members' team identification. In conclusion, the findings of this experiment suggest that leaders' team confidence can enhance members' team confidence and performance by fostering members' identification with the team. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Communication confidence in persons with aphasia.

    Science.gov (United States)

    Babbitt, Edna M; Cherney, Leora R

    2010-01-01

    Communication confidence is a construct that has not been explored in the aphasia literature. Recently, national and international organizations have endorsed broader assessment methods that address quality of life and include participation, activity, and impairment domains as well as psychosocial areas. Individuals with aphasia encounter difficulties in all these areas on a daily basis in living with a communication disorder. Improvements are often reflected in narratives that are not typically included in standard assessments. This article illustrates how a new instrument measuring communication confidence might fit into a broad assessment framework and discusses the interaction of communication confidence, autonomy, and self-determination for individuals living with aphasia.

  18. Confidence building in implementation of geological disposal

    International Nuclear Information System (INIS)

    Umeki, Hiroyuki

    2004-01-01

    Long-term safety of the disposal system should be demonstrated to the satisfaction of the stakeholders. Convincing arguments are therefore required that instil in the stakeholders confidence in the safety of a particular concept for the siting and design of a geological disposal, given the uncertainties that inevitably exist in its a priori description and in its evolution. The step-wise approach associated with making safety case at each stage is a key to building confidence in the repository development programme. This paper discusses aspects and issues on confidence building in the implementation of HLW disposal in Japan. (author)

  19. Confidence rating of marine eutrophication assessments

    DEFF Research Database (Denmark)

    Murray, Ciarán; Andersen, Jesper Harbo; Kaartokallio, Hermanni

    2011-01-01

    of the 'value' of the indicators on which the primary assessment is made. Such secondary assessment of confidence represents a first step towards linking status classification with information regarding their accuracy and precision and ultimately a tool for improving or targeting actions to improve the health......This report presents the development of a methodology for assessing confidence in eutrophication status classifications. The method can be considered as a secondary assessment, supporting the primary assessment of eutrophication status. The confidence assessment is based on a transparent scoring...

  20. Planning an Availability Demonstration Test with Consideration of Confidence Level

    Directory of Open Access Journals (Sweden)

    Frank Müller

    2017-08-01

    Full Text Available The full service life of a technical product or system is usually not completed after an initial failure. With appropriate measures, the system can be returned to a functional state. Availability is an important parameter for evaluating such repairable systems: Failure and repair behaviors are required to determine this availability. These data are usually given as mean value distributions with a certain confidence level. Consequently, the availability value also needs to be expressed with a confidence level. This paper first highlights the bootstrap Monte Carlo simulation (BMCS for availability demonstration and inference with confidence intervals based on limited failure and repair data. The BMCS enables point-, steady-state and average availability to be determined with a confidence level based on the pure samples or mean value distributions in combination with the corresponding sample size of failure and repair behavior. Furthermore, the method enables individual sample sizes to be used. A sample calculation of a system with Weibull-distributed failure behavior and a sample of repair times is presented. Based on the BMCS, an extended, new procedure is introduced: the “inverse bootstrap Monte Carlo simulation” (IBMCS to be used for availability demonstration tests with consideration of confidence levels. The IBMCS provides a test plan comprising the required number of failures and repair actions that must be observed to demonstrate a certain availability value. The concept can be applied to each type of availability and can also be applied to the pure samples or distribution functions of failure and repair behavior. It does not require special types of distribution. In other words, for example, a Weibull, a lognormal or an exponential distribution can all be considered as distribution functions of failure and repair behavior. After presenting the IBMCS, a sample calculation will be carried out and the potential of the BMCS and the IBMCS

  1. Prevalence of autosomal dominant polycystic kidney disease in the European Union.

    Science.gov (United States)

    Willey, Cynthia J; Blais, Jaime D; Hall, Anthony K; Krasa, Holly B; Makin, Andrew J; Czerwiec, Frank S

    2017-08-01

    Autosomal dominant polycystic kidney disease (ADPKD) is a leading cause of end-stage renal disease, but estimates of its prevalence vary by >10-fold. The objective of this study was to examine the public health impact of ADPKD in the European Union (EU) by estimating minimum prevalence (point prevalence of known cases) and screening prevalence (minimum prevalence plus cases expected after population-based screening). A review of the epidemiology literature from January 1980 to February 2015 identified population-based studies that met criteria for methodological quality. These examined large German and British populations, providing direct estimates of minimum prevalence and screening prevalence. In a second approach, patients from the 2012 European Renal Association‒European Dialysis and Transplant Association (ERA-EDTA) Registry and literature-based inflation factors that adjust for disease severity and screening yield were used to estimate prevalence across 19 EU countries (N = 407 million). Population-based studies yielded minimum prevalences of 2.41 and 3.89/10 000, respectively, and corresponding estimates of screening prevalences of 3.3 and 4.6/10 000. A close correspondence existed between estimates in countries where both direct and registry-derived methods were compared, which supports the validity of the registry-based approach. Using the registry-derived method, the minimum prevalence was 3.29/10 000 (95% confidence interval 3.27-3.30), and if ADPKD screening was implemented in all countries, the expected prevalence was 3.96/10 000 (3.94-3.98). ERA-EDTA-based prevalence estimates and application of a uniform definition of prevalence to population-based studies consistently indicate that the ADPKD point prevalence is <5/10 000, the threshold for rare disease in the EU. © The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA.

  2. An Exact Confidence Region in Multivariate Calibration

    OpenAIRE

    Mathew, Thomas; Kasala, Subramanyam

    1994-01-01

    In the multivariate calibration problem using a multivariate linear model, an exact confidence region is constructed. It is shown that the region is always nonempty and is invariant under nonsingular transformations.

  3. Weighting Mean and Variability during Confidence Judgments

    Science.gov (United States)

    de Gardelle, Vincent; Mamassian, Pascal

    2015-01-01

    Humans can not only perform some visual tasks with great precision, they can also judge how good they are in these tasks. However, it remains unclear how observers produce such metacognitive evaluations, and how these evaluations might be dissociated from the performance in the visual task. Here, we hypothesized that some stimulus variables could affect confidence judgments above and beyond their impact on performance. In a motion categorization task on moving dots, we manipulated the mean and the variance of the motion directions, to obtain a low-mean low-variance condition and a high-mean high-variance condition with matched performances. Critically, in terms of confidence, observers were not indifferent between these two conditions. Observers exhibited marked preferences, which were heterogeneous across individuals, but stable within each observer when assessed one week later. Thus, confidence and performance are dissociable and observers’ confidence judgments put different weights on the stimulus variables that limit performance. PMID:25793275

  4. Distinguishing highly confident accurate and inaccurate memory: insights about relevant and irrelevant influences on memory confidence

    OpenAIRE

    Chua, Elizabeth F.; Hannula, Deborah E.; Ranganath, Charan

    2012-01-01

    It is generally believed that accuracy and confidence in one’s memory are related, but there are many instances when they diverge. Accordingly, it is important to disentangle the factors which contribute to memory accuracy and confidence, especially those factors that contribute to confidence, but not accuracy. We used eye movements to separately measure fluent cue processing, the target recognition experience, and relative evidence assessment on recognition confidence and accuracy. Eye movem...

  5. How do regulators measure public confidence?

    International Nuclear Information System (INIS)

    Schmitt, A.; Besenyei, E.

    2006-01-01

    The conclusions and recommendations of this session can be summarized this way. - There are some important elements of confidence: visibility, satisfaction, credibility and reputation. The latter can consist of trust, positive image and knowledge of the role the organisation plays. A good reputation is hard to achieve but easy to lose. - There is a need to define what public confidence is and what to measure. The difficulty is that confidence is a matter of perception of the public, so what we try to measure is the perception. - It is controversial how to take into account the results of confidence measurement because of the influence of the context. It is not an exact science, results should be examined cautiously and surveys should be conducted frequently, at least every two years. - Different experiences were explained: - Quantitative surveys - among the general public or more specific groups like the media; - Qualitative research - with test groups and small panels; - Semi-quantitative studies - among stakeholders who have regular contracts with the regulatory body. It is not clear if the results should be shared with the public or just with other authorities and governmental organisations. - Efforts are needed to increase visibility, which is a prerequisite for confidence. - A practical example of organizing an emergency exercise and an information campaign without taking into account the real concerns of the people was given to show how public confidence can be decreased. - We learned about a new method - the so-called socio-drama - which addresses another issue also connected to confidence - the notion of understanding between stakeholders around a nuclear site. It is another way of looking at confidence in a more restricted group. (authors)

  6. Confidence in leadership among the newly qualified.

    Science.gov (United States)

    Bayliss-Pratt, Lisa; Morley, Mary; Bagley, Liz; Alderson, Steven

    2013-10-23

    The Francis report highlighted the importance of strong leadership from health professionals but it is unclear how prepared those who are newly qualified feel to take on a leadership role. We aimed to assess the confidence of newly qualified health professionals working in the West Midlands in the different competencies of the NHS Leadership Framework. Most respondents felt confident in their abilities to demonstrate personal qualities and work with others, but less so at managing or improving services or setting direction.

  7. [Sources of leader's confidence in organizations].

    Science.gov (United States)

    Ikeda, Hiroshi; Furukawa, Hisataka

    2006-04-01

    The purpose of this study was to examine the sources of confidence that organization leaders had. As potential sources of the confidence, we focused on fulfillment of expectations made by self and others, reflection on good as well as bad job experiences, and awareness of job experiences in terms of commonality, differentiation, and multiple viewpoints. A questionnaire was administered to 170 managers of Japanese companies. Results were as follows: First, confidence in leaders was more strongly related to fulfillment of expectations made by self and others than reflection on and awareness of job experiences. Second, the confidence was weakly related to internal processing of job experiences, in the form of commonality awareness and reflection on good job experiences. And finally, years of managerial experiences had almost no relation to the confidence. These findings suggested that confidence in leaders was directly acquired from fulfillment of expectations made by self and others, rather than indirectly through internal processing of job experiences. Implications of the findings for leadership training were also discussed.

  8. Prevalence of upper limb disorders among female librarians.

    Science.gov (United States)

    Pandy, R

    2013-09-01

    Work as a librarian involves exposure to potential risk factors for developing upper limb disorders. The prevalence of upper limb symptoms has, however, not previously been assessed in this occupational group. To estimate the 7-day and annual prevalence of self-reported neck and upper limb symptoms in librarians and to examine associations with specific tasks and ergonomic risk factors. A cross-sectional study using components of the standardized Nordic questionnaire. The study population consisted of librarians employed by a large local authority, and data collection was by means of a self-administered questionnaire. from studies on keyboard workers and on the general population were used as comparators. The 7-day prevalence of self-reported neck and upper limb pain in female librarians was 42% (95% confidence interval (CI) 33.7-50.5) and the annual prevalence was 65% (95% CI 56.6-72.8). The prevalence of reported wrist and hand pain increased with increased working involving a wide thumb-index span (P librarians was high, but there was insufficient evidence to confirm whether the prevalence was higher than in the general population or among keyboard workers. Working with a wide thumb-index span was associated with reporting upper limb symptoms.

  9. Prevalence of Listeria monocytogenes in European cheeses

    DEFF Research Database (Denmark)

    Martinez Rios, Veronica; Dalgaard, Paw

    2017-01-01

    , respectively, pasteurized or un-pasteurized milk. Data from a total of 130,604 samples were analysed. Mean prevalence for presence during 2005-2015 estimated from scientific literature (2.3% with confidence interval (CI): 1.4-3.8%) was more than three times higher than results from EFSA reports (0.7%; CI: 0.......05) for cheeses produced from pasteurized (0.9%; CI: 0.4-1.9%) or un-pasteurized (1.0%; CI: 0.4-2.2%) milk. For cheese samples reported by EFSA 0.2% CI: 0.1-0.4% had concentration of L. monocytogenes above the critical European limits of 100 cfu/g. In addition, this systematic review focused on groups...

  10. CONFIDENCE LEVELS AND/VS. STATISTICAL HYPOTHESIS TESTING IN STATISTICAL ANALYSIS. CASE STUDY

    Directory of Open Access Journals (Sweden)

    ILEANA BRUDIU

    2009-05-01

    Full Text Available Estimated parameters with confidence intervals and testing statistical assumptions used in statistical analysis to obtain conclusions on research from a sample extracted from the population. Paper to the case study presented aims to highlight the importance of volume of sample taken in the study and how this reflects on the results obtained when using confidence intervals and testing for pregnant. If statistical testing hypotheses not only give an answer "yes" or "no" to some questions of statistical estimation using statistical confidence intervals provides more information than a test statistic, show high degree of uncertainty arising from small samples and findings build in the "marginally significant" or "almost significant (p very close to 0.05.

  11. The Prevalence of Personality Disorders: A Cross Sectional Study in Tabriz

    Directory of Open Access Journals (Sweden)

    Maryam Sepehri

    2017-10-01

    Full Text Available Background and Objectives: Personality disorders considered as an important health problem are associated with significant consequences in the community. The disorders complicate the treatment process of other diseases and conditions as well. The aim of this study was to estimate the prevalence of personality disorder in Tabriz city, northwest Iran. Material and Methods: The short form of the Minnesota Multiphasic Personality Inventory (MMPI, 71 questions was used to measure the personality disorders in a sample of 150 individuals (aged 18-62 years including staff and clients of the primary health care settings in Tabriz, northwest Iran. The clinical profile of the participants was assessed using MMPI questionnaire/software. The patients' test data were then interpreted by the study investigators. Results: The overall prevalence of the personality disorder was 20% (95% Confidence Intervals: 13.5 to 26.4 in the study population. The same rate was calculated 23.7% (95% Confidence Intervals: 15.2 to 32.1 in women, and 20.9% (95% Confidence Intervals: 13.3 to 28.5 for married individuals. Conclusion: According to our findings, personality disorders are common in the community. One in five persons was detected as having personality disorders. Understanding the epidemiology of personality disorders and the relevant comorbidities in general population is important for policy-making in mental health programs at community level.

  12. Increasing Product Confidence-Shifting Paradigms.

    Science.gov (United States)

    Phillips, Marla; Kashyap, Vishal; Cheung, Mee-Shew

    2015-01-01

    Leaders in the pharmaceutical, medical device, and food industries expressed a unilateral concern over product confidence throughout the total product lifecycle, an unsettling fact for these leaders to manage given that their products affect the lives of millions of people each year. Fueled by the heparin incident of intentional adulteration in 2008, initial efforts for increasing product confidence were focused on improving the confidence of incoming materials, with a belief that supplier performance must be the root cause. As in the heparin case, concern over supplier performance extended deep into the supply chain to include suppliers of the suppliers-which is often a blind spot for pharmaceutical, device, and food manufacturers. Resolved to address the perceived lack of supplier performance, these U.S. Food and Drug Administration (FDA)-regulated industries began to adopt the supplier relationship management strategy, developed by the automotive industry, that emphasizes "management" of suppliers for the betterment of the manufacturers. Current product and supplier management strategies, however, have not led to a significant improvement in product confidence. As a result of the enduring concern by industry leaders over the lack of product confidence, Xavier University launched the Integrity of Supply Initiative in 2012 with a team of industry leaders and FDA officials. Through a methodical research approach, data generated by the pharmaceutical, medical device, and food manufacturers surprisingly pointed to themselves as a source of the lack of product confidence, and revealed that manufacturers either unknowingly increase the potential for error or can control/prevent many aspects of product confidence failure. It is only through this paradigm shift that manufacturers can work collaboratively with their suppliers as equal partners, instead of viewing their suppliers as "lesser" entities needing to be controlled. The basis of this shift provides manufacturers

  13. Confidence-building and Canadian leadership

    Energy Technology Data Exchange (ETDEWEB)

    Cleminson, F.R. [Dept. of Foreign Affairs and International Trade, Verification, Non-Proliferation, Arms Control and Disarmament Div (IDA), Ottawa, Ontario (Canada)

    1998-07-01

    Confidence-building has come into its own as a 'tool of choice' in facilitating the non-proliferation, arms control and disarmament (NACD) agenda, whether regional or global. From the Middle East Peace Process (MEPP) to the ASEAN Intersessional Group on Confidence-Building (ARF ISG on CBMS), confidence-building has assumed a central profile in regional terms. In the Four Power Talks begun in Geneva on December 9, 1997, the United States identified confidence-building as one of two subject areas for initial discussion as part of a structured peace process between North and South Korea. Thus, with CBMs assuming such a high profile internationally, it seems prudent for Canadians to pause and take stock of the significant role which Canada has already played in the conceptual development of the process over the last two decades. Since the Helsinki accords of 1975, Canada has developed a significant expertise in this area through an unbroken series of original, basic research projects. These have contributed to defining the process internationally from concept to implementation. Today, these studies represent a solid and unique Departmental investment in basic research from which to draw in meeting Canada's current commitments to multilateral initiatives in the area of confidence-building and to provide a 'step up' in terms of future-oriented leadership. (author)

  14. Confidence Leak in Perceptual Decision Making.

    Science.gov (United States)

    Rahnev, Dobromir; Koizumi, Ai; McCurdy, Li Yan; D'Esposito, Mark; Lau, Hakwan

    2015-11-01

    People live in a continuous environment in which the visual scene changes on a slow timescale. It has been shown that to exploit such environmental stability, the brain creates a continuity field in which objects seen seconds ago influence the perception of current objects. What is unknown is whether a similar mechanism exists at the level of metacognitive representations. In three experiments, we demonstrated a robust intertask confidence leak-that is, confidence in one's response on a given task or trial influencing confidence on the following task or trial. This confidence leak could not be explained by response priming or attentional fluctuations. Better ability to modulate confidence leak predicted higher capacity for metacognition as well as greater gray matter volume in the prefrontal cortex. A model based on normative principles from Bayesian inference explained the results by postulating that observers subjectively estimate the perceptual signal strength in a stable environment. These results point to the existence of a novel metacognitive mechanism mediated by regions in the prefrontal cortex. © The Author(s) 2015.

  15. ADAM SMITH: THE INVISIBLE HAND OR CONFIDENCE

    Directory of Open Access Journals (Sweden)

    Fernando Luis, Gache

    2010-01-01

    Full Text Available In 1776 Adam Smith raised the matter that an invisible hand was the one which moved the markets to obtain its efficiency. Despite in the present paper we are going to raise the hypothesis, that this invisible hand is in fact the confidence that each person feels when he is going to do business. That in addition it is unique, because it is different from the confidence of the others and that is a variable nonlinear that essentially is ligatured to respective personal histories. For that we are going to take as its bases the paper by Leopoldo Abadía (2009, with respect to the financial economy crisis that happened in 2007-2008, to evidence the form in which confidence operates. Therefore the contribution that we hope to do with this paper is to emphasize that, the level of confidence of the different actors, is the one which really moves the markets, (therefore the economy and that the crisis of the subprime mortgages is a confidence crisis at world-wide level.

  16. Confidence-building and Canadian leadership

    International Nuclear Information System (INIS)

    Cleminson, F.R.

    1998-01-01

    Confidence-building has come into its own as a 'tool of choice' in facilitating the non-proliferation, arms control and disarmament (NACD) agenda, whether regional or global. From the Middle East Peace Process (MEPP) to the ASEAN Intersessional Group on Confidence-Building (ARF ISG on CBMS), confidence-building has assumed a central profile in regional terms. In the Four Power Talks begun in Geneva on December 9, 1997, the United States identified confidence-building as one of two subject areas for initial discussion as part of a structured peace process between North and South Korea. Thus, with CBMs assuming such a high profile internationally, it seems prudent for Canadians to pause and take stock of the significant role which Canada has already played in the conceptual development of the process over the last two decades. Since the Helsinki accords of 1975, Canada has developed a significant expertise in this area through an unbroken series of original, basic research projects. These have contributed to defining the process internationally from concept to implementation. Today, these studies represent a solid and unique Departmental investment in basic research from which to draw in meeting Canada's current commitments to multilateral initiatives in the area of confidence-building and to provide a 'step up' in terms of future-oriented leadership. (author)

  17. Determination of confidence limits for experiments with low numbers of counts

    International Nuclear Information System (INIS)

    Kraft, R.P.; Burrows, D.N.; Nousek, J.A.

    1991-01-01

    Two different methods, classical and Bayesian, for determining confidence intervals involving Poisson-distributed data are compared. Particular consideration is given to cases where the number of counts observed is small and is comparable to the mean number of background counts. Reasons for preferring the Bayesian over the classical method are given. Tables of confidence limits calculated by the Bayesian method are provided for quick reference. 12 refs

  18. Prevalence and causes of corneal blindness.

    Science.gov (United States)

    Wang, Haijing; Zhang, Yaoguang; Li, Zhijian; Wang, Tiebin; Liu, Ping

    2014-04-01

    The study aimed to assess the prevalence and causes of corneal blindness in a rural northern Chinese population. Cross-sectional study. The cluster random sampling method was used to select the sample. This population-based study included 11 787 participants of all ages in rural Heilongjiang Province, China. These participants underwent a detailed interview and eye examination that included the measurement of visual acuity, slit-lamp biomicroscopy and direct ophthalmoscopy. An eye was considered to have corneal blindness if the visual acuity was blindness and low vision. Among the 10 384 people enrolled in the study, the prevalence of corneal blindness is 0.3% (95% confidence interval 0.2-0.4%). The leading cause was keratitis in childhood (40.0%), followed by ocular trauma (33.3%) and keratitis in adulthood (20.0%). Age and illiteracy were found to be associated with an increased prevalence of corneal blindness. Blindness because of corneal diseases in rural areas of Northern China is a significant public health problem that needs to be given more attention. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

  19. High confidence in falsely recognizing prototypical faces.

    Science.gov (United States)

    Sampaio, Cristina; Reinke, Victoria; Mathews, Jeffrey; Swart, Alexandra; Wallinger, Stephen

    2018-06-01

    We applied a metacognitive approach to investigate confidence in recognition of prototypical faces. Participants were presented with sets of faces constructed digitally as deviations from prototype/base faces. Participants were then tested with a simple recognition task (Experiment 1) or a multiple-choice task (Experiment 2) for old and new items plus new prototypes, and they showed a high rate of confident false alarms to the prototypes. Confidence and accuracy relationship in this face recognition paradigm was found to be positive for standard items but negative for the prototypes; thus, it was contingent on the nature of the items used. The data have implications for lineups that employ match-to-suspect strategies.

  20. A systematic review of maternal confidence for physiologic birth: characteristics of prenatal care and confidence measurement.

    Science.gov (United States)

    Avery, Melissa D; Saftner, Melissa A; Larson, Bridget; Weinfurter, Elizabeth V

    2014-01-01

    Because a focus on physiologic labor and birth has reemerged in recent years, care providers have the opportunity in the prenatal period to help women increase confidence in their ability to give birth without unnecessary interventions. However, most research has only examined support for women during labor. The purpose of this systematic review was to examine the research literature for information about prenatal care approaches that increase women's confidence for physiologic labor and birth and tools to measure that confidence. Studies were reviewed that explored any element of a pregnant woman's interaction with her prenatal care provider that helped build confidence in her ability to labor and give birth. Timing of interaction with pregnant women included during pregnancy, labor and birth, and the postpartum period. In addition, we looked for studies that developed a measure of women's confidence related to labor and birth. Outcome measures included confidence or similar concepts, descriptions of components of prenatal care contributing to maternal confidence for birth, and reliability and validity of tools measuring confidence. The search of MEDLINE, CINAHL, PsycINFO, and Scopus databases provided a total of 893 citations. After removing duplicates and articles that did not meet inclusion criteria, 6 articles were included in the review. Three relate to women's confidence for labor during the prenatal period, and 3 describe tools to measure women's confidence for birth. Research about enhancing women's confidence for labor and birth was limited to qualitative studies. Results suggest that women desire information during pregnancy and want to use that information to participate in care decisions in a relationship with a trusted provider. Further research is needed to develop interventions to help midwives and physicians enhance women's confidence in their ability to give birth and to develop a tool to measure confidence for use during prenatal care. © 2014 by

  1. Predicting fecal coliform using the interval-to-interval approach and SWAT in the Miyun watershed, China.

    Science.gov (United States)

    Bai, Jianwen; Shen, Zhenyao; Yan, Tiezhu; Qiu, Jiali; Li, Yangyang

    2017-06-01

    Pathogens in manure can cause waterborne-disease outbreaks, serious illness, and even death in humans. Therefore, information about the transformation and transport of bacteria is crucial for determining their source. In this study, the Soil and Water Assessment Tool (SWAT) was applied to simulate fecal coliform bacteria load in the Miyun Reservoir watershed, China. The data for the fecal coliform were obtained at three sampling sites, Chenying (CY), Gubeikou (GBK), and Xiahui (XH). The calibration processes of the fecal coliform were conducted using the CY and GBK sites, and validation was conducted at the XH site. An interval-to-interval approach was designed and incorporated into the processes of fecal coliform calibration and validation. The 95% confidence interval of the predicted values and the 95% confidence interval of measured values were considered during calibration and validation in the interval-to-interval approach. Compared with the traditional point-to-point comparison, this method can improve simulation accuracy. The results indicated that the simulation of fecal coliform using the interval-to-interval approach was reasonable for the watershed. This method could provide a new research direction for future model calibration and validation studies.

  2. Confidence building - is science the only approach

    International Nuclear Information System (INIS)

    Bragg, K.

    1990-01-01

    The Atomic Energy Control Board (AECB) has begun to develop some simplified methods to determine if it is possible to provide confidence that dose, risk and environmental criteria can be respected without undue reliance on detailed scientific models. The progress to date will be outlined and the merits of this new approach will be compared to the more complex, traditional approach. Stress will be given to generating confidence in both technical and non-technical communities as well as the need to enhance communication between them. 3 refs., 1 tab

  3. Self Confidence Spillovers and Motivated Beliefs

    DEFF Research Database (Denmark)

    Banerjee, Ritwik; Gupta, Nabanita Datta; Villeval, Marie Claire

    that success when competing in a task increases the performers’ self-confidence and competitiveness in the subsequent task. We also find that such spillovers affect the self-confidence of low-status individuals more than that of high-status individuals. Receiving good news under Affirmative Action, however......Is success in a task used strategically by individuals to motivate their beliefs prior to taking action in a subsequent, unrelated, task? Also, is the distortion of beliefs reinforced for individuals who have lower status in society? Conducting an artefactual field experiment in India, we show...

  4. Prevalence and type distribution of human papillomavirus in squamous cell carcinoma and intraepithelial neoplasia of the vulva

    DEFF Research Database (Denmark)

    Faber, Mette T; Sand, Freja Lærke; Albieri, Vanna

    2017-01-01

    In this updated systematic review and meta-analysis, we estimate the pooled prevalence of human papillomavirus (HPV) DNA and HPV type distribution in squamous cell carcinoma of the vulva (vulvar cancer) and vulvar intraepithelial neoplasia (VIN). PubMed, Embase and Cochrane Library databases were...... used to identify studies published between 1990 and 2015 and using a PCR-based or hybrid capture test to evaluate the presence of HPV DNA in vulvar cancer or VIN. Pooled estimates of the HPV prevalence with corresponding 95% confidence intervals (CI) were calculated based on a random effects model...... samples. Thus, HPV vaccination targeting these HPV types may prevent a substantial number of vulvar lesions....

  5. Prevalence of cluster headache in the Republic of Georgia: results of a population-based study and methodological considerations

    DEFF Research Database (Denmark)

    Katsarava, Z; Dzagnidze, A; Kukava, M

    2009-01-01

    We present a study of the general-population prevalence of cluster headache in the Republic of Georgia and discuss the advantages and challenges of different methodological approaches. In a community-based survey, specially trained medical residents visited 500 adjacent households in the capital...... with possible cluster headache, who were then personally interviewed by one of two headache-experienced neurologists. Cluster headache was confirmed in one subject. The prevalence of cluster headache was therefore estimated to be 87/100,000 (95% confidence interval

  6. Confident Communication: Speaking Tips for Educators.

    Science.gov (United States)

    Parker, Douglas A.

    This resource book seeks to provide the building blocks needed for public speaking while eliminating the fear factor. The book explains how educators can perfect their oratorical capabilities as well as enjoy the security, confidence, and support needed to create and deliver dynamic speeches. Following an Introduction: A Message for Teachers,…

  7. Principles of psychological confidence of NPP operators

    International Nuclear Information System (INIS)

    Alpeev, A.S.

    1994-01-01

    The problems of operator interaction with subsystems supporting his activity are discussed from the point of view of formation of his psychological confidence on the basis of the automation intellectual means capabilities. The functions of operator activity supporting subsystems, which realization will provide to decrease greatly the portion of accidents at NPPs connected with mistakes in operator actions, are derived. 6 refs

  8. Growing confidence, building skills | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    In 2012 Rashid explored the influence of think tanks on policy in Bangladesh, as well as their relationships with international donors and media. In 2014, he explored two-way student exchanges between Canadian and ... his IDRC experience “gave me the confidence to conduct high quality research in social sciences.”.

  9. Detecting Disease in Radiographs with Intuitive Confidence

    Directory of Open Access Journals (Sweden)

    Stefan Jaeger

    2015-01-01

    Full Text Available This paper argues in favor of a specific type of confidence for use in computer-aided diagnosis and disease classification, namely, sine/cosine values of angles represented by points on the unit circle. The paper shows how this confidence is motivated by Chinese medicine and how sine/cosine values are directly related with the two forces Yin and Yang. The angle for which sine and cosine are equal (45° represents the state of equilibrium between Yin and Yang, which is a state of nonduality that indicates neither normality nor abnormality in terms of disease classification. The paper claims that the proposed confidence is intuitive and can be readily understood by physicians. The paper underpins this thesis with theoretical results in neural signal processing, stating that a sine/cosine relationship between the actual input signal and the perceived (learned input is key to neural learning processes. As a practical example, the paper shows how to use the proposed confidence values to highlight manifestations of tuberculosis in frontal chest X-rays.

  10. Current Developments in Measuring Academic Behavioural Confidence

    Science.gov (United States)

    Sander, Paul

    2009-01-01

    Using published findings and by further analyses of existing data, the structure, validity and utility of the Academic Behavioural Confidence scale (ABC) is critically considered. Validity is primarily assessed through the scale's relationship with other existing scales as well as by looking for predicted differences. The utility of the ABC scale…

  11. Evaluating Measures of Optimism and Sport Confidence

    Science.gov (United States)

    Fogarty, Gerard J.; Perera, Harsha N.; Furst, Andrea J.; Thomas, Patrick R.

    2016-01-01

    The psychometric properties of the Life Orientation Test-Revised (LOT-R), the Sport Confidence Inventory (SCI), and the Carolina SCI (CSCI) were examined in a study involving 260 athletes. The study aimed to test the dimensional structure, convergent and divergent validity, and invariance over competition level of scores generated by these…

  12. Distinguishing highly confident accurate and inaccurate memory: insights about relevant and irrelevant influences on memory confidence.

    Science.gov (United States)

    Chua, Elizabeth F; Hannula, Deborah E; Ranganath, Charan

    2012-01-01

    It is generally believed that accuracy and confidence in one's memory are related, but there are many instances when they diverge. Accordingly it is important to disentangle the factors that contribute to memory accuracy and confidence, especially those factors that contribute to confidence, but not accuracy. We used eye movements to separately measure fluent cue processing, the target recognition experience, and relative evidence assessment on recognition confidence and accuracy. Eye movements were monitored during a face-scene associative recognition task, in which participants first saw a scene cue, followed by a forced-choice recognition test for the associated face, with confidence ratings. Eye movement indices of the target recognition experience were largely indicative of accuracy, and showed a relationship to confidence for accurate decisions. In contrast, eye movements during the scene cue raised the possibility that more fluent cue processing was related to higher confidence for both accurate and inaccurate recognition decisions. In a second experiment we manipulated cue familiarity, and therefore cue fluency. Participants showed higher confidence for cue-target associations for when the cue was more familiar, especially for incorrect responses. These results suggest that over-reliance on cue familiarity and under-reliance on the target recognition experience may lead to erroneous confidence.

  13. Building Public Confidence in Nuclear Activities

    International Nuclear Information System (INIS)

    Isaacs, T

    2002-01-01

    Achieving public acceptance has become a central issue in discussions regarding the future of nuclear power and associated nuclear activities. Effective public communication and public participation are often put forward as the key building blocks in garnering public acceptance. A recent international workshop in Finland provided insights into other features that might also be important to building and sustaining public confidence in nuclear activities. The workshop was held in Finland in close cooperation with Finnish stakeholders. This was most appropriate because of the recent successes in achieving positive decisions at the municipal, governmental, and Parliamentary levels, allowing the Finnish high-level radioactive waste repository program to proceed, including the identification and approval of a proposed candidate repository site. Much of the workshop discussion appropriately focused on the roles of public participation and public communications in building public confidence. It was clear that well constructed and implemented programs of public involvement and communication and a sense of fairness were essential in building the extent of public confidence needed to allow the repository program in Finland to proceed. It was also clear that there were a number of other elements beyond public involvement that contributed substantially to the success in Finland to date. And, in fact, it appeared that these other factors were also necessary to achieving the Finnish public acceptance. In other words, successful public participation and communication were necessary but not sufficient. What else was important? Culture, politics, and history vary from country to country, providing differing contexts for establishing and maintaining public confidence. What works in one country will not necessarily be effective in another. Nonetheless, there appear to be certain elements that might be common to programs that are successful in sustaining public confidence and some of

  14. Building Public Confidence in Nuclear Activities

    International Nuclear Information System (INIS)

    Isaacs, T

    2002-01-01

    Achieving public acceptance has become a central issue in discussions regarding the future of nuclear power and associated nuclear activities. Effective public communication and public participation are often put forward as the key building blocks in garnering public acceptance. A recent international workshop in Finland provided insights into other features that might also be important to building and sustaining public confidence in nuclear activities. The workshop was held in Finland in close cooperation with Finnish stakeholders. This was most appropriate because of the recent successes in achieving positive decisions at the municipal, governmental, and Parliamentary levels, allowing the Finnish high-level radioactive waste repository program to proceed, including the identification and approval of a proposed candidate repository site Much of the workshop discussion appropriately focused on the roles of public participation and public communications in building public confidence. It was clear that well constructed and implemented programs of public involvement and communication and a sense of fairness were essential in building the extent of public confidence needed to allow the repository program in Finland to proceed. It was also clear that there were a number of other elements beyond public involvement that contributed substantially to the success in Finland to date. And, in fact, it appeared that these other factors were also necessary to achieving the Finnish public acceptance. In other words, successful public participation and communication were necessary but not sufficient. What else was important? Culture, politics, and history vary from country to country, providing differing contexts for establishing and maintaining public confidence. What works in one country will not necessarily be effective in another. Nonetheless, there appear to be certain elements that might be common to programs that are successful in sustaining public confidence, and some of

  15. Self-reported diabetes in older people: comparison of prevalences and control measures

    Directory of Open Access Journals (Sweden)

    Sheila Rizzato Stopa

    2014-08-01

    Full Text Available OBJECTIVE The objective of this study was to analyze the prevalence of diabetes in older people and the adopted control measures. METHODS Data regarding older diabetic individuals who participated in the Health Surveys conducted in the Municipality of Sao Paulo, SP, ISA-Capital, in 2003 and 2008, which were cross-sectional studies, were analyzed. Prevalences and confidence intervals were compared between 2003 and 2008, according to sociodemographic variables. The combination of the databases was performed when the confidence intervals overlapped. The Chi-square (level of significance of 5% and the Pearson’s Chi-square (Rao-Scott tests were performed. The variables without overlap between the confidence intervals were not tested. RESULTS The age of the older adults was 60-69 years. The majority were women, Caucasian, with an income of between > 0.5 and 2.5 times the minimum salary and low levels of schooling. The prevalence of diabetes was 17.6% (95%CI 14.9;20.6 in 2003 and 20.1% (95%CI 17.3;23.1 in 2008, which indicates a growth over this period (p at the limit of significance. The most prevalent measure adopted by the older adults to control diabetes was hypoglycemic agents, followed by diet. Physical activity was not frequent, despite the significant differences observed between 2003 and 2008 results. The use of public health services to control diabetes was significantly higher in older individuals with lower income and lower levels of education. CONCLUSIONS Diabetes is a complex and challenging disease for patients and the health systems. Measures that encourage health promotion practices are necessary because they presented a smaller proportion than the use of hypoglycemic agents. Public health policies should be implemented, and aimed mainly at older individuals with low income and schooling levels. These changes are essential to improve the health condition of older diabetic patients.

  16. Prevalence of Creatine Deficiency Syndromes in Children With Nonsyndromic Autism.

    Science.gov (United States)

    Schulze, Andreas; Bauman, Margaret; Tsai, Anne Chun-Hui; Reynolds, Ann; Roberts, Wendy; Anagnostou, Evdokia; Cameron, Jessie; Nozzolillo, Alixandra A; Chen, Shiyi; Kyriakopoulou, Lianna; Scherer, Stephen W; Loh, Alvin

    2016-01-01

    Creatine deficiency may play a role in the neurobiology of autism and may represent a treatable cause of autism. The goal of the study was to ascertain the prevalence of creatine deficiency syndromes (CDSs) in children with autism spectrum disorder (ASD). In a prospective multicenter study, 443 children were investigated after a confirmed diagnosis of ASD. Random spot urine screening for creatine metabolites (creatine, guanidinoacetate, creatinine, and arginine) with liquid chromatography-tandem mass spectrometry and second-tier testing with high-performance liquid chromatography methodology was followed by recall testing in 24-hour urines and confirmatory testing by Sanger-based DNA sequencing of GAMT, GATM, and SLC6A8 genes. Additional diagnostic tests included plasma creatine metabolites and in vivo brain proton magnetic resonance spectroscopy. The creatine metabolites in spot urine in the autism group were compared with 128 healthy controls controlled for age. In 443 subjects with ASD investigated for CDS, we had 0 events (event: 0, 95% confidence interval 0-0.0068), therefore with 95% confidence the prevalence of CDS is creatine metabolites (P > .0125) in urine. Our study revealed a very low prevalence of CDS in children with nonsyndromic ASD and no obvious association between creatine metabolites and autism. Unlike our study population, we expect more frequent CDS among children with severe developmental delay, speech impairment, seizures, and movement disorders in addition to impairments in social communication, restricted interests, and repetitive behaviors. Copyright © 2016 by the American Academy of Pediatrics.

  17. Global and regional estimates of COPD prevalence: Systematic review and meta–analysis

    Directory of Open Access Journals (Sweden)

    Davies Adeloye

    2015-12-01

    Full Text Available The burden of chronic obstructive pulmonary disease (COPD across many world regions is high. We aim to estimate COPD prevalence and number of disease cases for the years 1990 and 2010 across world regions based on the best available evidence in publicly accessible scientific databases. We conducted a systematic search of Medline, EMBASE and Global Health for original, population–based studies providing spirometry–based prevalence rates of COPD across the world from January 1990 to December 2014. Random effects meta–analysis was conducted on extracted crude prevalence rates of COPD, with overall summaries of the meta–estimates (and confidence intervals reported separately for World Health Organization (WHO regions, the World Bank's income categories and settings (urban and rural. We developed a meta–regression epidemiological model that we used to estimate the prevalence of COPD in people aged 30 years or more. Our search returned 37 472 publications. A total of 123 studies based on a spirometry–defined prevalence were retained for the review. From the meta–regression epidemiological model, we estimated about 227.3 million COPD cases in the year 1990 among people aged 30 years or more, corresponding to a global prevalence of 10.7% (95% confidence interval (CI 7.3%–14.0% in this age group. The number of COPD cases increased to 384 million in 2010, with a global prevalence of 11.7% (8.4%–15.0%. This increase of 68.9% was mainly driven by global demographic changes. Across WHO regions, the highest prevalence was estimated in the Americas (13.3% in 1990 and 15.2% in 2010, and the lowest in South East Asia (7.9% in 1990 and 9.7% in 2010. The percentage increase in COPD cases between 1990 and 2010 was the highest in the Eastern Mediterranean region (118.7%, followed by the African region (102.1%, while the European region recorded the lowest increase (22.5%. In 1990, we estimated about 120.9 million COPD cases among urban dwellers

  18. No association between gender inequality and peak HIV prevalence in developing countries - an ecological study.

    Science.gov (United States)

    Kenyon, Chris R; Buyze, Jozefien

    2015-01-01

    The prevalence of both gender inequality and HIV prevalence vary considerably both within all developing countries and within those in sub-Saharan Africa. We test the hypothesis that the extent of gender inequality is associated with national peak HIV prevalence. Linear regression was used to test the association between national peak HIV prevalence and three markers of gender equality - the gender-related development index (GDI), the gender empowerment measure (GEM), and the gender inequality index (GII). No evidence was found of a positive relationship between gender inequality and HIV prevalence, either in the analyses of all developing countries or those limited to Africa. In the bivariate analyses limited to Africa, there was a positive association between the two measures of gender "equality" and peak HIV prevalence (GDI: coefficient 28, 95% confidence interval (CI) 9.1-46.8; GEM: coefficient 54.8, 95% CI 20.5-89.1). There was also a negative association between the marker of gender "inequality" and peak HIV prevalence (GII: coefficient -66.9, 95% CI -112.8 to -21.0). These associations all disappeared on multivariate analyses. We could not find any evidence to support the hypothesis that variations in the extent of gender inequality explain variations in HIV prevalence in developing countries.

  19. Challenge for reconstruction of public confidence

    International Nuclear Information System (INIS)

    Matsuura, S.

    2001-01-01

    Past incidents and scandals that have had a large influence on damaging public confidence in nuclear energy safety are presented. Radiation leak on nuclear-powered ship 'Mutsu' (1974), the T.M.I. incident in 1979, Chernobyl accident (1986), the sodium leak at the Monju reactor (1995), fire and explosion at a low level waste asphalt solidification facility (1997), J.C.O. incident (Tokai- MURA, 1999), are so many examples that have created feelings of distrust and anxiety in society. In order to restore public confidence there is no other course but to be prepared for difficulty and work honestly to our fullest ability, with all steps made openly and accountably. (N.C.)

  20. Tables of Confidence Limits for Proportions

    Science.gov (United States)

    1990-09-01

    0.972 180 49 0.319 0.332 0,357 175 165 0.964 0.969 0.976 ISO 50 0.325 0.338 0.363 175 166 0.969 0.973 0.980 180 51 0.331 0.344 0.368 175 167 0.973 0.977...0.528 180 18 0.135 0 145 0.164 180 19 0.141 0.151 0.171 ISO 80 0.495 0,508 0.534 347 UPPER CONFIDENCE LIMIT FOR PROPORTIONS CONFIDENCE LEVEL...500 409 0.8401 0.8459 0.8565 500 355 0.7364 0.7434 0.7564 500 356 0.7383 0.7453 0.7582 500 410 0.8420 0.8478 0 8583 500 357 0.7402 0.7472 0.7602 500

  1. Social media sentiment and consumer confidence

    OpenAIRE

    Daas, Piet J.H.; Puts, Marco J.H.

    2014-01-01

    Changes in the sentiment of Dutch public social media messages were compared with changes in monthly consumer confidence over a period of three-and-a-half years, revealing that both were highly correlated (up to r = 0.9) and that both series cointegrated. This phenomenon is predominantly affected by changes in the sentiment of all Dutch public Facebook messages. The inclusion of various selections of public Twitter messages improved this association and the response to changes in sentiment. G...

  2. Confidence, Visual Research, and the Aesthetic Function

    Directory of Open Access Journals (Sweden)

    Stan Ruecker

    2007-05-01

    Full Text Available The goal of this article is to identify and describe one of the primary purposes of aesthetic quality in the design of computer interfaces and visualization tools. We suggest that humanists can derive advantages in visual research by acknowledging by their efforts to advance aesthetic quality that a significant function of aesthetics in this context is to inspire the user’s confidence. This confidence typically serves to create a sense of trust in the provider of the interface or tool. In turn, this increased trust may result in an increased willingness to engage with the object, on the basis that it demonstrates an attention to detail that promises to reward increased engagement. In addition to confidence, the aesthetic may also contribute to a heightened degree of satisfaction with having spent time using or investigating the object. In the realm of interface design and visualization research, we propose that these aesthetic functions have implications not only for the quality of interactions, but also for the results of the standard measures of performance and preference.

  3. Confidence-Based Learning in Investment Analysis

    Science.gov (United States)

    Serradell-Lopez, Enric; Lara-Navarra, Pablo; Castillo-Merino, David; González-González, Inés

    The aim of this study is to determine the effectiveness of using multiple choice tests in subjects related to the administration and business management. To this end we used a multiple-choice test with specific questions to verify the extent of knowledge gained and the confidence and trust in the answers. The tests were performed in a group of 200 students at the bachelor's degree in Business Administration and Management. The analysis made have been implemented in one subject of the scope of investment analysis and measured the level of knowledge gained and the degree of trust and security in the responses at two different times of the course. The measurements have been taken into account different levels of difficulty in the questions asked and the time spent by students to complete the test. The results confirm that students are generally able to obtain more knowledge along the way and get increases in the degree of trust and confidence in the answers. It is confirmed as the difficulty level of the questions set a priori by the heads of the subjects are related to levels of security and confidence in the answers. It is estimated that the improvement in the skills learned is viewed favourably by businesses and are especially important for job placement of students.

  4. Predictor sort sampling and one-sided confidence bounds on quantiles

    Science.gov (United States)

    Steve Verrill; Victoria L. Herian; David W. Green

    2002-01-01

    Predictor sort experiments attempt to make use of the correlation between a predictor that can be measured prior to the start of an experiment and the response variable that we are investigating. Properly designed and analyzed, they can reduce necessary sample sizes, increase statistical power, and reduce the lengths of confidence intervals. However, if the non- random...

  5. Exact nonparametric confidence bands for the survivor function.

    Science.gov (United States)

    Matthews, David

    2013-10-12

    A method to produce exact simultaneous confidence bands for the empirical cumulative distribution function that was first described by Owen, and subsequently corrected by Jager and Wellner, is the starting point for deriving exact nonparametric confidence bands for the survivor function of any positive random variable. We invert a nonparametric likelihood test of uniformity, constructed from the Kaplan-Meier estimator of the survivor function, to obtain simultaneous lower and upper bands for the function of interest with specified global confidence level. The method involves calculating a null distribution and associated critical value for each observed sample configuration. However, Noe recursions and the Van Wijngaarden-Decker-Brent root-finding algorithm provide the necessary tools for efficient computation of these exact bounds. Various aspects of the effect of right censoring on these exact bands are investigated, using as illustrations two observational studies of survival experience among non-Hodgkin's lymphoma patients and a much larger group of subjects with advanced lung cancer enrolled in trials within the North Central Cancer Treatment Group. Monte Carlo simulations confirm the merits of the proposed method of deriving simultaneous interval estimates of the survivor function across the entire range of the observed sample. This research was supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada. It was begun while the author was visiting the Department of Statistics, University of Auckland, and completed during a subsequent sojourn at the Medical Research Council Biostatistics Unit in Cambridge. The support of both institutions, in addition to that of NSERC and the University of Waterloo, is greatly appreciated.

  6. The incidence and clinical associated factors of interval colorectal cancers in Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Cheng-En Tsai

    2018-03-01

    Conclusion: The prevalence of interval CRC in the present study is 3.28%. Comorbidity with ESRD and shorter ascending colon withdrawal time could be factors associated with interval CRC. Good colon preparation for the patients with ESRD and more ascending colon withdrawal time could reduce the interval CRC.

  7. Interval stability for complex systems

    Science.gov (United States)

    Klinshov, Vladimir V.; Kirillov, Sergey; Kurths, Jürgen; Nekorkin, Vladimir I.

    2018-04-01

    Stability of dynamical systems against strong perturbations is an important problem of nonlinear dynamics relevant to many applications in various areas. Here, we develop a novel concept of interval stability, referring to the behavior of the perturbed system during a finite time interval. Based on this concept, we suggest new measures of stability, namely interval basin stability (IBS) and interval stability threshold (IST). IBS characterizes the likelihood that the perturbed system returns to the stable regime (attractor) in a given time. IST provides the minimal magnitude of the perturbation capable to disrupt the stable regime for a given interval of time. The suggested measures provide important information about the system susceptibility to external perturbations which may be useful for practical applications. Moreover, from a theoretical viewpoint the interval stability measures are shown to bridge the gap between linear and asymptotic stability. We also suggest numerical algorithms for quantification of the interval stability characteristics and demonstrate their potential for several dynamical systems of various nature, such as power grids and neural networks.

  8. Prevalence of Antenatal Depressive Symptoms and Associated

    African Journals Online (AJOL)

    GB

    2017-01-01

    Jan 1, 2017 ... unrestricted use, distribution, and reproduction in ... using odds ratio and 95% confidence interval. RESULT: .... translators with the assistance of a mental health specialist. .... involved in private jobs, were 4 times more likely.

  9. Incidence, prevalence, diagnostic delay, and clinical presentation of female 46,XY disorders of sex development

    DEFF Research Database (Denmark)

    Berglund, Agnethe; Johannsen, Trine H; Krag, Kirstine Stochholm

    2016-01-01

    CONTEXT: The prevalence of phenotypic females with a 46,XY karyotype is low, thus current knowledge about age and clinical presentation at diagnosis is sparse even for the most frequent conditions, androgen insensitivity syndrome (AIS), and gonadal dysgenesis. OBJECTIVE: To estimate incidence......, prevalence, age at diagnosis, and clinical presentation at diagnosis in 46,XY females. DESIGN AND SETTING: A nationwide study covering all known females with a 46,XY karyotype in Denmark since 1960. The diagnosis of 46,XY disorder of sex development (DSD) was determined by medical record evaluation, data.......0-13.5; range, 0-34 y) in AIS and 17.0 years (95% confidence interval, 15.5-19.0; range, 0-28 y) in gonadal dysgenesis (P = .001). Clinical presentation was dependent on cause of DSD. CONCLUSIONS: The first estimate on prevalence of 46,XY females is 6.4 per 100 000 live born females. The presentation of AIS...

  10. Obesity and prevalence of risk behaviour for eating disorders among young Danish women

    DEFF Research Database (Denmark)

    Waaddegaard, Mette; Davidsen, Michael; Kjøller, Mette

    2009-01-01

    AIMS: Danish women aged 16-29 from two nationwide, representative, cross-sectional interview/questionnaire surveys from 2000 and 2005 are analyzed for trends in prevalence of risk behaviour for developing eating disorders and associations to BMI and age. METHODS: Participants completed the Danish...... Health Interview Survey and an 8-item screen, RiBED-8, for risk behaviour for eating disorders. To analyze how the prevalence of risk behaviour depends on age, BMI, and year of survey, logistic regression analyses were applied. On acceptance of no interaction, the effect of each variable was tested...... and described using odds ratios with 95% confidence intervals. RESULTS: Women aged 16-19 or with a BMI of>25 had the greatest chance of reporting risk behaviour for eating disorders. However, many women in their 20s also had risk behaviour. Prevalence of risk behaviour for eating disorders did not change from...

  11. Gastric dilation-volvulus in dogs attending UK emergency-care veterinary practices: prevalence, risk factors and survival.

    Science.gov (United States)

    O'Neill, D G; Case, J; Boag, A K; Church, D B; McGreevy, P D; Thomson, P C; Brodbelt, D C

    2017-11-01

    To report prevalence, risk factors and clinical outcomes for presumptive gastric dilation-volvulus diagnosed among an emergency-care population of UK dogs. The study used a cross-sectional design using emergency-care veterinary clinical records from the VetCompass Programme spanning September 1, 2012 to February 28, 2014 and risk factor analysis using multivariable logistic regression modelling. The study population comprised 77,088 dogs attending 50 Vets Now clinics. Overall, 492 dogs had presumptive gastric dilation-volvulus diagnoses, giving a prevalence of 0·64% (95% Confidence interval: 0·58 to 0·70%). Compared with cross-bred dogs, breeds with the highest odds ratios for the diagnosis of presumptive gastric dilation-volvulus were the great Dane (odds ratio: 114·3, 95% Confidence interval 55·1 to 237·1, Pdogs aged up to 12 years and neutered male dogs had 1·3 (95% Confidence interval 1·0 to 1·8, P=0·041) times the odds compared with entire females. Of the cases that were presented alive, 49·7% survived to discharge overall, but 79·3% of surgical cases survived to discharge. Approximately 80% of surgically managed cases survived to discharge. Certain large breeds were highly predisposed. © 2017 British Small Animal Veterinary Association.

  12. Transparency as an element of public confidence

    International Nuclear Information System (INIS)

    Kim, H.K.

    2007-01-01

    In the modern society, there is increasing demands for greater transparency. It has been discussed with respect to corruption or ethics issues in social science. The need for greater openness and transparency in nuclear regulation is widely recognised as public expectations on regulator grow. It is also related to the digital and information technology that enables disclosures of every activity and information of individual and organisation, characterised by numerous 'small brothers'. Transparency has become a key word in this ubiquitous era. Transparency in regulatory activities needs to be understood in following contexts. First, transparency is one of elements to build public confidence in regulator and eventually to achieve regulatory goal of providing the public with satisfaction at nuclear safety. Transparent bases of competence, independence, ethics and integrity of working process of regulatory body would enhance public confidence. Second, activities transmitting information on nuclear safety and preparedness to be accessed are different types of transparency. Communication is an active method of transparency. With increasing use of web-sites, 'digital transparency' is also discussed as passive one. Transparency in regulatory process may be more important than that of contents. Simply providing more information is of little value and specific information may need to be protected for security reason. Third, transparency should be discussed in international, national and organizational perspectives. It has been demanded through international instruments. for each country, transparency is demanded by residents, public, NGOs, media and other stakeholders. Employees also demand more transparency in operating and regulatory organisations. Whistle-blower may appear unless they are satisfied. Fourth, pursuing transparency may cause undue social cost or adverse effects. Over-transparency may decrease public confidence and the process for transparency may also hinder

  13. Asymptotically Honest Confidence Regions for High Dimensional

    DEFF Research Database (Denmark)

    Caner, Mehmet; Kock, Anders Bredahl

    While variable selection and oracle inequalities for the estimation and prediction error have received considerable attention in the literature on high-dimensional models, very little work has been done in the area of testing and construction of confidence bands in high-dimensional models. However...... develop an oracle inequality for the conservative Lasso only assuming the existence of a certain number of moments. This is done by means of the Marcinkiewicz-Zygmund inequality which in our context provides sharper bounds than Nemirovski's inequality. As opposed to van de Geer et al. (2014) we allow...

  14. National Debate and Public Confidence in Sweden

    International Nuclear Information System (INIS)

    Lindquist, Ted

    2014-01-01

    Ted Lindquist, coordinator of the Association of Swedish Municipalities with Nuclear Facilities (KSO), closed the first day of conferences. He showed what the nuclear landscape was in Sweden, and in particular that through time there has been a rather good support from the population. He explained that the reason could be the confidence of the public in the national debate. On a more local scale, Ted Lindquist showed how overwhelmingly strong the support was in towns where the industry would like to operate long-term storage facilities

  15. Mycoplasma genitalium and Trichomonas vaginalis in France: a point prevalence study in people screened for sexually transmitted diseases.

    Science.gov (United States)

    Pereyre, S; Laurier Nadalié, C; Bébéar, C

    2017-02-01

    Mycoplasma genitalium and Trichomonas vaginalis are common causes of sexually transmitted infections, but limited prevalence data are available in France. We aimed to evaluate the prevalence of M. genitalium and T. vaginalis infections and to assess prevalence by gender, age, sample collection sites and clinical symptoms. A multicentre collection of specimens was intended to obtain a nationwide overview of the epidemiology. Between September 2014 and January 2015, a total of 2652 consecutive urogenital specimens submitted to the microbiology diagnostic departments of 16 French university hospitals for Chlamydia trachomatis and Neisseria gonorrhoeae detection were collected. M. genitalium and T. vaginalis prevalence were evaluated using a commercial real-time PCR kit. Clinical data from patients were anonymously collected. T. vaginalis and M. genitalium prevalence were 1.7% (95% confidence interval 1.3-2.4) and 3.4% (95% confidence interval 2.8-4.2), respectively, and did not differ between gender or age groups, except M. genitalium prevalence between men and women in the 35- to 44-year age group (5.9 vs. 1.5%; p 0.03). M. genitalium prevalence was significantly higher in patients receiving care in sexually transmitted infection clinics, abortion centres, family planning clinics and prisons than in gynaecologic, obstetric and reproduction centres (4.0 vs. 1.7%, p 0.009). Among M. genitalium- and T. vaginalis-positive patients, 70.9 and 61.5% were asymptomatic, respectively. The low T. vaginalis prevalence does not justify systematic screening for this organism in France. Conversely, selective screening for M. genitalium may be warranted in care settings that receive presumably high-risk sexual behaviour patients, regardless of symptoms. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  16. ERICA: smoking prevalence in Brazilian adolescents

    Science.gov (United States)

    Figueiredo, Valeska Carvalho; Szklo, André Salem; Costa, Letícia Casado; Kuschnir, Maria Cristina C; da Silva, Thiago Luiz Nogueira; Bloch, Katia Vergetti; Szklo, Moyses

    2016-01-01

    ABSTRACT OBJECTIVE To estimate the prevalences of tobacco use, tobacco experimentation, and frequent smoking among Brazilian adolescents. METHODS We evaluated participants of the cross-sectional, nation-wide, school-based Study of Cardiovascular Risks in Adolescents (ERICA), which included 12- to 17-year-old adolescents from municipalities of over 100 thousand inhabitants. The study sample had a clustered, stratified design and was representative of the whole country, its geographical regions, and all 27 state capitals. The information was obtained with self-administered questionnaires. Tobacco experimentation was defined as having tried cigarettes at least once in life. Adolescents who had smoked on at least one day over the previous 30 days were considered current cigarette smokers. Having smoked cigarettes for at least seven consecutive days was an indicator for regular consumption of tobacco. Considering the complex sampling design, prevalences and 95% confidence intervals were estimated according to sociodemographic and socio-environmental characteristics. RESULTS We evaluated 74,589 adolescents. Among these, 18.5% (95%CI 17.7-19.4) had smoked at least once in life, 5.7% (95%CI 5.3-6.2) smoked at the time of the research, and 2.5% (95%CI 2.2-2.8) smoked often. Adolescents aged 15 to 17 years had higher prevalences for all indicators than those aged 12 to 14 years. The prevalences did not differ significantly between sexes. The highest prevalences were found in the South region and the lowest ones, in the Northeast region. Regardless of sex, the prevalences were found to be higher for adolescents who had had paid jobs, who lived with only one parent, and who reported having been in contact with smokers either inside or outside their homes. Female public school adolescents were found to smoke more than the ones from private schools. CONCLUSIONS Tobacco use among adolescents is still a challenge. Intending to reduce the prevalence of tobacco use among young

  17. ERICA: smoking prevalence in Brazilian adolescents

    Directory of Open Access Journals (Sweden)

    Valeska Carvalho Figueiredo

    2016-02-01

    Full Text Available ABSTRACT OBJECTIVE To estimate the prevalences of tobacco use, tobacco experimentation, and frequent smoking among Brazilian adolescents. METHODS We evaluated participants of the cross-sectional, nation-wide, school-based Study of Cardiovascular Risks in Adolescents (ERICA, which included 12- to 17-year-old adolescents from municipalities of over 100 thousand inhabitants. The study sample had a clustered, stratified design and was representative of the whole country, its geographical regions, and all 27 state capitals. The information was obtained with self-administered questionnaires. Tobacco experimentation was defined as having tried cigarettes at least once in life. Adolescents who had smoked on at least one day over the previous 30 days were considered current cigarette smokers. Having smoked cigarettes for at least seven consecutive days was an indicator for regular consumption of tobacco. Considering the complex sampling design, prevalences and 95% confidence intervals were estimated according to sociodemographic and socio-environmental characteristics. RESULTS We evaluated 74,589 adolescents. Among these, 18.5% (95%CI 17.7-19.4 had smoked at least once in life, 5.7% (95%CI 5.3-6.2 smoked at the time of the research, and 2.5% (95%CI 2.2-2.8 smoked often. Adolescents aged 15 to 17 years had higher prevalences for all indicators than those aged 12 to 14 years. The prevalences did not differ significantly between sexes. The highest prevalences were found in the South region and the lowest ones, in the Northeast region. Regardless of sex, the prevalences were found to be higher for adolescents who had had paid jobs, who lived with only one parent, and who reported having been in contact with smokers either inside or outside their homes. Female public school adolescents were found to smoke more than the ones from private schools. CONCLUSIONS Tobacco use among adolescents is still a challenge. Intending to reduce the prevalence of tobacco use

  18. Increased Prevalence of Sleep-Disordered Breathing in Adults

    Science.gov (United States)

    Peppard, Paul E.; Young, Terry; Barnet, Jodi H.; Palta, Mari; Hagen, Erika W.; Hla, Khin Mae

    2013-01-01

    Sleep-disordered breathing is a common disorder with a range of harmful sequelae. Obesity is a strong causal factor for sleep-disordered breathing, and because of the ongoing obesity epidemic, previous estimates of sleep-disordered breathing prevalence require updating. We estimated the prevalence of sleep-disordered breathing in the United States for the periods of 1988–1994 and 2007–2010 using data from the Wisconsin Sleep Cohort Study, an ongoing community-based study that was established in 1988 with participants randomly selected from an employed population of Wisconsin adults. A total of 1,520 participants who were 30–70 years of age had baseline polysomnography studies to assess the presence of sleep-disordered breathing. Participants were invited for repeat studies at 4-year intervals. The prevalence of sleep-disordered breathing was modeled as a function of age, sex, and body mass index, and estimates were extrapolated to US body mass index distributions estimated using data from the National Health and Nutrition Examination Survey. The current prevalence estimates of moderate to severe sleep-disordered breathing (apnea-hypopnea index, measured as events/hour, ≥15) are 10% (95% confidence interval (CI): 7, 12) among 30–49-year-old men; 17% (95% CI: 15, 21) among 50–70-year-old men; 3% (95% CI: 2, 4) among 30–49-year-old women; and 9% (95% CI: 7, 11) among 50–70 year-old women. These estimated prevalence rates represent substantial increases over the last 2 decades (relative increases of between 14% and 55% depending on the subgroup). PMID:23589584

  19. Diagnosing Anomalous Network Performance with Confidence

    Energy Technology Data Exchange (ETDEWEB)

    Settlemyer, Bradley W [ORNL; Hodson, Stephen W [ORNL; Kuehn, Jeffery A [ORNL; Poole, Stephen W [ORNL

    2011-04-01

    Variability in network performance is a major obstacle in effectively analyzing the throughput of modern high performance computer systems. High performance interconnec- tion networks offer excellent best-case network latencies; how- ever, highly parallel applications running on parallel machines typically require consistently high levels of performance to adequately leverage the massive amounts of available computing power. Performance analysts have usually quantified network performance using traditional summary statistics that assume the observational data is sampled from a normal distribution. In our examinations of network performance, we have found this method of analysis often provides too little data to under- stand anomalous network performance. Our tool, Confidence, instead uses an empirically derived probability distribution to characterize network performance. In this paper we describe several instances where the Confidence toolkit allowed us to understand and diagnose network performance anomalies that we could not adequately explore with the simple summary statis- tics provided by traditional measurement tools. In particular, we examine a multi-modal performance scenario encountered with an Infiniband interconnection network and we explore the performance repeatability on the custom Cray SeaStar2 interconnection network after a set of software and driver updates.

  20. The relationship between confidence in charitable organizations and volunteering revisited

    NARCIS (Netherlands)

    Bekkers, René H.F.P.; Bowman, Woods

    2009-01-01

    Confidence in charitable organizations (charitable confidence) would seem to be an important prerequisite for philanthropic behavior. Previous research relying on cross-sectional data has suggested that volunteering promotes charitable confidence and vice versa. This research note, using new

  1. Social phobia and depression: prevalence and comorbidity.

    Science.gov (United States)

    Ohayon, Maurice M; Schatzberg, Alan F

    2010-03-01

    Social phobia may seriously impair the functioning of affected individuals. It is frequently associated with other mental disorders. To estimate the co-occurrence of social phobia with major depressive disorder (MDD) and to analyze their interaction. Subjects were 18,980 individuals, aged 15 years or older, representative of the general population of the United Kingdom, Germany, Italy, Spain and Portugal, who were interviewed by telephone. DSM-IV diagnoses were made with the Sleep-EVAL system. The point prevalence for social phobia was 4.4% (95% confidence interval: 4.1-4.7%) of the sample. It was higher in women (odds ratio: 1.6) and decreased with age. MDDs were found in 19.5% of participants with social phobia. Co-occurrence of another anxiety disorder was high and increased when a MDD was present (65.2%). The odds of developing a major depressive episode 2 years after the appearance of the social phobia was of 5.74. Social phobia is highly prevalent in the general population. It increases the risk of developing a MDD and has a high comorbidity with other mental disorders. Social phobia is often present in the course of depression, more obviously during remission period of MDD. Physicians must explore and treat more systematically this frequent pathology. Copyright 2010 Elsevier Inc. All rights reserved.

  2. Smoking prevalence among monks in Thailand.

    Science.gov (United States)

    Kungskulniti, Nipapun; Charoenca, Naowarut; Kengganpanich, Tharadol; Kusolwisitkul, Wilai; Pichainarong, Natchaporn; Kerdmongkol, Patcharaporn; Silapasuwan, Phimpan; Hamann, Stephen L; Arpawong, Thalida Em

    2012-09-01

    Previous studies among Buddhist monks in Thailand have reported smoking rates to be as high as 55%. Because 95% of Thais are Buddhist, monks are highly influential in establishing normative behavioral patterns. As the first population-based study on smoking among Buddhist monks in Thailand, this study aims to determine the smoking prevalence in six regions of the country, and to examine smoking knowledge, risk perceptions, behaviors, and associated demographics among full-fledged and novice monks (n = 6,213). Results demonstrated that the overall prevalence for current smoking monks is 24.4% (95% confidence interval [24.453, 24.464]), with regional differences ranging from 14.6% (North) to 40.5% (East). Findings suggest that integrating prevention and cessation programming into religious courses may be one avenue for reaching many incoming monks. Further, involving monks in tobacco control education and setting a nonsmoking standard among them is vital to the success of reducing smoking rates among the general population in Thailand.

  3. Experimental uncertainty estimation and statistics for data having interval uncertainty.

    Energy Technology Data Exchange (ETDEWEB)

    Kreinovich, Vladik (Applied Biomathematics, Setauket, New York); Oberkampf, William Louis (Applied Biomathematics, Setauket, New York); Ginzburg, Lev (Applied Biomathematics, Setauket, New York); Ferson, Scott (Applied Biomathematics, Setauket, New York); Hajagos, Janos (Applied Biomathematics, Setauket, New York)

    2007-05-01

    This report addresses the characterization of measurements that include epistemic uncertainties in the form of intervals. It reviews the application of basic descriptive statistics to data sets which contain intervals rather than exclusively point estimates. It describes algorithms to compute various means, the median and other percentiles, variance, interquartile range, moments, confidence limits, and other important statistics and summarizes the computability of these statistics as a function of sample size and characteristics of the intervals in the data (degree of overlap, size and regularity of widths, etc.). It also reviews the prospects for analyzing such data sets with the methods of inferential statistics such as outlier detection and regressions. The report explores the tradeoff between measurement precision and sample size in statistical results that are sensitive to both. It also argues that an approach based on interval statistics could be a reasonable alternative to current standard methods for evaluating, expressing and propagating measurement uncertainties.

  4. Rural-urban disparities in the prevalence of diabetes and coronary heart disease.

    Science.gov (United States)

    O'Connor, A; Wellenius, G

    2012-10-01

    To examine the rural-urban differences in the prevalence of diabetes and coronary heart disease, and the extent to which they are explained by the presence of established risk factors including poverty. Cross-sectional study of more than 214,000 respondents using data from the US Centers for Disease Control and Prevention's (CDC's) 2008 Behavioral Risk Factor Surveillance System. Logistic regression models were utilized; prevalence odds ratios with corresponding confidence intervals and P-values are provided. The crude prevalence rates of diabetes and coronary heart disease were 8.6% (P = 0.001) and 38.8% (P rural areas compared with urban areas, respectively. The higher prevalence in rural areas of many of the common risk factors for these conditions, including poverty (P rural areas [prevalence odds ratio (POR) = 0.94, P = 0.032], but the prevalence of coronary heart disease was higher (POR = 1.09, P = 0.011). The higher prevalence of diabetes and coronary heart disease in rural populations in the USA presents a formidable public health challenge. It exacerbates many of the pre-existing rural health disparities, including a lack of access to financial resources and primary care providers. Copyright © 2012 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  5. Estimated prevalence of dengue viremia in Puerto Rican blood donations, 1995 through 2010.

    Science.gov (United States)

    Petersen, Lyle R; Tomashek, Kay M; Biggerstaff, Brad J

    2012-08-01

    Dengue virus (DENV) nucleic acid amplification testing of blood donations during epidemics in endemic locations, including Puerto Rico, has suggested possible sizable transfusion transmission risk. Estimates of the long-term prevalence of DENV viremic donations will help evaluate the potential magnitude of this risk in Puerto Rico. Estimates of the prevalence of DENV viremia in the Puerto Rican population at large from 1995 through 2010 were derived from dengue case reports and their onset dates obtained from islandwide surveillance, estimates of case underreporting, and extant data on the duration of DENV viremia and the unapparent-to-apparent dengue infection ratio. Under the assumptions that viremia prevalence in blood donors was similar to that of the population at large and that symptomatic persons do not donate, statistical resampling methods were used to estimate the prevalence of dengue viremia in blood donations. Over the 16-year period, the maximum and mean daily prevalences of dengue viremia (per 10,000) in blood donations in Puerto Rico were estimated at 45.0 (95% confidence interval [CI], 36.5-55.4) and 7.0 (95% CI, 3.9-10.1), respectively. Prevalence varied considerably by season and year. These data suggest a substantial prevalence of DENV viremia in Puerto Rican blood donations, particularly during outbreaks. © 2012 American Association of Blood Banks.

  6. Prevalence of Genital Tuberculosis among Infertile Women: A Systematic Review and Meta-analysis

    Directory of Open Access Journals (Sweden)

    Kefayat Chaman-Ara

    2016-04-01

    Full Text Available Genital tuberculosis is a kind of infectious diseases with a relatively high prevalence in developing countries. The aim of this study was to investigate the prevalence of genital tuberculosis among infertile women. A PubMed, Science Direct, Scopus, Google Scholar, SID, Magiran and Cochrane databases (from 1980 to the present, date of last search March 2016 was carried out using the search keywords tuberculosis, genital tuberculosis, female genital, genital tract, genital system, female infertility, endometrial tuberculosis, anti-tubercular therapy, bacteriological, tuberculin antigen, histological, infertility, fallopian tube diseases, prevalence, rate, percent in order to find the studies which have reported the prevalence of genital tuberculosis among infertile women. Data were extracted from retrieved studies and a meta-analysis was done. 23 studies were found. In these studies a total of 4361 infertile women have been studied. The prevalence of genital tuberculosis among infertile women with 95% confidence interval was 24.2% (18.5-29.99. The prevalence of genital tuberculosis among infertile women is high. It seems that exact planning and action for the prevention and treatment of genital tuberculosis can reduce the infertility prevalence and prevent the negative consequences of infertility

  7. Prevalence and change of central obesity among US Asian adults: NHANES 2011-2014.

    Science.gov (United States)

    Liu, Xuefeng; Chen, Yang; Boucher, Nicole L; Rothberg, Amy E

    2017-08-25

    Central obesity is a major risk factor for cardiometabolic diseases. The prevalence of central obesity has not been reported fully among Asian adults in the United States (US). Cross-sectional data of 1288 Asian adults aged 20 years or over was selected from the US National Health and Nutrition Examination Survey with a stratified multi-stage sampling design. The prevalence of central obesity was calculated with 95% confidence intervals (CIs) and Chi-square tests were conducted to test the significance of the prevalence differences across characteristic groups. The overall prevalence of central obesity among US Asian adults was 58.1% in 2011-2014. The prevalence of central obesity was higher in older adults (73.5%) than in young adults (45.4%) (p young adults (39.2% vs 51.5%), men (45.4% vs 56.6%), adults with college education or above (54.2% vs 61.7%) and non-poor adults (55.4% vs 62.4%). Compared with men, women had higher prevalence in each subgroup of age, education, poverty, and length of time (except for the subgroup of "born in the US") (all p obesity is prevalent in Asian adults, particularly in older adults and women. More efforts are needed to prevent and treat obesity in Asian adults as Asians are incurring the greatest increase in type 2 diabetes in parallel with the rising rate of central adiposity.

  8. [Prevalence of metabolic syndrome in Mapuche individuals living in urban and rural environment in Chile].

    Science.gov (United States)

    Ibáñez, Luis; Sanzana, Ruth; Salas, Carlos; Navarrete, Claudia; Cartes-Velásquez, Ricardo; Rainqueo, Angélica; Jara, Tamara; Pérez-Bravo, Francisco; Ulloa, Natalia; Calvo, Carlos; Miquel, Juan F; Celis-Morales, Carlos

    2014-08-01

    Metabolic Syndrome (MS) increases the risk of diabetes and mortality associated with cardiovascular disease. However, the prevalence of MS could differ by ethnicity and lifestyle factors. To determine the prevalence of MS in Mapuche individuals living in urban and rural environments in Chile and to investigate whether the prevalence and risk of MS in urban and rural environments differs by sex, age and nutritional status. A total of 1077 Mapuche participants were recruited from urban (MU = 288) and rural (MR = 789) settings. Body mass index, waist circumference and blood pressure were measured. A fasting blood sample was obtained to measure serum glucose, HDL cholesterol and triacylglycerol. The prevalence of MS was determined using the unified IDF and ATP-III criteria. An environment and sex interaction was found for the prevalence of MS (p = 0.042). The prevalence was significantly lower in male MR (13%) compared to other groups (22, 23 and 25% among female MR, female MU and male MU respectively). Also, the prevalence of central obesity and low HDL-cholesterol were significantly lower in male MR. MU are at an increased risk of developing MS compared to MR, with an odds ratio of 1.59 (95% confidence intervals 1.1 to 2.2). This risk increases along with age or body mass index of the population. The adoption of an urbanized lifestyle increases the risk of developing MS in Mapuche individuals. This risk is enhanced by age and nutritional status.

  9. Relationships between dietary habits and the prevalence of fatigue in medical students.

    Science.gov (United States)

    Tanaka, Masaaki; Mizuno, Kei; Fukuda, Sanae; Shigihara, Yoshihito; Watanabe, Yasuyoshi

    2008-10-01

    Fatigue, which is a common complaint among medical students, is related to poor academic outcomes. Because impaired dietary habits, such as skipping breakfast and taking meals irregularly, are correlated with poor school performances, whether those dietary habits were associated with the prevalence of fatigue was determined in medical students. The study group consisted of 127 healthy second-year medical students attending Osaka City University Graduate School of Medicine. They completed a questionnaire dealing with fatigue (Japanese version of the Chalder Fatigue Scale), lifestyle, and academic performance. On multivariate logistic regression analyses adjusted for age, gender, body mass index, and nocturnal sleeping hours, skipping breakfast (completely skipping breakfast everyday versus having breakfast everyday; odds ratio 7.81, 95% confidence interval 2.00-30.52, P = 0.003) and taking meals irregularly (completely irregular versus always regular; odds ratio 6.89, 95% confidence interval 1.20-39.55, P = 0.030) were positively correlated with the prevalence of fatigue. Skipping breakfast and taking meals irregularly are associated with the prevalence of fatigue in medical students.

  10. Comparing interval estimates for small sample ordinal CFA models.

    Science.gov (United States)

    Natesan, Prathiba

    2015-01-01

    Robust maximum likelihood (RML) and asymptotically generalized least squares (AGLS) methods have been recommended for fitting ordinal structural equation models. Studies show that some of these methods underestimate standard errors. However, these studies have not investigated the coverage and bias of interval estimates. An estimate with a reasonable standard error could still be severely biased. This can only be known by systematically investigating the interval estimates. The present study compares Bayesian, RML, and AGLS interval estimates of factor correlations in ordinal confirmatory factor analysis models (CFA) for small sample data. Six sample sizes, 3 factor correlations, and 2 factor score distributions (multivariate normal and multivariate mildly skewed) were studied. Two Bayesian prior specifications, informative and relatively less informative were studied. Undercoverage of confidence intervals and underestimation of standard errors was common in non-Bayesian methods. Underestimated standard errors may lead to inflated Type-I error rates. Non-Bayesian intervals were more positive biased than negatively biased, that is, most intervals that did not contain the true value were greater than the true value. Some non-Bayesian methods had non-converging and inadmissible solutions for small samples and non-normal data. Bayesian empirical standard error estimates for informative and relatively less informative priors were closer to the average standard errors of the estimates. The coverage of Bayesian credibility intervals was closer to what was expected with overcoverage in a few cases. Although some Bayesian credibility intervals were wider, they reflected the nature of statistical uncertainty that comes with the data (e.g., small sample). Bayesian point estimates were also more accurate than non-Bayesian estimates. The results illustrate the importance of analyzing coverage and bias of interval estimates, and how ignoring interval estimates can be misleading

  11. Prevalence and incidence of epilepsy: A systematic review and meta-analysis of international studies.

    Science.gov (United States)

    Fiest, Kirsten M; Sauro, Khara M; Wiebe, Samuel; Patten, Scott B; Kwon, Churl-Su; Dykeman, Jonathan; Pringsheim, Tamara; Lorenzetti, Diane L; Jetté, Nathalie

    2017-01-17

    To review population-based studies of the prevalence and incidence of epilepsy worldwide and use meta-analytic techniques to explore factors that may explain heterogeneity between estimates. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed. We searched MEDLINE and EMBASE for articles published on the prevalence or incidence of epilepsy since 1985. Abstract, full-text review, and data abstraction were conducted in duplicate. Meta-analyses and meta-regressions were used to explore the association between prevalence or incidence, age group, sex, country level income, and study quality. A total of 222 studies were included (197 on prevalence, 48 on incidence). The point prevalence of active epilepsy was 6.38 per 1,000 persons (95% confidence interval [95% CI] 5.57-7.30), while the lifetime prevalence was 7.60 per 1,000 persons (95% CI 6.17-9.38). The annual cumulative incidence of epilepsy was 67.77 per 100,000 persons (95% CI 56.69-81.03) while the incidence rate was 61.44 per 100,000 person-years (95% CI 50.75-74.38). The prevalence of epilepsy did not differ by age group, sex, or study quality. The active annual period prevalence, lifetime prevalence, and incidence rate of epilepsy were higher in low to middle income countries. Epilepsies of unknown etiology and those with generalized seizures had the highest prevalence. This study provides a comprehensive synthesis of the prevalence and incidence of epilepsy from published international studies and offers insight into factors that contribute to heterogeneity between estimates. Significant gaps (e.g., lack of incidence studies, stratification by age groups) were identified. Standardized reporting of future epidemiologic studies of epilepsy is needed. © 2016 American Academy of Neurology.

  12. Poverty and prevalence of antimicrobial resistance in invasive isolates.

    Science.gov (United States)

    Alvarez-Uria, Gerardo; Gandra, Sumanth; Laxminarayan, Ramanan

    2016-11-01

    To evaluate the association between the income status of a country and the prevalence of antimicrobial resistance (AMR) in the three most common bacteria causing infections in hospitals and in the community: third-generation cephalosporin (3GC)-resistant Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), and 3GC-resistant Klebsiella species. Using 2013-2014 country-specific data from the ResistanceMap repository and the World Bank, the association between the prevalence of AMR in invasive samples and the gross national income (GNI) per capita was investigated through linear regression with robust standard errors. To account for non-linear association with the dependent variable, GNI per capita was log-transformed. The models predicted an 11.3% (95% confidence interval (CI) 6.5-16.2%), 18.2% (95% CI 11-25.5%), and 12.3% (95% CI 5.5-19.1%) decrease in the prevalence of 3GC-resistant E. coli, 3GC-resistant Klebsiella species, and MRSA, respectively, for each log GNI per capita. The association was stronger for 3GC-resistant E. coli and Klebsiella species than for MRSA. A significant negative association between GNI per capita and the prevalence of MRSA and 3GC-resistant E. coli and Klebsiella species was found. These results underscore the urgent need for new policies aimed at reducing AMR in resource-poor settings. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. The prevalence of posttraumatic stress among women requesting induced abortion.

    Science.gov (United States)

    Wallin Lundell, Inger; Sundström Poromaa, Inger; Frans, Orjan; Helström, Lotti; Högberg, Ulf; Moby, Lena; Nyberg, Sigrid; Sydsjö, Gunilla; Georgsson Öhman, Susanne; Östlund, Ingrid; Skoog Svanberg, Agneta

    2013-12-01

    To describe the prevalence and pattern of traumatic experiences, to assess the prevalence of posttraumatic stress disorder (PTSD) and posttraumatic stress symptoms (PTSS), to identify risk factors for PTSD and PTSS, and to analyse the association of PTSD and PTSS with concomitant anxiety and depressive symptoms in women requesting induced abortion. A Swedish multi-centre study of women requesting an induced abortion. The Screen Questionnaire - Posttraumatic Stress Disorder was used for research diagnoses of PTSD and PTSS. Anxiety and depressive symptoms were evaluated by the Hospital Anxiety and Depression Scale (HADS). Of the 1514 respondents, almost half reported traumatic experiences. Lifetime- and point prevalence of PTSD were 7% (95% confidence interval [CI]: 5.8-8.5) and 4% (95% CI: 3.1-5.2), respectively. The prevalence of PTSS was 23% (95% CI: 21.1-25.4). Women who reported symptoms of anxiety or depression when requesting abortion were more likely to have ongoing PTSD or PTSS. Also single-living women and smokers displayed higher rates of ongoing PTSD. Although PTSD is rare among women who request an induced abortion, a relatively high proportion suffers from PTSS. Abortion seeking women with trauma experiences and existing or preexisting mental disorders need more consideration and alertness when counselled for termination.

  14. Confidence crisis of results in biomechanics research.

    Science.gov (United States)

    Knudson, Duane

    2017-11-01

    Many biomechanics studies have small sample sizes and incorrect statistical analyses, so reporting of inaccurate inferences and inflated magnitude of effects are common in the field. This review examines these issues in biomechanics research and summarises potential solutions from research in other fields to increase the confidence in the experimental effects reported in biomechanics. Authors, reviewers and editors of biomechanics research reports are encouraged to improve sample sizes and the resulting statistical power, improve reporting transparency, improve the rigour of statistical analyses used, and increase the acceptance of replication studies to improve the validity of inferences from data in biomechanics research. The application of sports biomechanics research results would also improve if a larger percentage of unbiased effects and their uncertainty were reported in the literature.

  15. Technology in a crisis of confidence

    Energy Technology Data Exchange (ETDEWEB)

    Damodaran, G R

    1979-04-01

    The power that technological progress has given to engineers is examined to see if there has been a corresponding growth in human happiness. A credit/debit approach is discussed, whereby technological advancement is measured against the criteria of social good. The credit side includes medicine, agriculture, and energy use, while the debit side lists pollution, unequal distribution of technology and welfare, modern weaponry, resource depletion, and a possible decline in the quality of life. The present anti-technologists claim the debit side is now predominant, but the author challenges this position by examining the role of technology and the engineer in the society. He sees a need for renewed self-confidence and a sense of direction among engineers, but is generally optimistic that technology and civilization will continue to be intertwined. (DCK)

  16. Considering public confidence in developing regulatory programs

    International Nuclear Information System (INIS)

    Collins, S.J.

    2001-01-01

    In the area of public trust and in any investment, planning and strategy are important. While it is accepted in the United States that an essential part of our mission is to leverage our resources to improving Public Confidence this performance goal must be planned for, managed and measured. Similar to our premier performance goal of Maintaining Safety, a strategy must be developed and integrated with our external stake holders but with internal regulatory staff as well. In order to do that, business is to be conducted in an open environment, the basis for regulatory decisions has to be available through public documents and public meetings, communication must be done in clear and consistent terms. (N.C.)

  17. Prevalence and reasons for initiating use of electronic cigarettes among adults in Montana, 2013.

    Science.gov (United States)

    Schmidt, Lisa; Reidmohr, Alison; Harwell, Todd S; Helgerson, Steven D

    2014-11-20

    We used data from the 2013 Montana Adult Tobacco Survey to estimate the prevalence of electronic cigarette (e-cigarette) use and reasons for initiation among Montana adults. More than 1 in 10 (11.2%, 95% confidence interval [CI], 9.1%-13.2%) adults reported ever using e-cigarettes, and 1.3% (95% CI, 0.7%-1.9%) reported current use. Most respondents reported "trying something new" (64%) or "trying to quit or reduce cigarette use" (56%) as a reason for initiating use. Ongoing surveillance of these addictive products is needed.

  18. Chinese Management Research Needs Self-Confidence but not Over-confidence

    DEFF Research Database (Denmark)

    Li, Xin; Ma, Li

    2018-01-01

    Chinese management research aims to contribute to global management knowledge by offering rigorous and innovative theories and practical recommendations both for managing in China and outside. However, two seemingly opposite directions that researchers are taking could prove detrimental......-confidence, limiting theoretical innovation and practical relevance. Yet going in the other direction of overly indigenous research reflects over-confidence, often isolating the Chinese management research from the mainstream academia and at times, even becoming anti-science. A more integrated approach of conducting...... to the healthy development of Chinese management research. We argue that the two directions share a common ground that lies in the mindset regarding the confidence in the work on and from China. One direction of simply following the American mainstream on academic rigor demonstrates a lack of self...

  19. Haemostatic reference intervals in pregnancy

    DEFF Research Database (Denmark)

    Szecsi, Pal Bela; Jørgensen, Maja; Klajnbard, Anna

    2010-01-01

    largely unchanged during pregnancy, delivery, and postpartum and were within non-pregnant reference intervals. However, levels of fibrinogen, D-dimer, and coagulation factors VII, VIII, and IX increased markedly. Protein S activity decreased substantially, while free protein S decreased slightly and total......Haemostatic reference intervals are generally based on samples from non-pregnant women. Thus, they may not be relevant to pregnant women, a problem that may hinder accurate diagnosis and treatment of haemostatic disorders during pregnancy. In this study, we establish gestational age......-20, 21-28, 29-34, 35-42, at active labor, and on postpartum days 1 and 2. Reference intervals for each gestational period using only the uncomplicated pregnancies were calculated in all 391 women for activated partial thromboplastin time (aPTT), fibrinogen, fibrin D-dimer, antithrombin, free protein S...

  20. Inverse Interval Matrix: A Survey

    Czech Academy of Sciences Publication Activity Database

    Rohn, Jiří; Farhadsefat, R.

    2011-01-01

    Roč. 22, - (2011), s. 704-719 E-ISSN 1081-3810 R&D Projects: GA ČR GA201/09/1957; GA ČR GC201/08/J020 Institutional research plan: CEZ:AV0Z10300504 Keywords : interval matrix * inverse interval matrix * NP-hardness * enclosure * unit midpoint * inverse sign stability * nonnegative invertibility * absolute value equation * algorithm Subject RIV: BA - General Mathematics Impact factor: 0.808, year: 2010 http://www.math.technion.ac.il/iic/ ela / ela -articles/articles/vol22_pp704-719.pdf

  1. A new model for cork weight estimation in Northern Portugal with methodology for construction of confidence intervals

    Science.gov (United States)

    Teresa J.F. Fonseca; Bernard R. Parresol

    2001-01-01

    Cork, a unique biological material, is a highly valued non-timber forest product. Portugal is the leading producer of cork with 52 percent of the world production. Tree cork weight models have been developed for Southern Portugal, but there are no representative published models for Northern Portugal. Because cork trees may have a different form between Northern and...

  2. A Validation Study of the Rank-Preserving Structural Failure Time Model: Confidence Intervals and Unique, Multiple, and Erroneous Solutions.

    Science.gov (United States)

    Ouwens, Mario; Hauch, Ole; Franzén, Stefan

    2018-05-01

    The rank-preserving structural failure time model (RPSFTM) is used for health technology assessment submissions to adjust for switching patients from reference to investigational treatment in cancer trials. It uses counterfactual survival (survival when only reference treatment would have been used) and assumes that, at randomization, the counterfactual survival distribution for the investigational and reference arms is identical. Previous validation reports have assumed that patients in the investigational treatment arm stay on therapy throughout the study period. To evaluate the validity of the RPSFTM at various levels of crossover in situations in which patients are taken off the investigational drug in the investigational arm. The RPSFTM was applied to simulated datasets differing in percentage of patients switching, time of switching, underlying acceleration factor, and number of patients, using exponential distributions for the time on investigational and reference treatment. There were multiple scenarios in which two solutions were found: one corresponding to identical counterfactual distributions, and the other to two different crossing counterfactual distributions. The same was found for the hazard ratio (HR). Unique solutions were observed only when switching patients were on investigational treatment for <40% of the time that patients in the investigational arm were on treatment. Distributions other than exponential could have been used for time on treatment. An HR equal to 1 is a necessary but not always sufficient condition to indicate acceleration factors associated with equal counterfactual survival. Further assessment to distinguish crossing counterfactual curves from equal counterfactual curves is especially needed when the time that switchers stay on investigational treatment is relatively long compared to the time direct starters stay on investigational treatment.

  3. Robust Coefficients Alpha and Omega and Confidence Intervals with Outlying Observations and Missing Data: Methods and Software

    Science.gov (United States)

    Zhang, Zhiyong; Yuan, Ke-Hai

    2016-01-01

    Cronbach's coefficient alpha is a widely used reliability measure in social, behavioral, and education sciences. It is reported in nearly every study that involves measuring a construct through multiple items. With non-tau-equivalent items, McDonald's omega has been used as a popular alternative to alpha in the literature. Traditional estimation…

  4. Robust Coefficients Alpha and Omega and Confidence Intervals with Outlying Observations and Missing Data Methods and Software

    Science.gov (United States)

    Zhang, Zhiyong; Yuan, Ke-Hai

    2016-01-01

    Cronbach's coefficient alpha is a widely used reliability measure in social, behavioral, and education sciences. It is reported in nearly every study that involves measuring a construct through multiple items. With non-tau-equivalent items, McDonald's omega has been used as a popular alternative to alpha in the literature. Traditional estimation…

  5. Meta-analysis to refine map position and reduce confidence intervals for delayed canopy wilting QTLs in soybean

    Science.gov (United States)

    Slow canopy wilting in soybean has been identified as a potentially beneficial trait for ameliorating drought effects on yield. Previous research identified QTLs for slow wilting from two different bi-parental populations and this information was combined with data from three other populations to id...

  6. Noise annoyance from stationary sources: Relationships with exposure metric day-evening-night level (DENL) and their confidence intervals

    NARCIS (Netherlands)

    Miedema, H.M.E.; Vos, H.

    2004-01-01

    Relationships between exposure to noise [metric: day-evening-night levels (DENL)] from stationary sources (shunting yards, a seasonal industry, and other industries) and annoyance are presented. Curves are presented for expected annoyance score, the percentage "highly annoyed" (%HA, cutoff at 72 on

  7. Derivation of confidence intervals of service measures in a base-stock inventory control system with low-frequent demand

    DEFF Research Database (Denmark)

    Larsen, Christian

    We explore a base-stock system with backlogging where the demand process is a compound renewal process and the compound element is a delayed geometric distribution. For this setting it is proven in [4] that the long-run average service measures order fill rate (OFR) and volume fill rate (VFR) are...

  8. Derivation of confidence intervals of service measures in a base-stock inventory control system with low-frequent demand

    DEFF Research Database (Denmark)

    Larsen, Christian

    2011-01-01

    We explore a base-stock system with backlogging where the demand process is a compound renewal process and the compound element is a delayed geometric distribution. For this setting it holds that the long-run average service measures order fill rate (OFR) and volume fill rate (VFR) are equal in v...

  9. ERICA: prevalence of asthma in Brazilian adolescents

    Directory of Open Access Journals (Sweden)

    Fábio Chigres Kuschnir

    2016-02-01

    Full Text Available ABSTRACT OBJECTIVE To describe the prevalence of asthma and physician-diagnosed asthma in Brazilian adolescents. METHODS Cross-sectional, national, school-based study with adolescents from 12 to 17 years old, participants in the Study of Cardiovascular Risks in Adolescents (ERICA. The study stratified the sample by region and grouped according to schools and classes with representativeness to the set of cities with more than 100,000 inhabitants of the Country, macro-regions, capitals, and Federal District. A questionnaire collected data through a self-filled in method. We calculated the prevalences and their confidence intervals of 95% (95%CI according to sex, age group, type of school and skin color. RESULTS Between 2013 and 2014, 74,589 adolescents were evaluated, 55.3% of the female sex. The total prevalence of active asthma was of 13.1% (95%CI 12.1-13.9, being higher in girls (14.8%; 95%CI 13.7-16.0 when compared to boys (11.2%; 95%CI 10.3-12.2 in all geographical strata examined. It was also higher between students of private schools (15.9%; 95%CI 14.2-17.7 when compared to public ones (12.4%; 95%CI 11.4-13.4. It was higher in the Southeast region (14.5%; 95%CI 12.9-16.1, and in the city of Sao Paulo (16.7%; 95%CI 14.7-18.7. The lowest prevalence was observed in North region (9.7%; 95%CI 9.7-10.5, and in Teresina (6.3%; 95%CI 4.9-7.7. The prevalence of physician-diagnosed asthma was of 8.7% (95%CI 8.2-9.1; higher in the North region (13.5%; 95%CI 12.7-14.2, and in Porto Alegre (19.8%; 95%CI 17.5-22.3. It was lower in the Midwest (6.9%; 95%CI 6.0-7.8, and in Cuiaba (4.8%; 95%CI 3.8-5.9. We found no significant difference in the expression of this rate between the sexes, as well as in other variables evaluated by the study. CONCLUSIONS The prevalence of asthma in Brazilian adolescents is high. Rates of active asthma and physician-diagnosed asthma vary widely in different regions and capitals evaluated by the ERICA. These results may assist in

  10. ERICA: prevalence of asthma in Brazilian adolescents

    Science.gov (United States)

    Kuschnir, Fábio Chigres; Gurgel, Ricardo Queiroz; Solé, Dirceu; Costa, Eduardo; Felix, Mara Morelo Rocha; de Oliveira, Cecília Lacroix; de Vasconcellos, Maurício Teixeira Leite; Kuschnir, Maria Cristina Caetano

    2016-01-01

    ABSTRACT OBJECTIVE To describe the prevalence of asthma and physician-diagnosed asthma in Brazilian adolescents. METHODS Cross-sectional, national, school-based study with adolescents from 12 to 17 years old, participants in the Study of Cardiovascular Risks in Adolescents (ERICA). The study stratified the sample by region and grouped according to schools and classes with representativeness to the set of cities with more than 100,000 inhabitants of the Country, macro-regions, capitals, and Federal District. A questionnaire collected data through a self-filled in method. We calculated the prevalences and their confidence intervals of 95% (95%CI) according to sex, age group, type of school and skin color. RESULTS Between 2013 and 2014, 74,589 adolescents were evaluated, 55.3% of the female sex. The total prevalence of active asthma was of 13.1% (95%CI 12.1-13.9), being higher in girls (14.8%; 95%CI 13.7-16.0) when compared to boys (11.2%; 95%CI 10.3-12.2) in all geographical strata examined. It was also higher between students of private schools (15.9%; 95%CI 14.2-17.7) when compared to public ones (12.4%; 95%CI 11.4-13.4). It was higher in the Southeast region (14.5%; 95%CI 12.9-16.1), and in the city of Sao Paulo (16.7%; 95%CI 14.7-18.7). The lowest prevalence was observed in North region (9.7%; 95%CI 9.7-10.5), and in Teresina (6.3%; 95%CI 4.9-7.7). The prevalence of physician-diagnosed asthma was of 8.7% (95%CI 8.2-9.1); higher in the North region (13.5%; 95%CI 12.7-14.2), and in Porto Alegre (19.8%; 95%CI 17.5-22.3). It was lower in the Midwest (6.9%; 95%CI 6.0-7.8), and in Cuiaba (4.8%; 95%CI 3.8-5.9). We found no significant difference in the expression of this rate between the sexes, as well as in other variables evaluated by the study. CONCLUSIONS The prevalence of asthma in Brazilian adolescents is high. Rates of active asthma and physician-diagnosed asthma vary widely in different regions and capitals evaluated by the ERICA. These results may assist in the

  11. Prevalence of Depression and Anxiety in Medical and Surgical Inpatients: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Siamak Molavi

    2007-12-01

    Full Text Available "nObjective: The objective of the present study was to perform a systematic review of studies that investigated the prevalence of anxiety and depression in medical inpatients. "nMethod: A search was conducted in Pubmed Medline, ISI Web of Science, PsychINFO, CINAHL, EMBASE, Irandoc, IranPsych, IranMedex, and dissertations. In the next step, the original studies which reported the prevalence of anxiety and/or depression in medical inpatients were included and then evaluated. These evaluations included two parts. The first part was the qualitative evaluation of the articles, which was carried out using a checklist. The second part was data extraction, performed with two researchers for each document. "nResults: Thirty nine studies (13 articles and 26 dissertations were finally included. Only in seven studies, diagnostic interview was used to diagnose patients with anxiety and depression. Results of the qualitative evaluation of articles showed that a high percentage of them lacked the appropriate methodology. The maximum and minimum prevalence of depression in the reviewed studies was 91.7% and 17% respectively. The maximum and minimum prevalence of anxiety in the reviewed articles was 78.33% and 6% respectively. The prevalence of depression and anxiety in all studies which had reported prevalence according to sex was higher in females. Meta-analysis with Random effect model indicates the heterogeneity of studies, so we just perform meta- analysis in two groups of patients, chronic renal failure patients and patients with ischemic heart disease. The combined estimation of the prevalence of depression and anxiety in patients with chronic renal failure according to this meta-analysis was 55.91 (confidence interval=37.14-74.69 and 46.72 (confidence interval=20.31-73.13 respectively. The combined estimation of the prevalence of depression and anxiety in patients with ischemic heart disease was 52.54 (confidence interval=42.82-62.26 and 30

  12. National HIV prevalence estimates for sub-Saharan Africa: controlling selection bias with Heckman-type selection models

    Science.gov (United States)

    Hogan, Daniel R; Salomon, Joshua A; Canning, David; Hammitt, James K; Zaslavsky, Alan M; Bärnighausen, Till

    2012-01-01

    Objectives Population-based HIV testing surveys have become central to deriving estimates of national HIV prevalence in sub-Saharan Africa. However, limited participation in these surveys can lead to selection bias. We control for selection bias in national HIV prevalence estimates using a novel approach, which unlike conventional imputation can account for selection on unobserved factors. Methods For 12 Demographic and Health Surveys conducted from 2001 to 2009 (N=138 300), we predict HIV status among those missing a valid HIV test with Heckman-type selection models, which allow for correlation between infection status and participation in survey HIV testing. We compare these estimates with conventional ones and introduce a simulation procedure that incorporates regression model parameter uncertainty into confidence intervals. Results Selection model point estimates of national HIV prevalence were greater than unadjusted estimates for 10 of 12 surveys for men and 11 of 12 surveys for women, and were also greater than the majority of estimates obtained from conventional imputation, with significantly higher HIV prevalence estimates for men in Cote d'Ivoire 2005, Mali 2006 and Zambia 2007. Accounting for selective non-participation yielded 95% confidence intervals around HIV prevalence estimates that are wider than those obtained with conventional imputation by an average factor of 4.5. Conclusions Our analysis indicates that national HIV prevalence estimates for many countries in sub-Saharan African are more uncertain than previously thought, and may be underestimated in several cases, underscoring the need for increasing participation in HIV surveys. Heckman-type selection models should be included in the set of tools used for routine estimation of HIV prevalence. PMID:23172342

  13. The theory of confidence-building measures

    International Nuclear Information System (INIS)

    Darilek, R.E.

    1992-01-01

    This paper discusses the theory of Confidence-Building Measures (CBMs) in two ways. First, it employs a top-down, deductively oriented approach to explain CBM theory in terms of the arms control goals and objectives to be achieved, the types of measures to be employed, and the problems or limitations likely to be encountered when applying CBMs to conventional or nuclear forces. The chapter as a whole asks how various types of CBMs might function during a political - military escalation from peacetime to a crisis and beyond (i.e. including conflict), as well as how they might operate in a de-escalatory environment. In pursuit of these overarching issues, the second section of the chapter raises a fundamental but complicating question: how might the next all-out war actually come aoubt - by unpremeditated escalation resulting from misunderstanding or miscalculation, or by premeditation resulting in a surprise attack? The second section of the paper addresses this question, explores its various implications for CBMs, and suggests the potential contribution of different types of CBMs toward successful resolution of the issues involved

  14. Trust versus confidence: Microprocessors and personnel monitoring

    International Nuclear Information System (INIS)

    Chiaro, P.J. Jr.

    1993-01-01

    Due to recent technological advances, substantial improvements have been made in personnel contamination monitoring. In all likelihood, these advances will close out the days of manually frisking personnel for radioactive contamination. Unfortunately, as microprocessor-based monitors become more widely used, not only at commercial power reactors but also at government facilities, questions concerning their trustworthiness arise. Algorithms make decisions that were previously made by technicians. Trust is placed not in technicians but in machines. In doing this it is assumed that the machine never misses. Inevitably, this trust drops, due largely to open-quotes false alarms.close quotes This is especially true when monitoring for alpha contamination. What is a open-quotes false alarm?close quotes Do these machines and their algorithms that we put our trust in make mistakes? An analysis was performed on half-body and hand-and-foot monitors at Oak Ridge National Laboratory (ORNL) in order to justify the suggested confidence level used for alarm point determination. Sources used in this analysis had activities approximating ORNL's contamination limits

  15. Trust versus confidence: Microprocessors and personnel monitoring

    International Nuclear Information System (INIS)

    Chiaro, P.J. Jr.

    1993-01-01

    Due to recent technological advances, substantial improvements have been made in personnel contamination monitoring. In all likelihood, these advances will close out the days of manually frisking personnel for radioactive contamination. Unfortunately, as microprocessor-based monitors become more widely used, not only at commercial power reactors but also at government facilities, questions concerning their trustworthiness arise. Algorithms make decisions that were previously made by technicians. Trust is placed not in technicians but in machines. In doing this it is assumed that the machine never misses. Inevitably, this trust drops, due largely to ''false alarms''. This is especially true when monitoring for alpha contamination. What is a ''false alarm''? Do these machines and their algorithms that we put our trust in make mistakes? An analysis was performed on half-body and hand-and-foot monitors at Oak Ridge National Laboratory (ORNL) in order to justify the suggested confidence level used for alarm point determination. Sources used in this analysis had activities approximating ORNL's contamination limits

  16. Trust versus confidence: Microprocessors and personnel monitoring

    International Nuclear Information System (INIS)

    Chiaro, P.J. Jr.

    1994-01-01

    Due to recent technological advances, substantial improvements have been made in personnel contamination monitoring. In all likelihood, these advances will close out the days of manually frisking personnel for radioactive contamination. Unfortunately, as microprocessor-based monitors become more widely used, not only at commercial power reactors but also at government facilities, questions concerning their trustworthiness arise. Algorithms make decisions that were previously made by technicians. Trust is placed not in technicians but in machines. In doing this it is assumed that the machine never misses. Inevitably, this trust drops, due largely to ''false alarms''. This is especially true when monitoring for alpha contamination. What is a ''false alarm''? Do these machines and their algorithms that they put their trust in make mistakes? An analysis was performed on half-body and hand-and-foot monitors at Oak Ridge National Laboratory (ORNL) in order to justify the suggested confidence level used for alarm point determination. Sources used in this analysis had activities approximating ORNL's contamination limits

  17. Period Prevalence and Reporting Rate of Needlestick Injuries to Nurses in Iran: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Rezaei, Satar; Hajizadeh, Mohammad; Zandian, Hamed; Fathi, Afshin; Nouri, Bijan

    2017-08-01

    The purpose of this systematic review and meta-analysis was to provide a precise estimate of the period prevalence of needlestick injuries (NSI) among nurses working in hospitals in Iran and the reporting rate of NSI to nurse managers. We searched both international (PubMed, Scopus and the Institute for Scientific Information) and Iranian (Scientific Information Database, Iranmedex and Magiran) scientific databases to find studies published from 2000 to 2016 of NSI among Iranian nurses. The following keywords in Persian and English were used: "needle-stick" or "needle stick" or "needlestick," with and without "injury" or "injuries," "prevalence" or "frequency," "nurses" or "nursing staff," and "Iran." In a sample of 21 articles with 6,480 participants, we estimated that the overall 1-year period prevalence of NSI was 44% (95% confidence interval [CI], 35-53%) among Iranian nurses. The overall 1-year period prevalence of reporting NSI to nurse managers was 42% (95% CI, 33-52%). In meta-regression analysis, sample size, mean age, years of experience, and gender ratio were not associated with prevalence of NSI or reporting rate. The year of data collection was positively associated with period prevalence of NSI (p managers. Results indicated a high NSI period prevalence and low NSI reporting rate among nurses in Iran. Thus, effective interventions are required in hospitals in Iran to reduce the prevalence and increase the reporting rate of NSI. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. Global Prevalence of Celiac Disease: Systematic Review and Meta-analysis.

    Science.gov (United States)

    Singh, Prashant; Arora, Ananya; Strand, Tor A; Leffler, Daniel A; Catassi, Carlo; Green, Peter H; Kelly, Ciaran P; Ahuja, Vineet; Makharia, Govind K

    2018-06-01

    Celiac disease is a major public health problem worldwide. Although initially it was reported from countries with predominant Caucasian populations, it now has been reported from other parts of the world. The exact global prevalence of celiac disease is not known. We conducted a systematic review and meta-analysis to estimate the global prevalence of celiac disease. We searched Medline, PubMed, and EMBASE for the keywords celiac disease, celiac, celiac disease, tissue transglutaminase antibody, anti-endomysium antibody, endomysial antibody, and prevalence for studies published from January 1991 through March 2016. Each article was cross-referenced with the words Asia, Europe, Africa, South America, North America, and Australia. The diagnosis of celiac disease was based on European Society of Pediatric Gastroenterology, Hepatology, and Nutrition guidelines. Of 3843 articles, 96 articles were included in the final analysis. The pooled global prevalence of celiac disease was 1.4% (95% confidence interval, 1.1%-1.7%) in 275,818 individuals, based on positive results from tests for anti-tissue transglutaminase and/or anti-endomysial antibodies (called seroprevalence). The pooled global prevalence of biopsy-confirmed celiac disease was 0.7% (95% confidence interval, 0.5%-0.9%) in 138,792 individuals. The prevalence values for celiac disease were 0.4% in South America, 0.5% in Africa and North America, 0.6% in Asia, and 0.8% in Europe and Oceania; the prevalence was higher in female vs male individuals (0.6% vs 0.4%; P celiac disease was significantly greater in children than adults (0.9% vs 0.5%; P celiac disease to be reported worldwide. The prevalence of celiac disease based on serologic test results is 1.4% and based on biopsy results is 0.7%. The prevalence of celiac disease varies with sex, age, and location. There is a need for population-based prevalence studies in many countries. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

  19. Dynamic Properties of QT Intervals

    Czech Academy of Sciences Publication Activity Database

    Halámek, Josef; Jurák, Pavel; Vondra, Vlastimil; Lipoldová, J.; Leinveber, Pavel; Plachý, M.; Fráňa, P.; Kára, T.

    2009-01-01

    Roč. 36, - (2009), s. 517-520 ISSN 0276-6574 R&D Projects: GA ČR GA102/08/1129; GA MŠk ME09050 Institutional research plan: CEZ:AV0Z20650511 Keywords : QT Intervals * arrhythmia diagnosis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering http://cinc.mit.edu/archives/2009/pdf/0517.pdf

  20. Haemostatic reference intervals in pregnancy

    DEFF Research Database (Denmark)

    Szecsi, Pal Bela; Jørgensen, Maja; Klajnbard, Anna

    2010-01-01

    Haemostatic reference intervals are generally based on samples from non-pregnant women. Thus, they may not be relevant to pregnant women, a problem that may hinder accurate diagnosis and treatment of haemostatic disorders during pregnancy. In this study, we establish gestational age-specific refe......Haemostatic reference intervals are generally based on samples from non-pregnant women. Thus, they may not be relevant to pregnant women, a problem that may hinder accurate diagnosis and treatment of haemostatic disorders during pregnancy. In this study, we establish gestational age......-specific reference intervals for coagulation tests during normal pregnancy. Eight hundred one women with expected normal pregnancies were included in the study. Of these women, 391 had no complications during pregnancy, vaginal delivery, or postpartum period. Plasma samples were obtained at gestational weeks 13......-20, 21-28, 29-34, 35-42, at active labor, and on postpartum days 1 and 2. Reference intervals for each gestational period using only the uncomplicated pregnancies were calculated in all 391 women for activated partial thromboplastin time (aPTT), fibrinogen, fibrin D-dimer, antithrombin, free protein S...

  1. Interval matrices: Regularity generates singularity

    Czech Academy of Sciences Publication Activity Database

    Rohn, Jiří; Shary, S.P.

    2018-01-01

    Roč. 540, 1 March (2018), s. 149-159 ISSN 0024-3795 Institutional support: RVO:67985807 Keywords : interval matrix * regularity * singularity * P-matrix * absolute value equation * diagonally singilarizable matrix Subject RIV: BA - General Mathematics Impact factor: 0.973, year: 2016

  2. Chaotic dynamics from interspike intervals

    DEFF Research Database (Denmark)

    Pavlov, A N; Sosnovtseva, Olga; Mosekilde, Erik

    2001-01-01

    Considering two different mathematical models describing chaotic spiking phenomena, namely, an integrate-and-fire and a threshold-crossing model, we discuss the problem of extracting dynamics from interspike intervals (ISIs) and show that the possibilities of computing the largest Lyapunov expone...

  3. The Prevalence of Burnout Among US Neurosurgery Residents.

    Science.gov (United States)

    Shakir, Hakeem J; McPheeters, Matthew J; Shallwani, Hussain; Pittari, Joseph E; Reynolds, Renée M

    2017-10-27

    Burnout is a syndrome of emotional exhaustion, depersonalization, and reduced personal accomplishment. Its prevalence among US physicians exceeds 50% and is higher among residents/fellows. This is important to the practice of neurosurgery, as burnout is associated with adverse physical health, increased risk of substance abuse, and increased medical errors. To date, no study has specifically addressed the prevalence of burnout among neurosurgery residents. To determine and compare the prevalence of burnout among US neurosurgery residents with published rates for residents/fellows and practicing physicians from other specialties. We surveyed 106 US neurosurgery residency training programs to perform a descriptive analysis of the prevalence of burnout among residents. Data on burnout among control groups were used to perform a cross-sectional analysis. Nonparametric tests assessed differences in burnout scores among neurosurgery residents, and the 2-tailed Fisher's exact test assessed burnout between neurosurgery residents and control populations. Of approximately 1200 US neurosurgery residents, 255 (21.3%) responded. The prevalence of burnout was 36.5% (95% confidence interval: 30.6%-42.7%). There was no significant difference in median burnout scores between gender (P = .836), age (P = .183), or postgraduate year (P = .963) among neurosurgery residents. Neurosurgery residents had a significantly lower prevalence of burnout (36.5%) than other residents/fellows (60.0%; P burnout than other residents/fellows and practicing physicians. The underlying causes for these findings were not assessed and are likely multifactorial. Future studies should address possible causes of these findings. Copyright © 2017 by the Congress of Neurological Surgeons

  4. Bipolar disorder prevalence: a systematic review and meta-analysis of the literature

    Directory of Open Access Journals (Sweden)

    Adauto S. Clemente

    2015-06-01

    Full Text Available Objective:Bipolar disorder (BD is common in clinical psychiatric practice, and several studies have estimated its prevalence to range from 0.5 to 5% in community-based samples. However, no systematic review and meta-analysis of the prevalence of BD type 1 and type 2 has been published in the literature. We carried out a systematic review and meta-analysis of the lifetime and 1-year prevalence of BD type 1 and type 2 and assessed whether the prevalence of BD changed according to the diagnostic criteria adopted (DSM-III, DSM-III-R vs. DSM-IV.Methods:We searched MEDLINE, Scopus, Web of Science, PsycINFO, and the reference lists of identified studies. The analyses included 25 population- or community-based studies and 276,221 participants.Results:The pooled lifetime prevalence of BD type 1 was 1.06% (95% confidence interval [95%CI] 0.81-1.31 and that of BD type 2 was 1.57% (95%CI 1.15-1.99. The pooled 1-year prevalence was 0.71% (95%CI 0.56-0.86 for BD type 1 and 0.50% (95%CI 0.35-0.64 for BD type 2. Subgroup analysis showed a significantly higher lifetime prevalence of BD type 1 according to the DSM-IV criteria compared to the DSM-III and DSM-IIIR criteria (p < 0.001.Conclusion:This meta-analysis confirms that estimates of BD type 1 and type 2 prevalence are low in the general population. The increase in prevalence from DSM-III and DSM-III-R to DSM-IV may reflect different factors, such as minor changes in diagnostic operationalization, use of different assessment instruments, or even a genuine increase in the prevalence of BD.

  5. Prevalence of functional disorders of androgen excess in unselected premenopausal women: a study in blood donors.

    Science.gov (United States)

    Sanchón, Raúl; Gambineri, Alessandra; Alpañés, Macarena; Martínez-García, M Ángeles; Pasquali, Renato; Escobar-Morreale, Héctor F

    2012-04-01

    The polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women. On the contrary, the prevalences of other disorders of androgen excess such as idiopathic hyperandrogenism and idiopathic hirsutism remain unknown. We aimed to obtain an unbiased estimate of the prevalence in premenopausal women of (i) signs of androgen excess and (ii) PCOS, idiopathic hyperandrogenism and idiopathic hirsutism. A multicenter prevalence survey included 592 consecutive premenopausal women (393 from Madrid, Spain and 199 from Bologna, Italy) reporting spontaneously for blood donation. Immediately before donation, we conducted clinical and biochemical phenotyping for androgen excess disorders. We determined the prevalence of (i) hirsutism, acne and alopecia as clinical signs of androgen excess and (ii) functional disorders of androgen excess, including PCOS, defined by the National Institute of Child Health and Human Development/National Institute of Health criteria, idiopathic hyperandrogenism and idiopathic hirsutism. Regarding clinical signs of hyperandrogenism, hirsutism and acne were equally frequent [12.2% prevalence; 95% confidence interval (CI): 9.5-14.8%], whereas alopecia was uncommon (1.7% prevalence, 95% CI: 0.7-2.7%). Regarding functional disorders of androgen excess, PCOS and idiopathic hirsutism were equally frequent (5.4% prevalence, 95% CI: 3.6-7.2) followed by idiopathic hyperandrogenism (3.9% prevalence, 95% CI: 2.3-5.4). Clinical signs of hyperandrogenism and functional disorders of androgen excess show a high prevalence in premenopausal women. The prevalences of idiopathic hyperandrogenism and idiopathic hirsutism are similar to that of PCOS, highlighting the need for further research on the pathophysiology, consequences for health and clinical implications of these functional forms of androgen excess.

  6. [Prevalence of anosognosia in Alzheimer's disease].

    Science.gov (United States)

    Turró-Garriga, Oriol; Conde-Sala, Josep Lluís; Reñé-Ramírez, Ramón; López-Pousa, Secundino; Gascón-Bayarri, Jordi; Garre-Olmo, Josep

    2014-07-07

    Anosognosia is a disorder that affects the clinical presentation of Alzheimer's disease (AD), increasing in frequency with the evolution of AD. The objective was to determine the prevalence of anosognosia and analyze the associated factors and predictors. Multicenter transversal and observational study of 345 AD patients. Anosognosia was assessed by Anosognosia Questionnaire-Dementia and the evolutionary stage with the Global Deterioration Scale (GDS). Tests used were Mini-Mental State Examination, Disability Assessment for Dementia and Neuropsychiatric Inventory to assess cognition, functional status and neuropsychiatric symptoms, respectively. We adjusted linear regression models to determine the associated variables and binary logistic regression (RLog) to identify predictors of anosognosia. The overall prevalence of anosognosia was 46.7% (95% confidence interval [95% CI] 41.3 to 52.1). The prevalence in stages was 28.4% (GDS 4), 64.6% (GDS 5) and 91.4% (GDS 6). The RLog identified as predictors older age (odds ratio [OR] 1.04; 95% CI 1.01-1.09), lower functional capacity (OR 0.96; 95% CI 0.93-0.98), lower cognitive level (OR 0.9; 95% CI 0.88-0.99), and greater apathy (OR 1.1; 95% CI 1.03-1.18), disinhibition (OR 1.2; 95% CI 1.09-1.50), irritability (OR 1.1; 95% CI 1.09-1.50) and motor disorders (OR 1.2; 95% CI 1.09-1.50). Anosognosia increases with further deterioration. In patients with a mild impairment, predictor variables were apathy, disinhibition and motor disorders. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  7. Trends in gastric cancer mortality and in the prevalence of Helicobacter pylori infection in Portugal.

    Science.gov (United States)

    Morais, Samantha; Ferro, Ana; Bastos, Ana; Castro, Clara; Lunet, Nuno; Peleteiro, Bárbara

    2016-07-01

    Portugal has the highest gastric cancer mortality rates in Western Europe, along with high prevalences of Helicobacter pylori infection. Monitoring their trends is essential to predict the burden of this cancer. We aimed to quantify time trends in gastric cancer mortality in Portugal and in each administrative region, and to compute short-term predictions, as well as to describe the prevalence of H. pylori infection, through a systematic review. Joinpoint analyses were used to identify significant changes in sex-specific trends in gastric cancer age-standardized mortality rates (ASMR) and to estimate annual percent changes (APC). The most recent trends were considered to compute estimates up to 2020 by adjusting Poisson regression models. We searched PubMed and IndexRMP to identify studies carried out in Portugal reporting the prevalence of H. pylori. Gastric cancer mortality has been decreasing in Portugal since 1971 in men (from ASMR=55.3/100 000; APC=-2.4, 95% confidence interval: -2.5 to -2.3) and since 1970 in women (from ASMR=28.0/100 000; APC=-2.8, 95% confidence interval: -2.9 to -2.7), although large regional differences were observed. Predicted ASMR for 2015 and 2020 were 18.8/100 000 and 16.7/100 000 for men and 8.5/100 000 and 7.4/100 000 for women, respectively. The prevalence of H. pylori varied from almost 5% at 0.5-2 years to just over 90% at 70 years or more. No consistent variation was observed since the 1990s. The downward trends in mortality rates are expected to remain in the next decades. The high prevalence of H. pylori infection across age groups and studies from different periods shows a large potential for decrease in the burden of gastric cancer in Portugal.

  8. Prevalence rates and epidemiological risk factors for astigmatism in Singapore school children.

    Science.gov (United States)

    Tong, Louis; Saw, Seang-Mei; Carkeet, Andrew; Chan, Wai-Ying; Wu, Hui-Min; Tan, Donald

    2002-09-01

    This study examined the prevalence rate of astigmatism and its epidemiological risk factors in Singapore school children. In a study of school children aged 7 to 9 years old in two schools in Singapore in 1999, a detailed questionnaire was administered to parents regarding reading or close-work habits, past history of close-work, family history, and socioeconomic factors. Cycloplegic refraction was performed five times in each eye. Defining astigmatism as worse than or equal to 0.5, 0.75, and 1 D cylinder in the right eye, the prevalence of astigmatism was calculated. The study population consisted of 1028 children. The prevalence rate of astigmatism (worse than or equal to 1 D cylinder) was 19.2% (95% confidence interval, 16.8 to 21.6). This was not different between genders, ethnic groups, or age (p > 0.05). With-the-rule astigmatism was more common than against-the-rule astigmatism. The prevalence of astigmatism and myopia was 9.8% (95% confidence interval, 8.0 to 11.6). A high AC/A ratio was associated (p = 0.003) with astigmatism, even after exclusion of myopic children. On vectorial analysis, J0 and J45 were associated with the number of hours of playing video games, whereas J45 was also associated with computer use. Only J45 was associated to male gender, a high AC/A ratio, and a family history of myopia. The prevalence rate of astigmatism (> or = 1 D) was 19%. Playing video games and computer use may be associated with astigmatism severity, although the presence of astigmatism (> or = 1 D) was not associated with any nearwork factors. A family history of myopia was associated with oblique astigmatism severity. A high AC/A ratio is associated with astigmatism, and this requires further investigation.

  9. Method for calculating the variance and prediction intervals for biomass estimates obtained from allometric equations

    CSIR Research Space (South Africa)

    Kirton, A

    2010-08-01

    Full Text Available for calculating the variance and prediction intervals for biomass estimates obtained from allometric equations A KIRTON B SCHOLES S ARCHIBALD CSIR Ecosystem Processes and Dynamics, Natural Resources and the Environment P.O. BOX 395, Pretoria, 0001, South... intervals (confidence intervals for predicted values) for allometric estimates can be obtained using an example of estimating tree biomass from stem diameter. It explains how to deal with relationships which are in the power function form - a common form...

  10. Examining Belief and Confidence in Schizophrenia

    Science.gov (United States)

    Joyce, Dan W.; Averbeck, Bruno B.; Frith, Chris D.; Shergill, Sukhwinder S.

    2018-01-01

    Background People with psychoses often report fixed, delusional beliefs that are sustained even in the presence of unequivocal contrary evidence. Such delusional beliefs are the result of integrating new and old evidence inappropriately in forming a cognitive model. We propose and test a cognitive model of belief formation using experimental data from an interactive “Rock Paper Scissors” game. Methods Participants (33 controls and 27 people with schizophrenia) played a competitive, time-pressured interactive two-player game (Rock, Paper, Scissors). Participant’s behavior was modeled by a generative computational model using leaky-integrator and temporal difference methods. This model describes how new and old evidence is integrated to form both a playing strategy to beat the opponent and provide a mechanism for reporting confidence in one’s playing strategy to win against the opponent Results People with schizophrenia fail to appropriately model their opponent’s play despite consistent (rather than random) patterns that can be exploited in the simulated opponent’s play. This is manifest as a failure to weigh existing evidence appropriately against new evidence. Further, participants with schizophrenia show a ‘jumping to conclusions’ bias, reporting successful discovery of a winning strategy with insufficient evidence. Conclusions The model presented suggests two tentative mechanisms in delusional belief formation – i) one for modeling patterns in other’s behavior, where people with schizophrenia fail to use old evidence appropriately and ii) a meta-cognitive mechanism for ‘confidence’ in such beliefs where people with schizophrenia overweight recent reward history in deciding on the value of beliefs about the opponent. PMID:23521846

  11. Population-based estimates of the prevalence of FMR1 expansion mutations in women with early menopause and primary ovarian insufficiency.

    Science.gov (United States)

    Murray, Anna; Schoemaker, Minouk J; Bennett, Claire E; Ennis, Sarah; Macpherson, James N; Jones, Michael; Morris, Danielle H; Orr, Nick; Ashworth, Alan; Jacobs, Patricia A; Swerdlow, Anthony J

    2014-01-01

    Primary ovarian insufficiency before the age of 40 years affects 1% of the female population and is characterized by permanent cessation of menstruation. Genetic causes include FMR1 expansion mutations. Previous studies have estimated mutation prevalence in clinical referrals for primary ovarian insufficiency, but these are likely to be biased as compared with cases in the general population. The prevalence of FMR1 expansion mutations in early menopause (between the ages of 40 and 45 years) has not been published. We studied FMR1 CGG repeat number in more than 2,000 women from the Breakthrough Generations Study who underwent menopause before the age of 46 years. We determined the prevalence of premutation (55-200 CGG repeats) and intermediate (45-54 CGG repeats) alleles in women with primary ovarian insufficiency (n = 254) and early menopause (n = 1,881). The prevalence of the premutation was 2.0% in primary ovarian insufficiency, 0.7% in early menopause, and 0.4% in controls, corresponding to odds ratios of 5.4 (95% confidence interval = 1.7-17.4; P = 0.004) for primary ovarian insufficiency and 2.0 (95% confidence interval = 0.8-5.1; P = 0.12) for early menopause. Combining primary ovarian insufficiency and early menopause gave an odds ratio of 2.4 (95% confidence interval = 1.02-5.8; P = 0.04). Intermediate alleles were not significant risk factors for either early menopause or primary ovarian insufficiency. FMR1 premutations are not as prevalent in women with ovarian insufficiency as previous estimates have suggested, but they still represent a substantial cause of primary ovarian insufficiency and early menopause.

  12. Decreasing prevalence of the full metabolic syndrome but a persistently high prevalence of dyslipidemia among adult Arabs.

    Directory of Open Access Journals (Sweden)

    Nasser M Al-Daghri

    Full Text Available A decade has passed since metabolic syndrome (MetS was documented to be highly prevalent in the kingdom of Saudi Arabia. No follow-up epidemiologic study was done. This study aims to fill this gap. In this cross-sectional, observational study, a total of 2850 randomly selected Saudi adults aged 18-55 years were recruited. Subjects' information was generated from a database of more than 10,000 Saudi citizens from the existing Biomarkers Screening in Riyadh Program (RIYADH Cohort, Saudi Arabia. Anthropometrics included body mass index (BMI, blood pressure, as well as waist and hip circumferences. Fasting blood glucose and lipid profile were determined using routine laboratory procedures. The definition of ATP-III (NHANES III was used for the diagnosis of the full MetS. The overall prevalence of complete MetS was 35.3% [Confidence-Interval (CI 33.5-37.01]. Age-adjusted prevalence according to the European standard population is 37.0%. Low HDL-cholesterol was the most prevalent of all MetS risk factors, affecting 88.6% (CI 87.5-89.7 and hypertriglyceridemia the second most prevalent, affecting 34% (CI 32.3-35.7 of the subjects. The prevalence of the full MetS decreased from previous estimates but remains high, while dyslipidemia remains extremely high, affecting almost 90% of middle-aged Arabs. Screening for dyslipidemia among Saudi adults is warranted, especially among those most at risk. Scientific inquiry into the molecular causes of these manifestations should be pursued as a first step in the discovery of etiologic therapies.

  13. Comparison between two population-based hepatitis B serosurveys with an 8-year interval in Shandong Province, China.

    Science.gov (United States)

    Liu, Jiaye; Lv, Jingjing; Yan, Bingyu; Feng, Yi; Song, Lizhi; Xu, Aiqiang; Zhang, Li; Yan, Yongping

    2017-08-01

    Tremendous progress has been made in hepatitis B virus (HBV) prevention and control in the last 30 years in China, but it continues to be a major public health problem. The most recently reported population-based seroepidemiological survey on HBV in Shandong Province in China was published in 2006, and an updated baseline for HBV prevalence was badly needed in the province to identify the change in HBV epidemiology in the last decade. Two population-based cross-sectional serosurveys were performed among the population aged 1-59 years in the same sample areas in Shandong Province, China in 2006 and 2014, respectively. Data on demographic characteristics were collected. A blood sample was obtained from each person and was tested for hepatitis B surface antigen (HBsAg), antibody against HBsAg (anti-HBs), and antibody against hepatitis B core antigen (anti-HBc). Overall, the prevalence rates of HBsAg, anti-HBs, and anti-HBc were 3.39% (95% confidence interval (CI) 2.51-4.26), 44.96% (95% CI 41.34-48.57), and 24.45% (95% CI 22.19-26.71), respectively, among the population aged 1-59 years in the 2006 serovsurvey; the corresponding prevalence rates were 2.49% (95% CI 1.81-3.17), 48.27% (95% CI 45.63-50.92), and 22.56% (95% CI 20.14-24.97), respectively, in 2014. The prevalence rates of HBsAg and anti-HBc were lower in 2014 than in 2006. Conversely, the prevalence of anti-HBs showed an increase. However, none of these differences were statistically significant (all p>0.05). The prevalence of HBsAg showed an increase among persons aged 20-24 years in 2014 (3.83%) compared with 2006 (2.98%) (t=0.45, p=0.67). Among all occupation groups, the prevalence of HBsAg was lower in 2014 than in 2006, while the prevalence of anti-HBc showed moderate increases in students and farmers (all p>0.05). The prevalence of HBsAg decreased more obviously in urban areas (65.49%) than rural areas (7.07%) from 2006 to 2014. The epidemiology of HBV infection has changed in Shandong Province, China

  14. The prevalence of insomnia in the general population in China: A meta-analysis.

    Directory of Open Access Journals (Sweden)

    Xiao-Lan Cao

    Full Text Available This is the first meta-analysis of the pooled prevalence of insomnia in the general population of China. A systematic literature search was conducted via the following databases: PubMed, PsycINFO, EMBASE and Chinese databases (China National Knowledge Interne (CNKI, WanFang Data and SinoMed. Statistical analyses were performed using the Comprehensive Meta-Analysis program. A total of 17 studies with 115,988 participants met the inclusion criteria for the analysis. The pooled prevalence of insomnia in China was 15.0% (95% Confidence interval [CI]: 12.1%-18.5%. No significant difference was found in the prevalence between genders or across time period. The pooled prevalence of insomnia in population with a mean age of 43.7 years and older (11.6%; 95% CI: 7.5%-17.6% was significantly lower than in those with a mean age younger than 43.7 years (20.4%; 95% CI: 14.2%-28.2%. The prevalence of insomnia was significantly affected by the type of assessment tools (Q = 14.1, P = 0.001. The general population prevalence of insomnia in China is lower than those reported in Western countries but similar to those in Asian countries. Younger Chinese adults appear to suffer from more insomnia than older adults.CRD 42016043620.

  15. Prevalence of depressive symptoms among medical students taught using problem-based learning versus traditional methods.

    Science.gov (United States)

    Aragão, José Aderval; Freire, Marianna Ribeiro de Menezes; Nolasco Farias, Lucas Guimarães; Diniz, Sarah Santana; Sant'anna Aragão, Felipe Matheus; Sant'anna Aragão, Iapunira Catarina; Lima, Tarcisio Brandão; Reis, Francisco Prado

    2018-06-01

    To compare depressive symptoms among medical students taught using problem-based learning (PBL) and the traditional method. Beck's Depression Inventory was applied to 215 medical students. The prevalence of depression was calculated as the number of individuals with depression divided by the total number in the sample from each course, with 95% confidence intervals. The statistical significance level used was 5% (p ≤ .05). Among the 215 students, 52.1% were male and 47.9% were female; and 51.6% were being taught using PBL methodology and 48.4% using traditional methods. The prevalence of depression was 29.73% with PBL and 22.12% with traditional methods. There was higher prevalence among females: 32.8% with PBL and 23.1% with traditional methods. The prevalence of depression with PBL among students up to 21 years of age was 29.4% and among those over 21 years, 32.1%. With traditional methods among students up to 21 years of age, it was 16.7%%, and among those over 21 years, 30.1%. The prevalence of depression with PBL was highest among students in the second semester and with traditional methods, in the eighth. Depressive symptoms were highly prevalent among students taught both with PBL and with traditional methods.

  16. Prevalence and profile of musculoskeletal injuries in ballet dancers: A systematic review and meta-analysis.

    Science.gov (United States)

    Smith, Toby O; Davies, Leigh; de Medici, Akbar; Hakim, Allan; Haddad, Fares; Macgregor, Alex

    2016-05-01

    To determine the prevalence of musculoskeletal disorders and anatomical regions which are most frequently injured in ballet dancers. Published (AMED, CiNAHL, EMBASE, SPORTDiscus, psycINFO, MEDLINE, the Cochrane Library) and grey literature databases (OpenGrey, the WHO International Clinical Trials Registry Platform, Current Controlled Trials and the UK National Research Register Archive) were searched from their inception to 25th May 2015 for papers presenting data on injury prevalence in ballet dancers. Two reviewers independently identified all eligible papers, data extracted and critically appraised studies. Study appraisal was conducted using the CASP appraisal tool. Pooled prevalence data with 95% confidence intervals were estimated to determine period prevalence of musculoskeletal disorders and anatomical regions affected. Nineteen studies were eligible, reporting 7332 injuries in 2617 ballet dancers. The evidence was moderate in quality. Period prevalence of musculoskeletal injury was 280% (95% CI: 217-343%). The most prevalent musculoskeletal disorders included: hamstring strain (51%), ankle tendinopathy (19%) and generalized low back pain (14%). No papers explored musculoskeletal disorders in retired ballet dancers. Whilst we have identified which regions and what musculoskeletal disorders are commonly seen ballet dancers. The long-term injury impact of musculoskeletal disorders in retired ballet dancers remains unknown. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The Relationship Between Child Mortality Rates and Prevalence of Celiac Disease.

    Science.gov (United States)

    Biagi, Federico; Raiteri, Alberto; Schiepatti, Annalisa; Klersy, Catherine; Corazza, Gino R

    2018-02-01

    Some evidence suggests that prevalence of celiac disease in the general population is increasing over time. Because the prognosis of celiac disease was a dismal one before discovering the role of gluten, our aim was to investigate a possible relationship between children under-5 mortality rates and prevalence rates of celiac disease. Thanks to a literature review, we found 27 studies performed in 17 different countries describing the prevalence of celiac disease in schoolchildren; between 1995 and 2011, 4 studies were performed in Italy. A meta-analysis of prevalence rates was performed. Prevalence was compared between specific country under-5 mortality groups, publication year, and age. In the last decades, under-5 mortality rates have been decreasing all over the world. This reduction is paralleled by an increase of the prevalence of celiac disease. The Spearman correlation coefficient was -63%, 95% confidence interval -82% to -33% (P celiac disease in the general population. In the near future, the number of patients with celiac disease will increase, thanks to the better environmental conditions that nowadays allow a better survival of children with celiac disease.

  18. Prevalence of Primary HPV in Djibouti: Feasibility of Screening for Early Diagnosis of Squamous Intraepithelial Lesions.

    Science.gov (United States)

    Petrelli, Alessio; Di Napoli, Anteo; Giorgi Rossi, Paolo; Rossi, Alessandra; Luccini, Daniele; Di Marco, Ilaria; Traoré, Amadou Laico; Gillio Tos, Anna; Trevisan, Morena; Mirisola, Concetta; Costanzo, Gianfranco

    2016-10-01

    In many African Sub-Saharan countries, human papilloma virus (HPV) prevalence data are not available. The current study estimated the prevalence of HPV virus in the female population of Djibouti. Approximately 1000 asymptomatic women 16 to 64 years old were enrolled from 3 of the main health structures of Djibouti in 2014 and 2015; 998 cervical samples were tested for HPV-DNA of high risk types, 499 during the first year, and 499 during the second. Positive samples were typed with an HPV genotyping kit. The women were an average age of 38.8 years (SD, 10.2); 54 women tested positive for HPV (prevalence rate, 5.4% [95% confidence interval, 4.0-6.8]). The highest prevalence was observed among the women younger than 35 years. HPV66 was the most prevalent (15.4% of the infections), followed by HPV31 and HPV52 (10.8% both) and HPV16 (9.2%). All 54 women who tested HPV-positive underwent a Pap test, which was positive in 8 cases (14.8%): 2 high-grade squamous intraepithelial lesion (HSIL) and 6 low-grade (LSIL). The HPV prevalence shows a curve by age similar to that of other African countries. The proportion of HPV16 is among the lowest ever seen in similar studies. The findings suggest to Djibouti the choice of a strategy of screening that includes forms of cytological triage, thus limiting recourse to colposcopy.

  19. Prevalence of facial trauma and associated factors in victims of road traffic accidents.

    Science.gov (United States)

    Nóbrega, Lorena Marques; Cavalcante, Gigliana M S; Lima, Monalyza M S M; Madruga, Renata C R; Ramos-Jorge, Maria Letícia; d'Avila, Sérgio

    2014-11-01

    The aim of this study was to determine the prevalence of facial trauma among victims of road traffic accidents and investigate factors associated with it. A cross-sectional study was carried out using the medical and dental charts of 2570 victims of road traffic accidents with bodily and/or facial injuries between 2008 and 2011. Sociodemographic variables of the victims and characteristics of the accidents and injuries were evaluated. Statistical analyses included the χ(2) test as well as the Poisson univariate and multivariate regression analyses for the determination of the final hierarchical model. The prevalence of facial injuries was 16.4%. Most of the victims were male. Among the victims with facial injuries, 44.3% had polytrauma to the face. The prevalence of facial injuries was high among accidents that occurred at night (Prevalence Ratio (PR), 1.42; 95% confidence interval [CI], 1.10-1.84; P = .007) and victims up to 9 years of age (PR, 2.31; 95% CI, 1.03-5.17; P = .041). Moreover, the prevalence of facial injuries was lower among victims of motorcycle accidents than victims of automobile accidents (PR, 0.59; 95% CI, 0.44-0.89; P = .001). The prevalence of facial injuries was high in this study and was significantly associated with the place of residence, time of day, age group, and type of accident. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Sonographic Characteristics and Interval Changes of Subacute Thyroiditis.

    Science.gov (United States)

    Lee, Yoo Jin; Kim, Dong Wook

    2016-08-01

    This study aimed to assess the sonographic characteristics and interval changes of subacute thyroiditis using follow-up sonography. From January 2008 to December 2014, 85 patients with clinically suspected subacute thyroiditis underwent sonographic examinations by a single radiologist. Subacute thyroiditis was confirmed on the basis of the clinical, sonographic, and cytohistopathologic findings. On the initial and follow-up sonograms, the individual sonographic findings and interval changes were retrospectively investigated by the same radiologist. According to the sonographic configuration, subacute thyroiditis lesions were categorized as nodular or non-nodular. The interval changes in the lesions were classified as follows: "disappeared," "decreased," "increased," "eventually smaller," "eventually larger," or "no interval change." Subacute thyroiditis was confirmed in 64 of the 85 patients. In these 64 patients, nodular (n = 39) and non-nodular (n = 35) lesions were found; 10 patients had both nodular and non-nodular lesions. Of the 64 patients, 41 underwent sonographic follow-up. In both nodular and non-nodular lesions, the common interval changes included disappeared, decreased, and eventually smaller patterns. Although the increased pattern was found only in 4 nodular lesions, there was no significant difference in the interval changes between nodular and non-nodular lesions. On follow-up sonography, a new lesion was detected in 6 patients. The prevalence rate of nodular subacute thyroiditis lesions on sonography was high, and the interval changes in the lesions were variable.

  1. Sources of sport confidence, imagery type and performance among competitive athletes: the mediating role of sports confidence.

    Science.gov (United States)

    Levy, A R; Perry, J; Nicholls, A R; Larkin, D; Davies, J

    2015-01-01

    This study explored the mediating role of sport confidence upon (1) sources of sport confidence-performance relationship and (2) imagery-performance relationship. Participants were 157 competitive athletes who completed state measures of confidence level/sources, imagery type and performance within one hour after competition. Among the current sample, confirmatory factor analysis revealed appropriate support for the nine-factor SSCQ and the five-factor SIQ. Mediational analysis revealed that sport confidence had a mediating influence upon the achievement source of confidence-performance relationship. In addition, both cognitive and motivational imagery types were found to be important sources of confidence, as sport confidence mediated imagery type- performance relationship. Findings indicated that athletes who construed confidence from their own achievements and report multiple images on a more frequent basis are likely to benefit from enhanced levels of state sport confidence and subsequent performance.

  2. Vaccination Confidence and Parental Refusal/Delay of Early Childhood Vaccines.

    Directory of Open Access Journals (Sweden)

    Melissa B Gilkey

    Full Text Available To support efforts to address parental hesitancy towards early childhood vaccination, we sought to validate the Vaccination Confidence Scale using data from a large, population-based sample of U.S. parents.We used weighted data from 9,354 parents who completed the 2011 National Immunization Survey. Parents reported on the immunization history of a 19- to 35-month-old child in their households. Healthcare providers then verified children's vaccination status for vaccines including measles, mumps, and rubella (MMR, varicella, and seasonal flu. We used separate multivariable logistic regression models to assess associations between parents' mean scores on the 8-item Vaccination Confidence Scale and vaccine refusal, vaccine delay, and vaccination status.A substantial minority of parents reported a history of vaccine refusal (15% or delay (27%. Vaccination confidence was negatively associated with refusal of any vaccine (odds ratio [OR] = 0.58, 95% confidence interval [CI], 0.54-0.63 as well as refusal of MMR, varicella, and flu vaccines specifically. Negative associations between vaccination confidence and measures of vaccine delay were more moderate, including delay of any vaccine (OR = 0.81, 95% CI, 0.76-0.86. Vaccination confidence was positively associated with having received vaccines, including MMR (OR = 1.53, 95% CI, 1.40-1.68, varicella (OR = 1.54, 95% CI, 1.42-1.66, and flu vaccines (OR = 1.32, 95% CI, 1.23-1.42.Vaccination confidence was consistently associated with early childhood vaccination behavior across multiple vaccine types. Our findings support expanding the application of the Vaccination Confidence Scale to measure vaccination beliefs among parents of young children.

  3. Prevalence of the metabolic syndrome in a psychiatric hospital in Mexico.

    Science.gov (United States)

    Díaz-Castro, Lina; Cabello-Rangel, Héctor; Cuevas-Pineda, Guillermo J; Reza-Garduño, Horacio; Castañeda-González, Carlos J

    2011-01-01

    The metabolic syndrome (MS) is formed by elevated blood pressure, hypercholesterolemia, hypertriglyceridemía, hyperglycemia and abdominal obesity. Mexico occupies the second place worldwide in prevalence of obesity. It has been reported that the use of psychopharmaceuticals increase the risk of MS. To detect prevalence of MS in patients with a psychiatric diagnosis with or without psychopharmaceutical treatment. An observational, descriptive study was designed. Informed consent was obtained, enrolling a sample of 216 patients in the six-month period, all of them over 18 years of age. The following variables were measured: blood pressure, weight, height, waist circumference, triglyceride, glucose and high-density lipoprotein serum levels, by colorimetric enzyme assay in Roche analyzer. Student's t-test, and Cochran-Mantel- Haenszel and Fisher's exact test. A total of 50% of the sample had a waist circumference >88 cm; 10% glycemia superior to 110 mg/dl, 30% triglycerides >150 mg/dl; 14% met the MS criteria. When patients with and without MS were grouped, and glucose and triglycerides were compared, a p 0.0001 was obtained. With a 93.4% confidence interval, the relationship between sedentary life and MS was accepted. Women, aged 40-59 years tended to have MS, with 98.4% CI. The only family background associated to MS was obesity (97.7% CI). There is a positive relationship between MS and the use of typical or atypical antipsychotics. SSRIs are significantly related with MS: p 0.072 and 91.5% confidence interval, benzodiazepines with p 0.073 and 92.7% confidence interval. Only 14% of the sample had MS. Psychopharmaceuticals were associated to MS, women between 40 to 59 years having a greater risk.

  4. Alternative confidence measure for local matching stereo algorithms

    CSIR Research Space (South Africa)

    Ndhlovu, T

    2009-11-01

    Full Text Available The authors present a confidence measure applied to individual disparity estimates in local matching stereo correspondence algorithms. It aims at identifying textureless areas, where most local matching algorithms fail. The confidence measure works...

  5. Small area variation in diabetes prevalence in Puerto Rico

    Directory of Open Access Journals (Sweden)

    Edward F. Tierney

    2013-06-01

    Full Text Available OBJECTIVE: To estimate the 2009 prevalence of diagnosed diabetes in Puerto Rico among adults ≥ 20 years of age in order to gain a better understanding of its geographic distribution so that policymakers can more efficiently target prevention and control programs. METHODS: A Bayesian multilevel model was fitted to the combined 2008-2010 Behavioral Risk Factor Surveillance System and 2009 United States Census data to estimate diabetes prevalence for each of the 78 municipios (counties in Puerto Rico. RESULTS: The mean unadjusted estimate for all counties was 14.3% (range by county, 9.9%-18.0%. The average width of the confidence intervals was 6.2%. Adjusted and unadjusted estimates differed little. CONCLUSIONS: These 78 county estimates are higher on average and showed less variability (i.e., had a smaller range than the previously published estimates of the 2008 diabetes prevalence for all United States counties (mean, 9.9%; range, 3.0%-18.2%.

  6. Prevalence of vulvovaginitis and bacterial vaginosis in patients with koilocytosis

    Directory of Open Access Journals (Sweden)

    Ana Claudia Camargo Campos

    Full Text Available CONTEXT AND OBJECTIVE: Empirical discussion regarding an association between koilocytosis and vulvovaginitis often occurs. Thus, the objective of this study was to assess the prevalence of microorganisms associated with bacterial vaginosis and vulvovaginitis in women with and without koilocytosis. DESIGN AND SETTING: Analytical cross-sectional study including two cohorts of women (with and without koilocytosis who attended a cancer hospital in the city of Goiânia, state of Goiás. METHODS: A total of 102 patients entered the study. The whiff test, Gram and Papanicolaou staining and bacterial and fungal culturing were performed. The results were observed using univariate analysis. The odds ratio and confidence interval (CI of the variables were calculated; P-values < 0.05 were considered significant. RESULTS: The prevalence of bacterial colonization was similar in patients with and without koilocytosis. The odds ratio for candidiasis was 1.43 (CI 1.05-1.95 and the odds ratio for trichomoniasis was 1.78 (CI 1.49-2.12, in patients with koilocytosis. CONCLUSIONS: The prevalence of candidiasis and trichomoniasis seems to be higher in patients with koilocytosis.

  7. Prevalence of vulvovaginitis and bacterial vaginosis in patients with koilocytosis.

    Science.gov (United States)

    Campos, Ana Claudia Camargo; Freitas-Junior, Ruffo; Ribeiro, Luiz Fernando Jubé; Paulinelli, Régis Resende; Reis, Cleomenes

    2008-11-01

    Empirical discussion regarding an association between koilocytosis and vulvovaginitis often occurs. Thus, the objective of this study was to assess the prevalence of microorganisms associated with bacterial vaginosis and vulvovaginitis in women with and without koilocytosis. Analytical cross-sectional study including two cohorts of women (with and without koilocytosis) who attended a cancer hospital in the city of Goiânia, state of Goiás. A total of 102 patients entered the study. The whiff test, Gram and Papanicolaou staining and bacterial and fungal culturing were performed. The results were observed using univariate analysis. The odds ratio and confidence interval (CI) of the variables were calculated; P-values < 0.05 were considered significant. The prevalence of bacterial colonization was similar in patients with and without koilocytosis. The odds ratio for candidiasis was 1.43 (CI 1.05-1.95) and the odds ratio for trichomoniasis was 1.78 (CI 1.49-2.12), in patients with koilocytosis. The prevalence of candidiasis and trichomoniasis seems to be higher in patients with koilocytosis.

  8. Simultaneous confidence bands for the integrated hazard function

    OpenAIRE

    Dudek, Anna; Gocwin, Maciej; Leskow, Jacek

    2006-01-01

    The construction of the simultaneous confidence bands for the integrated hazard function is considered. The Nelson--Aalen estimator is used. The simultaneous confidence bands based on bootstrap methods are presented. Two methods of construction of such confidence bands are proposed. The weird bootstrap method is used for resampling. Simulations are made to compare the actual coverage probability of the bootstrap and the asymptotic simultaneous confidence bands. It is shown that the equal--tai...

  9. Prevalence of Cleft Lip/Palate in the Fangshan District of Beijing, 2006-2012.

    Science.gov (United States)

    Yang, Yanfen; Liu, Hui; Ma, Ruixin; Jin, Lei

    2018-01-01

    To estimate the cleft lip with or without cleft palate (CL/P) prevalence among births between 2006 and 2012 in Fangshan district of Beijing, China. Surveillance data analysis. All hospitals that provide obstetric services in the district. The CL/P cases presented for this report were from 13 weeks' gestation to 7 days postpartum. The CL/P prevalence was defined as the number of cases per 10 000 births, including live births and stillbirths at 28 weeks' gestation or beyond. The overall CL/P prevalence was 18.9 (95% confidence interval [CI]: 15.1-22.7) per 10 000 births. From 2006 to 2012, the CL/P prevalence was 19.3, 20.2, 10.9, 16.1, 17.5, 25.4, and 22.3 per 10 000 births; annually, no significant change was noted ( P for trend = .311). The prevalence of cleft palate, cleft lip, and cleft lip and palate were 3.4 (95% CI: 2.0-5.4), 6.2 (95% CI: 4.2-8.8), and 9.4 (95% CI: 6.9-12.4) per 10 000 births, respectively. The CL/P prevalence among the nonpermanent residents (31.4 per 10 000 births) was 2.31 times that of permanent residents (13.6 per 10 000 births). Among nonpermanent residents, the CL/P prevalence showed an upward trend over the study period ( P for trend = .036), that increased from 38.8 (95% CI: 16.5-76.6) per 10 000 births in 2006 to 54.6 (95% CI: 25.7-100.4) per 10 000 births in 2012. The overall CL/P prevalence was stable in the Fangshan district. However, the CL/P prevalence of the nonpermanent residents increased significantly.

  10. Prevalence and change of central obesity among US Asian adults: NHANES 2011–2014

    Directory of Open Access Journals (Sweden)

    Xuefeng Liu

    2017-08-01

    Full Text Available Abstract Background Central obesity is a major risk factor for cardiometabolic diseases. The prevalence of central obesity has not been reported fully among Asian adults in the United States (US. Methods Cross-sectional data of 1288 Asian adults aged 20 years or over was selected from the US National Health and Nutrition Examination Survey with a stratified multi-stage sampling design. The prevalence of central obesity was calculated with 95% confidence intervals (CIs and Chi-square tests were conducted to test the significance of the prevalence differences across characteristic groups. Results The overall prevalence of central obesity among US Asian adults was 58.1% in 2011–2014. The prevalence of central obesity was higher in older adults (73.5% than in young adults (45.4% (p < 0.0001. Women had 13.4% higher prevalence than men (64.4% vs 51.0%, p < 0.0001. The prevalence increased over time (2011–2012 vs 2013–2014 in young adults (39.2% vs 51.5%, men (45.4% vs 56.6%, adults with college education or above (54.2% vs 61.7% and non-poor adults (55.4% vs 62.4%. Compared with men, women had higher prevalence in each subgroup of age, education, poverty, and length of time (except for the subgroup of “born in the US” (all p < 0.05 and in the subgroup of “married or living with partner” for marital status (p < 0.0001. Conclusion Central obesity is prevalent in Asian adults, particularly in older adults and women. More efforts are needed to prevent and treat obesity in Asian adults as Asians are incurring the greatest increase in type 2 diabetes in parallel with the rising rate of central adiposity.

  11. Epilepsy prevalence, potential causes and social beliefs in Ebonyi State and Benue State, Nigeria.

    Science.gov (United States)

    Osakwe, Chijioke; Otte, Willem M; Alo, Chimhurumnanya

    2014-02-01

    Epilepsy is a common neurological disorder in Nigeria. Many individuals are affected in rural areas, although prevalence data is not available. In this study we aimed to establish the prevalence of epilepsy in a rural community in south-east Nigeria, a community suspected for having a high number of people living with epilepsy. We compared this with the prevalence in a nearby semi-urban community in north-central Nigeria. In both communities we identified potential causes of epilepsy and obtained information on the social beliefs regarding epilepsy. We used door-to-door surveys and focus group discussions. The epilepsy prevalence in the rural community was 20.8/1000 [95% confidence interval (CI): 15.7-27.4]. The prevalence in the semi-rural community was lower, namely 4.7/1000 [CI: 3.2-6.9]. The difference in prevalence was highly significant (χ(2)-test, pepilepsy were in the age range of 7-24 years. Causes that might be contributory to the prevalence of epilepsy in both communities included poor obstetric practices, frequent febrile convulsions, head trauma, meningitis and neurocysticercosis. In both communities we found stigma of people with epilepsy. In conclusion, the epilepsy prevalence in the semi-urban community is similar to that in industrialized countries. In contrast, the rural community has a much higher prevalence. This may require the establishment of specific community-based epilepsy control programs. Community interventions should focus on treatment of acute epilepsy and on stigma reduction. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Age-specific prevalence of human papilloma virus infection among Nigerian women.

    Science.gov (United States)

    Akarolo-Anthony, Sally N; Famooto, Ayo O; Dareng, Eileen O; Olaniyan, Olayinka B; Offiong, Richard; Wheeler, Cosette M; Adebamowo, Clement A

    2014-06-27

    Inconsistent trends in HPV prevalence by age have been described in Africa. We examined the age prevalence pattern and distribution of 37 HPV-DNA types among urban Nigerian women. The study population was a sample of 278 women who presented to cervical cancer screening programs in Abuja, Nigeria, between April and August 2012. Using a nurse administered questionnaire, information on demographic characteristics and risk factors of cervical cancer was collected and samples of cervical exfoliated cells were obtained from all participants. Roche Linear Array HPV Genotyping Test® was used to characterize prevalent HPV and log-binomial regression models were used to examine the association between potential correlates and the prevalence of HPV infection. The mean age (SD) of the women enrolled was 38 (8) years. The overall prevalence of HPV was 37%. HPV 35 was the most prevalent HPV type in the study population. Among women age ≤ 30 years, 52% had HPV infection compared to 23% of those women who were older than 45 years (p = 0.006). We observed a significant linear association between age and the prevalence of HPV infections. The prevalence ratio (PR) and 95% confidence interval (CI) was 2.26 (1.17, 4.34) for any HPV infection, 3.83 (1.23, 11.94) for Group 1 HPV (definite carcinogens), and 2.19 (0.99, 4.84) for Group 2a or 2b HPV (probable or possible carcinogens) types, among women aged 18-30 years, compared to women who were older than 45 years. The prevalence of HPV infection was highest among younger women and decreased steadily with age among this population of urban Nigerian women.

  13. 49 CFR 1103.23 - Confidences of a client.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Confidences of a client. 1103.23 Section 1103.23... Responsibilities Toward A Client § 1103.23 Confidences of a client. (a) The practitioner's duty to preserve his client's confidence outlasts the practitioner's employment by the client, and this duty extends to the...

  14. Contrasting Academic Behavioural Confidence in Mexican and European Psychology Students

    Science.gov (United States)

    Ochoa, Alma Rosa Aguila; Sander, Paul

    2012-01-01

    Introduction: Research with the Academic Behavioural Confidence scale using European students has shown that students have high levels of confidence in their academic abilities. It is generally accepted that people in more collectivist cultures have more realistic confidence levels in contrast to the overconfidence seen in individualistic European…

  15. Prevalence Incidence Mixture Models

    Science.gov (United States)

    The R package and webtool fits Prevalence Incidence Mixture models to left-censored and irregularly interval-censored time to event data that is commonly found in screening cohorts assembled from electronic health records. Absolute and relative risk can be estimated for simple random sampling, and stratified sampling (the two approaches of superpopulation and a finite population are supported for target populations). Non-parametric (absolute risks only), semi-parametric, weakly-parametric (using B-splines), and some fully parametric (such as the logistic-Weibull) models are supported.

  16. Prevalence of Gestational Diabetes Mellitus in Eastern and Southeastern Asia: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Binns, Colin W.; Duong, Dat Van; Lee, Andy H.

    2018-01-01

    Aim To review the prevalence of gestational diabetes mellitus (GDM) in Eastern and Southeastern Asia. Methods We systematically searched for observational studies on GDM prevalence from January 2000 to December 2016. Inclusion criteria were original English papers, with full texts published in peer-reviewed journals. The quality of included studies was evaluated using the guidelines of the National Health and Medical Research Council, Australia. Fixed effects and random effects models were used to estimate the summary prevalence of GDM and the corresponding 95% confidence intervals (CI). Results A total of 4415 papers were screened, and 48 studies with 63 GDM prevalence observations were included in the final review. The pooled prevalence of GDM was 10.1% (95% CI: 6.5%–15.7%), despite substantial variations across nations. The prevalence of GDM in lower- or upper-middle income countries was about 64% higher than in their high-income counterparts. Moreover, the one-step screening method was twice more likely to be used in diagnosing GDM when compared to the two-step screening procedure. Conclusions The prevalence of GDM in Eastern and Southeastern Asia was high and varied among and within countries. There is a need for international uniformity in screening strategies and diagnostic criteria for GDM. PMID:29675432

  17. Effort-Reward Imbalance at Work and the Prevalence of Unsuccessfully Treated Hypertension Among White-Collar Workers.

    Science.gov (United States)

    Trudel, Xavier; Milot, Alain; Gilbert-Ouimet, Mahée; Duchaine, Caroline; Guénette, Line; Dalens, Violaine; Brisson, Chantal

    2017-08-15

    We examined the association between effort-reward imbalance (ERI) exposure at work and unsuccessfully treated hypertension among white-collar workers from a large cohort in Quebec City, Canada. The study used a repeated cross-sectional design involving 3 waves of data collection (2000-2009). The study sample was composed of 474 workers treated for hypertension, accounting for 739 observations. At each observation, ERI was measured using validated scales, and ambulatory blood pressure (BP) was measured every 15 minutes during the working day. Unsuccessfully treated hypertension was defined as daytime ambulatory BP of at least 135/85 mm Hg and was further divided into masked and sustained hypertension. Adjusted prevalence ratios and 95% confidence intervals were estimated. Participants in the highest tertile of ERI exposure had a higher prevalence of unsuccessfully treated hypertension (prevalence ratio = 1.45, 95% confidence interval: 1.16, 1.81) after adjustment for gender, age, education, family history of cardiovascular diseases, body mass index, diabetes, smoking, sedentary behaviors, and alcohol intake. The present study supports the effect of adverse psychosocial work factors from the ERI model on BP control in treated workers. Reducing these frequent exposures at work might lead to substantial benefits on BP control at the population level. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Dijets at large rapidity intervals

    CERN Document Server

    Pope, B G

    2001-01-01

    Inclusive diet production at large pseudorapidity intervals ( Delta eta ) between the two jets has been suggested as a regime for observing BFKL dynamics. We have measured the dijet cross section for large Delta eta in pp collisions at square root s = 1800 and 630 GeV using the DOE detector. The partonic cross section increases strongly with the size of Delta eta . The observed growth is even stronger than expected on the basis of BFKL resummation in the leading logarithmic approximation. The growth of the partonic cross section can be accommodated with an effective BFKL intercept of alpha /sub BFKL/(20 GeV) = 1.65 +or- 0.07.

  19. Variational collocation on finite intervals

    International Nuclear Information System (INIS)

    Amore, Paolo; Cervantes, Mayra; Fernandez, Francisco M

    2007-01-01

    In this paper, we study a set of functions, defined on an interval of finite width, which are orthogonal and which reduce to the sinc functions when the appropriate limit is taken. We show that these functions can be used within a variational approach to obtain accurate results for a variety of problems. We have applied them to the interpolation of functions on finite domains and to the solution of the Schroedinger equation, and we have compared the performance of the present approach with others

  20. Prevalence and correlates of gender-based violence among female university students in Northern Nigeria.

    Science.gov (United States)

    Iliyasu, Zubairu; Abubakar, Isa S; Aliyu, Muktar H; Galadanci, Hadiza S; Salihu, Hamisu M

    2011-09-01

    Gender-based violence (GBV) is a major public health and human rights problem worldwide. The extent of this problem in educational institutions has not been explored in Northern Nigeria. Using self administered questionnaires, we determined the prevalence and risk factors for gender-based violence among 300 female university students in Kano, Northern Nigeria. The overall prevalence of gender-based violence was 58.8% [95% Confidence Interval (CI) = 52.9% to 64.5%]. Specifically, 22.8%, 22.2% and 50.8% of students experienced physical, sexual or emotional violence respectively. Religious affiliation ethnicity, indigeneship, marital status, campus residence and faculty affiliation were significant predictors of GBV. GBV awareness creation programs, legal protection and implementation of an effective redress mechanism are recommended to curb this menace.

  1. Prevalence of hepatitis C virus infection among recyclable waste collectors in Central-West Brazil.

    Science.gov (United States)

    Marinho, Thaís Augusto; Lopes, Carmen Luci Rodrigues; Teles, Sheila Araújo; Reis, Nádia Rúbia Silva; Carneiro, Megmar Aparecida dos Santos; de Andrade, Andreia Alves; Martins, Regina Maria Bringel

    2013-06-01

    The prevalence of hepatitis C virus (HCV) in a population of recyclable waste collectors (n = 431) was assessed using a cross-sectional survey in all 15 cooperatives in the city of Goiânia, Central-West Brazil. The HCV prevalence was 1.6% (95% confidence interval: 0.6-3.6) and a history of sexually transmitted infections was independently associated with this infection. HCV RNA (corresponding to genotype 1; subtypes 1a and 1b) was detected in five/seven anti-HCV-positive samples. Although the study population reported a high rate (47.3%) of sharps and needle accidents, HCV infection was not more frequent in recyclable waste collectors than in the general Brazilian population.

  2. Known risk factors do not explain disparities in gallstone prevalence between Denmark and northeast Germany

    DEFF Research Database (Denmark)

    Friedrich, Nele; Völzke, Henry; Hampe, Jochen

    2009-01-01

    OBJECTIVES: Gallstones are a common disease worldwide, with disparities in the prevalence of the disease in different settings. The aim of the present study was to assess if different distributions of risk factors could explain the disparities in the prevalence of gallstone disease between Denmark...... and northeast Germany. METHODS: Data of 5,559 subjects from the Danish MONICA survey and of 3,647 subjects of the German Study of Health in Pomerania were investigated. Gallstone disease was defined as a prior history of cholecystectomy or the presence of sonographically diagnosed gallstones. Logistic...... regression models were performed to assess the confounding effect of selected risk factors on regional disparities in gallstone disease. RESULTS: After adjustment for age and vocational training, German subjects (women: Odds ratio, OR, 2.46 (95% confidence interval, CI: 2.07-2.91); men: OR, 1.89 (95% CI: 1...

  3. Prevalence of faecal incontinence in community-dwelling older people in Bali, Indonesia.

    Science.gov (United States)

    Suyasa, I Gede Putu Darma; Xiao, Lily Dongxia; Lynn, Penelope Ann; Skuza, Pawel Piotr; Paterson, Jan

    2015-06-01

    To explore the prevalence rate of faecal incontinence in community-dwelling older people, associated factors, impact on quality of life and practices in managing faecal incontinence. Using a cross-sectional design, 600 older people aged 60+ were randomly selected from a population of 2916 in Bali, Indonesia using a simple random sampling technique. Three hundred and three participants were interviewed (response rate 51%). The prevalence of faecal incontinence was 22.4% (95% confidence interval (CI) 18.0-26.8). Self-reported constipation (odds ratio (OR) 3.68, 95% CI 1.87-7.24) and loose stools (OR 2.66, 95% CI 1.47-4.78) were significantly associated with faecal incontinence. There was a strong positive correlation between total bowel control score and total quality-of-life score (P Bali. © 2014 ACOTA.

  4. Country of birth and other factors associated with hepatitis B prevalence in a population with high levels of immigration.

    Science.gov (United States)

    Reekie, Joanne; Gidding, Heather F; Kaldor, John M; Liu, Bette

    2013-09-01

    While hepatitis B virus (HBV) prevalence is known to vary greatly between countries, systematically collected population-level prevalence data from some countries is limited. Antenatal HBV screening programs in countries with substantial migrant populations provide the opportunity to systematically examine HBV prevalence in order to inform local and regional HBV estimates. A comprehensive register of Australian mothers giving birth from January 2000 to December 2008 was linked to a register of HBV notifications. Age-standardized prevalence of chronic HBV were calculated overall and by the mother's country of birth. Multiple logistic regression was used to investigate other factors associated with HBV prevalence. Five hundred twenty-three thousand six hundred sixty-five women were included and linked to 3861 HBV notifications. The age-standardized HBV prevalence was low (0.75%, 95% confidence interval 0.72-0.79). The highest HBV prevalence rates were observed in women born in Cambodia (8.60%), Taiwan (8.10%), Vietnam (7.49%), China (6.80%), and Tonga (6.51%). Among Australia-born women, those who smoked during pregnancy, were from a more disadvantaged socioeconomic background, and lived in remote areas were more likely to have HBV. There was also a trend suggesting a decrease in the prevalence of HBV over time. Antenatal screening for HBV can provide systematic population estimates of HBV prevalence in migrants and also identify other high prevalence groups. Longer follow-up will be required to confirm the small decrease in HBV prevalence observed in this study. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  5. Increasing atrial fibrillation prevalence in acute ischemic stroke and TIA.

    Science.gov (United States)

    Otite, Fadar Oliver; Khandelwal, Priyank; Chaturvedi, Seemant; Romano, Jose G; Sacco, Ralph L; Malik, Amer M

    2016-11-08

    To evaluate trends in atrial fibrillation (AF) prevalence in acute ischemic stroke (AIS) and TIA in the United States. We used the Nationwide Inpatient Sample to retrospectively compute weighted prevalence of AF in AIS (n = 4,355,140) and TIA (n = 1,816,459) patients admitted to US hospitals from 2004 to 2013. Multivariate-adjusted models were used to evaluate the association of AF with clinical factors, mortality, length of stay, and cost. From 2004 to 2013, AF prevalence increased by 22% in AIS (20%-24%) and by 38% in TIA (12%-17%). AF prevalence varied by age (AIS: 6% in 50-59 vs 37% in ≥80 years; TIA: 4% in 50-59 vs 24% in ≥80 years), sex (AIS: male 19% vs female 25%; TIA: male 15% vs female 14%), race (AIS: white 26% vs black 12%), and region (AIS: Northeast 25% vs South 20%). Advancing age, female sex, white race, high income, and large hospital size were associated with increased odds of AF in AIS. AF in AIS was a risk factor for in-hospital death (odds ratio 1.93, 95% confidence interval 1.89-1.98) but mortality in AIS with AF decreased from 11.6% to 8.3% (p TIA has continued to increase. Disparity in AF prevalence in AIS and TIA exists by patient and hospital factors. AF is associated with increased mortality in AIS. Innovative AIS preventive strategies are needed in patients with AF, especially in the elderly. © 2016 American Academy of Neurology.

  6. Prevalence of chronic kidney disease in Peruvian primary care setting.

    Science.gov (United States)

    Herrera-Añazco, Percy; Taype-Rondan, Alvaro; Lazo-Porras, María; Alberto Quintanilla, E; Ortiz-Soriano, Victor Manuel; Hernandez, Adrian V

    2017-07-19

    Chronic Kidney Disease (CKD) is a worldwide public health problem. There are few studies in Latin America, especially in primary care settings. Our objective was to determine the prevalence, stages, and associated factors of CKD in primary care setting. We did a retrospective secondary analysis of a database from the Diabetes and Hypertension Primary Care Center of the Peruvian Social Security System (EsSalud) in Lima, Peru. We defined CKD as the presence of eGFR 30 mg/day in 24 h, according to Kidney Disease: Improving Global Outcomes (KDIGO). Factors associated with CKD were evaluated with Poisson Regression models; these factors included age, gender, type 2 diabetes mellitus (DM2), hypertension (HTN), body mass index (BMI), and uric acid. Associations were described as crude and adjusted prevalence ratios (PR) and their 95% confidence intervals (95% CI). We evaluated 1211 patients (women [59%], mean age 65.8 years [SD: 12.7]). Prevalence of CKD was 18%. Using the estimated glomerular filtration rate (eGFR), the prevalence was 9.3% (95% CI 5.3 - 13.3) in patients without HTN or DM2; 20.2% (95% CI 17.6 - 22.8) in patients with HTN, and 23.9% (95% CI 19.4 - 28.4) in patients with DM2. The most common stages were 1 and 2 with 41.5% and 48%, respectively. Factors associated with CKD in the adjusted analysis were: age in years (PR = 1.03, 95% CI 1.01 - 1.04), DM2 (PR = 3.37, 95% CI 1.09 - 10.39), HTN plus DM2 (PR = 3.90, 95% CI 1.54 - 9.88), and uric acid from 5 to DM2, older age and hyperuricemia have higher prevalence of CKD.

  7. Prevalence and correlates of positive mental health in Chinese adolescents.

    Science.gov (United States)

    Guo, Cheng; Tomson, Göran; Keller, Christina; Söderqvist, Fredrik

    2018-02-17

    Studies investigating the prevalence of positive mental health and its correlates are still scarce compared to the studies on mental disorders, although there is growing interest of assessing positive mental health in adolescents. So far, no other study examining the prevalence and determinants of positive mental health in Chinese adolescents has been found. The purpose of this study was to assess the prevalence and correlates of positive mental health in Chinese adolescents. This cross-sectional study used a questionnaire including Mental Health Continuum-Short Form (MHC-SF) and items regarding multiple aspects of adolescent life. The sample involved a total of 5399 students from grade 8 and 10 in Weifang, China. Multivariate Logistic regression analyses were performed to evaluate the associations between potential indicators regarding socio-economic situations, life style, social support and school life and positive mental health and calculate odds ratios and 95% confidence intervals. More than half (57.4%) of the participants were diagnosed as flourishing. The correlated factors of positive mental health in regression models included gender, perceived family economy, the occurrence of sibling(s), satisfaction of self-appearance, physical activity, sleep quality, stress, social trust, desire to learn, support from teachers and parents as well as whether being bullied at school (OR ranging from 1.23 to 2.75). The Hosmer-Lemeshow p-value for the final regression model (0.45) indicated adequate model fit. This study gives the first overview on prevalence and correlates of positive mental health in Chinese adolescents. The prevalence of positive mental health in Chinese adolescents is higher than reported in most of the previous studies also using MHC-SF. Our findings suggest that adolescents with advantageous socio-economic situations, life style, social support and school life are experiencing better positive mental health than others.

  8. Prevalence rate of chronic overuse pain in taekwondo athletes.

    Science.gov (United States)

    Koh, Jae-Ok

    2017-10-01

    The aim of this study was to estimate the prevalence of chronic overuse pain (COP) and to identify possible risk factors of COP in sport poomsae taekwondo. This is a cross-sectional survey. A total of 263 sport-poomsae competitors (112 females; 151 males; aged between 12-44 years), who competed at the 2014 sport poomsae taekwondo competition, participated in this study. The prevalence rate of COP and possible risk factors associated with COP were analyzed by using Chi-square tests and independent t-tests. A total of 173 athletes reported that they experienced COP (65.8%; 95% confidence interval [CI]: 60.5-71.5). Female athletes showed a higher prevalence rate than their male counterparts (75.9% vs. 58.3%). Lower body (61.5%) and knee joints (26.4%) were the two primarily injured body part. A total of 101 athletes reported that they injured in the previous year. Among those, 81.2% were suffered from COP. The technique that caused pain most frequently was side-kick among females and front-kick among males. Prevalence rates of COP were significantly different by sex, education level, training hour, and a history of injury. The prevalence of COP is high among sport poomsae taekwondo athletes. Competitors who are female, have a history of injury, and train for extended hours were more likely to experience COP. To identify other potential risk factors of COP in sport poomsae taekwondo, more research is needed to build upon the findings.

  9. Comprehensive Plan for Public Confidence in Nuclear Regulator

    International Nuclear Information System (INIS)

    Choi, Kwang Sik; Choi, Young Sung; Kim, Ho ki

    2008-01-01

    Public confidence in nuclear regulator has been discussed internationally. Public trust or confidence is needed for achieving regulatory goal of assuring nuclear safety to the level that is acceptable by the public or providing public ease for nuclear safety. In Korea, public ease or public confidence has been suggested as major policy goal in the 'Nuclear regulatory policy direction' annually announced. This paper reviews theory of trust, its definitions and defines nuclear safety regulation, elements of public trust or public confidence developed based on the study conducted so far. Public ease model developed and 10 measures for ensuring public confidence are also presented and future study directions are suggested

  10. Parents' obesity-related behavior and confidence to support behavioral change in their obese child: data from the STAR study.

    Science.gov (United States)

    Arsenault, Lisa N; Xu, Kathleen; Taveras, Elsie M; Hacker, Karen A

    2014-01-01

    Successful childhood obesity interventions frequently focus on behavioral modification and involve parents or family members. Parental confidence in supporting behavior change may be an element of successful family-based prevention efforts. We aimed to determine whether parents' own obesity-related behaviors were related to their confidence in supporting their child's achievement of obesity-related behavioral goals. Cross-sectional analyses of data collected at baseline of a randomized control trial testing a treatment intervention for obese children (n = 787) in primary care settings (n = 14). Five obesity-related behaviors (physical activity, screen time, sugar-sweetened beverage, sleep duration, fast food) were self-reported by parents for themselves and their child. Behaviors were dichotomized on the basis of achievement of behavioral goals. Five confidence questions asked how confident the parent was in helping their child achieve each goal. Logistic regression modeling high confidence was conducted with goal achievement and demographics as independent variables. Parents achieving physical activity or sleep duration goals were significantly more likely to be highly confident in supporting their child's achievement of those goals (physical activity, odds ratio 1.76; 95% confidence interval 1.19-2.60; sleep, odds ratio 1.74; 95% confidence interval 1.09-2.79) independent of sociodemographic variables and child's current behavior. Parental achievements of TV watching and fast food goals were also associated with confidence, but significance was attenuated after child's behavior was included in models. Parents' own obesity-related behaviors are factors that may affect their confidence to support their child's behavior change. Providers seeking to prevent childhood obesity should address parent/family behaviors as part of their obesity prevention strategies. Copyright © 2014 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  11. Psychiatric disorders in Norwegian 8- to 10-year-olds: an epidemiological survey of prevalence, risk factors, and service use

    DEFF Research Database (Denmark)

    Heiervang, Einar; Stormark, Kjell M; Lundervold, Astri J

    2007-01-01

    population included all 9,430 children attending grades 2 to 4 in Bergen schools during the academic year 2002/2003. The main screening instrument was the Strengths and Difficulties Questionnaire, whereas diagnoses were based on the Development and Well-Being Assessment. Information about child and family......%) were assessed with the Development and Well-Being Assessment in the second phase. The weighted prevalence for any DSM-IV psychiatric disorder was 7.0% (95% confidence interval 5.6%-8.5%). Disorders were associated with age, gender, learning difficulties, family type, and poverty. Although 75...

  12. Effects of postidentification feedback on eyewitness identification and nonidentification confidence.

    Science.gov (United States)

    Semmler, Carolyn; Brewer, Neil; Wells, Gary L

    2004-04-01

    Two experiments investigated new dimensions of the effect of confirming feedback on eyewitness identification confidence using target-absent and target-present lineups and (previously unused) unbiased witness instructions (i.e., "offender not present" option highlighted). In Experiment 1, participants viewed a crime video and were later asked to try to identify the thief from an 8-person target-absent photo array. Feedback inflated witness confidence for both mistaken identifications and correct lineup rejections. With target-present lineups in Experiment 2, feedback inflated confidence for correct and mistaken identifications and lineup rejections. Although feedback had no influence on the confidence-accuracy correlation, it produced clear overconfidence. Confidence inflation varied with the confidence measure reference point (i.e., retrospective vs. current confidence) and identification response latency.

  13. Effects of confidence and anxiety on flow state in competition.

    Science.gov (United States)

    Koehn, Stefan

    2013-01-01

    Confidence and anxiety are important variables that underlie the experience of flow in sport. Specifically, research has indicated that confidence displays a positive relationship and anxiety a negative relationship with flow. The aim of this study was to assess potential direct and indirect effects of confidence and anxiety dimensions on flow state in tennis competition. A sample of 59 junior tennis players completed measures of Competitive State Anxiety Inventory-2d and Flow State Scale-2. Following predictive analysis, results showed significant positive correlations between confidence (intensity and direction) and anxiety symptoms (only directional perceptions) with flow state. Standard multiple regression analysis indicated confidence as the only significant predictor of flow. The results confirmed a protective function of confidence against debilitating anxiety interpretations, but there were no significant interaction effects between confidence and anxiety on flow state.

  14. Incidence, Prevalence, Diagnostic Delay, and Clinical Presentation of Female 46,XY Disorders of Sex Development.

    Science.gov (United States)

    Berglund, Agnethe; Johannsen, Trine H; Stochholm, Kirstine; Viuff, Mette H; Fedder, Jens; Main, Katharina M; Gravholt, Claus H

    2016-12-01

    The prevalence of phenotypic females with a 46,XY karyotype is low, thus current knowledge about age and clinical presentation at diagnosis is sparse even for the most frequent conditions, androgen insensitivity syndrome (AIS), and gonadal dysgenesis. To estimate incidence, prevalence, age at diagnosis, and clinical presentation at diagnosis in 46,XY females. A nationwide study covering all known females with a 46,XY karyotype in Denmark since 1960. The diagnosis of 46,XY disorder of sex development (DSD) was determined by medical record evaluation, data from the Danish National Patient Registry, and genetic testing, if available. A total of 166 females registered as 46,XY females in the Danish Cytogenetic Central Registry were identified. A total of 124 females were classified as having 46,XY DSD, 78 with AIS and 25 with gonadal dysgenesis, whereas the remaining subjects had a variety of different diagnoses. The prevalence of 46,XY females was 6.4 per 100 000 live born females, and for AIS and gonadal dysgenesis, it was 4.1 and 1.5 per 100 000, respectively. Median age at diagnosis was 7.5 years (95% confidence interval, 4.0-13.5; range, 0-34 y) in AIS and 17.0 years (95% confidence interval, 15.5-19.0; range, 0-28 y) in gonadal dysgenesis (P = .001). Clinical presentation was dependent on cause of DSD. The first estimate on prevalence of 46,XY females is 6.4 per 100 000 live born females. The presentation of AIS and gonadal dysgenesis is distinctly different, with AIS being diagnosed during childhood and gonadal dysgenesis during pubertal years. The presenting phenotype is dependent on the cause of 46,XY DSD.

  15. Prevalence of osteoporosis and incidence of hip fracture in women - secular trends over 30 years

    Directory of Open Access Journals (Sweden)

    Sernbo Ingemar

    2010-03-01

    Full Text Available Abstract Background The number of hip fractures during recent decades has been reported to be increasing, partly because of an increasing proportion of elderly women in the society. However, whether changes in hip fracture annual incidence in women are attributable to secular changes in the prevalence of osteoporosis is unclear. Methods Bone mineral density was evaluated by single-photon absorptiometry at the distal radius in 456 women aged 50 years or above and living in the same city. The measurements were obtained by the same densitometer during three separate time periods: 1970-74 (n = 106, 1987-93 (n = 175 and 1998-1999 (n = 178, and the age-adjusted prevalence of osteoporosis in these three cohorts was calculated. Additionally, all hip fractures sustained in the target population of women aged 50 years or above between 1967 and 2001 were registered, whereupon the crude and the age-adjusted annual incidence of hip fractures were calculated. Results There was no significant difference in the age-adjusted prevalence of osteoporosis when the three cohorts were compared (P = 1.00. The crude annual incidence (per 10,000 women of hip fracture in the target population increased by 110% from 40 in 1967 to 84 in 2001. The overall trend in the crude incidence between 1967 and 2001 was increasing (1.58 per 10,000 women per year; 95 percent confidence interval, 1.17 to 1.99, whereas the age-adjusted incidence was stable over the same period (0.22 per 10,000 women per year; 95 percent confidence interval, -0.16 to 0.60. Conclusions The increased number of hip fracture in elderly women is more likely to be attributable to demographic changes in the population than to secular increase in the prevalence of osteoporosis.

  16. Some Characterizations of Convex Interval Games

    NARCIS (Netherlands)

    Brânzei, R.; Tijs, S.H.; Alparslan-Gok, S.Z.

    2008-01-01

    This paper focuses on new characterizations of convex interval games using the notions of exactness and superadditivity. We also relate big boss interval games with concave interval games and obtain characterizations of big boss interval games in terms of exactness and subadditivity.

  17. The prevalence of recurrent abdominal pain in 11- to 16-year-old Malaysian schoolchildren.

    Science.gov (United States)

    Boey, C; Yap, S; Goh, K L

    2000-04-01

    To determine the prevalence of recurrent abdominal pain (RAP) among Malaysian school children aged from 11 to 16 years. A preliminary cross-sectional survey in which three urban schools and three rural schools were selected randomly. Two classes were selected randomly from each year. A questionnaire was given to each child asking him or her about whether they had experienced abdominal pain occurring at least three times over a period of at least 3 months, interfering with normal daily activity. 1 Interfering with normal daily activity was defined as missing school and/or having to stop doing a routine daily activity on account of the pain. Girls whose pains were related to periods were excluded. After the forms had been completed, each child was again interviewed to ensure that Apley's criteria1 was fulfilled in cases of RAP. The overall prevalence of RAP among 1549 schoolchildren (764 boys; 785 girls) was 10.2% (95% confidence interval (CI), 8.8-11.8). There appeared to be a higher prevalence in rural schoolchildren (P = 0.008; odds ratio (OR) 1.58), in those with a lower family income (P family size. : In spite of differences in time and culture, the overall prevalence of 10.2% found in this study is similar to that determined by Apley.1 There are significant differences in the prevalence of RAP between children from rural and urban schools, among children with different family incomes and among children whose parents have different educational backgrounds.

  18. Tobacco Usage in Uttarakhand: A Dangerous Combination of High Prevalence, Widespread Ignorance, and Resistance to Quitting

    Directory of Open Access Journals (Sweden)

    Nathan John Grills

    2015-01-01

    Full Text Available Background. Nearly one-third of adults in India use tobacco, resulting in 1.2 million deaths. However, little is known about knowledge, attitudes, and practices (KAP related to smoking in the impoverished state of Uttarakhand. Methods. A cross-sectional epidemiological prevalence survey was undertaken. Multistage cluster sampling selected 20 villages and 50 households to survey from which 1853 people were interviewed. Tobacco prevalence and KAP were analyzed by income level, occupation, age, and sex. 95% confidence intervals were calculated using standard formulas and incorporating assumptions in relation to the clustering effect. Results. The overall prevalence of tobacco usage, defined using WHO criteria, was 38.9%. 93% of smokers and 86% of tobacco chewers were male. Prevalence of tobacco use, controlling for other factors, was associated with lower education, older age, and male sex. 97.6% of users and 98.1% of nonusers wanted less tobacco. Except for lung cancer (89% awareness, awareness of diseases caused by tobacco usage was low (cardiac: 67%; infertility: 32.5%; stroke: 40.5%. Conclusion. A dangerous combination of high tobacco usage prevalence, ignorance about its dangers, and few quit attempts being made suggests the need to develop effective and evidence based interventions to prevent a health and development disaster in Uttarakhand.

  19. Intake of dairy products and the prevalence of dental caries in young children.

    Science.gov (United States)

    Tanaka, Keiko; Miyake, Yoshihiro; Sasaki, Satoshi

    2010-07-01

    In vitro studies show that milk or milk components may have cariostatic properties. However, the results of epidemiological studies on the association between intake of dairy products and dental caries have been inconsistent. The purpose of this cross-sectional study was to examine the association between intake of dairy products and the prevalence of dental caries in young children. Study subjects were 2058 Japanese children aged 3 years. Information on diet was assessed with a self-administered brief diet history questionnaire for children. The consumption of dairy products was categorized into 3 levels in order to represent the tertiles as closely as possible. Dental caries was assessed by a visual examination. Adjustment was made for sex, toothbrushing frequency, use of fluoride, between-meal snack frequency, maternal smoking during pregnancy, environmental tobacco smoke exposure at home, and paternal and maternal educational levels. Compared with yogurt consumption at the lowest tertile ( or =4 times/week) was significantly associated with a lower prevalence of dental caries, showing a clear dose-response relationship (adjusted prevalence ratio=0.78, 95% confidence interval: 0.62-0.98, P for trend=0.04). There were no material associations between intake of cheese, bread and butter, or milk and the prevalence of dental caries. These data suggest that a high consumption of yogurt may be associated with a lower prevalence of dental caries in young children. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. The Synchronous Prevalence of Colorectal Neoplasms in Patients with Stomach Cancer

    Science.gov (United States)

    Lee, Sang Su; Kim, Cha Young; Ha, Chang Yoon; Min, Hyun Ju; Kim, Hyun Jin; Kim, Tae Hyo

    2011-01-01

    Purpose The association between stomach cancer and colorectal cancer is controversial. The purpose of this study was to determine the synchronous prevalence of colorectal neoplasms in patients with stomach cancer. Methods A total of 123 patients with stomach cancer (86 male) and 246 consecutive, age- and sex-matched persons without stomach cancer were analyzed from July 2005 to June 2010. All of them underwent colonoscopy within 6 months after undergoing gastroscopy. Results The prevalence of colorectal neoplasms was significantly higher in the stomach cancer group (35.8%) than in the control group (17.9%) (P neoplasms were more prevalent in the patients with stomach cancer (odds ratio [OR], 3.10; 95% confidence interval [CI], 1.71 to 5.63). In particular, the difference in the prevalence of colorectal neoplasms was more prominent in the patients above 50 years old (OR, 3.54; 95% CI, 1.80 to 6.98). Conclusion The results showed that the synchronous prevalence of colorectal neoplasms was higher in patients with stomach cancer than in those without stomach cancer. Therefore, patients with stomach cancer should be regarded as a high-risk group for colorectal neoplasms, and colonoscopy should be recommended for screening. PMID:22102975

  1. Meta-analysis of classical swine fever prevalence in pigs in India: A 5-year study

    Science.gov (United States)

    Patil, S. S.; Suresh, K. P.; Saha, S.; Prajapati, A.; Hemadri, D.; Roy, P.

    2018-01-01

    Aim: The aim of the study was to determine the overall prevalence of classical swine fever (CSF) in pigs in India, through a systematic review and meta-analysis of published data. Materials and Methods: Consortium for e-Resources in Agriculture, India, Google Scholar, PubMed, annual reports of All India Coordinated Research Project on Animal Disease Monitoring and Surveillance, and All India Animal Disease database of NIVEDI (NADRES) were used for searching and retrieval of CSF prevalence data (seroprevalence, virus antigen, and virus nucleic acid detection) in India using a search strategy combining keywords and related database-specific subject terms from January 2011 to December 2015 in English only. Results: A total of 22 data reports containing 6,158 samples size from 18 states of India were used for the quantitative synthesis, and overall 37% (95% confidence interval [CI]=0.24, 0.51) CSF prevalence in India was estimated. The data were classified into 4 different geographical zones of the country: 20% (95% CI=0.05, 0.55), 31% (95% CI=0.18, 0.47), 55% (95% CI=0.32, 0.76), and 34% (95% CI=0.14, 0.62). CSF prevalence was estimated in northern, eastern, western, and southern regions, respectively. Conclusion: This study indicates that overall prevalence of CSF in India is much lower than individual published reports. PMID:29657420

  2. The prevalence of mobile phone use among motorcyclists in three Mexican cities.

    Science.gov (United States)

    Pérez-Núñez, Ricardo; Hidalgo-Solórzano, Elisa; Vera-López, Juan Daniel; Lunnen, Jeffrey C; Chandran, Aruna; Híjar, Martha; Hyder, Adnan A

    2014-01-01

    To quantify the prevalence of mobile phone use among motorcyclists in 3 Mexican cities and to identify associated factors. Two rounds of roadside observations were conducted in Guadalajara-Zapopan, León, and Cuernavaca from December 2011 to May 2012. Observation sites were selected randomly and all motorcyclists circulating at those sites were recorded. Motorcyclists observed talking into a phone (either handheld or hands-free) or texting were recorded as using a mobile phone while driving. A total of 4244 motorcyclists were observed. The overall prevalence of mobile phone use was 0.64 percent (95% confidence interval [CI]: 0.42-0.92); it was highest in Guadalajara-Zapopan (1.03%; 95% CI: 0.61-1.63) and among motorcyclists not using a helmet (1.45% versus 0.4%; P = .000) and those riding on 1-lane roads (1.6% versus 0.8% on 2-lane roads and 0.5% in 3- to 5-lane roads; P = .046). To our knowledge this is the first study that reports the prevalence of mobile phone use while driving among motorcyclists. The observed prevalence is higher than the prevalence stated in a previous report from China on electric bicycle riders. This risk factor should be monitored in the future given the growing popularity of motorcycles and the availability of mobile devices. Current legislation should be enforced to avoid potential injuries and deaths attributable to this risk factor.

  3. Excessive sleepiness prevalence in public transportation drivers of a developing country.

    Science.gov (United States)

    Risco, Jorge; Ruiz, Paulo; Mariños, Alejandro; Juarez, Alan; Ramos, Mariana; Salmavides, Frine; Vega, Johann; Kruger, Hever; Vizcarra, Darwin

    2013-01-01

    To determine the prevalence of excessive sleepiness (ES) in bus and auto-rickshaw drivers from Lima, Peru. We conducted a cross-sectional study of Lima's bus and auto-rickshaw drivers to estimate ES prevalence in this population. Survey sites were private transportation companies, systematically selected with a snowball approach. ES was assessed with the Spanish-validated version of the Epworth sleep questionnaire (ESQ) with a cutoff score >10. We obtained relevant demographic information. Four hundred and thirty-four bus and auto-rickshaw drivers were eligible for analysis. The overall ES prevalence was 32.7 percent (95% confidence interval [CI]: 28-37.2). ES prevalence was higher in bus drivers than in auto-rickshaw drivers, 38 percent (95% CI: 31.7-44.2) and 26.9 percent (95% CI: 20.6-33.1), respectively (P = .01). We used data from all subjects to obtain regression equations for ESQ score with several predictors. Being a bus driver, working additional nighttime hours per week, having depression or anxiety, and alcohol abuse had small but significant associations with ESQ scores. ES prevalence in Lima's public transportation drivers is in a medium range as suggested by previous regional studies.

  4. [Prevalence and predictors of psychoactive substance use among men in prisons].

    Science.gov (United States)

    Caravaca-Sánchez, Francisco; Falcón Romero, María; Luna, Aurelio

    2015-01-01

    The use of psychoactive substances among the prison population is an important public health issue because of its magnitude and health consequences. The aim of this study was to estimate the prevalence of psychoactive substance use among the prison population and to analyse its association with sociodemographic and penitentiary factors, particularly the size of the prison. Data were gathered using a self-administered questionnaire among 2,484 random male inmates in eight prisons of different sizes in Spain. The prevalence of psychoactive substance use with 95% confidence intervals (95% CI) during the last 6 months in prison were estimated. Prevalence ratios were used to estimate the association between psychoactive substance use and sociodemographic and penitentiary characteristics. The prevalence of psychoactive substance use in the past 6 months in prison was 59.9% (95% CI: 57.9-62.0). Notable among the sociodemographic variables associated with substance use were drug consumption prior to imprisonment (6.90; 95% CI: 5.51-8.65) and recidivism in prison (2.41; 95% CI: 2.04-2.85). The largest prisons showed a higher frequency of drug use than other prisons. A high prevalence of psychoactive substance use was found in prisons and significant differences were found according to delinquent profile and the size of the prison. Copyright © 2015 SESPAS. Published by Elsevier Espana. All rights reserved.

  5. Prevalence and incidence rate of injuries in runners at a local athletic club in Cape Town

    Directory of Open Access Journals (Sweden)

    C. Hendricks

    2013-12-01

    Full Text Available People across the world are running on a daily basis to improvetheir health status. However, running can predispose an individual to injuryto the back and lower limb. Baseline data on prevalence, incidence rate ofinjury and aetiological factors associated with running injuries are neededby physiotherapists to develop and implement effective prevention programmesto allow optimal performance in runners. Thus, the purpose of this study wasto determine the prevalence and incidence of injuries in runners at a localathletic club.Methods: A prospective, non-experimental cohort study was conductedover a 16 week period. A sample of 50 runners completed a self-administeredquestionnaire and an injury report form recording injuries sustained during the 16 week study period. Injury prevalence andcumulative incidence was calculated as a proportion rate along with 95% confidence interval.Results: The prevalence rate of injuries was 32%. The incidence rate of injuries was 0.67 per 1000km run (95% CI: 0.41- 1.08.The most common anatomical sites for new injuries were the calf (20% and the knee (18%.Conclusions: The study found a moderate prevalence and incidence rate of injury in runners, thus the need for physiotherapyledinjury surveillance and prevention programmes have been highlighted.

  6. Trends of obesity prevalence among Spanish adults with diabetes, 1987-2012.

    Science.gov (United States)

    Basterra-Gortari, Francisco Javier; Bes-Rastrollo, Maira; Ruiz-Canela, Miguel; Gea, Alfredo; Sayón-Orea, Carmen; Martínez-González, Miguel Ángel

    2018-04-24

    Our aim was to examine the secular trends in obesity prevalence among Spanish adults with diabetes. Data were collected from 8 waves (from 1987 to 2012) of the National Health Surveys (NHS). NHS are cross-sectional studies conducted in representative samples of the Spanish adult population. Data of 7378 adults (≥16 years) who reported having been diagnosed of diabetes were analyzed. Previously validated self-reported weight and height were used to estimate body mass index (BMI). Obesity was defined as a BMI of 30kg/m 2 or greater. Age-adjusted obesity prevalence for each wave was calculated by the direct standardization method. From 1987 to 2012 age-adjusted prevalence of obesity among persons with diabetes increased from 18.2% (95% confidence interval [CI]: 14.2-22.2%) to 39.8% (95% CI: 36.8-42.8%). Age-adjusted prevalence of obesity in males with diabetes increased from 13.2% (95% CI: 7.3-19.1%) to 38.0% (95% CI: 33.8-42.1%) and in females from 23.0% (95% CI: 17.6-28.4%) to 42.3% (95% CI: 38.0-46.6%). Between 1987 and 2012 the prevalence of obesity markedly increased in Spain among adults with diabetes. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

  7. Prevalence and factors associated with latent tuberculosis infection in an indigenous population in the Brazilian Amazon.

    Science.gov (United States)

    Malacarne, Jocieli; Rios, Diana Patricia Giraldo; Silva, Cosme Marcelo Furtado Passos da; Braga, José Ueleres; Camacho, Luiz Antonio Bastos; Basta, Paulo Cesar

    2016-01-01

    Recent studies have shown a high incidence and prevalence of latent tuberculosis infection (LTBI) in indigenous populations around the World. We aimed to estimate the prevalence and annual risk of infection (ARI) as well as to identify factors associated with LTBI in an indigenous population from the Brazilian Amazon. We conducted a cross-sectional study in 2011. We performed tuberculin skin tests (TSTs), smears and cultures of sputum samples, and chest radiographs for individuals who reported cough for two or more weeks. Associations between LTBI (TST ≥5mm) and socio-demographic, clinical, and epidemiological characteristics were investigated using Poisson regression with robust variance. Prevalence ratio (PR) was used as the measure of association. We examined 263 individuals. The prevalence of LTBI was 40.3%, and the ARI was 2.4%. Age ≥15 years [PR=5.5; 95% confidence interval (CI): 3.5-8.6], contact with tuberculosis (TB) patients (PR=3.8; 95% CI: 1.2-11.9), previous TB history (PR=1.4; 95% CI: 1.2-1.7), and presence of Bacillus Calmette-Guérin (BCG) scar (PR=1.9, 95% CI: 1.2-2.9) were associated with LTBI. Although some adults may have been infected years prior, the high prevalence of infection and its strong association with age ≥15 years, history of TB, and recent contact with TB patients suggest that the TB transmission risk is high in the study area.

  8. Prevalence of metabolic syndrome in Central America: a cross-sectional population-based study

    Directory of Open Access Journals (Sweden)

    Roy A. Wong-McClure

    2015-09-01

    Full Text Available OBJECTIVE: To report the prevalence of metabolic syndrome (MetS as found by the Central American Diabetes Initiative (CAMDI study for five major Central American populations: Belize (national; Costa Rica (San José; Guatemala (Guatemala City; Honduras (Tegucigalpa; and Nicaragua (Managua. METHODS: Study data on 6 185 adults aged 20 years or older with anthropometric and laboratory determination of MetS from population-based surveys were analyzed. Overall, the survey response rate was 82.0%. MetS prevalence was determined according to criteria from the Adult Treatment Panel III of the National Cholesterol Education Program. The study's protocol was reviewed and approved by the bioethical committee of each country studied. RESULTS: The overall standardized prevalence of MetS in the Central American region was 30.3% (95% confidence interval (CI: 27.1-33.4. There was wide variability by gender and work conditions, with higher prevalence among females and unpaid workers. The standardized percentage of the population free of any component of MetS was lowest in Costa Rica (9.0%; CI: 6.5-11.4 and highest in Honduras (21.1%; CI: 16.4-25.9. CONCLUSIONS: Overall prevalence of MetS in Central America is high. Strengthening surveillance of chronic diseases and establishing effective programs for preventing cardiovascular diseases might reduce the risk of MetS in Central America.

  9. Missed nursing care and its relationship with confidence in delegation among hospital nurses.

    Science.gov (United States)

    Saqer, Tahani J; AbuAlRub, Raeda F

    2018-04-06

    To (i) identify the types and reasons for missed nursing care among Jordanian hospital nurses; (ii) identify predictors of missed nursing care based on study variables; and (iii) examine the relationship between nurses' confidence in delegation and missed nursing care. Missed nursing care is a global concern for nurses and nurse administrators. Investigating the relation between the confidence in delegation and missed nursing care might help in designing strategies that enable nurses to minimise missed care and enhance quality of services. A correlational research design was used for this study. A convenience sample of 362 hospital nurses completed the missed nursing care survey, and confidence and intent to delegate scale. The results of the study revealed that ambulating and feeding patients on time, doing mouth care and attending interdisciplinary care conferences were the most frequent types of missed care. The mean score for missed nursing care was (2.78) on a scale from 1-5. The most prevalent reasons for missed care were "labour resources, followed by material resources, and then communication". Around 45% of the variation in the perceived level of "missed nursing care" was explained by background variables and perceived reasons for missed nursing. However, the relationship between confidence in delegation and missed care was insignificant. The results of this study add to the body of international literature on most prevalent types and reasons for missed nursing care in a different cultural context. Highlighting most prevalent reasons for missed nursing care could help nurse administrators in designing responsive strategies to eliminate or reduces such reasons. © 2018 John Wiley & Sons Ltd.

  10. Beyond hypercorrection: remembering corrective feedback for low-confidence errors.

    Science.gov (United States)

    Griffiths, Lauren; Higham, Philip A

    2018-02-01

    Correcting errors based on corrective feedback is essential to successful learning. Previous studies have found that corrections to high-confidence errors are better remembered than low-confidence errors (the hypercorrection effect). The aim of this study was to investigate whether corrections to low-confidence errors can also be successfully retained in some cases. Participants completed an initial multiple-choice test consisting of control, trick and easy general-knowledge questions, rated their confidence after answering each question, and then received immediate corrective feedback. After a short delay, they were given a cued-recall test consisting of the same questions. In two experiments, we found high-confidence errors to control questions were better corrected on the second test compared to low-confidence errors - the typical hypercorrection effect. However, low-confidence errors to trick questions were just as likely to be corrected as high-confidence errors. Most surprisingly, we found that memory for the feedback and original responses, not confidence or surprise, were significant predictors of error correction. We conclude that for some types of material, there is an effortful process of elaboration and problem solving prior to making low-confidence errors that facilitates memory of corrective feedback.

  11. Factors affecting midwives' confidence in intrapartum care: a phenomenological study.

    Science.gov (United States)

    Bedwell, Carol; McGowan, Linda; Lavender, Tina

    2015-01-01

    midwives are frequently the lead providers of care for women throughout labour and birth. In order to perform their role effectively and provide women with the choices they require midwives need to be confident in their practice. This study explores factors which may affect midwives' confidence in their practice. hermeneutic phenomenology formed the theoretical basis for the study. Prospective longitudinal data collection was completed using diaries and semi-structured interviews. Twelve midwives providing intrapartum care in a variety of settings were recruited to ensure a variety of experiences in different contexts were captured. the principal factor affecting workplace confidence, both positively and negatively, was the influence of colleagues. Perceived autonomy and a sense of familiarity could also enhance confidence. However, conflict in the workplace was a critical factor in reducing midwives' confidence. Confidence was an important, but fragile, phenomenon to midwives and they used a variety of coping strategies, emotional intelligence and presentation management to maintain it. this is the first study to highlight both the factors influencing midwives' workplace confidence and the strategies midwives employed to maintain their confidence. Confidence is important in maintaining well-being and workplace culture may play a role in explaining the current low morale within the midwifery workforce. This may have implications for women's choices and care. Support, effective leadership and education may help midwives develop and sustain a positive sense of confidence. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Survey of the prevalence and methodology of quality assurance for B-mode ultrasound image quality among veterinary sonographers.

    Science.gov (United States)

    Hoscheit, Larry P; Heng, Hock Gan; Lim, Chee Kin; Weng, Hsin-Yi

    2018-05-01

    Image quality in B-mode ultrasound is important as it reflects the diagnostic accuracy and diagnostic information provided during clinical scanning. Quality assurance programs for B-mode ultrasound systems/components are comprised of initial quality acceptance testing and subsequent regularly scheduled quality control testing. The importance of quality assurance programs for B-mode ultrasound image quality using ultrasound phantoms is well documented in the human medical and medical physics literature. The purpose of this prospective, cross-sectional, survey study was to determine the prevalence and methodology of quality acceptance testing and quality control testing of image quality for ultrasound system/components among veterinary sonographers. An online electronic survey was sent to 1497 members of veterinary imaging organizations: the American College of Veterinary Radiology, the Veterinary Ultrasound Society, and the European Association of Veterinary Diagnostic Imaging, and a total of 167 responses were received. The results showed that the percentages of veterinary sonographers performing quality acceptance testing and quality control testing are 42% (64/151; 95% confidence interval 34-52%) and 26% (40/156: 95% confidence interval 19-33%) respectively. Of the respondents who claimed to have quality acceptance testing or quality control testing of image quality in place for their ultrasound system/components, 0% have performed quality acceptance testing or quality control testing correctly (quality acceptance testing 95% confidence interval: 0-6%, quality control testing 95% confidence interval: 0-11%). Further education and guidelines are recommended for veterinary sonographers in the area of quality acceptance testing and quality control testing for B-mode ultrasound equipment/components. © 2018 American College of Veterinary Radiology.

  13. Prevalence of Musculoskeletal Disorders Among Surgeons Performing Minimally Invasive Surgery: A Systematic Review.

    Science.gov (United States)

    Alleblas, Chantal C J; de Man, Anne Marie; van den Haak, Lukas; Vierhout, Mark E; Jansen, Frank Willem; Nieboer, Theodoor E

    2017-12-01

    The aim of this study was to review musculoskeletal disorder (MSD) prevalence among surgeons performing minimally invasive surgery. Advancements in laparoscopic surgery have primarily focused on enhancing patient benefits. However, compared with open surgery, laparoscopic surgery imposes greater ergonomic constraints on surgeons. Recent reports indicate a 73% to 88% prevalence of physical complaints among laparoscopic surgeons, which is greater than in the general working population, supporting the need to address the surgeons' physical health. To summarize the prevalence of MSDs among surgeons performing laparoscopic surgery, we performed a systematic review of studies addressing physical ergonomics as a determinant, and reporting MSD prevalence. On April 15 2016, we searched Pubmed, EMBASE, the Cochrane Library, Web of Science, CINAHL, and PsychINFO. Meta-analyses were performed using the Hartung-Knapp-Sidik-Jonkman method. We identified 35 articles, including 7112 respondents. The weighted average prevalence of complaints was 74% [95% confidence interval (95% CI) 65-83]. We found high inconsistency across study results (I = 98.3%) and the overall response rate was low. If all nonresponders were without complaints, the prevalence would be 22% (95% CI 16-30). From the available literature, we found a 74% prevalence of physical complaints among laparoscopic surgeons. However, the low response rates and the high inconsistency across studies leave some uncertainty, suggesting an actual prevalence of between 22% and 74%. Fatigue and MSDs impact psychomotor performance; therefore, these results warrant further investigation. Continuous changes are enacted to increase patient safety and surgical care quality, and should also include efforts to improve surgeons' well-being.

  14. Dietary patterns of Korean adults and the prevalence of metabolic syndrome: a cross-sectional study.

    Science.gov (United States)

    Woo, Hae Dong; Shin, Aesun; Kim, Jeongseon

    2014-01-01

    The prevalence of metabolic syndrome has been increasing in Korea and has been associated with dietary habits. The aim of our study was to identify the relationship between dietary patterns and the prevalence of metabolic syndrome. Using a validated food frequency questionnaire, we employed a cross-sectional design to assess the dietary intake of 1257 Korean adults aged 31 to 70 years. To determine the participants' dietary patterns, we considered 37 predefined food groups in principal components analysis. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III. The abdominal obesity criterion was modified using Asian guidelines. Prevalence ratios and 95% confidence intervals for the metabolic syndrome were calculated across the quartiles of dietary pattern scores using log binomial regression models. The covariates used in the model were age, sex, total energy intake, tobacco intake, alcohol consumption, and physical activity. The prevalence of metabolic syndrome was 19.8% in men and 14.1% in women. The PCA identified three distinct dietary patterns: the 'traditional' pattern, the 'meat' pattern, and the 'snack' pattern. There was an association of increasing waist circumference and body mass index with increasing score in the meat dietary pattern. The multivariate-adjusted prevalence ratio of metabolic syndrome for the highest quartile of the meat pattern in comparison with the lowest quartile was 1.47 (95% CI: 1.00-2.15, p for trend = 0.016). A positive association between the prevalence of metabolic syndrome and the dietary pattern score was found only for men with the meat dietary pattern (2.15, 95% CI: 1.10-4.21, p for trend = 0.005). The traditional pattern and the snack pattern were not associated with an increased prevalence of metabolic syndrome. The meat dietary pattern was associated with a higher prevalence of metabolic syndrome in Korean male adults.

  15. Dietary patterns of Korean adults and the prevalence of metabolic syndrome: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Hae Dong Woo

    Full Text Available The prevalence of metabolic syndrome has been increasing in Korea and has been associated with dietary habits. The aim of our study was to identify the relationship between dietary patterns and the prevalence of metabolic syndrome. Using a validated food frequency questionnaire, we employed a cross-sectional design to assess the dietary intake of 1257 Korean adults aged 31 to 70 years. To determine the participants' dietary patterns, we considered 37 predefined food groups in principal components analysis. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III. The abdominal obesity criterion was modified using Asian guidelines. Prevalence ratios and 95% confidence intervals for the metabolic syndrome were calculated across the quartiles of dietary pattern scores using log binomial regression models. The covariates used in the model were age, sex, total energy intake, tobacco intake, alcohol consumption, and physical activity. The prevalence of metabolic syndrome was 19.8% in men and 14.1% in women. The PCA identified three distinct dietary patterns: the 'traditional' pattern, the 'meat' pattern, and the 'snack' pattern. There was an association of increasing waist circumference and body mass index with increasing score in the meat dietary pattern. The multivariate-adjusted prevalence ratio of metabolic syndrome for the highest quartile of the meat pattern in comparison with the lowest quartile was 1.47 (95% CI: 1.00-2.15, p for trend = 0.016. A positive association between the prevalence of metabolic syndrome and the dietary pattern score was found only for men with the meat dietary pattern (2.15, 95% CI: 1.10-4.21, p for trend = 0.005. The traditional pattern and the snack pattern were not associated with an increased prevalence of metabolic syndrome. The meat dietary pattern was associated with a higher prevalence of metabolic syndrome in Korean male adults.

  16. Can confidence indicators forecast the probability of expansion in Croatia?

    Directory of Open Access Journals (Sweden)

    Mirjana Čižmešija

    2016-04-01

    Full Text Available The aim of this paper is to investigate how reliable are confidence indicators in forecasting the probability of expansion. We consider three Croatian Business Survey indicators: the Industrial Confidence Indicator (ICI, the Construction Confidence Indicator (BCI and the Retail Trade Confidence Indicator (RTCI. The quarterly data, used in the research, covered the periods from 1999/Q1 to 2014/Q1. Empirical analysis consists of two parts. The non-parametric Bry-Boschan algorithm is used for distinguishing periods of expansion from the period of recession in the Croatian economy. Then, various nonlinear probit models were estimated. The models differ with respect to the regressors (confidence indicators and the time lags. The positive signs of estimated parameters suggest that the probability of expansion increases with an increase in Confidence Indicators. Based on the obtained results, the conclusion is that ICI is the most powerful predictor of the probability of expansion in Croatia.

  17. Confidence mediates the sex difference in mental rotation performance.

    Science.gov (United States)

    Estes, Zachary; Felker, Sydney

    2012-06-01

    On tasks that require the mental rotation of 3-dimensional figures, males typically exhibit higher accuracy than females. Using the most common measure of mental rotation (i.e., the Mental Rotations Test), we investigated whether individual variability in confidence mediates this sex difference in mental rotation performance. In each of four experiments, the sex difference was reliably elicited and eliminated by controlling or manipulating participants' confidence. Specifically, confidence predicted performance within and between sexes (Experiment 1), rendering confidence irrelevant to the task reliably eliminated the sex difference in performance (Experiments 2 and 3), and manipulating confidence significantly affected performance (Experiment 4). Thus, confidence mediates the sex difference in mental rotation performance and hence the sex difference appears to be a difference of performance rather than ability. Results are discussed in relation to other potential mediators and mechanisms, such as gender roles, sex stereotypes, spatial experience, rotation strategies, working memory, and spatial attention.

  18. Coping skills: role of trait sport confidence and trait anxiety.

    Science.gov (United States)

    Cresswell, Scott; Hodge, Ken

    2004-04-01

    The current research assesses relationships among coping skills, trait sport confidence, and trait anxiety. Two samples (n=47 and n=77) of international competitors from surf life saving (M=23.7 yr.) and touch rugby (M=26.2 yr.) completed the Athletic Coping Skills Inventory, Trait Sport Confidence Inventory, and Sport Anxiety Scale. Analysis yielded significant correlations amongst trait anxiety, sport confidence, and coping. Specifically confidence scores were positively associated with coping with adversity scores and anxiety scores were negatively associated. These findings support the inclusion of the personality characteristics of confidence and anxiety within the coping model presented by Hardy, Jones, and Gould, Researchers should be aware that confidence and anxiety may influence the coping processes of athletes.

  19. Chlamydia prevalence among women and men entering the National Job Training Program: United States, 2003-2007.

    Science.gov (United States)

    Satterwhite, Catherine Lindsey; Tian, Lin H; Braxton, Jimmy; Weinstock, Hillard

    2010-02-01

    To analyze 5-year prevalence trends in Chlamydia trachomatis infections among high-risk young men and women aged 16 to 24 years entering the National Job Training Program, where universal screening is required. Entrance exams conducted in over 100 National Job Training Program centers from 2003 to 2007 were considered. Women provided cervical specimens tested using either a DNA hybridization probe (PACE 2, Gen-Probe, San Diego, CA) or a strand displacement amplification test (SDA, BD ProbeTec ET, Becton-Dickinson, Sparks, MD). In the absence of a pelvic exam, urine specimens were tested using SDA. PACE 2 testing was performed predominately from 2002 to 2005; from 2005 to 2007, SDA was used. All male testing was conducted using SDA on urine specimens. Chlamydia prevalence trends were assessed for women and men, using logistic regression models. Adjusted odds ratios (AOR), 95% confidence intervals (CI), and P-values were calculated. Approximately 15,000 women and 30,000 men were screened annually for chlamydia. Among both sexes, adjusted prevalence declined significantly from 2003 to 2007. In 2003, crude prevalence among women was 9.9%; in 2007, prevalence was 13.7%. However, after controlling for covariates, including increasingly sensitive tests, the model indicated a significant declining prevalence trend (AOR: 0.95, CI: 0.93-0.97, 4.6% decrease in odds per year). Among men, crude prevalence in 2003 was 8.4%; in 2007, prevalence was 8.3%; after controlling for possible confounding, a significant decline in prevalence was also detected (AOR: 0.98, CI: 0.96-0.99, 1.9% decrease in odds per year). In a relatively stable, high-risk population of young women and men, adjusted chlamydia prevalence declined from 2003 to 2007. Test technology plays a critical role in interpreting rates and should be considered whenever chlamydia rates are examined.

  20. Assessing Mediational Models: Testing and Interval Estimation for Indirect Effects.

    Science.gov (United States)

    Biesanz, Jeremy C; Falk, Carl F; Savalei, Victoria

    2010-08-06

    Theoretical models specifying indirect or mediated effects are common in the social sciences. An indirect effect exists when an independent variable's influence on the dependent variable is mediated through an intervening variable. Classic approaches to assessing such mediational hypotheses ( Baron & Kenny, 1986 ; Sobel, 1982 ) have in recent years been supplemented by computationally intensive methods such as bootstrapping, the distribution of the product methods, and hierarchical Bayesian Markov chain Monte Carlo (MCMC) methods. These different approaches for assessing mediation are illustrated using data from Dunn, Biesanz, Human, and Finn (2007). However, little is known about how these methods perform relative to each other, particularly in more challenging situations, such as with data that are incomplete and/or nonnormal. This article presents an extensive Monte Carlo simulation evaluating a host of approaches for assessing mediation. We examine Type I error rates, power, and coverage. We study normal and nonnormal data as well as complete and incomplete data. In addition, we adapt a method, recently proposed in statistical literature, that does not rely on confidence intervals (CIs) to test the null hypothesis of no indirect effect. The results suggest that the new inferential method-the partial posterior p value-slightly outperforms existing ones in terms of maintaining Type I error rates while maximizing power, especially with incomplete data. Among confidence interval approaches, the bias-corrected accelerated (BC a ) bootstrapping approach often has inflated Type I error rates and inconsistent coverage and is not recommended; In contrast, the bootstrapped percentile confidence interval and the hierarchical Bayesian MCMC method perform best overall, maintaining Type I error rates, exhibiting reasonable power, and producing stable and accurate coverage rates.

  1. Influence of coronary artery disease prevalence on predictive values of coronary CT angiography: a meta-regression analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schlattmann, Peter [University Hospital of Friedrich-Schiller University Jena, Department of Medical Statistics, Informatics and Documentation, Jena (Germany); Schuetz, Georg M. [Freie Universitaet Berlin, Charite, Medical School, Department of Radiology, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, Marc [Freie Universitaet Berlin, Charite, Medical School, Department of Radiology, Humboldt-Universitaet zu Berlin, Berlin (Germany); Charite, Institut fuer Radiologie, Berlin (Germany)

    2011-09-15

    To evaluate the impact of coronary artery disease (CAD) prevalence on the predictive values of coronary CT angiography. We performed a meta-regression based on a generalised linear mixed model using the binomial distribution and a logit link to analyse the influence of the prevalence of CAD in published studies on the per-patient negative and positive predictive values of CT in comparison to conventional coronary angiography as the reference standard. A prevalence range in which the negative predictive value was higher than 90%, while at the same time the positive predictive value was higher than 70% was considered appropriate. The summary negative and positive predictive values of coronary CT angiography were 93.7% (95% confidence interval [CI] 92.8-94.5%) and 87.5% (95% CI, 86.5-88.5%), respectively. With 95% confidence, negative and positive predictive values higher than 90% and 70% were available with CT for a CAD prevalence of 18-63%. CT systems with >16 detector rows met these requirements for the positive (P < 0.01) and negative (P < 0.05) predictive values in a significantly broader range than systems with {<=}16 detector rows. It is reasonable to perform coronary CT angiography as a rule-out test in patients with a low-to-intermediate likelihood of disease. (orig.)

  2. Influence of coronary artery disease prevalence on predictive values of coronary CT angiography: a meta-regression analysis

    International Nuclear Information System (INIS)

    Schlattmann, Peter; Schuetz, Georg M.; Dewey, Marc

    2011-01-01

    To evaluate the impact of coronary artery disease (CAD) prevalence on the predictive values of coronary CT angiography. We performed a meta-regression based on a generalised linear mixed model using the binomial distribution and a logit link to analyse the influence of the prevalence of CAD in published studies on the per-patient negative and positive predictive values of CT in comparison to conventional coronary angiography as the reference standard. A prevalence range in which the negative predictive value was higher than 90%, while at the same time the positive predictive value was higher than 70% was considered appropriate. The summary negative and positive predictive values of coronary CT angiography were 93.7% (95% confidence interval [CI] 92.8-94.5%) and 87.5% (95% CI, 86.5-88.5%), respectively. With 95% confidence, negative and positive predictive values higher than 90% and 70% were available with CT for a CAD prevalence of 18-63%. CT systems with >16 detector rows met these requirements for the positive (P < 0.01) and negative (P < 0.05) predictive values in a significantly broader range than systems with ≤16 detector rows. It is reasonable to perform coronary CT angiography as a rule-out test in patients with a low-to-intermediate likelihood of disease. (orig.)

  3. Is consumer confidence an indicator of JSE performance?

    OpenAIRE

    Kamini Solanki; Yudhvir Seetharam

    2014-01-01

    While most studies examine the impact of business confidence on market performance, we instead focus on the consumer because consumer spending habits are a natural extension of trading activity on the equity market. This particular study examines investor sentiment as measured by the Consumer Confidence Index in South Africa and its effect on the Johannesburg Stock Exchange (JSE). We employ Granger causality tests to investigate the relationship across time between the Consumer Confidence Ind...

  4. Missing the Mark? A Two Time Point Cohort Study Estimating Intestinal Parasite Prevalence in Informal Settlements in Lima, Peru.

    Science.gov (United States)

    Cooper, Michael Townsend; Searing, Rapha A; Thompson, David M; Bard, David; Carabin, Hélène; Gonzales, Carlos; Zavala, Carmen; Woodson, Kyle; Naifeh, Monique

    2017-01-01

    Objectives: The World Health Organization's (WHO) recommendations list Peru as potentially needing prevention of soil-transmitted helminthiasis (STH). Prevalence of STH varies regionally and remains understudied in the newest informal settlements of the capital city, Lima. The purpose of this study was to evaluate the need for Mass Drug Administration (MDA) of antiparasitic drugs in the newest informal settlements of Lima. The aim of this study was to estimate the season-specific prevalence of STH to determine if these prevalence estimates met the WHO threshold for MDA in 3 informal settlements. Methods : A 2 time point cohort study was conducted among a sample of 140 children aged 1 to 10 years living in 3 purposively sampled informal settlements of Lima, Peru. Children were asked to provide 2 stool samples that were analyzed with the spontaneous sedimentation in tube technique. The season-specific prevalence proportions of MDA-targeted STH were estimated using a hidden (latent) Markov modeling approach to adjust for repeated measurements over the 2 seasons and the imperfect validity of the screening tests. Results : The prevalence of MDA targeted STH was low at 2.2% (95% confidence interval = 0.3% to 6%) and 3.8% (95% confidence interval = 0.7% to 9.3%) among children sampled in the summer and winter months, respectively, when using the most conservative estimate of test sensitivity. These estimates were below the WHO threshold for MDA (20%). Conclusions : Empiric treatment for STH by organizations active in the newest informal settlements is not supported by the data and could contribute to unnecessary medication exposures and poor allocation of resources.

  5. Preservice teachers' perceived confidence in teaching school violence prevention.

    Science.gov (United States)

    Kandakai, Tina L; King, Keith A

    2002-01-01

    To examine preservice teachers' perceived confidence in teaching violence prevention and the potential effect of violence-prevention training on preservice teachers' confidence in teaching violence prevention. Six Ohio universities participated in the study. More than 800 undergraduate and graduate students completed surveys. Violence-prevention training, area of certification, and location of student- teaching placement significantly influenced preservice teachers' perceived confidence in teaching violence prevention. Violence-prevention training positively influences preservice teachers' confidence in teaching violence prevention. The results suggest that such training should be considered as a requirement for teacher preparation programs.

  6. The antecedents and belief-polarized effects of thought confidence.

    Science.gov (United States)

    Chou, Hsuan-Yi; Lien, Nai-Hwa; Liang, Kuan-Yu

    2011-01-01

    This article investigates 2 possible antecedents of thought confidence and explores the effects of confidence induced before or during ad exposure. The results of the experiments indicate that both consumers' dispositional optimism and spokesperson attractiveness have significant effects on consumers' confidence in thoughts that are generated after viewing the advertisement. Higher levels of thought confidence will influence the quality of the thoughts that people generate, lead to either positively or negatively polarized message processing, and therefore induce better or worse advertising effectiveness, depending on the valence of thoughts. The authors posit the belief-polarization hypothesis to explain these findings.

  7. High prevalence of food sensitization among adults with allergic diseases who live in the Guadalajara metropolitan area

    Directory of Open Access Journals (Sweden)

    Martín Bedolla-Barajas

    2017-02-01

    Full Text Available Background: The prevalence of food sensitization in adults shows differences owing to geographic, regional and cultural circumstances. Objective: To identify the prevalence and factors associated with food sensitization in adults with allergic diseases. Methods: Cross-sectional study, where medical records of adult patients with any allergic disease and who tested positive to airborne allergens on at least one skin test were reviewed. Age, sex, underlying allergic disease and skin test result were recorded. Statistical analyses included food sensitization prevalence with the corresponding confidence intervals (CI, as well as a multivariate analysis to determine associated factors. Results: We included 258 patients with a mean of 36 years of age; 75 % were of the female sex. The most common underlying condition was allergic rhinitis (59 %. The prevalence of food sensitization was 37 % (95 % CI, 31.5-43.3 and it did not vary significantly according to sex or allergic disease in question. The most sensitizing food was soybeans (44.8 %, and associated factors were sensitization to cat dander (OR = 1.8; 95 % CI, 1.03-3.2 and 5 or more positive skin tests (OR = 4.3, 95 % CI 2.3-8.1. Conclusions: The prevalence of food sensitization in people with allergic disease was 40 %. Further studies are required to determine its prevalence in the general population.

  8. Intraclass Correlation Coefficients in Hierarchical Design Studies with Discrete Response Variables: A Note on a Direct Interval Estimation Procedure

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.

    2015-01-01

    A latent variable modeling procedure that can be used to evaluate intraclass correlation coefficients in two-level settings with discrete response variables is discussed. The approach is readily applied when the purpose is to furnish confidence intervals at prespecified confidence levels for these coefficients in setups with binary or ordinal…

  9. Periodontal Bacteria and Prediabetes Prevalence in ORIGINS: The Oral Infections, Glucose Intolerance, and Insulin Resistance Study.

    Science.gov (United States)

    Demmer, R T; Jacobs, D R; Singh, R; Zuk, A; Rosenbaum, M; Papapanou, P N; Desvarieux, M

    2015-09-01

    Periodontitis and type 2 diabetes mellitus are known to be associated. The relationship between periodontal microbiota and early diabetes risk has not been studied. We investigated the association between periodontal bacteria and prediabetes prevalence among diabetes-free adults. ORIGINS (the Oral Infections, Glucose Intolerance and Insulin Resistance Study) cross sectionally enrolled 300 diabetes-free adults aged 20 to 55 y (mean ± SD, 34 ± 10 y; 77% female). Prediabetes was defined as follows: 1) hemoglobin A1c values ranging from 5.7% to 6.4% or 2) fasting plasma glucose ranging from 100 to 125 mg/dL. In 1,188 subgingival plaque samples, 11 bacterial species were assessed at baseline, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Actinomyces naeslundii. Full-mouth clinical periodontal examinations were performed, and participants were defined as having no/mild periodontitis vs. moderate/severe periodontitis per the definition of the Centers for Disease Control and Prevention / American Academy of Periodontology. Modified Poisson regression evaluated prediabetes prevalence across bacterial tertiles. Prevalence ratios and 95% confidence intervals for third vs. first tertiles are presented. All analyses were adjusted for cardiometabolic risk factors. All results presented currently arise from the baseline cross section. Prediabetes prevalence was 18%, and 58% of participants had moderate/severe periodontitis. Prevalence ratios (95% confidence intervals) summarizing associations between bacterial levels and prediabetes were as follows: A. actinomycetemcomitans, 2.48 (1.34, 4.58), P = 0.004; P. gingivalis, 3.41 (1.78, 6.58), P = 0.0003; T. denticola, 1.99 (0.992, 4.00), P = 0.052; T. forsythia, 1.95 (1.0, 3.84), P = 0.05; A. naeslundii, 0.46 (0.25, 0.85), P = 0.01. The prevalence ratio for prediabetes among participants with moderate/severe vs. no/mild periodontitis was 1.47 (0.78, 2.74), P

  10. Interpregnancy intervals: impact of postpartum contraceptive effectiveness and coverage.

    Science.gov (United States)

    Thiel de Bocanegra, Heike; Chang, Richard; Howell, Mike; Darney, Philip

    2014-04-01

    The purpose of this study was to determine the use of contraceptive methods, which was defined by effectiveness, length of coverage, and their association with short interpregnancy intervals, when controlling for provider type and client demographics. We identified a cohort of 117,644 women from the 2008 California Birth Statistical Master file with second or higher order birth and at least 1 Medicaid (Family Planning, Access, Care, and Treatment [Family PACT] program or Medi-Cal) claim within 18 months after index birth. We explored the effect of contraceptive method provision on the odds of having an optimal interpregnancy interval and controlled for covariates. The average length of contraceptive coverage was 3.81 months (SD = 4.84). Most women received user-dependent hormonal contraceptives as their most effective contraceptive method (55%; n = 65,103 women) and one-third (33%; n = 39,090 women) had no contraceptive claim. Women who used long-acting reversible contraceptive methods had 3.89 times the odds and women who used user-dependent hormonal methods had 1.89 times the odds of achieving an optimal birth interval compared with women who used barrier methods only; women with no method had 0.66 times the odds. When user-dependent methods are considered, the odds of having an optimal birth interval increased for each additional month of contraceptive coverage by 8% (odds ratio, 1.08; 95% confidence interval, 1.08-1.09). Women who were seen by Family PACT or by both Family PACT and Medi-Cal providers had significantly higher odds of optimal birth intervals compared with women who were served by Medi-Cal only. To achieve optimal birth spacing and ultimately to improve birth outcomes, attention should be given to contraceptive counseling and access to contraceptive methods in the postpartum period. Copyright © 2014 Mosby, Inc. All rights reserved.

  11. Prevalence of workplace violence against nurses in Hong Kong.

    Science.gov (United States)

    Kwok, R P W; Law, Y K; Li, K E; Ng, Y C; Cheung, M H; Fung, V K P; Kwok, K T T; Tong, J M K; Yen, P F; Leung, W C

    2006-02-01

    To determine the prevalence and nature of workplace violence against nurses, and how nurses deal with such aggression; and to identify the risk factors related to violence in the hospital environment. Cross-sectional questionnaire study. University teaching hospital, Hong Kong. All nursing staff in the hospital, except nurses who were unable to read Chinese or who did not have patient contact (eg those worked in administrative positions), were invited to complete a questionnaire. Demographic data of the respondents, incidence of and risk factors contributing to workplace violence. A total of 420 nurses returned the completed questionnaire (response rate, 25%). Three hundred and twenty (76%; 95% confidence interval, 72-80%) nurses reported abuse of any kind--verbal abuse, 73%; bullying, 45%; physical abuse, 18%; and sexual harassment, 12%. Most (82%) nurses who experienced verbal abuse tended to confide in friends, family members, or colleagues. Some (42%) ignored the incident. Risk factors for workplace violence included: working in male wards and in certain specialties such as the Accident and Emergency Department, Community Nursing Service, and the Orthopaedics and Traumatology Department. Workplace violence against nurses is a significant problem in Hong Kong. Further large-scale studies should be conducted to more closely examine the problem.

  12. Direct Interval Forecasting of Wind Power

    DEFF Research Database (Denmark)

    Wan, Can; Xu, Zhao; Pinson, Pierre

    2013-01-01

    This letter proposes a novel approach to directly formulate the prediction intervals of wind power generation based on extreme learning machine and particle swarm optimization, where prediction intervals are generated through direct optimization of both the coverage probability and sharpness...

  13. A note on birth interval distributions

    International Nuclear Information System (INIS)

    Shrestha, G.

    1989-08-01

    A considerable amount of work has been done regarding the birth interval analysis in mathematical demography. This paper is prepared with the intention of reviewing some probability models related to interlive birth intervals proposed by different researchers. (author). 14 refs

  14. The Prevalence of Tic Disorders and Clinical Characteristics in Children

    Science.gov (United States)

    Scahill, Lawrence; Specht, Matthew; Page, Christopher

    2014-01-01

    Background Prevalence is a simple statement about the frequency of a disease in the population. For many medical conditions, including Tourette syndrome, there are true cases that have not been previously diagnosed due to problems of access to appropriate clinical services. Therefore, to obtain a trustworthy estimate of prevalence, it is necessary to go beyond cases identified in clinical settings and evaluate community samples. Method We reviewed 11 community surveys in children with Tourette syndrome (TS) published since 2000. We also examined the frequency of co-occurring psychiatric conditions in community samples and large clinically-ascertained samples. Results Transient tics are relatively common affecting as many as 20% of school-age children. The 11 studies reviewed here offer a wide range of estimates from 2.6 to 38 per 1000 children for TS. Six studies provide estimates in a narrower range from 4.3 to 7.6 per 1000, but the confidence interval around this narrower range remains wide. Six studies provided results on chronic tic disorders ranging from 3 to 50 per 1000 for Chronic Motor Tic Disorder and 2.5 to 9.4 per 1000 for Chronic Vocal Tic Disorder. Community samples and large clinically-ascertained samples consistently show high rates of ADHD, disruptive behavior and anxiety disorders in children with TS. Conclusions The wide range of prevalence estimates for TS and chronic tic disorders is likely due to differences in sample size and assessment methods. The best estimate of prevalence for TS in school-age children is likely to fall between 4 and 8 cases per 1000. Clinical assessment of children with chronic tic disorders warrants examination of other problems such as ADHD, disruptive behavior and anxiety. PMID:25436183

  15. Prevalence of blindness and diabetic retinopathy in northern Jordan.

    Science.gov (United States)

    Rabiu, Mansur M; Al Bdour, Muawyah D; Abu Ameerh, Mohammed A; Jadoon, Muhammed Z

    2015-01-01

    To estimate the prevalence of blindness, visual impairment, diabetes, and diabetic retinopathy in north Jordan (Irbid) using the rapid assessment of avoidable blindness and diabetic retinopathy methodology. A multistage cluster random sampling technique was used to select participants for this survey. A total of 108 clusters were selected using probability proportional to size method while subjects within the clusters were selected using compact segment method. Survey teams moved from house to house in selected segments examining residents 50 years and older until 35 participants were recruited. All eligible people underwent a standardized examination protocol, which included ophthalmic examination and random blood sugar test using digital glucometers (Accu-Chek) in their homes. Diabetic retinopathy among diabetic patients was assessed through dilated fundus examination. A total of 3638 out of the 3780 eligible participants were examined. Age- and sex-adjusted prevalence of blindness, severe visual impairment, and visual impairment with available correction were 1.33% (95% confidence interval [CI] 0.87-1.73), 1.82% (95% CI 1.35-2.25), and 9.49% (95% CI 8.26-10.74), respectively, all higher in women. Untreated cataract and diabetic retinopathy were the major causes of blindness, accounting for 46.7% and 33.2% of total blindness cases, respectively. Glaucoma was the third major cause, accounting for 8.9% of cases. The prevalence of diabetes mellitus was 28.6% (95% CI 26.9-30.3) among the study population and higher in women. The prevalence of any retinopathy among diabetic patients was 48.4%. Cataract and diabetic retinopathy are the 2 major causes of blindness and visual impairment in northern Jordan. For both conditions, women are primarily affected, suggesting possible limitations to access to services. A diabetic retinopathy screening program needs to proactively create sex-sensitive awareness and provide easily accessible screening services with prompt treatment.

  16. The Prevalence of Injury in Permanent Residences of Duzce City

    Directory of Open Access Journals (Sweden)

    Atilla Senih Mayda

    2008-04-01

    Full Text Available AIM/BACKGROUND: Objective of this cross-sectional study is to determine the prevalence of injury and risk factors in permanent residences of Duzce. METHODS: The sample size of this study is calculated as 715 people when population of the region is 13565, injury prevalence is 20.9% taken from a study in Duzce, expected lowest frequency as 18% and in 95% confidence interval. Number of people could be reached was designed as 1170 when 300 house was visited as mean household was 3.9 people which was taken from a study carried out in this region. Data is collected in 15-30 April in the year 2006. Totally, reached sample is 767 people. Injury status, status after injury are dependant variables and age, gender, education status, profession, chronic illness, tobacco-alcohol consumption, marital status are independent variables. RESULTS: Distribution of the group as gender was male 352 (45.9%, female 415 (54. %1. Mean education year of male (4.5±1.5 year was higher than female (4.2±1.6 year (t= 2.97, p=0.03. Injury prevalence was 10.0% (n=767. Sort of injury was fall 31 people (40.2%, cut 11 (14. %3, burn 10 (13.0%. Place that injury take place was house 41 (55.4%, road 17 (23.0%, school 4 (5.4%. Lesions were; cut-wounded injury in 20 people (28.2%, rotten in 10 (14.1%, sprain in 8 (11.3%. Number of injured people was 77 and 28 (36.4% of them applied to hospital. CONCLUSION: Valid prevalance of injuries can be indicated by field studies as quarter of injured people applied to health departments. [TAF Prev Med Bull 2008; 7(2.000: 133-136

  17. [Prevalence and user profile of electronic cigarettes in Spain (2014)].

    Science.gov (United States)

    Lidón-Moyano, Cristina; Martínez-Sánchez, Jose M; Fu, Marcela; Ballbè, Montse; Martín-Sánchez, Juan Carlos; Fernández, Esteve

    To describe the prevalence and user profile of electronic cigarettes among Spanish adults and evaluate the potential dual use of these devices with combustible or conventional tobacco in 2014 in Spain. Cross-sectional study of a representative sample of the Spanish adult (16-75 years old) population (n=1,016). A computer-assisted telephone survey was conducted in 2014. The prevalence and 95% confidence intervals (95% CI) for the use of electronic cigarettes stratified by gender, age, tobacco consumption and social status were calculated. The sample was weighted and a logistic regression model adjusted to obtain the crude odds ratios (OR) adjusted by gender, age and social status. 10.3% (95% CI: 8.6-12.4) of the Spanish adult population stated being ever users of electronic cigarettes (2% current users, 3.2% past users and 5.1% experimental users). Among current electronic cigarette users, 57.2% also smoked combustible or conventional tobacco, 28% had never smoked and 14.8% were former smokers. The prevalence of electronic cigarette use was higher in the younger population (adjusted OR=23.8; 95% CI: 2.5-227.7) and smokers of combustible tobacco (adjusted OR=10.1; 95% CI: 5.8-17.5). The use of electronic cigarettes in Spain is scarce and is most prevalent among young people and tobacco smokers. Nevertheless, one out of four current electronic cigarette users have never smoked. Hence, the regulation of these devices should be reinforced to avoid a possible gateway to nicotine products among never smokers. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Prevalence and factors associated with urinary incontinence in climacteric

    Directory of Open Access Journals (Sweden)

    Máyra Cecilia Dellú

    Full Text Available SUMMARY Objective: To estimate the prevalence and identify associated factors to urinary incontinence (UI in climacteric women. Method: In a cross-sectional study with a stratified random sample, 1,200 women aged between 35 and 72 years were studied, enrolled in the Family Health Strategy in the city of Pindamonhangaba, São Paulo. Urinary incontinence was investigated using the International Consultation of Incontinence Questionnaire - Short Form, while associated factors were assessed based on a self-reported questionnaire with socio-demographic, obstetric and gynecological history, morbidities and drug use. The prevalence of urinary incontinence was estimated with a 95% confidence interval (95CI and the associated factors were identified through multiple logistic regression model performed using Stata software, version 11.0. Results: Women had a mean age of 51.9 years, most were in menopause (59.4%, married (87.5%, Catholic (48.9%, and declared themselves black or brown (47.2%. The mean age of menopause of women with UI was 47.3 years. The prevalence of UI was 20.4% (95CI: 17.8-23.1%. The factors associated with UI were urinary loss during pregnancy (p=0.000 and after delivery (p=0.000, genital prolapse (p=0.000, stress (p=0.001, depression (p=0.002, and obesity (p=0.006. Conclusion: The prevalence of UI was lower but similar to that found in most similar studies. Factors associated with the genesis of UI were urinary loss during pregnancy and after delivery, genital prolapse and obesity.

  19. Prevalence of fibromyalgia in a low socioeconomic status population

    Directory of Open Access Journals (Sweden)

    Pereira Carlos AB

    2009-06-01

    Full Text Available Abstract Background The aim of this study was to estimate the prevalence of fibromyalgia, as well as to assess the major symptoms of this syndrome in an adult, low socioeconomic status population assisted by the primary health care system in a city in Brazil. Methods We cross-sectionally sampled individuals assisted by the public primary health care system (n = 768, 35–60 years old. Participants were interviewed by phone and screened about pain. They were then invited to be clinically assessed (304 accepted. Pain was estimated using a Visual Analogue Scale (VAS. Fibromyalgia was assessed using the Fibromyalgia Impact Questionnaire (FIQ, as well as screening for tender points using dolorimetry. Statistical analyses included Bayesian Statistics and the Kruskal-Wallis Anova test (significance level = 5%. Results From the phone-interview screening, we divided participants (n = 768 in three groups: No Pain (NP (n = 185; Regional Pain (RP (n = 388 and Widespread Pain (WP (n = 106. Among those participating in the clinical assessments, (304 subjects, the prevalence of fibromyalgia was 4.4% (95% confidence interval [2.6%; 6.3%]. Symptoms of pain (VAS and FIQ, feeling well, job ability, fatigue, morning tiredness, stiffness, anxiety and depression were statically different among the groups. In multivariate analyses we found that individuals with FM and WP had significantly higher impairment than those with RP and NP. FM and WP were similarly disabling. Similarly, RP was no significantly different than NP. Conclusion Fibromyalgia is prevalent in the low socioeconomic status population assisted by the public primary health care system. Prevalence was similar to other studies (4.4% in a more diverse socioeconomic population. Individuals with FM and WP have significant impact in their well being.

  20. Identifying the bad guy in a lineup using confidence judgments under deadline pressure.

    Science.gov (United States)

    Brewer, Neil; Weber, Nathan; Wootton, David; Lindsay, D Stephen

    2012-10-01

    Eyewitness-identification tests often culminate in witnesses not picking the culprit or identifying innocent suspects. We tested a radical alternative to the traditional lineup procedure used in such tests. Rather than making a positive identification, witnesses made confidence judgments under a short deadline about whether each lineup member was the culprit. We compared this deadline procedure with the traditional sequential-lineup procedure in three experiments with retention intervals ranging from 5 min to 1 week. A classification algorithm that identified confidence criteria that optimally discriminated accurate from inaccurate decisions revealed that decision accuracy was 24% to 66% higher under the deadline procedure than under the traditional procedure. Confidence profiles across lineup stimuli were more informative than were identification decisions about the likelihood that an individual witness recognized the culprit or correctly recognized that the culprit was not present. Large differences between the maximum and the next-highest confidence value signaled very high accuracy. Future support for this procedure across varied conditions would highlight a viable alternative to the problematic lineup procedures that have traditionally been used by law enforcement.

  1. Confidence limits for regional cerebral blood flow values obtained with circular positron system, using krypton-77

    International Nuclear Information System (INIS)

    Meyer, E.; Yamamoto, Y.L.; Thompson, C.J.

    1978-01-01

    The 90% confidence limits have been determined for regional cerebral blood flow (rCBF) values obtained in each cm 2 of a cross section of the human head after inhalation of radioactive krypton-77, using the MNI circular positron emission tomography system (Positome). CBF values for small brain tissue elements are calculated by linear regression analysis on the semi-logarithmically transformed clearance curve. A computer program displays CBF values and their estimated error in numeric and gray scale forms. The following typical results have been obtained on a control subject: mean CBF in the entire cross section of the head: 54.6 + - 5 ml/min/100 g tissue, rCBF for small area of frontal gray matter: 75.8 + - 9 ml/min/100 g tissue. Confidence intervals for individual rCBF values varied between + - 13 and + - 55% except for areas pertaining to the ventricular system where particularly poor statistics have been obtained. Knowledge of confidence limits for rCBF values improves their diagnostic significance, particularly with respect to the assessment of reduced rCBF in stroke patients. A nomogram for convenient determination of 90% confidence limits for slope values obtained in linear regression analysis has been designed with the number of fitted points (n) and the correlation coefficient (r) as parameters. (author)

  2. Optimal Data Interval for Estimating Advertising Response

    OpenAIRE

    Gerard J. Tellis; Philip Hans Franses

    2006-01-01

    The abundance of highly disaggregate data (e.g., at five-second intervals) raises the question of the optimal data interval to estimate advertising carryover. The literature assumes that (1) the optimal data interval is the interpurchase time, (2) too disaggregate data causes a disaggregation bias, and (3) recovery of true parameters requires assumption of the underlying advertising process. In contrast, we show that (1) the optimal data interval is what we call , (2) too disaggregate data do...

  3. Dynamic visual noise reduces confidence in short-term memory for visual information.

    Science.gov (United States)

    Kemps, Eva; Andrade, Jackie

    2012-05-01

    Previous research has shown effects of the visual interference technique, dynamic visual noise (DVN), on visual imagery, but not on visual short-term memory, unless retention of precise visual detail is required. This study tested the prediction that DVN does also affect retention of gross visual information, specifically by reducing confidence. Participants performed a matrix pattern memory task with three retention interval interference conditions (DVN, static visual noise and no interference control) that varied from trial to trial. At recall, participants indicated whether or not they were sure of their responses. As in previous research, DVN did not impair recall accuracy or latency on the task, but it did reduce recall confidence relative to static visual noise and no interference. We conclude that DVN does distort visual representations in short-term memory, but standard coarse-grained recall measures are insensitive to these distortions.

  4. Understanding public confidence in government to prevent terrorist attacks.

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, T. E.; Ramaprasad, A,; Samsa, M. E.; Decision and Information Sciences; Univ. of Illinois at Chicago

    2008-04-02

    A primary goal of terrorism is to instill a sense of fear and vulnerability in a population and to erode its confidence in government and law enforcement agencies to protect citizens against future attacks. In recognition of its importance, the Department of Homeland Security includes public confidence as one of the principal metrics used to assess the consequences of terrorist attacks. Hence, a detailed understanding of the variations in public confidence among individuals, terrorist event types, and as a function of time is critical to developing this metric. In this exploratory study, a questionnaire was designed, tested, and administered to small groups of individuals to measure public confidence in the ability of federal, state, and local governments and their public safety agencies to prevent acts of terrorism. Data was collected from three groups before and after they watched mock television news broadcasts portraying a smallpox attack, a series of suicide bomber attacks, a refinery explosion attack, and cyber intrusions on financial institutions, resulting in identity theft. Our findings are: (a) although the aggregate confidence level is low, there are optimists and pessimists; (b) the subjects are discriminating in interpreting the nature of a terrorist attack, the time horizon, and its impact; (c) confidence recovery after a terrorist event has an incubation period; and (d) the patterns of recovery of confidence of the optimists and the pessimists are different. These findings can affect the strategy and policies to manage public confidence after a terrorist event.

  5. Animal Spirits and Extreme Confidence: No Guts, No Glory?

    NARCIS (Netherlands)

    M.G. Douwens-Zonneveld (Mariska)

    2012-01-01

    textabstractThis study investigates to what extent extreme confidence of either management or security analysts may impact financial or operating performance. We construct a multidimensional degree of company confidence measure from a wide range of corporate decisions. We empirically test this

  6. Trust, confidence, and the 2008 global financial crisis.

    Science.gov (United States)

    Earle, Timothy C

    2009-06-01

    The 2008 global financial crisis has been compared to a "once-in-a-century credit tsunami," a disaster in which the loss of trust and confidence played key precipitating roles and the recovery from which will require the restoration of these crucial factors. Drawing on the analogy between the financial crisis and environmental and technological hazards, recent research on the role of trust and confidence in the latter is used to provide a perspective on the former. Whereas "trust" and "confidence" are used interchangeably and without explicit definition in most discussions of the financial crisis, this perspective uses the TCC model of cooperation to clearly distinguish between the two and to demonstrate how this distinction can lead to an improved understanding of the crisis. The roles of trust and confidence-both in precipitation and in possible recovery-are discussed for each of the three major sets of actors in the crisis, the regulators, the banks, and the public. The roles of trust and confidence in the larger context of risk management are also examined; trust being associated with political approaches, confidence with technical. Finally, the various stances that government can take with regard to trust-such as supportive or skeptical-are considered. Overall, it is argued that a clear understanding of trust and confidence and a close examination of the specific, concrete circumstances of a crisis-revealing when either trust or confidence is appropriate-can lead to useful insights for both recovery and prevention of future occurrences.

  7. True and False Memories, Parietal Cortex, and Confidence Judgments

    Science.gov (United States)

    Urgolites, Zhisen J.; Smith, Christine N.; Squire, Larry R.

    2015-01-01

    Recent studies have asked whether activity in the medial temporal lobe (MTL) and the neocortex can distinguish true memory from false memory. A frequent complication has been that the confidence associated with correct memory judgments (true memory) is typically higher than the confidence associated with incorrect memory judgments (false memory).…

  8. The Metamemory Approach to Confidence: A Test Using Semantic Memory

    Science.gov (United States)

    Brewer, William F.; Sampaio, Cristina

    2012-01-01

    The metamemory approach to memory confidence was extended and elaborated to deal with semantic memory tasks. The metamemory approach assumes that memory confidence is based on the products and processes of a completed memory task, as well as metamemory beliefs that individuals have about how their memory products and processes relate to memory…

  9. Confidence Sharing in the Vocational Counselling Interview: Emergence and Repercussions

    Science.gov (United States)

    Olry-Louis, Isabelle; Bremond, Capucine; Pouliot, Manon

    2012-01-01

    Confidence sharing is an asymmetrical dialogic episode to which both parties consent, in which one reveals something personal to the other who participates in the emergence and unfolding of the confidence. We describe how this is achieved at a discursive level within vocational counselling interviews. Based on a corpus of 64 interviews, we analyse…

  10. A scale for consumer confidence in the safety of food

    NARCIS (Netherlands)

    Jonge, de J.; Trijp, van J.C.M.; Lans, van der I.A.; Renes, R.J.; Frewer, L.J.

    2008-01-01

    The aim of this study was to develop and validate a scale to measure general consumer confidence in the safety of food. Results from exploratory and confirmatory analyses indicate that general consumer confidence in the safety of food consists of two distinct dimensions, optimism and pessimism,

  11. Confidence Scoring of Speaking Performance: How Does Fuzziness become Exact?

    Science.gov (United States)

    Jin, Tan; Mak, Barley; Zhou, Pei

    2012-01-01

    The fuzziness of assessing second language speaking performance raises two difficulties in scoring speaking performance: "indistinction between adjacent levels" and "overlap between scales". To address these two problems, this article proposes a new approach, "confidence scoring", to deal with such fuzziness, leading to "confidence" scores between…

  12. Monitoring consumer confidence in food safety: an exploratory study

    NARCIS (Netherlands)

    Jonge, de J.; Frewer, L.J.; Trijp, van J.C.M.; Renes, R.J.; Wit, de W.; Timmers, J.C.M.

    2004-01-01

    Abstract: In response to the potential for negative economic and societal effects resulting from a low level of consumer confidence in food safety, it is important to know how confidence is potentially influenced by external events. The aim of this article is to describe the development of a monitor

  13. Modeling Confidence and Response Time in Recognition Memory

    Science.gov (United States)

    Ratcliff, Roger; Starns, Jeffrey J.

    2009-01-01

    A new model for confidence judgments in recognition memory is presented. In the model, the match between a single test item and memory produces a distribution of evidence, with better matches corresponding to distributions with higher means. On this match dimension, confidence criteria are placed, and the areas between the criteria under the…

  14. Music educators : their artistry and self-confidence

    NARCIS (Netherlands)

    Lion-Slovak, Brigitte; Stöger, Christine; Smilde, Rineke; Malmberg, Isolde; de Vugt, Adri

    2013-01-01

    How does artistic identity influence the self-confidence of music educators? What is the interconnection between the artistic and the teacher identity? What is actually meant by artistic identity in music education? What is a fruitful environment for the development of artistic self-confidence of

  15. To protect and serve: Restoring public confidence in the SAPS ...

    African Journals Online (AJOL)

    Persistent incidents of brutality, criminal behaviour and abuse of authority by members of South Africa's police agencies have serious implications for public trust and confidence in the police. A decline in trust and confidence in the police is inevitably harmful to the ability of the government to reduce crime and improve public ...

  16. Improved realism of confidence for an episodic memory event

    Directory of Open Access Journals (Sweden)

    Sandra Buratti

    2012-09-01

    Full Text Available We asked whether people can make their confidence judgments more realistic (accurate by adjusting them, with the aim of improving the relationship between the level of confidence and the correctness of the answer. This adjustment can be considered to include a so-called second-order metacognitive judgment. The participants first gave confidence judgments about their answers to questions about a video clip they had just watched. Next, they attempted to increase their accuracy by identifying confidence judgments in need of adjustment and then modifying them. The participants managed to increase their metacognitive realism, thus decreasing their absolute bias and improving their calibration, although the effects were small. We also examined the relationship between confidence judgments that were adjusted and the retrieval fluency and the phenomenological memory quality participants experienced when first answering the questions; this quality was one of either Remember (associated with concrete, vivid details or Know (associated with a feeling of familiarity. Confidence judgments associated with low retrieval fluency and the memory quality of knowing were modified more often. In brief, our results provide evidence that people can improve the realism of their confidence judgments, mainly by decreasing their confidence for incorrect answers. Thus, this study supports the conclusion that people can perform successful second-order metacognitive judgments.

  17. Variance misperception explains illusions of confidence in simple perceptual decisions

    NARCIS (Netherlands)

    Zylberberg, Ariel; Roelfsema, Pieter R.; Sigman, Mariano

    2014-01-01

    Confidence in a perceptual decision is a judgment about the quality of the sensory evidence. The quality of the evidence depends not only on its strength ('signal') but critically on its reliability ('noise'), but the separate contribution of these quantities to the formation of confidence judgments

  18. On-line confidence monitoring during decision making.

    Science.gov (United States)

    Dotan, Dror; Meyniel, Florent; Dehaene, Stanislas

    2018-02-01

    Humans can readily assess their degree of confidence in their decisions. Two models of confidence computation have been proposed: post hoc computation using post-decision variables and heuristics, versus online computation using continuous assessment of evidence throughout the decision-making process. Here, we arbitrate between these theories by continuously monitoring finger movements during a manual sequential decision-making task. Analysis of finger kinematics indicated that subjects kept separate online records of evidence and confidence: finger deviation continuously reflected the ongoing accumulation of evidence, whereas finger speed continuously reflected the momentary degree of confidence. Furthermore, end-of-trial finger speed predicted the post-decisional subjective confidence rating. These data indicate that confidence is computed on-line, throughout the decision process. Speed-confidence correlations were previously interpreted as a post-decision heuristics, whereby slow decisions decrease subjective confidence, but our results suggest an adaptive mechanism that involves the opposite causality: by slowing down when unconfident, participants gain time to improve their decisions. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. A simultaneous confidence band for sparse longitudinal regression

    KAUST Repository

    Ma, Shujie; Yang, Lijian; Carroll, Raymond J.

    2012-01-01

    Functional data analysis has received considerable recent attention and a number of successful applications have been reported. In this paper, asymptotically simultaneous confidence bands are obtained for the mean function of the functional regression model, using piecewise constant spline estimation. Simulation experiments corroborate the asymptotic theory. The confidence band procedure is illustrated by analyzing CD4 cell counts of HIV infected patients.

  20. Prevalence and public-health significance of HIV infection and anaemia among pregnant women attending antenatal clinics in south-eastern Nigeria.

    Science.gov (United States)

    Uneke, C J; Duhlinska, D D; Igbinedion, E B

    2007-09-01

    HIV infection and anaemia are major public-health problems in Africa and are important factors associated with an increased risk of adverse pregnancy outcomes. The objective of this study was to determine the prevalence of HIV infection and anaemia among pregnant women attending antenatal clinics in southeastern Nigeria. To achieve this, a cross-sectional survey was conducted during July 2005-June 2006 using standard techniques. Of 815 pregnant women studied, 31 (3.8%, 95% confidence interval [CI] 2.5-5.1) were HIV-positive. Maternal age and gestational age were not associated with HIV infection (p > 0.05). The prevalence of anaemia (Hb anaemia (Hb prevalence of anaemia was observed among individuals in their second pregnancy trimester (p anaemia are preventable, antenatal care services could serve as a pivotal entry point for simultaneous delivery of interventions for the prevention and control of HIV infection and anaemia in pregnant women.

  1. What are effective techniques for improving public confidence or restoring lost confidence in a regulator?

    International Nuclear Information System (INIS)

    Harbitz, O.; Isaksson, R.

    2006-01-01

    The conclusions and recommendations of this session can be summarized this way. The following list contains thoughts related to restoring lost confidence: - hard, long lasting event; - strategy: maximum transparency; - to listen, be open, give phone numbers etc. - ways to rebuild trust: frequent communication, being there, open and transparent; - don't be too defensive; if things could be done better, say it; - technical staff and public affair staff together from the beginning - answer all questions; - classifications, actions, instructions that differ much from the earlier ones must be well explained and motivated - and still cause a lot of problems; - things may turn out to be political; - communicative work in an early stage saves work later; - communication experts must be working shoulder to shoulder with other staff; On handling emergencies in general, some recipes proposed are: - better to over react than to under react; - do not avoid extreme actions: hit hard, hit fast; - base your decisions in strict principles; - first principle: public safety first; - when you are realizing plant A, you must have a plant B in your pocket: - be transparent - from the beginning; - crisis communication: early, frequent etc - people need to see political leaders, someone who is making decisions - technical experts are needed but are not enough. On how to involve stakeholders and the public in decision making, recommendations are: - new kind of thinking -. demanding for a organisation; - go to local level, meet local people, speak language people understand, you have to start from the very beginning - introducing yourself tell who you are and why you are there. (authors)

  2. An Adequate First Order Logic of Intervals

    DEFF Research Database (Denmark)

    Chaochen, Zhou; Hansen, Michael Reichhardt

    1998-01-01

    This paper introduces left and right neighbourhoods as primitive interval modalities to define other unary and binary modalities of intervals in a first order logic with interval length. A complete first order logic for the neighbourhood modalities is presented. It is demonstrated how the logic can...... support formal specification and verification of liveness and fairness, and also of various notions of real analysis....

  3. Consistency and refinement for Interval Markov Chains

    DEFF Research Database (Denmark)

    Delahaye, Benoit; Larsen, Kim Guldstrand; Legay, Axel

    2012-01-01

    Interval Markov Chains (IMC), or Markov Chains with probability intervals in the transition matrix, are the base of a classic specification theory for probabilistic systems [18]. The standard semantics of IMCs assigns to a specification the set of all Markov Chains that satisfy its interval...

  4. Multivariate interval-censored survival data

    DEFF Research Database (Denmark)

    Hougaard, Philip

    2014-01-01

    Interval censoring means that an event time is only known to lie in an interval (L,R], with L the last examination time before the event, and R the first after. In the univariate case, parametric models are easily fitted, whereas for non-parametric models, the mass is placed on some intervals, de...

  5. Family Health Histories and Their Impact on Retirement Confidence.

    Science.gov (United States)

    Zick, Cathleen D; Mayer, Robert N; Smith, Ken R

    2015-08-01

    Retirement confidence is a key social barometer. In this article, we examine how personal and parental health histories relate to working-age adults' feelings of optimism or pessimism about their overall retirement prospects. This study links survey data on retirement planning with information on respondents' own health histories and those of their parents. The multivariate models control for the respondents' socio-demographic and economic characteristics along with past retirement planning activities when estimating the relationships between family health histories and retirement confidence. Retirement confidence is inversely related to parental history of cancer and cardiovascular disease but not to personal health history. In contrast, retirement confidence is positively associated with both parents being deceased. As members of the public become increasingly aware of how genetics and other family factors affect intergenerational transmission of chronic diseases, it is likely that the link between family health histories and retirement confidence will intensify. © The Author(s) 2015.

  6. Multivoxel neurofeedback selectively modulates confidence without changing perceptual performance

    Science.gov (United States)

    Cortese, Aurelio; Amano, Kaoru; Koizumi, Ai; Kawato, Mitsuo; Lau, Hakwan

    2016-01-01

    A central controversy in metacognition studies concerns whether subjective confidence directly reflects the reliability of perceptual or cognitive processes, as suggested by normative models based on the assumption that neural computations are generally optimal. This view enjoys popularity in the computational and animal literatures, but it has also been suggested that confidence may depend on a late-stage estimation dissociable from perceptual processes. Yet, at least in humans, experimental tools have lacked the power to resolve these issues convincingly. Here, we overcome this difficulty by using the recently developed method of decoded neurofeedback (DecNef) to systematically manipulate multivoxel correlates of confidence in a frontoparietal network. Here we report that bi-directional changes in confidence do not affect perceptual accuracy. Further psychophysical analyses rule out accounts based on simple shifts in reporting strategy. Our results provide clear neuroscientific evidence for the systematic dissociation between confidence and perceptual performance, and thereby challenge current theoretical thinking. PMID:27976739

  7. Maternal Confidence for Physiologic Childbirth: A Concept Analysis.

    Science.gov (United States)

    Neerland, Carrie E

    2018-06-06

    Confidence is a term often used in research literature and consumer media in relation to birth, but maternal confidence has not been clearly defined, especially as it relates to physiologic labor and birth. The aim of this concept analysis was to define maternal confidence in the context of physiologic labor and childbirth. Rodgers' evolutionary method was used to identify attributes, antecedents, and consequences of maternal confidence for physiologic birth. Databases searched included Ovid MEDLINE, CINAHL, PsycINFO, and Sociological Abstracts from the years 1995 to 2015. A total of 505 articles were retrieved, using the search terms pregnancy, obstetric care, prenatal care, and self-efficacy and the keyword confidence. Articles were identified for in-depth review and inclusion based on whether the term confidence was used or assessed in relationship to labor and/or birth. In addition, a hand search of the reference lists of the selected articles was performed. Twenty-four articles were reviewed in this concept analysis. We define maternal confidence for physiologic birth as a woman's belief that physiologic birth can be achieved, based on her view of birth as a normal process and her belief in her body's innate ability to birth, which is supported by social support, knowledge, and information founded on a trusted relationship with a maternity care provider in an environment where the woman feels safe. This concept analysis advances the concept of maternal confidence for physiologic birth and provides new insight into how women's confidence for physiologic birth might be enhanced during the prenatal period. Further investigation of confidence for physiologic birth across different cultures is needed to identify cultural differences in constructions of the concept. © 2018 by the American College of Nurse-Midwives.

  8. Prevalence of Hypertension in Low- and Middle-Income Countries

    Science.gov (United States)

    Sarki, Ahmed M.; Nduka, Chidozie U.; Stranges, Saverio; Kandala, Ngianga-Bakwin; Uthman, Olalekan A.

    2015-01-01

    Abstract We aimed to obtain overall and regional estimates of hypertension prevalence, and to examine the pattern of this disease condition across different socio-demographic characteristics in low-and middle-income countries. We searched electronic databases from inception to August 2015. We included population-based studies that reported hypertension prevalence using the current definition of blood pressure ≥140/90 mm Hg or self-reported use of antihypertensive medication. We used random-effects meta-analyses to pool prevalence estimates of hypertension, overall, by World Bank region and country income group. Meta-regression analyses were performed to explore sources of heterogeneity across the included studies. A total of 242 studies, comprising data on 1,494,609 adults from 45 countries, met our inclusion criteria. The overall prevalence of hypertension was 32.3% (95% confidence interval [CI] 29.4–35.3), with the Latin America and Caribbean region reporting the highest estimates (39.1%, 95% CI 33.1–45.2). Pooled prevalence estimate was also highest across upper middle income countries (37.8%, 95% CI 35.0–40.6) and lowest across low-income countries (23.1%, 95% CI 20.1–26.2). Prevalence estimates were significantly higher in the elderly (≥65 years) compared with younger adults (hypertension prevalence (31.9% vs 30.8%, P = 0.6). Persons without formal education (49.0% vs 24.9%, P hypertensive, compared with those who were educated, normal weight, and rural settlers respectively. This study provides contemporary and up-to-date estimates that reflect the significant burden of hypertension in low- and middle-income countries, as well as evidence that hypertension remains a major public health issue across the various socio-demographic subgroups. On average, about 1 in 3 adults in the developing world is hypertensive. The findings of this study will be useful for the design of hypertension screening and treatment programmes in low- and middle

  9. Power, effects, confidence, and significance: an investigation of statistical practices in nursing research.

    Science.gov (United States)

    Gaskin, Cadeyrn J; Happell, Brenda

    2014-05-01

    To (a) assess the statistical power of nursing research to detect small, medium, and large effect sizes; (b) estimate the experiment-wise Type I error rate in these studies; and (c) assess the extent to which (i) a priori power analyses, (ii) effect sizes (and interpretations thereof), and (iii) confidence intervals were reported. Statistical review. Papers published in the 2011 volumes of the 10 highest ranked nursing journals, based on their 5-year impact factors. Papers were assessed for statistical power, control of experiment-wise Type I error, reporting of a priori power analyses, reporting and interpretation of effect sizes, and reporting of confidence intervals. The analyses were based on 333 papers, from which 10,337 inferential statistics were identified. The median power to detect small, medium, and large effect sizes was .40 (interquartile range [IQR]=.24-.71), .98 (IQR=.85-1.00), and 1.00 (IQR=1.00-1.00), respectively. The median experiment-wise Type I error rate was .54 (IQR=.26-.80). A priori power analyses were reported in 28% of papers. Effect sizes were routinely reported for Spearman's rank correlations (100% of papers in which this test was used), Poisson regressions (100%), odds ratios (100%), Kendall's tau correlations (100%), Pearson's correlations (99%), logistic regressions (98%), structural equation modelling/confirmatory factor analyses/path analyses (97%), and linear regressions (83%), but were reported less often for two-proportion z tests (50%), analyses of variance/analyses of covariance/multivariate analyses of variance (18%), t tests (8%), Wilcoxon's tests (8%), Chi-squared tests (8%), and Fisher's exact tests (7%), and not reported for sign tests, Friedman's tests, McNemar's tests, multi-level models, and Kruskal-Wallis tests. Effect sizes were infrequently interpreted. Confidence intervals were reported in 28% of papers. The use, reporting, and interpretation of inferential statistics in nursing research need substantial

  10. Prevalence of xerostomia in patients attending Shorish dental speciality in Sulaimani city

    Science.gov (United States)

    2015-01-01

    Objectives: The aim of this study was to investigate the prevalence of xerostomia among dental patients and explore the possible risk factors and symptoms associated with this condition. Patient and Methods: The prevalence of xerostomia and its associations were investigated among patients (n=1132) who were visiting the department of oral medicine at shorish dental speciality in sulaimani city. The age range was between 10-79 years. 512 (45.2%) of participants were males and 620 (54.8%) were females. The data collected were age, sex, systemic diseases, medications and habit of smoking. Logistic regression models to estimate odds ratios and 95% confidence intervals were used to investigate the association of xerostomia with age, systemic diseases and medications and Chi Square test was also used to analyze the data. Results: Prevalence of xerostomia was 16.07%. Prevalence of xerostomia was significantly higher among females (19.51%) than males (11.91%) (P=0.001). The most common diseases with the highest prevalence of xerostomia were psychological disorders (57.14%) followed by diabetes mellitus (53.84%), neurological disorders (40%), thyroid disorders (37.5%) and hypertension (36.48%). The most common medication with the highest prevalence of xerostomia was antihistamine (66.66%) followed by psychotherapeutic medications (60%), pain medications (55.88%), endocrinologic agents (51.21%), antidyslipidic agents (50%) and antihypertensive medication (38.98%). Xerostomia was significantly associated with ageing (OR: 1.02, P=0.000), systemic diseases (OR: 2.80, P=0.000) and medications (OR: 5.17, P=0.000). There was a high prevalence of reported symptoms of xerostomia and these symptoms were more prevalent among females, Prevalence of xerostomia was higher in heavy smoker patients (19.48%) than non smoker patients but not significantly (16.14%) (p= 0.44). Conclusions: There was a high prevalence of xerostomia among dental patients; xerostomia was significantly more

  11. Prevalence of Helicobacter pylori in patients with gastro-oesophageal reflux disease: systematic review

    Science.gov (United States)

    Raghunath, Anan; Hungin, A Pali S; Wooff, David; Childs, Susan

    2003-01-01

    Objectives To ascertain the prevalence of Helicobacter pylori in patients with gastro-oesophageal reflux disease and its association with the disease. Design Systematic review of studies reporting the prevalence of H pylori in patients with and without gastro-oesophageal reflux disease. Data sources Four electronic databases, searched to November 2001, experts, pharmaceutical companies, and journals. Main outcome measure Odds ratio for prevalence of H pylori in patients with gastro-oesophageal reflux disease. Results 20 studies were included. The pooled estimate of the odds ratio for prevalence of H pylori was 0.60 (95% confidence interval 0.47 to 0.78), indicating a lower prevalence in patients with gastro-oesophageal reflux disease. Substantial heterogeneity was observed between studies. Location seemed to be an important factor, with a much lower prevalence of H pylori in patients with gastro-oesophageal reflux disease in studies from the Far East, despite a higher overall prevalence of infection than western Europe and North America. Year of study was not a source of heterogeneity. Conclusion The prevalence of H pylori infection was significantly lower in patients with than without gastro-oesophageal reflux, with geographical location being a strong contributor to the heterogeneity between studies. Patients from the Far East with reflux disease had a lower prevalence of H pylori infection than patients from western Europe and North America, despite a higher prevalence in the general population. What is already known on this topicThe relation between H pylori infection and gastro-oesophageal reflux disease is controversialStudies on the prevalence of H pylori in patients with gastro-oesophageal reflux disease have given conflicting resultsRecent guidelines recommend eradication of H pylori in patients requiring long term proton pump inhibitors, essentially for reflux diseaseWhat this study addsDespite heterogeneity between studies, the prevalence of H pylori was

  12. Recent HIV prevalence trends among pregnant women and all women in sub-Saharan Africa: implications for HIV estimates.

    Science.gov (United States)

    Eaton, Jeffrey W; Rehle, Thomas M; Jooste, Sean; Nkambule, Rejoice; Kim, Andrea A; Mahy, Mary; Hallett, Timothy B

    2014-11-01

    National population-wide HIV prevalence and incidence trends in sub-Saharan Africa (SSA) are indirectly estimated using HIV prevalence measured among pregnant women attending antenatal clinics (ANC), among other data. We evaluated whether recent HIV prevalence trends among pregnant women are representative of general population trends. Serial population-based household surveys in 13 SSA countries. We calculated HIV prevalence trends among all women aged 15-49 years and currently pregnant women between surveys conducted from 2003 to 2008 (period 1) and 2009 to 2012 (period 2). Log-binomial regression was used to test for a difference in prevalence trend between the two groups. Prevalence among pregnant women was age-standardized to represent the age distribution of all women. Pooling data for all countries, HIV prevalence declined among pregnant women from 6.5 [95% confidence interval (CI) 5.3-7.9%] to 5.3% (95% CI 4.2-6.6%) between periods 1 and 2, whereas it remained unchanged among all women at 8.4% (95% CI 8.0-8.9%) in period 1 and 8.3% (95% CI 7.9-8.8%) in period 2. Prevalence declined by 18% (95% CI -9-38%) more in pregnant women than nonpregnant women. Estimates were similar in Western, Eastern, and Southern regions of SSA; none were statistically significant (P>0.05). HIV prevalence decreased significantly among women aged 15-24 years while increasing significantly among women 35-49 years, who represented 29% of women but only 15% of pregnant women. Age-standardization of prevalence in pregnant women did not reconcile the discrepant trends because at older ages prevalence was lower among pregnant women than nonpregnant women. As HIV prevalence in SSA has shifted toward older, less-fertile women, HIV prevalence among pregnant women has declined more rapidly than prevalence in women overall. Interpretation of ANC prevalence data to inform national HIV estimates should account for both age-specific fertility patterns and HIV-related sub-fertility.

  13. Prevalence of Mental Health problems in sentenced men in prisons from Andalucía (Spain).

    Science.gov (United States)

    López, M; Saavedra, F J; López, A; Laviana, M

    2016-12-01

    To estimate the prevalence of different mental health problems in men serving prison sentences in Andalusia. Descriptive, cross-sectional study of a random sample of 472 men interned in two prisons located in Andalusia. We collected socio-demographic and general criminal and penitentiary data, and we identified mental health problems with two validated instruments for epidemiological research in mental health: the SCID-I interview to diagnose Axis 1 disorders of the DSM-IV and the self-applied questionnaire IPDE to estimate personality disorders. We analyzed the data (proportions and confidence intervals) with the SPSS-18 statistical package. 82.6% of the sample had a history of having suffered some type of mental health problem throughout their life (prevalence-life) and 25.8 have suffered from them in the past month (month prevalence). The most common disorders of the Axis I (DSM-IV) are related to abuse of and dependence on psychoactive substances (prevalence life of 65.9% and month prevalence of 6.6%), with an important but less frequent presence of affective (31.4%-9.3%), anxiety (30.9%-10, 4%) and psychotic disorders (9.5%-3, 4%). As regards personality disorders, the estimated probable prevalence lies between the 56.6% ("5" cutoff point) and the 79.9 ("4" cut-off point). The male inmate population in prisons in Andalucía shows a high prevalence of mental health problems, similar to that found in other Spanish and international prisons, but their care needs should take into account the different pathologies that they present.

  14. Prevalence of Mental Health problems in sentenced men in prisons from Andalucía (Spain

    Directory of Open Access Journals (Sweden)

    M. López

    Full Text Available Objectives: To estimate the prevalence of different mental health problems in men serving prison sentences in Andalusia. Methods: Descriptive, cross-sectional study of a random sample of 472 men interned in two prisons located in Andalusia. We collected socio-demographic and general criminal and penitentiary data, and we identified mental health problems with two validated instruments for epidemiological research in mental health: the SCID-I interview to diagnose Axis 1 disorders of the DSM-IV and the self-applied questionnaire IPDE to estimate personality disorders. We analyzed the data (proportions and confidence intervals with the SPSS-18 statistical package. Results: 82.6% of the sample had a history of having suffered some type of mental health problem throughout their life (prevalence-life and 25.8 have suffered from them in the past month (month prevalence. The most common disorders of the Axis I (DSM-IV are related to abuse of and dependence on psychoactive substances (prevalence life of 65.9% and month prevalence of 6.6%, with an important but less frequent presence of affective (31.4%-9.3%, anxiety (30.9%-10, 4% and psychotic disorders (9.5%-3, 4%. As regards personality disorders, the estimated probable prevalence lies between the 56.6% ("5" cutoff point and the 79.9 ("4" cut-off point. Conclusions: The male inmate population in prisons in Andalucía shows a high prevalence of mental health problems, similar to that found in other Spanish and international prisons, but their care needs should take into account the different pathologies that they present.

  15. The prevalence of the metabolic syndrome in Portugal: the PORMETS study.

    Science.gov (United States)

    Raposo, Luís; Severo, Milton; Barros, Henrique; Santos, Ana Cristina

    2017-06-08

    The PORMETS study was designed to estimate the prevalence of metabolic syndrome and its determinants in the overall and administrative regions of the Portuguese mainland. A cross-sectional study of a representative sample of non-institutionalized Portuguese adults selected from primary health care centres lists including 1695 men and 2309 women was conducted from February 2007 to July 2009. A structured questionnaire was administered, collecting information on personal medical history and socio-demographic and behavioural characteristics. Anthropometrics, blood pressure, and venous blood samples were obtained. Metabolic syndrome was defined according to three operational definitions. The prevalence ratios and their respective 95% confidence intervals were calculated using binomial generalized linear regression, with the log link function. The prevalence rates of metabolic syndrome in this sample of Portuguese adults were 36.5%, 49.6%, and 43.1%, using the Adult Treatment Panel III, International Diabetes Federation and Joint Interim Statement definitions, respectively. The most prevalent feature of metabolic syndrome in this sample was high blood pressure (64.3%) and the lowest was high fasting glucose (24.9%). After adjustment for age and gender, significant differences were observed for the 18 districts of the Portugal mainland. Additionally, metabolic syndrome was significantly more frequent in non-urban areas than in urban ones (p = 0.001). The prevalence of metabolic syndrome was significantly higher in women (p˂0.001) and older participants (p˂0.001), as well as in those who reported being housewives (p = 0.010), retired (p = 0.046) or unemployed (p = 0.024). This study showed that metabolic syndrome is highly prevalent in the Portuguese adult population. Regional differences in the prevalence of this syndrome were observed, and this condition was more common in non-urban areas and less favoured socio-economic categories.

  16. The prevalence of colorectal adenomas in asymptomatic Korean men and women.

    Science.gov (United States)

    Yang, Moon Hee; Rampal, Sanjay; Sung, Jidong; Choi, Yoon-Ho; Son, Hee Jung; Lee, Jun Haeng; Kim, Young-Ho; Chang, Dong Kyung; Rhee, Poong-Lyul; Rhee, Jong Chul; Guallar, Eliseo; Cho, Juhee

    2014-03-01

    Colorectal cancer incidence is rapidly rising in many Asian countries, with rates approaching those of Western countries. This study aimed to evaluate the prevalence and trends of colorectal adenomas by age, sex, and risk strata in asymptomatic Koreans. Cross-sectional study of 19,372 consecutive participants aged 20 to 79 years undergoing screening colonoscopy at the Center for Health Promotion of the Samsung Medical Center in Korea from January 2006 to June 2009. Among participants at average risk, those without a history of colorectal polyps or a family history of colorectal cancer, the prevalence of colorectal adenomas and advanced adenomas were 34.5% and 3.1%, respectively, in men and 20.0% and 1.6%, respectively, in women. The prevalence of adenomas increased with age in both men and women, with a more marked increase for advanced adenoma. Participants with a family history of colorectal cancer or with a history of colorectal polyps had significantly higher prevalence of adenomas compared with participants of average risk (36.9% vs. 26.9%; age- and sex-adjusted prevalence ratio = 1.16; 95% confidence interval, 1.09-1.22). The prevalence of adenomas increased annually in both men and women. In this large study of asymptomatic Korean men and women participating in a colonoscopy screening program, the prevalence of colorectal adenomas was comparable and possibly higher than previously reported in Western countries. Cost-effectiveness studies investigating the optimal age for starting colonoscopy screening and etiological studies to identify the reasons for the increasing trend in colorectal adenomas in Koreans are needed. ©2014 AACR.

  17. Prevalence and correlates for diarrhoea in the mountainous informal settlements of Huye town, Rwanda.

    Science.gov (United States)

    Uwizeye, Dieudonné; Sokoni, Cosmas H; Kabiru, Caroline W

    2014-01-01

    Dwellers of urban informal settlements in developing countries are consistently reported to be victims of high diarrhoea prevalence. Studies have frequently reported the association between high diarrhoea prevalence and other factors, such as poor living conditions, inadequate hygiene, and sanitation in these settings. However, little is known about the dynamics of diarrhoea prevalence in mountainous urban informal settlements similar to the Rwandan context. This study was conducted in the Matyazo cell of Huye town to review the prevalence and correlates of diarrhoea. A survey of 214 households and transect walks in the neighbourhoods were conducted during the rainy and dry seasons. Logistic regression was used to analyse the survey data while the thematic analysis technique was used to analyse qualitative data. Results indicated a substantial reduction of diarrhoea prevalence from the rainy to the dry season. It was also found that the prevalence was unequally distributed in the neighbourhoods according to household location. After controlling for other household characteristics and sanitation conditions of around homes, the study indicated that households established at 1800 metres or more above sea level were protected against diarrhoea during both rainy seasons (Adjusted Odds Ratio_ AOR: .42, 95% Confidence Interval_ CI: .13-.81) and dry seasons (AOR: .58, CI: .12-.90) while households found further from the road were likely to suffer from diarrhoea during rainy seasons (AOR: 3.32, CI: 1.47-7.48) as well as in dry seasons (AOR: 1.60, CI: 1.26-4.10). Poor sanitation within and around homes was also found to be associated with the increase of diarrhoea in either season. However, the evidence was not sufficient enough to confirm a significant association between diarrhoea prevalence and other household characteristics. We believe this is due to the strength of environmental factors in mountainous settings.

  18. Prevalence and incidence of multiple sclerosis in central Poland, 2010-2014.

    Science.gov (United States)

    Brola, Waldemar; Sobolewski, Piotr; Flaga, Stanisław; Fudala, Małgorzata; Szczuchniak, Wiktor; Stoiński, Jan; Rosołowska, Anita; Wójcik, Jacek; Kapica-Topczewska, Katarzyna; Ryglewicz, Danuta

    2016-08-11

    Comprehensive epidemiologic data for multiple sclerosis (MS) in Poland are limited. The aim of this cross-sectional population-based study was to determine the incidence and prevalence of MS in the Swietokrzyskie Region (central Poland). This study identified MS cases every year between 1 January 2010 and 31 December 2014. The study area population on the prevalence day (December 31, 2014) was 1,263,176 (646,506 women and 616,670 men). A total of 1462 patients with a clinically definite diagnosis of MS according to McDonald's criteria (2005), recorded in the Polish Multiple Sclerosis Registry, were considered for estimation of crude, age- and sex-specific prevalence, and incidence. The overall crude prevalence rate of confirmed MS patients was 115.7/100,000 (95 % confidence interval (CI), 111.2-121.4). A significantly higher prevalence was recorded in females (159.6/100,000; 95 % CI, 151.1-165.3) than in males (69.7/100,000; 95 % CI, 62.4-77.3) (P < 0.001). Age-adjusted rates for the Polish and European Standard Population were 109.8/100,000 (95 % CI, 105.4-114.8) and 106.6/100,000 (95 % CI, 101.1-111.2), respectively. The female/male ratio was 2.4. The mean annual incidence was 4.2/100,000 (95 % CI. 3.7-4.4). The incidence and prevalence of MS in the Swietokrzyskie region confirm that central Poland is a high risk area for MS. Compared with previous epidemiologic studies from Poland, the prevalence of MS has increased during recent years.

  19. Prevalence of burnout among nurses in Iran: a systematic review and meta-analysis.

    Science.gov (United States)

    Rezaei, S; Karami Matin, B; Hajizadeh, M; Soroush, A; Nouri, B

    2018-01-30

    This study aimed to summarize the available information in the literature to make an accurate estimate of the prevalence of burnout among Iranian nurses. Burnout is a work-related stress syndrome that has negative impact on healthcare providers, patients and healthcare delivery systems. A comprehensive search of literature using international [PubMed, Scopus and the Institute for Scientific Information (ISI)] and Iranian scientific data bases [Scientific Information Database (SID), IranMedex and Magiran] was conducted to identify English and Persian language studies, published between 2000 and 2016, that examined the prevalence of burnout among nurses in Iran. The I-squared test and Chi-squared-based Q-test suggested heterogeneity of reported prevalence among the qualified studies; thus, a random-effects model was applied to estimate the overall prevalence of burnout among nurses in Iran. Based on 21 selected articles with 4180 participants, the overall prevalence of burnout among Iranian nurses was estimated to be 36% [95% confidence interval (CI), 20-53%] in Iran. Meta-regression indicated that sample size and year of data collection, mean age of samples, female to male ratio and geographic regions were not statistically significantly associated with the prevalence of burnout. Also, based on Egger's test and funnel plot, there is no publication bias among studies included in the analysis. Professional burnout affects more than one-third of nursing staff in Iran; thus, effective interventions and strategies are required to reduce and prevent burnout among nurses. Due to the negative consequences of burnout on patients, nurses and organizations, nursing and healthcare managers should intervene to prevent and reduce burnout among nurses in Iran. Policy attention should focus on developing effective interventions to prevent and minimize the burden of burnout among nurses in Iran. Nurses' involvement in the policy-making process is crucial in the implementation of

  20. [Prevalence of Hypothyroidism in Andalusia, Spain, Determined by Thyroid Hormone Comsumption].

    Science.gov (United States)

    Escribano-Serrano, José; Mancera-Romero, José; Santos-Sánchez, Vanessa; Payá-Giner, Carolina; Méndez-Esteban, Mª Isabel; García-Bonilla, Antonio; Márquez-Ferrando, Manuela; Hormigo-Pozo, Antonio; Michán-Doña, Alfredo

    2016-12-02

    Hypothyroidism is the most common condition linked to a hormone deficiency, nevertheless data on its prevalence are scarce in Spain. For that reason, we have estimated its prevalence through the registration of patients who had used thyroid hormones in Andalusia (South Spain). Data of patients who had withdrawn levothyroxine under the public system during 2014 from the base of the Andalusian Health Service were considered. Prevalence were calculated with confidence intervals of 95% for each management area, stratified by sex and age groups, and differences between them were evaluated. 321,368 people (98% older than 18 years and 83% female) were identified as levothyroxine users and a prevalence of hypothyroidism of 3.95% (95%CI:3.94-3.96) was estimated for the general population. The condition was more common in females, in the older 18 years 7.81% (95%CI:7.80 to 7.82) compared to males 1.75% (95%CI:1.73-1.77) with a ratio of 4.5-fold. It increases in the population of women older than 45 years, 10.32% (95%CI:10.30-0.32) and in the over 60 years 11.37% (95%CI: 11.35-11.40). The prevalence in adult women in the western provinces is 7.38% (95%CI:7.36-7.40), in the eastern provinces 8.59% (95%CI:8.57-8.62) and in coastal areas 6.70% (95%CI: 6.68-6.72) compared to the mountainous ones, which is 8.91% (95%CI:8.88-8.94). The results denote a high prevalence of hypothyroidism in the adult population of Andalusia compared to the nearby countries, with a clear increased associated with females and age. Furthermore, the prevalence of the illness presents also a geographically-related variability.

  1. Prevalence of obesity and diabetes in Spanish adults 1987-2012.

    Science.gov (United States)

    Basterra-Gortari, Francisco Javier; Bes-Rastrollo, Maira; Ruiz-Canela, Miguel; Gea, Alfredo; Martinez-Gonzalez, Miguel Ángel

    2017-03-22

    The prevalence of obesity and diabetes mellitus (DM) has increased worldwide. Our objective was to examine trends in the prevalence of overweight, obesity, morbid obesity and DM in Spain from 1987 to 2012. Data were obtained from 8 waves of the national health surveys which are cross-sectional studies conducted in representative samples of the Spanish adult population. Self-reported data of 156,440 adults (≥16 years) from 1987 to 2012 were used. Body mass index (BMI) was calculated from self-reported weight and height. Overweight was defined as a BMI of 25.0 to 29.9kg/m 2 , obesity as a BMI≥30kg/m 2 and morbid obesity as a BMI≥40kg/m 2 . DM was considered present if the participant reported having been diagnosed. Age-adjusted prevalence was adjusted by the direct standardisation method to the 2003 survey population. From 1987 to 2012 age-adjusted prevalence of overweight increased from 34.0% (95% confidence interval [95% CI] 33.2-34.8) to 35.8% (95% CI 35.0-36.6), prevalence of obesity from 8.0% (95% CI 7.5-8.5) to 16.5% (95% CI 15.7-17.1%) and DM prevalence from 4.2% (95% CI 3.9-4.5) to 7.1% (95% CI 6.7-7.4%). Morbid obesity increased from 0.20% (95% CI 0.13-0.27) in 1993 to 0.88% (95% CI 0.70-1.05) in 2012. The growth rate was greater among males. An increasing trend of the prevalence of overweight, obesity, morbid obesity and DM was found in Spain from 1987 to 2012, particularly in males. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  2. Do women with migraine have higher prevalence of temporomandibular disorders?

    Directory of Open Access Journals (Sweden)

    Maria C Gonçalves

    Full Text Available OBJECTIVES: The aim of this study was to assess the prevalence of Temporomandibular Disorders (TMD, using the Research Diagnostic Criteria for TMD (RDC/TMD in women with episodic and chronic migraine (M and CM, as well as in asymptomatic women. METHOD: Sample consisted of 61 women, being 38 with M and 23 with CM, identified from a headache outpatient center; we also investigated 30 women without headaches for at least 3 months (women without headache group - WHG. Assessment of TMD was conducted by a physical therapist who was blind to the headache status. RESULTS: The prevalence of TMD, assessed through the RDC, was 33.3% in the WHG, 86.8% in the M group and 91.3% of the CM group. Differences were significant when comparing M and CM groups with WHG (p0.05 as well as higher risk for TMD [odds ratio (OR=3.15, 95% confidence interval (CI 1.73-5.71 and OR=3.97, 95%CI 1.76-8.94]. CONCLUSION: Women with migraine are more likely to have muscular and articular TMD, suggesting that both disorders might be clinically associated, which demonstrate the importance of physical therapy assessment in the multidisciplinary team.

  3. Prevalence of supplement use in recreationally active Kazakhstan university students.

    Science.gov (United States)

    Vinnikov, Denis; Romanova, Zhanna; Dushpanova, Anar; Absatarova, Karashash; Utepbergenova, Zhazira

    2018-01-01

    Little is known about the supplements use and recreational sport practices in Kazakhstan university students. Therefore, the aim of this study was to ascertain supplements use prevalence and their predictors in this population. Cross-sectional survey of both undergraduate and graduate level students was completed in 2017 et al.-Farabi Kazakh National University, the largest higher institution in the country, from almost all Schools. A 45-item questionnaire was used to record physical activity, supplements use, lifestyle attributes (smoking, alcohol, sleep, etc.) and eating habits, and adjusted regression models were used to verify predictors of supplements use. Of the entire sample of 889 students (70% females), 526 (59%) were practicing recreational physical activity (RPA), and walking, jogging and track and field was the most popular activity type (38%). N  = 151 (29%) students reported the use of any supplement (31% in men and 27% in women), whereas the most popular supplement type were vitamins. Supplement use was most prevalent in swimmers (55%). Age (odds ratio (OR) 1.19 (95% confidence interval (CI) 1.04-1.37), use of fitness tracker (OR 6.26 (95% CI 3.90-10.03)) and low-fat diet (OR 1.95 (95% CI 1.23-3.10)), but not income predicted supplements use in adjusted models. With more than half of students exercising regularly, only less than one-third use supplements with a very strong association with fitness tracker use.

  4. Prevalence of antenatal depressive symptoms among women in Sabah, Malaysia.

    Science.gov (United States)

    Mohamad Yusuff, Aza Sherin; Tang, Li; Binns, Colin W; Lee, Andy H

    2016-01-01

    To investigate the prevalence of antenatal depression and to assess whether the common risk factors identified in previous studies were applicable to women in Sabah, Malaysia. A prospective cohort study of 2072 women was conducted in Sabah during 2009-2010. Participants were recruited at 36-38 weeks of gestation to complete a self-administered questionnaire regarding their demographic, socioeconomic and health characteristics. The presence of depression was assessed using the validated Malay version of the Edinburgh Postnatal Depression Scale. The prevalence of antenatal depression was 13.8% [95% confidence interval (CI) 12.3%, 15.3%]. Women who were happy with the pregnancy [odds ratio (OR) 0.43, 95% CI 0.21, 0.89] and those with a planned pregnancy (OR 0.45, 95% CI 0.33, 0.60) were less likely to suffer from antenatal depression. Pregnant mothers who were taking oral contraceptives before pregnancy (OR 1.63, 95% CI 1.20, 2.22) and women who experienced antenatal anxiety (OR 3.17, 95% CI 2.35, 4.26) appeared to have an increased risk of antenatal depression. A substantial proportion of women suffered from antenatal depression in Sabah, Malaysia. Screening and culturally tailored intervention programs targeting vulnerable subgroups of women in the early stage of pregnancy are recommended to deal with the problem.

  5. Migraine is the most prevalent primary headache in individuals with temporomandibular disorders.

    Science.gov (United States)

    Franco, Ana L; Gonçalves, Daniela A G; Castanharo, Sabrina M; Speciali, José G; Bigal, Marcelo E; Camparis, Cinara M

    2010-01-01

    To assess the prevalence of primary headaches (HA) in adults with temporomandibular disorders (TMD) who were assessed in a specialty orofacial pain clinic, as well as in controls without TMD. The sample consisted of 158 individuals with TMD seen at a university-based specialty clinic, as well as 68 controls. The Research Diagnostic Criteria for TMD were used to diagnose the TMD patients. HAs were assessed using a structured interview and classified according to the Second Edition of the International Classification for Headache Disorders. Data were analyzed by chi-square tests with a significance level of 5% and odds ratio (OR) tests with a 95% confidence interval (CI). HAs occurred in 45.6% of the control group (30.9% had migraine and 14.7% had tension-type headache [TTH]) and in 85.5% of individuals with TMD. Among individuals with TMD, migraine was the most prevalent primary HA (55.3%), followed by TTH (30.2%); 14.5% had no HA. In contrast to controls, the odds ratio (OR) for HA in those with TMD was 7.05 (95% confidence interval [CI] = 3.65-13.61; P = .000), for migraine, the OR was 2.76 (95% CI = 1.50-5.06; P = .001), and for TTH, the OR was 2.51 (95% CI = 1.18-5.35; P = .014). Myofascial pain/arthralgia was the most common TMD diagnosis (53.2%). The presence of HA or specific HAs was not associated with the time since the onset of TMD (P = .714). However, migraine frequency was positively associated with TMD pain severity (P = .000). TMD was associated with increased primary HA prevalence rates. Migraine was the most common primary HA diagnosis in individuals with TMD.

  6. Prevalence of Vitamin D Deficiency in Adult Outpatients With Bipolar Disorder or Schizophrenia.

    Science.gov (United States)

    Boerman, Remco; Cohen, Dan; Schulte, Peter F J; Nugter, Annet

    2016-12-01

    Several studies show an association between schizophrenia and low levels of vitamin D. To date, there are only few studies about the prevalence of vitamin D deficiency in patients with bipolar disorder. We hypothesized that vitamin D deficiency is less common among patients with bipolar disorder than among patients with schizophrenia or schizoaffective disorder. A second hypothesis is that vitamin D deficiency is more prevalent among patients with schizophrenia, schizoaffective disorder, or bipolar disorders than among the general Dutch population.Most studies have been conducted with hospitalized patients; in this study, we only included outpatients. All outpatients of a center for bipolar disorders and all outpatients of 3 flexible assertive community treatment teams were asked to participate in this cross-sectional study. We included 118 patients with bipolar disorder and 202 patients with schizophrenia or schizoaffective disorder. Vitamin D levels were deficient in 30.3% (95% confidence interval, 25.5-35.6) of the cases. The type of psychiatric disorder was not a predictor of vitamin D deficiency. The absolute difference in risk of deficiency between the study population and the Dutch Caucasian population was 23.8% (95% confidence interval, 18.3%-29.3%). In this study, vitamin D deficiency was 4.7 times more common among outpatients with bipolar disorder, schizophrenia, or schizoaffective disorder than among the Dutch general population.Given the high prevalence of vitamin D deficiency, we believe that outpatients with bipolar disorder, schizophrenia, or schizoaffective disorder should be considered at risk of having low levels of vitamin D. Annual measurement of vitamin D levels in psychiatric outpatients with these disorders seems to be justified to maintain bone health, muscle strength, and to prevent osteoporosis.

  7. Acromegaly incidence, prevalence, complications and long-term prognosis: a nationwide cohort study.

    Science.gov (United States)

    Dal, Jakob; Feldt-Rasmussen, Ulla; Andersen, Marianne; Kristensen, Lars Ø; Laurberg, Peter; Pedersen, Lars; Dekkers, Olaf M; Sørensen, Henrik Toft; Jørgensen, Jens Otto L

    2016-09-01

    Valid data on acromegaly incidence, complications and mortality are scarce. The Danish Health Care System enables nationwide studies with complete follow-up and linkage among health-related databases to assess acromegaly incidence, prevalence, complications and mortality in a population-based cohort study. All incident cases of acromegaly in Denmark (1991-2010) were identified from health registries and validated by chart review. We estimated the annual incidence rate of acromegaly per 10(6) person-years (py) with 95% confidence intervals (95% CIs). For every patient, 10 persons were sampled from the general population as a comparison cohort. Cox regression and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used. Mean age at diagnosis (48.7 years (CI: 95%: 47.2-50.1)) and annual incidence rate (3.8 cases/10(6) persons (95% CI: 3.6-4.1)) among the 405 cases remained stable. The prevalence in 2010 was 85 cases/10(6) persons. The patients were at increased risk of diabetes mellitus (HR: 4.0 (95% CI: 2.7-5.8)), heart failure (HR: 2.5 (95% CI: 1.4-4.5)), venous thromboembolism (HR: 2.3 (95% CI: 1.1-5.0)), sleep apnoea (HR: 11.7 (95% CI: 7.0-19.4)) and arthropathy (HR: 2.1 (95% CI: 1.6-2.6)). The complication risk was also increased before the diagnosis of acromegaly. Overall mortality risk was elevated (HR: 1.3 (95% CI: 1.0-1.7)) but uninfluenced by treatment modality. (i) The incidence rate and age at diagnosis of acromegaly have been stable over decades, and the prevalence is higher than previously reported. (ii) The risk of complications is very high even before the diagnosis. (iii) Mortality risk remains elevated but uninfluenced by mode of treatment. © 2016 European Society of Endocrinology.

  8. Prevalence study of yaws in the Democratic Republic of Congo using the lot quality assurance sampling method.

    Directory of Open Access Journals (Sweden)

    Sibylle Gerstl

    Full Text Available BACKGROUND: Until the 1970s the prevalence of non-venereal trepanomatosis, including yaws, was greatly reduced after worldwide mass treatment. In 2005, cases were again reported in the Democratic Republic of the Congo. We carried out a survey to estimate the village-level prevalence of yaws in the region of Equator in the north of the country in order to define appropriate strategies to effectively treat the affected population. METHODOLOGY/PRINCIPAL FINDINGS: We designed a community-based survey using the Lot Quality Assurance Sampling method to classify the prevalence of active yaws in 14 groups of villages (lots. The classification into high, moderate, or low yaws prevalence corresponded to World Health Organization prevalence thresholds for identifying appropriate operational treatment strategies. Active yaws cases were defined by suggestive clinical signs and positive rapid plasma reagin and Treponema pallidum hemagglutination serological tests. The overall prevalence in the study area was 4.7% (95% confidence interval: 3.4-6.0. Two of 14 lots had high prevalence (>10%, three moderate prevalence (5-10% and nine low prevalence (<5%.. CONCLUSIONS/SIGNIFICANCE: Although yaws is no longer a World Health Organization priority disease, the presence of yaws in a region where it was supposed to be eradicated demonstrates the importance of continued surveillance and control efforts. Yaws should remain a public health priority in countries where previously it was known to be endemic. The integration of sensitive surveillance systems together with free access to effective treatment is recommended. As a consequence of our study results, more than 16,000 people received free treatment against yaws.

  9. Human Papillomavirus Infection Among 2460 Men in Denmark: Prevalence in Relation to Age Using 2 Human Papillomavirus DNA Testing Methods.

    Science.gov (United States)

    Hebnes, Julie Buchholt; Munk, Christian; Nøhr, Bugge; Nielsen, Ann; Jørgensen, Hans Ole; Iftner, Thomas; Kjaer, Susanne Krüger

    2015-08-01

    It is crucial to understand the epidemiology and natural history of human papillomavirus (HPV) infection in both men and women, to prevent the increasing HPV-related disease burden in men. Data on HPV prevalence among men in the general population are limited. In this cross-sectional population-based study, we aimed to estimate genital HPV infection prevalence in Danish men using 2 different test methods. Penile swab samples from 2460 male employees and conscripts at military barracks in Denmark were tested for HPV DNA with the hybrid capture 2 (HC2) method, and a polymerase chain reaction (PCR) assay, Inno-LiPA. The overall and age- and type-specific prevalence of HPV infection with 95% confidence intervals (CIs) were estimated, and the correlation between the 2 assays was assessed. The overall HPV prevalence was 22.2% (95% CI, 20.6-23.9) in the HC2 test and 41.8% (95% CI, 39.9-43.8) with PCR. Of the PCR-positive samples, 50.9% were negative in the HC2 test. Of 183 PCR-positive samples that could not be genotyped (HPVX), 88.0% (95% CI, 83.2-92.7) were HC2 negative. The most prevalent types were HPV-51, HPV-16, HPV-66, HPV-53, and HPV-6. The prevalence of high-risk and low-risk HPV peaked among men aged 20 to 29 years, whereas the HPVX prevalence increased with age. Human papillomavirus is highly prevalent in the general male population of Denmark, with HPV-16 and HPV-51 being the most prevalent. Polymerase chain reaction detects twice as many positive samples as HC2 but includes HPVX, possibly representing cutaneous HPV types found on normal genital skin.

  10. Prevalence of bovine trypanosomosis in Wemberma district of West ...

    African Journals Online (AJOL)

    From three peasant associations in the district (one from the midland and two from lowland), 384 cattle ... to 2212 meter above sea level (masl). Based on altitude ... for prevalence study from infinite population with 95% confidence level, 5 % of.

  11. Prevalence of Toxocara cati and other parasites in cats' faeces collected from the open spaces of public institutions: Buenos Aires, Argentina.

    Science.gov (United States)

    Sommerfelt, I E; Cardillo, N; López, C; Ribicich, M; Gallo, C; Franco, A

    2006-09-10

    Toxocarosis is a worldwide parasitic infection that affects both cats and dogs. Toxocara cati (Schrank, 1788) syn. Toxocara mystax (Zeder, 1800) prevalence was studied in faeces from stray cats collected from the open spaces of public institutions of Buenos Aires city, both building and surrounding open spaces are fenced off. Of the 465 samples obtained from March to June of 2005, 58.3% were found to have parasite eggs. The following parasites were identified from the 271 positive samples: T. cati (61.2%), Cystoisospora spp. (20.3%), Trichuris spp. (17.0%), Toxascaris leonina (15.1%), Ancylostoma spp. (14%) and Aelurostrongylus abstrusus (2.6%). T. cati prevalence was 35.7% (95% confidence interval: 31.2-40.1), with a 42.2% single isolations. The most frequent combination was T. cati and Cystoisospora spp. (9%). More than half the areas studied showed over 40% prevalence. Seventy-one percent of the collected samples were fresh with a variable moist consistency and 29% were older with a dry consistency. A statistically significant association was found between sample consistency and presence of parasites (chi2 = 10.81; p = 0.001) as also between sample consistency and presence of T. cati (chi2 = 11.27; p = 0.0007). Moist consistencies were significantly different from the rest: consistency (wet or dry) versus parasites (z = 1.95; p = 0.02) (95% confidence interval: 0.004-0.203); consistency (wet or dry) versus T. cati (z = 3.25; p = 0.0006) (95% confidence interval: 0.075-0.254). The cat population that inhabits these public green spaces contaminates the environment, thus transforming them into dangerous spaces with a variable rate for the human population that spends time in these places.

  12. High prevalence of frequent attendance in the over 65s.

    Science.gov (United States)

    McMahon, C Geraldine; Power Foley, Megan; Robinson, David; O'Donnell, Kate; Poulton, Miriam; Kenny, Rose A; Bennett, Kathleen

    2018-02-01

    Characteristics of older frequent users of Emergency Departments (EDs) are poorly understood. Our aim was to examine the characteristics of the ED frequent attenders (FAs) by age (under 65 and over 65 years). We examined the prevalence of FA attending the ED of an Urban Teaching Hospital in a cross-sectional study between 2009 and 2011. FA was defined as an individual who presented to the ED four or more times over a 12-month period. Randomly selected groups of FA and non-FA from two age groups (under 65 and over 65 years) were then examined to compare the characteristics between older FAs and non-FAs and older FAs and younger FAs. Logistic regression was used to calculate the odds ratio and 95% confidence intervals for 12-month mortality in FA compared with non-FA aged at least 65 years. Overall, 137 150 ED attendances were recorded between 2009 and 2011. A total of 21.6% were aged at least 65 years, 4.4% of whom were FAs, accounting for 18.4% of attendances by patients older than 65 years. There was a bimodal age distribution of FA (mean±SD; under 65 years 40±12.7; and over 65 years 76.9±7.4). Older FAs were five times more likely to present outside normal working hours and 5.5 times more likely to require admission. Cardiovascular emergencies were the most common complaint, in contrast with the younger FA group, where injury and psychosocial conditions dominated. The odds ratio for death at 12 months was 2.07 (95% confidence interval 0.93-4.63; P=0.07), adjusting for age and sex. One-in-five ED patients older than 65 years of age are FAs. Older FAs largely present with complex medical conditions. Enhanced access to expert gerontology assessment should be considered as part of effective intervention strategies for older ED users.

  13. Disconnections Between Teacher Expectations and Student Confidence in Bioethics

    Science.gov (United States)

    Hanegan, Nikki L.; Price, Laura; Peterson, Jeremy

    2008-09-01

    This study examines how student practice of scientific argumentation using socioscientific bioethics issues affects both teacher expectations of students’ general performance and student confidence in their own work. When teachers use bioethical issues in the classroom students can gain not only biology content knowledge but also important decision-making skills. Learning bioethics through scientific argumentation gives students opportunities to express their ideas, formulate educated opinions and value others’ viewpoints. Research has shown that science teachers’ expectations of student success and knowledge directly influence student achievement and confidence levels. Our study analyzes pre-course and post-course surveys completed by students enrolled in a university level bioethics course ( n = 111) and by faculty in the College of Biology and Agriculture faculty ( n = 34) based on their perceptions of student confidence. Additionally, student data were collected from classroom observations and interviews. Data analysis showed a disconnect between faculty and students perceptions of confidence for both knowledge and the use of science argumentation. Student reports of their confidence levels regarding various bioethical issues were higher than faculty reports. A further disconnect showed up between students’ preferred learning styles and the general faculty’s common teaching methods; students learned more by practicing scientific argumentation than listening to traditional lectures. Students who completed a bioethics course that included practice in scientific argumentation, significantly increased their confidence levels. This study suggests that professors’ expectations and teaching styles influence student confidence levels in both knowledge and scientific argumentation.

  14. Sex differences in confidence influence patterns of conformity.

    Science.gov (United States)

    Cross, Catharine P; Brown, Gillian R; Morgan, Thomas J H; Laland, Kevin N

    2017-11-01

    Lack of confidence in one's own ability can increase the likelihood of relying on social information. Sex differences in confidence have been extensively investigated in cognitive tasks, but implications for conformity have not been directly tested. Here, we tested the hypothesis that, in a task that shows sex differences in confidence, an indirect effect of sex on social information use will also be evident. Participants (N = 168) were administered a mental rotation (MR) task or a letter transformation (LT) task. After providing an answer, participants reported their confidence before seeing the responses of demonstrators and being allowed to change their initial answer. In the MR, but not the LT, task, women showed lower levels of confidence than men, and confidence mediated an indirect effect of sex on the likelihood of switching answers. These results provide novel, experimental evidence that confidence is a general explanatory mechanism underpinning susceptibility to social influences. Our results have implications for the interpretation of the wider literature on sex differences in conformity. © 2016 The British Psychological Society.

  15. Prevalence of mental illness among inmates at Mukobeko maximum security prison in Zambia: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Mweene T Mweene

    2016-01-01

    Full Text Available Objectives: The objective of this study is to determine the prevalence and sociodemographic correlates for mental illness among inmates at Mukobeko Maximum Security Prison, Zambia. Materials and Methods: A cross sectional study was conducted to assess psychiatric disturbance using a Self-Reported Questionnaire (SRQ20. A cut off point of 7/8 was used. The Chi-square test and Fishers′ exact test were used to determine associations at the 5% significance level, and magnitude of association was estimated using the odds ratio and its 95% confidence interval. Results: Of the 394 inmates in prison, 29.2% had a current mental illness. Gender status was significantly associated with mental illness. Male participants were 35% (odds ratio = 0.65, 95% confidence interval [0.51, 0.82] less likely to have mental illness compared to female participants. Conclusions: The prevalence of mental illness is high in Mukobeko Maximum Security Prison in Zambia. Gender-specific interventions should be designed to reduce the level of mental illness in this prison.

  16. Confidence in Alternative Dispute Resolution: Experience from Switzerland

    Directory of Open Access Journals (Sweden)

    Christof Schwenkel

    2014-06-01

    Full Text Available Alternative Dispute Resolution plays a crucial role in the justice system of Switzerland. With the unified Swiss Code of Civil Procedure, it is required that each litigation session shall be preceded by an attempt at conciliation before a conciliation authority. However, there has been little research on conciliation authorities and the public's perception of the authorities. This paper looks at public confidence in conciliation authorities and provides results of a survey conducted with more than 3,400 participants. This study found that public confidence in Swiss conciliation authorities is generally high, exceeds the ratings for confidence in cantonal governments and parliaments, but is lower than confidence in courts.Since the institutional models of the conciliation authorities (meaning the organization of the authorities and the selection of the conciliators differ widely between the 26 Swiss cantons, the influence of the institutional models on public confidence is analyzed. Contrary to assumptions based on New Institutional-ism approaches, this study reports that the institutional models do not impact public confidence. Also, the relationship between a participation in an election of justices of the peace or conciliators and public confidence in these authorities is found to be at most very limited (and negative. Similar to common findings on courts, the results show that general contacts with conciliation authorities decrease public confidence in these institutions whereas a positive experience with a conciliation authority leads to more confidence.The Study was completed as part of the research project 'Basic Research into Court Management in Switzerland', supported by the Swiss National Science Foundation (SNSF. Christof Schwenkel is a PhD student at the University of Lucerne and a research associate and project manager at Interface Policy Studies. A first version of this article was presented at the 2013 European Group for Public

  17. Food skills confidence and household gatekeepers' dietary practices.

    Science.gov (United States)

    Burton, Melissa; Reid, Mike; Worsley, Anthony; Mavondo, Felix

    2017-01-01

    Household food gatekeepers have the potential to influence the food attitudes and behaviours of family members, as they are mainly responsible for food-related tasks in the home. The aim of this study was to determine the role of gatekeepers' confidence in food-related skills and nutrition knowledge on food practices in the home. An online survey was completed by 1059 Australian dietary gatekeepers selected from the Global Market Insite (GMI) research database. Participants responded to questions about food acquisition and preparation behaviours, the home eating environment, perceptions and attitudes towards food, and demographics. Two-step cluster analysis was used to identify groups based on confidence regarding food skills and nutrition knowledge. Chi-square tests and one-way ANOVAs were used to compare the groups on the dependent variables. Three groups were identified: low confidence, moderate confidence and high confidence. Gatekeepers in the highest confidence group were significantly more likely to report lower body mass index (BMI), and indicate higher importance of fresh food products, vegetable prominence in meals, product information use, meal planning, perceived behavioural control and overall diet satisfaction. Gatekeepers in the lowest confidence group were significantly more likely to indicate more perceived barriers to healthy eating, report more time constraints and more impulse purchasing practices, and higher convenience ingredient use. Other smaller associations were also found. Household food gatekeepers with high food skills confidence were more likely to engage in several healthy food practices, while those with low food skills confidence were more likely to engage in unhealthy food practices. Food education strategies aimed at building food-skills and nutrition knowledge will enable current and future gatekeepers to make healthier food decisions for themselves and for their families. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Determining the confidence levels of sensor outputs using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Broten, G S; Wood, H C [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Electrical Engineering

    1996-12-31

    This paper describes an approach for determining the confidence level of a sensor output using multi-sensor arrays, sensor fusion and artificial neural networks. The authors have shown in previous work that sensor fusion and artificial neural networks can be used to learn the relationships between the outputs of an array of simulated partially selective sensors and the individual analyte concentrations in a mixture of analyses. Other researchers have shown that an array of partially selective sensors can be used to determine the individual gas concentrations in a gaseous mixture. The research reported in this paper shows that it is possible to extract confidence level information from an array of partially selective sensors using artificial neural networks. The confidence level of a sensor output is defined as a numeric value, ranging from 0% to 100%, that indicates the confidence associated with a output of a given sensor. A three layer back-propagation neural network was trained on a subset of the sensor confidence level space, and was tested for its ability to generalize, where the confidence level space is defined as all possible deviations from the correct sensor output. A learning rate of 0.1 was used and no momentum terms were used in the neural network. This research has shown that an artificial neural network can accurately estimate the confidence level of individual sensors in an array of partially selective sensors. This research has also shown that the neural network`s ability to determine the confidence level is influenced by the complexity of the sensor`s response and that the neural network is able to estimate the confidence levels even if more than one sensor is in error. The fundamentals behind this research could be applied to other configurations besides arrays of partially selective sensors, such as an array of sensors separated spatially. An example of such a configuration could be an array of temperature sensors in a tank that is not in

  19. HIV prevalence and correlates of unprotected anal intercourse among men who have sex with men, Jinan, China.

    Science.gov (United States)

    Ruan, Shiman; Yang, Hui; Zhu, Yanwen; Ma, Yanhui; Li, Jinxing; Zhao, Jinkou; McFarland, Willi; Raymond, H Fisher

    2008-05-01

    China's HIV epidemic may be shifting towards predominantly sexual transmission and emerging data point to potential increases in HIV prevalence among men who have sex with men (MSM). There is particular need to assess the extent of risk behavior among MSM outside of China's most cosmopolitan cities. We conducted a respondent-driven sampling survey (N = 428) to measure HIV seroprevalence and risk behavior among MSM in Jinan, China, the provincial capital of Shandong. HIV prevalence was 0.5% (95% confidence interval [CI] 0.1-1.0). Unprotected anal intercourse (UAI) in the last 6 months (reported by 61.4%) was associated with buying or selling sex to a man in the last 6 months, syphilis infection, multiple partners in the last month, low HIV knowledge and migrant status. No participant had previously tested for HIV. Risk for HIV transmission is widespread among MSM throughout China; basic prevention programs are urgently needed.

  20. The prevalence of hypertension in relation with the normal albuminuria range in type 2 diabetes mellitus within the South Korean population: The Korean National Health and Nutrition Examination Survey, 2011-2012.

    Science.gov (United States)

    Shin, Koh-Eun; Roh, Yong-Kyun; Cho, Kyung-Hwan; Han, Kyung-Do; Park, Yong-Gyu; Kim, Do-Hoon; Kim, Yang-Hyun

    2017-06-01

    The coexistence of hypertension (HTN) and diabetes mellitus (DM) increases the risk of cardiovascular disease. In some studies, normal albuminuria has also been associated with cardiovascular disease and HTN. Therefore, we examined the relationships between albuminuria and the prevalence of HTN and its control rate in type 2 DM patients. We analyzed data from the 2011-2012 Korea National Health and Nutrition Examination Survey, and 1188 subjects with type 2 DM were included in the study. We divided albuminuria into 3 albuminuria tertiles (T): T1: hypertension had more ACR T3 (odds ratio=2.018, 95% confidence interval=1.445-2.818) than subjects without HTN. Subjects with controlled HTN had less ACR T3 than subjects without controlled HTN (odds ratio=0.566, 95% confidence interval=0.384-0.836). When, we redivided albuminuria by Diabetes Europe. Published by Elsevier Ltd. All rights reserved.