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Sample records for survival analysis interestingly

  1. Survival Analysis

    CERN Document Server

    Miller, Rupert G

    2011-01-01

    A concise summary of the statistical methods used in the analysis of survival data with censoring. Emphasizes recently developed nonparametric techniques. Outlines methods in detail and illustrates them with actual data. Discusses the theory behind each method. Includes numerous worked problems and numerical exercises.

  2. Survival analysis models and applications

    CERN Document Server

    Liu, Xian

    2012-01-01

    Survival analysis concerns sequential occurrences of events governed by probabilistic laws.  Recent decades have witnessed many applications of survival analysis in various disciplines. This book introduces both classic survival models and theories along with newly developed techniques. Readers will learn how to perform analysis of survival data by following numerous empirical illustrations in SAS. Survival Analysis: Models and Applications: Presents basic techniques before leading onto some of the most advanced topics in survival analysis.Assumes only a minimal knowledge of SAS whilst enablin

  3. Applied survival analysis using R

    CERN Document Server

    Moore, Dirk F

    2016-01-01

    Applied Survival Analysis Using R covers the main principles of survival analysis, gives examples of how it is applied, and teaches how to put those principles to use to analyze data using R as a vehicle. Survival data, where the primary outcome is time to a specific event, arise in many areas of biomedical research, including clinical trials, epidemiological studies, and studies of animals. Many survival methods are extensions of techniques used in linear regression and categorical data, while other aspects of this field are unique to survival data. This text employs numerous actual examples to illustrate survival curve estimation, comparison of survivals of different groups, proper accounting for censoring and truncation, model variable selection, and residual analysis. Because explaining survival analysis requires more advanced mathematics than many other statistical topics, this book is organized with basic concepts and most frequently used procedures covered in earlier chapters, with more advanced topics...

  4. Model selection criterion in survival analysis

    Science.gov (United States)

    Karabey, Uǧur; Tutkun, Nihal Ata

    2017-07-01

    Survival analysis deals with time until occurrence of an event of interest such as death, recurrence of an illness, the failure of an equipment or divorce. There are various survival models with semi-parametric or parametric approaches used in medical, natural or social sciences. The decision on the most appropriate model for the data is an important point of the analysis. In literature Akaike information criteria or Bayesian information criteria are used to select among nested models. In this study,the behavior of these information criterion is discussed for a real data set.

  5. Frailty Models in Survival Analysis

    CERN Document Server

    Wienke, Andreas

    2010-01-01

    The concept of frailty offers a convenient way to introduce unobserved heterogeneity and associations into models for survival data. In its simplest form, frailty is an unobserved random proportionality factor that modifies the hazard function of an individual or a group of related individuals. "Frailty Models in Survival Analysis" presents a comprehensive overview of the fundamental approaches in the area of frailty models. The book extensively explores how univariate frailty models can represent unobserved heterogeneity. It also emphasizes correlated frailty models as extensions of

  6. Statistical analysis of survival data.

    Science.gov (United States)

    Crowley, J; Breslow, N

    1984-01-01

    A general review of the statistical techniques that the authors feel are most important in the analysis of survival data is presented. The emphasis is on the study of the duration of time between any two events as applied to people and on the nonparametric and semiparametric models most often used in these settings. The unifying concept is the hazard function, variously known as the risk, the force of mortality, or the force of transition.

  7. Making relative survival analysis relatively easy.

    Science.gov (United States)

    Pohar, Maja; Stare, Janez

    2007-12-01

    In survival analysis we are interested in time from the beginning of an observation until certain event (death, relapse, etc.). We assume that the final event is well defined, so that we are never in doubt whether the final event has occurred or not. In practice this is not always true. If we are interested in cause-specific deaths, then it may sometimes be difficult or even impossible to establish the cause of death, or there may be different causes of death, making it impossible to assign death to just one cause. Suicides of terminal cancer patients are a typical example. In such cases, standard survival techniques cannot be used for estimation of mortality due to a certain cause. The cure to the problem are relative survival techniques which compare the survival experience in a study cohort to the one expected should they follow the background population mortality rates. This enables the estimation of the proportion of deaths due to a certain cause. In this paper, we briefly review some of the techniques to model relative survival, and outline a new fitting method for the additive model, which solves the problem of dependency of the parameter estimation on the assumption about the baseline excess hazard. We then direct the reader's attention to our R package relsurv that provides functions for easy and flexible fitting of all the commonly used relative survival regression models. The basic features of the package have been described in detail elsewhere, but here we additionally explain the usage of the new fitting method and the interface for using population mortality data freely available on the Internet. The combination of the package and the data sets provides a powerful informational tool in the hands of a skilled statistician/informatician.

  8. SURVIVAL ANALYSIS AND LENGTH-BIASED SAMPLING

    Directory of Open Access Journals (Sweden)

    Masoud Asgharian

    2010-12-01

    Full Text Available When survival data are colleted as part of a prevalent cohort study, the recruited cases have already experienced their initiating event. These prevalent cases are then followed for a fixed period of time at the end of which the subjects will either have failed or have been censored. When interests lies in estimating the survival distribution, from onset, of subjects with the disease, one must take into account that the survival times of the cases in a prevalent cohort study are left truncated. When it is possible to assume that there has not been any epidemic of the disease over the past period of time that covers the onset times of the subjects, one may assume that the underlying incidence process that generates the initiating event times is a stationary Poisson process. Under such assumption, the survival times of the recruited subjects are called “lengthbiased”. I discuss the challenges one is faced with in analyzing these type of data. To address the theoretical aspects of the work, I present asymptotic results for the NPMLE of the length-biased as well as the unbiased survival distribution. I also discuss estimating the unbiased survival function using only the follow-up time. This addresses the case that the onset times are either unknown or known with uncertainty. Some of our most recent work and open questions will be presented. These include some aspects of analysis of covariates, strong approximation, functional LIL and density estimation under length-biased sampling with right censoring. The results will be illustrated with survival data from patients with dementia, collected as part of the Canadian Study of Health and Aging (CSHA.

  9. Empirical likelihood method in survival analysis

    CERN Document Server

    Zhou, Mai

    2015-01-01

    Add the Empirical Likelihood to Your Nonparametric ToolboxEmpirical Likelihood Method in Survival Analysis explains how to use the empirical likelihood method for right censored survival data. The author uses R for calculating empirical likelihood and includes many worked out examples with the associated R code. The datasets and code are available for download on his website and CRAN.The book focuses on all the standard survival analysis topics treated with empirical likelihood, including hazard functions, cumulative distribution functions, analysis of the Cox model, and computation of empiric

  10. VARIATION ANALYSIS ON NATIONAL STANDARD INTEREST RATE

    Directory of Open Access Journals (Sweden)

    Michel Ferreira Cardia Haddad

    2012-06-01

    Full Text Available This study’s main objective is to analyse an econometric model for forecasting purposes concerning the interest rate which is adopted as standard reference within the Brazilian economy, namely, the Actual-Selic rate, so as to verify the feasibility of performing short term predictions as to its variations. Thus the major variables that impact the Actual-Selic rate, such as price variations of agricultural and power commodities, national industrial production level, exchange rate and public sector net debt, are detailed. The modern macroeconomic approach describes the relevance of the Central Bank upon achievement of its goals so as to maintain the economic stability, amongst which lies the convergence of verified interest rates with the Selic rate target, as set forth by the Monetary Policy Committee (COPOM. Furthermore, this study poses to explain the relevance in forecasting, with a reasonable level of accuracy, the benchmark interest rate of Brazilian economy. The proposed model may be used to support decision making concerning investment strategies and as an additional tool for the monitoring of the achievement of macroeconomic policy objectives.

  11. Emergence of interest groups on hazardous waste siting: how do they form and survive

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R.G.; Payne, B.A.

    1985-10-30

    This paper discusses the two components of the facilitative setting that are important for group formation. The first component, the ideological component, provides the basic ideas that are adopted by the emerging group. The ideological setting for group formation is produced by such things as antinuclear news coverage and concentration of news stories on hazardous waste problems, on ideas concerning the credibility of the federal government, and on the pervasivensee of ideas about general environmental problems. The organizational component of the facilitative setting provides such things as leadership ability, flexible time, resources, and experience. These are important for providing people, organization, and money to achieve group goals. By and large, the conditions conducive to group formation, growth, and survival are outside the control of decision-makers. Agencies and project sponsors are currently caught in a paradox. Actively involving the public in the decision-making process tends to contribute to the growth and survival of various interest groups. Not involving the public means damage to credibility and conflict with values concerning participatory democracy. Resolution in this area can only be achieved when a comprehensive, coordinated national approach to hazardous waste management emerges. 26 refs.

  12. Relevance Vector Machine for Survival Analysis.

    Science.gov (United States)

    Kiaee, Farkhondeh; Sheikhzadeh, Hamid; Mahabadi, Samaneh Eftekhari

    2016-03-01

    An accelerated failure time (AFT) model has been widely used for the analysis of censored survival or failure time data. However, the AFT imposes the restrictive log-linear relation between the survival time and the explanatory variables. In this paper, we introduce a relevance vector machine survival (RVMS) model based on Weibull AFT model that enables the use of kernel framework to automatically learn the possible nonlinear effects of the input explanatory variables on target survival times. We take advantage of the Bayesian inference technique in order to estimate the model parameters. We also introduce two approaches to accelerate the RVMS training. In the first approach, an efficient smooth prior is employed that improves the degree of sparsity. In the second approach, a fast marginal likelihood maximization procedure is used for obtaining a sparse solution of survival analysis task by sequential addition and deletion of candidate basis functions. These two approaches, denoted by smooth RVMS and fast RVMS, typically use fewer basis functions than RVMS and improve the RVMS training time; however, they cause a slight degradation in the RVMS performance. We compare the RVMS and the two accelerated approaches with the previous sparse kernel survival analysis method on a synthetic data set as well as six real-world data sets. The proposed kernel survival analysis models have been discovered to be more accurate in prediction, although they benefit from extra sparsity. The main advantages of our proposed models are: 1) extra sparsity that leads to a better generalization and avoids overfitting; 2) automatic relevance sample determination based on data that provide more accuracy, in particular for highly censored survival data; and 3) flexibility to utilize arbitrary number and types of kernel functions (e.g., non-Mercer kernels and multikernel learning).

  13. [Dealing with competing events in survival analysis].

    Science.gov (United States)

    Béchade, Clémence; Lobbedez, Thierry

    2015-04-01

    Survival analyses focus on the occurrences of an event of interest, in order to determine risk factors and estimate a risk. Competing events prevent from observing the event of interest. If there are competing events, it can lead to a bias in the risk's estimation. The aim of this article is to explain why Cox model is not appropriate when there are competing events, and to present Fine and Gray model, which can help when dealing with competing risks. Copyright © 2015 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  14. Survival Analysis of Patients with End Stage Renal Disease

    Science.gov (United States)

    Urrutia, J. D.; Gayo, W. S.; Bautista, L. A.; Baccay, E. B.

    2015-06-01

    This paper provides a survival analysis of End Stage Renal Disease (ESRD) under Kaplan-Meier Estimates and Weibull Distribution. The data were obtained from the records of V. L. MakabaliMemorial Hospital with respect to time t (patient's age), covariates such as developed secondary disease (Pulmonary Congestion and Cardiovascular Disease), gender, and the event of interest: the death of ESRD patients. Survival and hazard rates were estimated using NCSS for Weibull Distribution and SPSS for Kaplan-Meier Estimates. These lead to the same conclusion that hazard rate increases and survival rate decreases of ESRD patient diagnosed with Pulmonary Congestion, Cardiovascular Disease and both diseases with respect to time. It also shows that female patients have a greater risk of death compared to males. The probability risk was given the equation R = 1 — e-H(t) where e-H(t) is the survival function, H(t) the cumulative hazard function which was created using Cox-Regression.

  15. Attenuation caused by infrequently updated covariates in survival analysis

    DEFF Research Database (Denmark)

    Andersen, Per Kragh; Liestøl, Knut

    2003-01-01

    Attenuation; Cox regression model; Measurement errors; Survival analysis; Time-dependent covariates......Attenuation; Cox regression model; Measurement errors; Survival analysis; Time-dependent covariates...

  16. Survival analysis of orthodontic mini-implants.

    Science.gov (United States)

    Lee, Shin-Jae; Ahn, Sug-Joon; Lee, Jae Won; Kim, Seong-Hun; Kim, Tae-Woo

    2010-02-01

    Survival analysis is useful in clinical research because it focuses on comparing the survival distributions and the identification of risk factors. Our aim in this study was to investigate the survival characteristics and risk factors of orthodontic mini-implants with survival analyses. One hundred forty-one orthodontic patients (treated from October 1, 2000, to November 29, 2007) were included in this survival study. A total of 260 orthodontic mini-implants that had sandblasted (large grit) and acid-etched screw parts were placed between the maxillary second premolar and the first molar. Failures of the implants were recorded as event data, whereas implants that were removed because treatment ended and those that were not removed during the study period were recorded as censored data. A nonparametric life table method was used to visualize the hazard function, and Kaplan-Meier survival curves were generated to identify the variables associated with implant failure. Prognostic variables associated with implant failure were identified with the Cox proportional hazard model. Of the 260 implants, 22 failed. The hazard function for implant failure showed that the risk is highest immediately after placement. The survival function showed that the median survival time of orthodontic mini-implants is sufficient for relatively long orthodontic treatments. The Cox proportional hazard model identified that increasing age is a decisive factor for implant survival. The decreasing pattern of the hazard function suggested gradual osseointegration of orthodontic mini-implants. When implants are placed in a young patient, special caution is needed to lessen the increased probability of failure, especially immediately after placement.

  17. Neyman, Markov processes and survival analysis.

    Science.gov (United States)

    Yang, Grace

    2013-07-01

    J. Neyman used stochastic processes extensively in his applied work. One example is the Fix and Neyman (F-N) competing risks model (1951) that uses finite homogeneous Markov processes to analyse clinical trials with breast cancer patients. We revisit the F-N model, and compare it with the Kaplan-Meier (K-M) formulation for right censored data. The comparison offers a way to generalize the K-M formulation to include risks of recovery and relapses in the calculation of a patient's survival probability. The generalization is to extend the F-N model to a nonhomogeneous Markov process. Closed-form solutions of the survival probability are available in special cases of the nonhomogeneous processes, like the popular multiple decrement model (including the K-M model) and Chiang's staging model, but these models do not consider recovery and relapses while the F-N model does. An analysis of sero-epidemiology current status data with recurrent events is illustrated. Fix and Neyman used Neyman's RBAN (regular best asymptotic normal) estimates for the risks, and provided a numerical example showing the importance of considering both the survival probability and the length of time of a patient living a normal life in the evaluation of clinical trials. The said extension would result in a complicated model and it is unlikely to find analytical closed-form solutions for survival analysis. With ever increasing computing power, numerical methods offer a viable way of investigating the problem.

  18. Survival analysis of patients on maintenance hemodialysis

    Directory of Open Access Journals (Sweden)

    A Chandrashekar

    2014-01-01

    Full Text Available Despite the continuous improvement of dialysis technology and pharmacological treatment, mortality rates for dialysis patients are still high. A 2-year prospective study was conducted at a tertiary care hospital to determine the factors influencing survival among patients on maintenance hemodialysis. 96 patients with end-stage renal disease surviving more than 3 months on hemodialysis (8-12 h/week were studied. Follow-up was censored at the time of death or at the end of 2-year study period, whichever occurred first. Of the 96 patients studied (mean age 49.74 ± 14.55 years, 75% male and 44.7% diabetics, 19 died with an estimated mortality rate of 19.8%. On an age-adjusted multivariate analysis, female gender and hypokalemia independently predicted mortality. In Cox analyses, patient survival was associated with delivered dialysis dose (single pool Kt/V, hazard ratio [HR] =0.01, P = 0.016, frequency of hemodialysis (HR = 3.81, P = 0.05 and serum albumin (HR = 0.24, P = 0.005. There was no significant difference between diabetes and non-diabetes in relation to death (Relative Risk = 1.109; 95% CI = 0.49-2.48, P = 0.803. This study revealed that mortality among hemodialysis patients remained high, mostly due to sepsis and ischemic heart disease. Patient survival was better with higher dialysis dose, increased frequency of dialysis and adequate serum albumin level. Efforts at minimizing infectious complications, preventing cardiovascular events and improving nutrition should increase survival among hemodialysis patients.

  19. FS5 sun exposure survivability analysis

    Directory of Open Access Journals (Sweden)

    Ming-Ying Hsu

    2017-01-01

    Full Text Available During the Acquisition and Safe Hold (ASH mode, FORMOAT-5 (FS5 satellite attitude is not fully controlled. Direct sun exposure on the Remote Sensing Instrument (RSI satellite telescope sensor may occur. The sun exposure effect on RSI sensor performance is investigated to evaluate the instrument’s survivability in orbit. Both satellite spin speed and sun exposure duration are considered as the key parameters in this study. A simple radiometry technique is used to calculate the total sun radiance exposure to examine the RSI sensor integrity. Total sun irradiance on the sensor is computed by considering the spectral variation effect through the RSI’s five-band filter. Experiments that directly expose the sensor to the sun on the ground were performed with no obvious performance degradation found. Based on both the analysis and experiment results, it is concluded that the FS5 RSI sensor can survive direct sun exposure during the ASH mode.

  20. Regression analysis of restricted mean survival time based on pseudo-observations

    DEFF Research Database (Denmark)

    Andersen, Per Kragh; Hansen, Mette Gerster; Klein, John P.

    censoring; hazard function; health economics; regression model; survival analysis; mean survival time; restricted mean survival time; pseudo-observations......censoring; hazard function; health economics; regression model; survival analysis; mean survival time; restricted mean survival time; pseudo-observations...

  1. Regression Analysis of Restricted Mean Survival Time Based on Pseudo-Observations

    DEFF Research Database (Denmark)

    Andersen, Per Kragh; Hansen, Mette Gerster; Klein, John P.

    2004-01-01

    censoring; hazard function; health economics; mean survival time; pseudo-observations; regression model; restricted mean survival time; survival analysis......censoring; hazard function; health economics; mean survival time; pseudo-observations; regression model; restricted mean survival time; survival analysis...

  2. [Clinical research XXI. From the clinical judgment to survival analysis].

    Science.gov (United States)

    Rivas-Ruiz, Rodolfo; Pérez-Rodríguez, Marcela; Palacios, Lino; Talavera, Juan O

    2014-01-01

    Decision making in health care implies knowledge of the clinical course of the disease. Knowing the course allows us to estimate the likelihood of occurrence of a phenomenon at a given time or its duration. Within the statistical models that allow us to have a summary measure to estimate the time of occurrence of a phenomenon in a given population are the linear regression (the outcome variable is continuous and normally distributed -time to the occurrence of the event-), logistic regression (outcome variable is dichotomous, and it is evaluated at one single interval), and survival curves (outcome event is dichotomous, and it can be evaluated at multiple intervals). The first reference we have of this type of analysis is the work of the astronomer Edmond Halley, an English physicist and mathematician, famous for the calculation of the appearance of the comet orbit, recognized as the first periodic comet (1P/Halley's Comet). Halley also contributed in the area of health to estimate the mortality rate for a Polish population. The survival curve allows us to estimate the probability of an event occurring at different intervals. Also, it leds us to estimate the median survival time of any phenomenon of interest (although the used term is survival, the outcome does not need to be death, it may be the occurrence of any other event).

  3. Acute pancreatitis: analysis of factors influencing survival.

    Science.gov (United States)

    Jacobs, M L; Daggett, W M; Civette, J M; Vasu, M A; Lawson, D W; Warshaw, A L; Nardi, G L; Bartlett, M K

    1977-01-01

    Of patients with acute pancreatitis (AP), there remains a group who suffer life-threatening complications despite current modes of therapy. To identify factors which distinguish this group from the entire patient population, a retrospectiva analysis of 519 cases of AP occurring over a 5-year period was undertaken. Thirty-one per cent of these patients had a history of alcoholism and 47% had a history of biliary disease. The overall mortality was 12.9%. Of symptoms and signs recorded at the time of admission, hypotension, tachycardia, fever, abdominal mass, and abnormal examination of the lung fields correlated positively with increased mortality. Seven features of the initial laboratory examination correlated with increased mortality. Shock, massive colloid requirement, hypocalcemia, renal failure, and respiratory failure requiring endotracheal intubation were complications associated with the poorest prognosis. Among patients in this series with three or more of these clinical characteristics, maximal nonoperative treatment yielded a survival rate of 29%, compared to the 64% survival rate for a group of patients treated operatively with cholecystostomy, gastrostomy, feeding jejunostomy, and sump drainage of the lesser sac and retroperitoneum.

  4. Interest in science: a RIASEC-based analysis of students' interests

    Science.gov (United States)

    Dierks, Pay O.; Höffler, Tim N.; Blankenburg, Janet S.; Peters, Heide; Parchmann, Ilka

    2016-01-01

    Considering the reported lack of interest in the STEM-domain and the consequential difficulties in recruiting talented and interested young academics, the development of effective enrichment measures is indispensable. This requires a precise picture of students' interests. The paper presents an approach to characterize interest profiles in explicitly science-related activities. Adapting Holland's RIASEC-model, an instrument was developed and tested which allows the description of interest in activities along Holland's dimensions (and a seventh dimension networking) within the confined science domain. The findings of a study with N = 247 students (age cohorts 12-19 years) uncovered interest differences for the environments school, enrichment, and (prospective) vocation. The mutual importance of the performed activity and the environment the activity is performed in is confirmed by a cross-classified model. Contrasting different subgroups revealed multiple results, e.g., girls showed more interest in artistic and social activities within the science domain. High achieving students showed more interest in science-related activities in all dimensions. In conclusion, using our adapted model, students' interest structure can be described in a differentiated manner. This could lay the foundation for further analyses of students' interest profiles and thereby contribute to future development of effective and congruent enrichment measures, thus enhancing interest in science.

  5. Budget Deficits and Interest Rates: An Empirical Analysis for Turkey

    Directory of Open Access Journals (Sweden)

    Tayfur BAYAT

    2012-05-01

    Full Text Available The aim of this study is to analyze causality between budget deficits and its ratio to gross domestic product and interest rate in the Turkish economy during years between 2006 and 2011. By doing so, we investigate the validity of crowding out view against the Ricardian equivalence hypothesis. To this end, we employee the conventional Toda-Yamamoto (1995 linear Granger type causality test and Hacker and Hatemi-J (2005, 2006 bootstrap process-based Toda-Yamamoto linear Granger type causality test. In this regard, we use Kwiatkowski, Phillips, Schmidt and Shin (1992, KPSS and Elliot, Rothenberg, Stock (1996, DF-GLS unit root tests. Analysis results show that there is no causal relation between budget deficits, budget deficit ratio to gross domestic product and nominal interest rate. Results reveal the existence of Ricardian equivalence hypothesis. Rational household predict that there is no difference between payment time of taxes and they know that expansionary fiscal policies financed by loan do not affect aggregate demand and capital allocation in a full-employment economy via nominal interest rate channel. Results of empirical analysis support Ricardian equivalence hypothesis and imply that there is no effect of financing type of budget deficit on nominal interest rate.

  6. The dChip survival analysis module for microarray data

    Directory of Open Access Journals (Sweden)

    Minvielle Stéphane

    2011-03-01

    Full Text Available Abstract Background Genome-wide expression signatures are emerging as potential marker for overall survival and disease recurrence risk as evidenced by recent commercialization of gene expression based biomarkers in breast cancer. Similar predictions have recently been carried out using genome-wide copy number alterations and microRNAs. Existing software packages for microarray data analysis provide functions to define expression-based survival gene signatures. However, there is no software that can perform survival analysis using SNP array data or draw survival curves interactively for expression-based sample clusters. Results We have developed the survival analysis module in the dChip software that performs survival analysis across the genome for gene expression and copy number microarray data. Built on the current dChip software's microarray analysis functions such as chromosome display and clustering, the new survival functions include interactive exploring of Kaplan-Meier (K-M plots using expression or copy number data, computing survival p-values from the log-rank test and Cox models, and using permutation to identify significant chromosome regions associated with survival. Conclusions The dChip survival module provides user-friendly way to perform survival analysis and visualize the results in the context of genes and cytobands. It requires no coding expertise and only minimal learning curve for thousands of existing dChip users. The implementation in Visual C++ also enables fast computation. The software and demonstration data are freely available at http://dchip-surv.chenglilab.org.

  7. Mathematical Methods in Survival Analysis, Reliability and Quality of Life

    CERN Document Server

    Huber, Catherine; Mesbah, Mounir

    2008-01-01

    Reliability and survival analysis are important applications of stochastic mathematics (probability, statistics and stochastic processes) that are usually covered separately in spite of the similarity of the involved mathematical theory. This title aims to redress this situation: it includes 21 chapters divided into four parts: Survival analysis, Reliability, Quality of life, and Related topics. Many of these chapters were presented at the European Seminar on Mathematical Methods for Survival Analysis, Reliability and Quality of Life in 2006.

  8. FCS Vehicle Transportability, Survivability, and Reliability Analysis

    National Research Council Canada - National Science Library

    Dion-Schwarz, Cynthia; Hirsch, Leon; Koehn, Phillip; Macheret, Jenya; Sparrow, Dave

    2005-01-01

    .... The investigation into metrics for transportability revealed that the C130 Transportability requirement for FCS vehicles is a constraint that leads to a less survivable platform but without improving Unit of Action (UA) transportability...

  9. Analysis of survival data from telemetry projects

    Science.gov (United States)

    Bunck, C.M.; Winterstein, S.R.; Pollock, K.H.

    1985-01-01

    Telemetry techniques can be used to study the survival rates of animal populations and are particularly suitable for species or settings for which band recovery models are not. Statistical methods for estimating survival rates and parameters of survival distributions from observations of radio-tagged animals will be described. These methods have been applied to medical and engineering studies and to the study of nest success. Estimates and tests based on discrete models, originally introduced by Mayfield, and on continuous models, both parametric and nonparametric, will be described. Generalizations, including staggered entry of subjects into the study and identification of mortality factors will be considered. Additional discussion topics will include sample size considerations, relocation frequency for subjects, and use of covariates.

  10. Graphics and statistics for cardiology: survival analysis.

    Science.gov (United States)

    May, Susanne; McKnight, Barbara

    2017-03-01

    Reports of data in the medical literature frequently lack information needed to assess the validity and generalisability of study results. Some recommendations and standards for reporting have been developed over the last two decades, but few are available specifically for survival data. We provide recommendations for tabular and graphical representations of survival data. We argue that data and analytic software should be made available to promote reproducible research. 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/.

  11. Survival analysis of piglet pre-weaning mortality

    OpenAIRE

    P. Carnier; E. Zanetti; F. Maretto; Cecchinato, A.

    2010-01-01

    Survival analysis methodology was applied in order to analyse sources of variation of preweaning survival time and to estimate variance components using data from a crossbred piglets population. A frailty sire model was used with the litter effect treated as an additional random source of variation. All the variables considered had a significant effect on survivability: sex, cross-fostering, parity of the nurse-sow and litter size. The variance estimates of sire and litter were closed to 0.08...

  12. Survival analysis of patients under chronic HIV-care and ...

    African Journals Online (AJOL)

    Background: Health care planning depends upon good knowledge of prevalence that requires a clear understanding of survival patterns of patients who receive medication, treatment and care. Survival analysis can bring to light the effect that some demographic, social, medical and clinical characteristics have on the ...

  13. Potential density and tree survival: an analysis based on South ...

    African Journals Online (AJOL)

    Finally, we present a tree survival analysis, based on the Weibull distribution function, for the Nelshoogte replicated CCT study, which has been observed for almost 40 years after planting and provides information about tree survival in response to planting espacements ranging from 494 to 2 965 trees per hectare.

  14. Multiple imputation of missing blood pressure covariates in survival analysis

    NARCIS (Netherlands)

    Buuren, S. van; Boshuizen, H.C.; Knook, D.L.

    1999-01-01

    This paper studies a non-response problem in survival analysis where the occurrence of missing data in the risk factor is related to mortality. In a study to determine the influence of blood pressure on survival in the very old (85+ years), blood pressure measurements are missing in about 12.5 per

  15. Survival analysis of mortality data among elderly patients in ...

    African Journals Online (AJOL)

    A study on the mortality among old patients 60 years or more, admitted at University of Ilorin Teaching Hospital (UITH), Ilorin was carried out using survival analysis approach. Results revealed that the median survival time, which is the time beyond which half of the patients are expected to stay in hospital before death was ...

  16. Survival analysis of piglet pre-weaning mortality

    Directory of Open Access Journals (Sweden)

    P. Carnier

    2010-04-01

    Full Text Available Survival analysis methodology was applied in order to analyse sources of variation of preweaning survival time and to estimate variance components using data from a crossbred piglets population. A frailty sire model was used with the litter effect treated as an additional random source of variation. All the variables considered had a significant effect on survivability: sex, cross-fostering, parity of the nurse-sow and litter size. The variance estimates of sire and litter were closed to 0.08 and 2 respectively and the heritability of pre-weaning survival was 0.03.

  17. Meta-analysis of survival prediction with Palliative Performance Scale.

    Science.gov (United States)

    Downing, Michael; Lau, Francis; Lesperance, Mary; Karlson, Nicholas; Shaw, Jack; Kuziemsky, Craig; Bernard, Steve; Hanson, Laura; Olajide, Lola; Head, Barbara; Ritchie, Christine; Harrold, Joan; Casarett, David

    2007-01-01

    This paper aims to reconcile the use of Palliative Performance Scale (PPSv2) for survival prediction in palliative care through an international collaborative study by five research groups. The study involves an individual patient data meta-analysis on 1,808 patients from four original datasets to reanalyze their survival patterns by age, gender, cancer status, and initial PPS score. Our findings reveal a strong association between PPS and survival across the four datasets. The Kaplan-Meier survival curves show each PPS level as distinct, with a strong ordering effect in which higher PPS levels are associated with increased length of survival. Using a stratified Cox proportional hazard model to adjust for study differences, we found females lived significantly longer than males, with a further decrease in hazard for females not diagnosed with cancer. Further work is needed to refine the reporting of survival times/probabilities and to improve prediction accuracy with the inclusion of other variables in the models.

  18. Covariate analysis of bivariate survival data

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, L.E.

    1992-01-01

    The methods developed are used to analyze the effects of covariates on bivariate survival data when censoring and ties are present. The proposed method provides models for bivariate survival data that include differential covariate effects and censored observations. The proposed models are based on an extension of the univariate Buckley-James estimators which replace censored data points by their expected values, conditional on the censoring time and the covariates. For the bivariate situation, it is necessary to determine the expectation of the failure times for one component conditional on the failure or censoring time of the other component. Two different methods have been developed to estimate these expectations. In the semiparametric approach these expectations are determined from a modification of Burke's estimate of the bivariate empirical survival function. In the parametric approach censored data points are also replaced by their conditional expected values where the expected values are determined from a specified parametric distribution. The model estimation will be based on the revised data set, comprised of uncensored components and expected values for the censored components. The variance-covariance matrix for the estimated covariate parameters has also been derived for both the semiparametric and parametric methods. Data from the Demographic and Health Survey was analyzed by these methods. The two outcome variables are post-partum amenorrhea and breastfeeding; education and parity were used as the covariates. Both the covariate parameter estimates and the variance-covariance estimates for the semiparametric and parametric models will be compared. In addition, a multivariate test statistic was used in the semiparametric model to examine contrasts. The significance of the statistic was determined from a bootstrap distribution of the test statistic.

  19. Model analysis of the link between interest rates and crashes

    Science.gov (United States)

    Broga, Kristijonas M.; Viegas, Eduardo; Jensen, Henrik Jeldtoft

    2016-09-01

    We analyse the effect of distinct levels of interest rates on the stability of the financial network under our modelling framework. We demonstrate that banking failures are likely to emerge early on under sustained high interest rates, and at much later stage-with higher probability-under a sustained low interest rate scenario. Moreover, we demonstrate that those bank failures are of a different nature: high interest rates tend to result in significantly more bankruptcies associated to credit losses whereas lack of liquidity tends to be the primary cause of failures under lower rates.

  20. A Follow-Up Analysis of Agricultural Interest

    Science.gov (United States)

    Pandya, Himanshu; Curtis, Samuel M.

    1978-01-01

    A followup survey of Pennsylvania eighth grade students previously inventoried for agricultural interest indicated that those students who later enrolled in high school vocational agriculture courses had shown higher interest scores on the inventory. Both sets of data are compared, with implications for vocational agriculture counseling. (MF)

  1. An empirical analysis of the German interest rate

    NARCIS (Netherlands)

    den Butter, F.A.G.; Jansen, P.W.

    2004-01-01

    The short run and long run influences of the main determinants of the German long-term interest rate are estimated using quarterly data for the period 1982-2001. A major reason for the focus on the German interest rate is that this rate, and hence its determinants, will be dominant in explaining the

  2. Survival

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data provide information on the survival of California red-legged frogs in a unique ecosystem to better conserve this threatened species while restoring...

  3. Structural diversity of biologically interesting datasets: a scaffold analysis approach

    Directory of Open Access Journals (Sweden)

    Khanna Varun

    2011-08-01

    Full Text Available Abstract Background The recent public availability of the human metabolome and natural product datasets has revitalized "metabolite-likeness" and "natural product-likeness" as a drug design concept to design lead libraries targeting specific pathways. Many reports have analyzed the physicochemical property space of biologically important datasets, with only a few comprehensively characterizing the scaffold diversity in public datasets of biological interest. With large collections of high quality public data currently available, we carried out a comparative analysis of current day leads with other biologically relevant datasets. Results In this study, we note a two-fold enrichment of metabolite scaffolds in drug dataset (42% as compared to currently used lead libraries (23%. We also note that only a small percentage (5% of natural product scaffolds space is shared by the lead dataset. We have identified specific scaffolds that are present in metabolites and natural products, with close counterparts in the drugs, but are missing in the lead dataset. To determine the distribution of compounds in physicochemical property space we analyzed the molecular polar surface area, the molecular solubility, the number of rings and the number of rotatable bonds in addition to four well-known Lipinski properties. Here, we note that, with only few exceptions, most of the drugs follow Lipinski's rule. The average values of the molecular polar surface area and the molecular solubility in metabolites is the highest while the number of rings is the lowest. In addition, we note that natural products contain the maximum number of rings and the rotatable bonds than any other dataset under consideration. Conclusions Currently used lead libraries make little use of the metabolites and natural products scaffold space. We believe that metabolites and natural products are recognized by at least one protein in the biosphere therefore, sampling the fragment and scaffold

  4. GDISC: a web portal for integrative analysis of gene-drug interaction for survival in cancer.

    Science.gov (United States)

    Spainhour, John Christian Givhan; Lim, Juho; Qiu, Peng

    2017-05-01

    Survival analysis has been applied to The Cancer Genome Atlas (TCGA) data. Although drug exposure records are available in TCGA, existing survival analyses typically did not consider drug exposure, partly due to naming inconsistencies in the data. We have spent extensive effort to standardize the drug exposure data, which enabled us to perform survival analysis on drug-stratified subpopulations of cancer patients. Using this strategy, we integrated gene copy number data, drug exposure data and patient survival data to infer gene-drug interactions that impact survival. The collection of all analyzed gene-drug interactions in 32 cancer types are organized and presented in a searchable web-portal called gene-drug Interaction for survival in cancer (GDISC). GDISC allows biologists and clinicians to interactively explore the gene-drug interactions identified in the context of TCGA, and discover interactions associated to their favorite cancer, drug and/or gene of interest. In addition, GDISC provides the standardized drug exposure data, which is a valuable resource for developing new methods for drug-specific analysis. GDISC is available at https://gdisc.bme.gatech.edu/. peng.qiu@bme.gatech.edu.

  5. An Analysis of How Enterprise Information Systems Challenge Vested Interests

    NARCIS (Netherlands)

    Boonstra, Albert; QuintelaVarajao, JE; CruzCunha, MM; Putnik, GD; Trigo, A

    2010-01-01

    The purpose of this paper is to develop and validate a model that demonstrates the influence of ERP implementation on the power and interests of actors in a manufacturing environment. An empirical in-depth longitudinal case study examines how a medium-sized company in the graphics industry

  6. Factor Analysis of the Kuder Occupational Interest Survey

    Science.gov (United States)

    Zytowski, Donald G.

    1976-01-01

    The scale scores of Kuder Occupational Interest Survey (KOIS) profiles of 1,084 males and females were converted to intraindividual form by means of a z-score transformation. The results are discussed in terms of their utility for interpretation of high ranking scales. (Author)

  7. Nonparametric survival analysis of infectious disease data.

    Science.gov (United States)

    Kenah, Eben

    2013-03-01

    This paper develops nonparametric methods based on contact intervals for the analysis of infectious disease data. The contact interval from person i to person j is the time between the onset of infectiousness in i and infectious contact from i to j, where we define infectious contact as a contact sufficient to infect a susceptible individual. The hazard function of the contact interval distribution equals the hazard of infectious contact from i to j, so it provides a summary of the evolution of infectiousness over time. When who-infects-whom is observed, the Nelson-Aalen estimator produces an unbiased estimate of the cumulative hazard function of the contact interval distribution. When who-infects-whom is not observed, we use an EM algorithm to average the Nelson-Aalen estimates from all possible combinations of who-infected-whom consistent with the observed data. This converges to a nonparametric maximum likelihood estimate of the cumulative hazard function that we call the marginal Nelson-Aalen estimate. We study the behavior of these methods in simulations and use them to analyze household surveillance data from the 2009 influenza A(H1N1) pandemic.

  8. Nonparametric survival analysis of infectious disease data

    Science.gov (United States)

    Kenah, Eben

    2012-01-01

    Summary This paper develops nonparametric methods based on contact intervals for the analysis of infectious disease data. The contact interval from person i to person j is the time between the onset of infectiousness in i and infectious contact from i to j, where we define infectious contact as a contact sufficient to infect a susceptible individual. The hazard function of the contact interval distribution equals the hazard of infectious contact from i to j, so it provides a summary of the evolution of infectiousness over time. When who-infects-whom is observed, the Nelson-Aalen estimator produces an unbiased estimate of the cumulative hazard function of the contact interval distribution. When who-infects-whom is not observed, we use an EM algorithm to average the Nelson-Aalen estimates from all possible combinations of who-infected-whom consistent with the observed data. This converges to a nonparametric maximum likelihood estimate of the cumulative hazard function that we call the marginal Nelson-Aalen estimate. We study the behavior of these methods in simulations and use them to analyze household surveillance data from the 2009 influenza A(H1N1) pandemic. PMID:23772180

  9. Statistical models and methods for reliability and survival analysis

    CERN Document Server

    Couallier, Vincent; Huber-Carol, Catherine; Mesbah, Mounir; Huber -Carol, Catherine; Limnios, Nikolaos; Gerville-Reache, Leo

    2013-01-01

    Statistical Models and Methods for Reliability and Survival Analysis brings together contributions by specialists in statistical theory as they discuss their applications providing up-to-date developments in methods used in survival analysis, statistical goodness of fit, stochastic processes for system reliability, amongst others. Many of these are related to the work of Professor M. Nikulin in statistics over the past 30 years. The authors gather together various contributions with a broad array of techniques and results, divided into three parts - Statistical Models and Methods, Statistical

  10. Survival analysis for customer satisfaction: A case study

    Science.gov (United States)

    Hadiyat, M. A.; Wahyudi, R. D.; Sari, Y.

    2017-11-01

    Most customer satisfaction surveys are conducted periodically to track their dynamics. One of the goals of this survey was to evaluate the service design by recognizing the trend of satisfaction score. Many researchers recommended in redesigning the service when the satisfaction scores were decreasing, so that the service life cycle could be predicted qualitatively. However, these scores were usually set in Likert scale and had quantitative properties. Thus, they should also be analyzed in quantitative model so that the predicted service life cycle would be done by applying the survival analysis. This paper discussed a starting point for customer satisfaction survival analysis with a case study in healthcare service.

  11. Analysis of the interests of Google users on toothache information.

    Science.gov (United States)

    Lotto, Matheus; Ayala Aguirre, Patricia Estefania; Rios, Daniela; Andrade Moreira Machado, Maria Aparecida; Pereira Cruvinel, Agnes Fátima; Cruvinel, Thiago

    2017-01-01

    The knowledge on health interests of a given population of Internet users might contribute to the increase of evidence on community's dental needs, and consequently, to the improvement of public health planning. The frequency of searches for specific issues on Google can be analyzed by the application of Google Trends. In this study, we aimed to characterize the interests on toothache information of Google users from the United States, United Kingdom, Australia and Brazil. The monthly variation of relative search volume (RSV) and the lists of main toothache-related queries were determined from January 2004 through April 2016 using Google Trends. Autoregressive Integrated Moving Average (ARIMA) forecasting models were developed to determine predictive RSV values for toothache for additional 12 months. Autocorrelation plots and general additive model (GAM) were applied to determine trends and seasonality in RSV curves. Through linear regression models, we assessed the association between the variation of annual means of RSV values and national statistics for toothache in the U.S. and U.K. Subsequently, the distribution of main queries according to the identification of endodontic pain, type of searching information, and the interest in self-management of toothache was evaluated for the four countries. The autocorrelation plots showed patterns of non-stationary time series. The monthly variation influenced the data of the U.S. and U.K., with the higher RSV values found respectively in January/July and December. Also, the interest on toothache in the U.K. increases in the second semester and in the fourth quarter, especially in December. Additionally, an annual variation affected significantly all time series, with the increment of RSV means over the years, varying from 265% in the U.S. to 745% in Brazil. In parallel, the increments in RSV values were also observed in all predictive curves. The annual variation of observed and fitted RSV values was directly associated

  12. Analysis of the interests of Google users on toothache information.

    Directory of Open Access Journals (Sweden)

    Matheus Lotto

    Full Text Available The knowledge on health interests of a given population of Internet users might contribute to the increase of evidence on community's dental needs, and consequently, to the improvement of public health planning. The frequency of searches for specific issues on Google can be analyzed by the application of Google Trends.In this study, we aimed to characterize the interests on toothache information of Google users from the United States, United Kingdom, Australia and Brazil.The monthly variation of relative search volume (RSV and the lists of main toothache-related queries were determined from January 2004 through April 2016 using Google Trends. Autoregressive Integrated Moving Average (ARIMA forecasting models were developed to determine predictive RSV values for toothache for additional 12 months. Autocorrelation plots and general additive model (GAM were applied to determine trends and seasonality in RSV curves. Through linear regression models, we assessed the association between the variation of annual means of RSV values and national statistics for toothache in the U.S. and U.K. Subsequently, the distribution of main queries according to the identification of endodontic pain, type of searching information, and the interest in self-management of toothache was evaluated for the four countries.The autocorrelation plots showed patterns of non-stationary time series. The monthly variation influenced the data of the U.S. and U.K., with the higher RSV values found respectively in January/July and December. Also, the interest on toothache in the U.K. increases in the second semester and in the fourth quarter, especially in December. Additionally, an annual variation affected significantly all time series, with the increment of RSV means over the years, varying from 265% in the U.S. to 745% in Brazil. In parallel, the increments in RSV values were also observed in all predictive curves. The annual variation of observed and fitted RSV values was

  13. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs

    OpenAIRE

    Lucy Asher; Harvey, Naomi D.; Martin Green; England, Gary C.W.

    2017-01-01

    Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that...

  14. Breastfeeding, birth intervals and child survival: analysis of the 1997 ...

    African Journals Online (AJOL)

    Original article. Breastfeeding, birth intervals and child survival: analysis of the 1997 community and family survey data in southern Ethiopia. Markos Ezra, Eshetu Gurmu. Abstract. Background: This paper uses the 1997 community and family survey data to primarily address the question of whether or not short birth intervals ...

  15. Use of parametric and non-parametric survival analysis techniques ...

    African Journals Online (AJOL)

    This paper presents parametric and non-parametric survival analysis procedures that can be used to compare acaricides. The effectiveness of Delta Tick Pour On and Delta Tick Spray in knocking down tsetse flies were determined. The two formulations were supplied by Chemplex. The comparison was based on data ...

  16. Using Survival Analysis to Understand Graduation of Students with Disabilities

    Science.gov (United States)

    Schifter, Laura A.

    2016-01-01

    This study examined when students with disabilities graduated high school and how graduation patterns differed for students based on selected demographic and educational factors. Utilizing statewide data on students with disabilities from Massachusetts from 2005 through 2012, the author conducted discrete-time survival analysis to estimate the…

  17. Integrative Genomics with Mediation Analysis in a Survival Context

    Directory of Open Access Journals (Sweden)

    Szilárd Nemes

    2013-01-01

    Full Text Available DNA copy number aberrations (DCNA and subsequent altered gene expression profiles may have a major impact on tumor initiation, on development, and eventually on recurrence and cancer-specific mortality. However, most methods employed in integrative genomic analysis of the two biological levels, DNA and RNA, do not consider survival time. In the present note, we propose the adoption of a survival analysis-based framework for the integrative analysis of DCNA and mRNA levels to reveal their implication on patient clinical outcome with the prerequisite that the effect of DCNA on survival is mediated by mRNA levels. The specific aim of the paper is to offer a feasible framework to test the DCNA-mRNA-survival pathway. We provide statistical inference algorithms for mediation based on asymptotic results. Furthermore, we illustrate the applicability of the method in an integrative genomic analysis setting by using a breast cancer data set consisting of 141 invasive breast tumors. In addition, we provide implementation in R.

  18. A gradient boosting algorithm for survival analysis via direct optimization of concordance index.

    Science.gov (United States)

    Chen, Yifei; Jia, Zhenyu; Mercola, Dan; Xie, Xiaohui

    2013-01-01

    Survival analysis focuses on modeling and predicting the time to an event of interest. Many statistical models have been proposed for survival analysis. They often impose strong assumptions on hazard functions, which describe how the risk of an event changes over time depending on covariates associated with each individual. In particular, the prevalent proportional hazards model assumes that covariates are multiplicatively related to the hazard. Here we propose a nonparametric model for survival analysis that does not explicitly assume particular forms of hazard functions. Our nonparametric model utilizes an ensemble of regression trees to determine how the hazard function varies according to the associated covariates. The ensemble model is trained using a gradient boosting method to optimize a smoothed approximation of the concordance index, which is one of the most widely used metrics in survival model performance evaluation. We implemented our model in a software package called GBMCI (gradient boosting machine for concordance index) and benchmarked the performance of our model against other popular survival models with a large-scale breast cancer prognosis dataset. Our experiment shows that GBMCI consistently outperforms other methods based on a number of covariate settings. GBMCI is implemented in R and is freely available online.

  19. Vulnerability survival analysis: a novel approach to vulnerability management

    Science.gov (United States)

    Farris, Katheryn A.; Sullivan, John; Cybenko, George

    2017-05-01

    Computer security vulnerabilities span across large, enterprise networks and have to be mitigated by security engineers on a routine basis. Presently, security engineers will assess their "risk posture" through quantifying the number of vulnerabilities with a high Common Vulnerability Severity Score (CVSS). Yet, little to no attention is given to the length of time by which vulnerabilities persist and survive on the network. In this paper, we review a novel approach to quantifying the length of time a vulnerability persists on the network, its time-to-death, and predictors of lower vulnerability survival rates. Our contribution is unique in that we apply the cox proportional hazards regression model to real data from an operational IT environment. This paper provides a mathematical overview of the theory behind survival analysis methods, a description of our vulnerability data, and an interpretation of the results.

  20. Breast Cancer Heterogeneity: MR Imaging Texture Analysis and Survival Outcomes.

    Science.gov (United States)

    Kim, Jae-Hun; Ko, Eun Sook; Lim, Yaeji; Lee, Kyung Soo; Han, Boo-Kyung; Ko, Eun Young; Hahn, Soo Yeon; Nam, Seok Jin

    2017-03-01

    Purpose To determine the relationship between tumor heterogeneity assessed by means of magnetic resonance (MR) imaging texture analysis and survival outcomes in patients with primary breast cancer. Materials and Methods Between January and August 2010, texture analysis of the entire primary breast tumor in 203 patients was performed with T2-weighted and contrast material-enhanced T1-weighted subtraction MR imaging for preoperative staging. Histogram-based uniformity and entropy were calculated. To dichotomize texture parameters for survival analysis, the 10-fold cross-validation method was used to determine cutoff points in the receiver operating characteristic curve analysis. The Cox proportional hazards model and Kaplan-Meier analysis were used to determine the association of texture parameters and morphologic or volumetric information obtained at MR imaging or clinical-pathologic variables with recurrence-free survival (RFS). Results There were 26 events, including 22 recurrences (10 local-regional and 12 distant) and four deaths, with a mean follow-up time of 56.2 months. In multivariate analysis, a higher N stage (RFS hazard ratio, 11.15 [N3 stage]; P = .002, Bonferroni-adjusted α = .0167), triple-negative subtype (RFS hazard ratio, 16.91; P breast cancers that appeared more heterogeneous on T2-weighted images (higher entropy) and those that appeared less heterogeneous on contrast-enhanced T1-weighted subtraction images (lower entropy) exhibited poorer RFS. © RSNA, 2016 Online supplemental material is available for this article.

  1. Prognostic and survival analysis of presbyopia: The healthy twin study

    Science.gov (United States)

    Lira, Adiyani; Sung, Joohon

    2015-12-01

    Presbyopia, a vision condition in which the eye loses its flexibility to focus on near objects, is part of ageing process which mostly perceptible in the early or mid 40s. It is well known that age is its major risk factor, while sex, alcohol, poor nutrition, ocular and systemic diseases are known as common risk factors. However, many other variables might influence the prognosis. Therefore in this paper we developed a prognostic model to estimate survival from presbyopia. 1645 participants which part of the Healthy Twin Study, a prospective cohort study that has recruited Korean adult twins and their family members based on a nation-wide registry at public health agencies since 2005, were collected and analyzed by univariate analysis as well as Cox proportional hazard model to reveal the prognostic factors for presbyopia while survival curves were calculated by Kaplan-Meier method. Besides age, sex, diabetes, and myopia; the proposed model shows that education level (especially engineering program) also contribute to the occurrence of presbyopia as well. Generally, at 47 years old, the chance of getting presbyopia becomes higher with the survival probability is less than 50%. Furthermore, our study shows that by stratifying the survival curve, MZ has shorter survival with average onset time about 45.8 compare to DZ and siblings with 47.5 years old. By providing factors that have more effects and mainly associate with presbyopia, we expect that we could help to design an intervention to control or delay its onset time.

  2. Lineament analysis of mineral areas of interest in Afghanistan

    Science.gov (United States)

    Hubbard, Bernard E.; Mack, Thomas J.; Thompson, Allyson L.

    2012-01-01

    During a preliminary mineral resource assessment of Afghanistan (Peters and others, 2007), 24 mineralized areas of interest (AOIs) were highlighted as the focus for future economic development throughout various parts of the country. In addition to located mineral resources of value, development of a viable mining industry in Afghanistan will require the location of suitable groundwater resources for drinking, processing of mineral ores for use or for export, and for agriculture and food production in areas surrounding and supporting future mining enterprises. This report and accompanying GIS datasets describe the results of both automated and manual mapping of lineaments throughout the 24 mineral occurrence AOIs described in detail by Peters and others (2007; 2011). For this study, we define lineaments as "mappable linear or curvilinear features of a surface whose parts align in a straight or slightly curving relationship that may be the expression of a fault or other linear zones of weakness" as derived from remote sensing sources such as optical imagery, radar imagery or digital elevation models (DEMs) (Sabins, 2007).

  3. Direct Survival Analysis: a new stock assessment method

    Directory of Open Access Journals (Sweden)

    Eduardo Ferrandis

    2007-03-01

    Full Text Available In this work, a new stock assessment method, Direct Survival Analysis, is proposed and described. The parameter estimation of the Weibull survival model proposed by Ferrandis (2007 is obtained using trawl survey data. This estimation is used to establish a baseline survival function, which is in turn used to estimate the specific survival functions in the different cohorts considered through an adaptation of the separable model of the fishing mortality rates introduced by Pope and Shepherd (1982. It is thus possible to test hypotheses on the evolution of survival during the period studied and to identify trends in recruitment. A link is established between the preceding analysis of trawl survey data and the commercial catch-at-age data that are generally obtained to evaluate the population using analytical models. The estimated baseline survival, with the proposed versions of the stock and catch equations and the adaptation of the Separable Model, may be applied to commercial catch-at-age data. This makes it possible to estimate the survival corresponding to the landing data, the initial size of the cohort and finally, an effective age of first capture, in order to complete the parameter model estimation and consequently the estimation of the whole survival and mortality, along with the reference parameters that are useful for management purposes. Alternatively, this estimation of an effective age of first capture may be obtained by adapting the demographic structure of trawl survey data to that of the commercial fleet through suitable selectivity models of the commercial gears. The complete model provides the evaluation of the stock at any age. The coherence (and hence the mutual “calibration” between the two kinds of information may be analysed and compared with results obtained by other methods, such as virtual population analysis (VPA, in order to improve the diagnosis of the state of exploitation of the population. The model may be

  4. Regression analysis with categorized regression calibrated exposure: some interesting findings

    Directory of Open Access Journals (Sweden)

    Hjartåker Anette

    2006-07-01

    Full Text Available Abstract Background Regression calibration as a method for handling measurement error is becoming increasingly well-known and used in epidemiologic research. However, the standard version of the method is not appropriate for exposure analyzed on a categorical (e.g. quintile scale, an approach commonly used in epidemiologic studies. A tempting solution could then be to use the predicted continuous exposure obtained through the regression calibration method and treat it as an approximation to the true exposure, that is, include the categorized calibrated exposure in the main regression analysis. Methods We use semi-analytical calculations and simulations to evaluate the performance of the proposed approach compared to the naive approach of not correcting for measurement error, in situations where analyses are performed on quintile scale and when incorporating the original scale into the categorical variables, respectively. We also present analyses of real data, containing measures of folate intake and depression, from the Norwegian Women and Cancer study (NOWAC. Results In cases where extra information is available through replicated measurements and not validation data, regression calibration does not maintain important qualities of the true exposure distribution, thus estimates of variance and percentiles can be severely biased. We show that the outlined approach maintains much, in some cases all, of the misclassification found in the observed exposure. For that reason, regression analysis with the corrected variable included on a categorical scale is still biased. In some cases the corrected estimates are analytically equal to those obtained by the naive approach. Regression calibration is however vastly superior to the naive method when applying the medians of each category in the analysis. Conclusion Regression calibration in its most well-known form is not appropriate for measurement error correction when the exposure is analyzed on a

  5. Bayesian survival analysis in clinical trials: What methods are used in practice?

    Science.gov (United States)

    Brard, Caroline; Le Teuff, Gwénaël; Le Deley, Marie-Cécile; Hampson, Lisa V

    2017-02-01

    Background Bayesian statistics are an appealing alternative to the traditional frequentist approach to designing, analysing, and reporting of clinical trials, especially in rare diseases. Time-to-event endpoints are widely used in many medical fields. There are additional complexities to designing Bayesian survival trials which arise from the need to specify a model for the survival distribution. The objective of this article was to critically review the use and reporting of Bayesian methods in survival trials. Methods A systematic review of clinical trials using Bayesian survival analyses was performed through PubMed and Web of Science databases. This was complemented by a full text search of the online repositories of pre-selected journals. Cost-effectiveness, dose-finding studies, meta-analyses, and methodological papers using clinical trials were excluded. Results In total, 28 articles met the inclusion criteria, 25 were original reports of clinical trials and 3 were re-analyses of a clinical trial. Most trials were in oncology (n = 25), were randomised controlled (n = 21) phase III trials (n = 13), and half considered a rare disease (n = 13). Bayesian approaches were used for monitoring in 14 trials and for the final analysis only in 14 trials. In the latter case, Bayesian survival analyses were used for the primary analysis in four cases, for the secondary analysis in seven cases, and for the trial re-analysis in three cases. Overall, 12 articles reported fitting Bayesian regression models (semi-parametric, n = 3; parametric, n = 9). Prior distributions were often incompletely reported: 20 articles did not define the prior distribution used for the parameter of interest. Over half of the trials used only non-informative priors for monitoring and the final analysis (n = 12) when it was specified. Indeed, no articles fitting Bayesian regression models placed informative priors on the parameter of interest. The prior for the treatment

  6. Gait analysis in demented subjects: Interests and perspectives

    Directory of Open Access Journals (Sweden)

    Olivier Beauchet

    2008-03-01

    Full Text Available Olivier Beauchet1, Gilles Allali2, Gilles Berrut3, Caroline Hommet4, Véronique Dubost5, Frédéric Assal21Department of Geriatrics, Angers University Hospital, France; 2Department of Neurology, Geneva University Hospital, France; 3Department of Geriatrics, Nantes University Hospital, France; 4Department of Internal Medicine and Geriatrics, Tours University Hospital, France; 5Department of Geriatrics, Dijon University Hospital, FranceAbstract: Gait disorders are more prevalent in dementia than in normal aging and are related to the severity of cognitive decline. Dementia-related gait changes (DRGC mainly include decrease in walking speed provoked by a decrease in stride length and an increase in support phase. More recently, dual-task related changes in gait were found in Alzheimer’s disease (AD and non-Alzheimer dementia, even at an early stage. An increase in stride-to-stride variability while usual walking and dual-tasking has been shown to be more specific and sensitive than any change in mean value in subjects with dementia. Those data show that DRGC are not only associated to motor disorders but also to problem with central processing of information and highlight that dysfunction of temporal and frontal lobe may in part explain gait impairment among demented subjects. Gait assessment, and more particularly dual-task analysis, is therefore crucial in early diagnosis of dementia and/or related syndromes in the elderly. Moreover, dual-task disturbances could be a specific marker of falling at a pre-dementia stage.Keywords: gait, prediction of dementia, risk of falling, older adult

  7. Novel head and neck cancer survival analysis approach: random survival forests versus Cox proportional hazards regression.

    Science.gov (United States)

    Datema, Frank R; Moya, Ana; Krause, Peter; Bäck, Thomas; Willmes, Lars; Langeveld, Ton; Baatenburg de Jong, Robert J; Blom, Henk M

    2012-01-01

    Electronic patient files generate an enormous amount of medical data. These data can be used for research, such as prognostic modeling. Automatization of statistical prognostication processes allows automatic updating of models when new data is gathered. The increase of power behind an automated prognostic model makes its predictive capability more reliable. Cox proportional hazard regression is most frequently used in prognostication. Automatization of a Cox model is possible, but we expect the updating process to be time-consuming. A possible solution lies in an alternative modeling technique called random survival forests (RSFs). RSF is easily automated and is known to handle the proportionality assumption coherently and automatically. Performance of RSF has not yet been tested on a large head and neck oncological dataset. This study investigates performance of head and neck overall survival of RSF models. Performances are compared to a Cox model as the "gold standard." RSF might be an interesting alternative modeling approach for automatization when performances are similar. RSF models were created in R (Cox also in SPSS). Four RSF splitting rules were used: log-rank, conservation of events, log-rank score, and log-rank approximation. Models were based on historical data of 1371 patients with primary head-and-neck cancer, diagnosed between 1981 and 1998. Models contain 8 covariates: tumor site, T classification, N classification, M classification, age, sex, prior malignancies, and comorbidity. Model performances were determined by Harrell's concordance error rate, in which 33% of the original data served as a validation sample. RSF and Cox models delivered similar error rates. The Cox model performed slightly better (error rate, 0.2826). The log-rank splitting approach gave the best RSF performance (error rate, 0.2873). In accord with Cox and RSF models, high T classification, high N classification, and severe comorbidity are very important covariates in the

  8. [Prognostic factors in renal cancer with venous thrombus survival analysis.

    Science.gov (United States)

    Pascual-Fernández, Angela; Calleja-Escudero, Jesús; Gómez de Segura, Cristina; Pesquera-Ortega, Laura; Taylor, James; Fajardo, José Antonio; González de Zárate, Javier; Monllor-Gisbert, Jesús; Cortiñas-González, José Ramón

    2017-07-01

    To analyze surgery for renal cancer with venous thrombus at different levels, perioperative complications and prognostic factors associated to overall, cancer-specific and disease-free survival. Retrospective analysis of 42 cases of renal cancer with venous thrombus performed between 2005 and 2015. The level reached by the thrombus was established according to the Mayo Clinic classification. Postoperative complications were staged according to Clavien-Dindo classification. Most frequent in males. Mean age 65.7 years. 16.6% were tumors with level II thrombus. Subcostal approach was performed in 58.9%. Extracorporeal circulation with cardiac arrest and hypothermia was established in 2 patients. Resection of metastatic disease was performed in 3 patients during radical nephrectomy. Reoperation was 2.3% while, perioperative mortality was 4.7%. 30% presented with metastases at diagnosis. Twenty patients progressed at 15.5 months (3-55). Overall survival was 60 months. The cancer-specific mortality was 75%. Disease-free survival was 30% at 55 months. Surgical treatment of renal cancer with venous thrombus requires a multidisciplinary management. The surgical technique varies according to the level reached by the venous thrombus. Tumor stage is the most important prognostic factor. Thrombus level influences prognosis, with longer survival for patients with tumor thrombus confined to the renal vein (pT3a) in comparison to tumors with thrombus in the atrium (pT3c).

  9. Evaluating disease management program effectiveness: an introduction to survival analysis.

    Science.gov (United States)

    Linden, Ariel; Adams, John L; Roberts, Nancy

    2004-01-01

    Currently, the most widely used method in the disease management industry for evaluating program effectiveness is the "total population approach." This model is a pretest-posttest design, with the most basic limitation being that without a control group, there may be sources of bias and/or competing extraneous confounding factors that offer plausible rationale explaining the change from baseline. Survival analysis allows for the inclusion of data from censored cases, those subjects who either "survived" the program without experiencing the event (e.g., achievement of target clinical levels, hospitalization) or left the program prematurely, due to disenrollement from the health plan or program, or were lost to follow-up. Additionally, independent variables may be included in the model to help explain the variability in the outcome measure. In order to maximize the potential of this statistical method, validity of the model and research design must be assured. This paper reviews survival analysis as an alternative, and more appropriate, approach to evaluating DM program effectiveness than the current total population approach.

  10. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs

    Science.gov (United States)

    Asher, Lucy; Harvey, Naomi D.; Green, Martin; England, Gary C. W.

    2017-01-01

    Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between) a binary event(s) and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM) can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses), and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided. PMID:28804710

  11. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs.

    Science.gov (United States)

    Asher, Lucy; Harvey, Naomi D; Green, Martin; England, Gary C W

    2017-01-01

    Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between) a binary event(s) and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM) can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses), and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided.

  12. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs

    Directory of Open Access Journals (Sweden)

    Lucy Asher

    2017-07-01

    Full Text Available Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between a binary event(s and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses, and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided.

  13. Multivariate Survival Mixed Models for Genetic Analysis of Longevity Traits

    DEFF Research Database (Denmark)

    Pimentel Maia, Rafael; Madsen, Per; Labouriau, Rodrigo

    2014-01-01

    A class of multivariate mixed survival models for continuous and discrete time with a complex covariance structure is introduced in a context of quantitative genetic applications. The methods introduced can be used in many applications in quantitative genetics although the discussion presented....... The discrete time models used are multivariate variants of the discrete relative risk models. These models allow for regular parametric likelihood-based inference by exploring a coincidence of their likelihood functions and the likelihood functions of suitably defined multivariate generalized linear mixed...... models. The models include a dispersion parameter, which is essential for obtaining a decomposition of the variance of the trait of interest as a sum of parcels representing the additive genetic effects, environmental effects and unspecified sources of variability; as required in quantitative genetic...

  14. Multivariate Survival Mixed Models for Genetic Analysis of Longevity Traits

    DEFF Research Database (Denmark)

    Pimentel Maia, Rafael; Madsen, Per; Labouriau, Rodrigo

    2013-01-01

    A class of multivariate mixed survival models for continuous and discrete time with a complex covariance structure is introduced in a context of quantitative genetic applications. The methods introduced can be used in many applications in quantitative genetics although the discussion presented....... The discrete time models used are multivariate variants of the discrete relative risk models. These models allow for regular parametric likelihood-based inference by exploring a coincidence of their likelihood functions and the likelihood functions of suitably defined multivariate generalized linear mixed...... models. The models include a dispersion parameter, which is essential for obtaining a decomposition of the variance of the trait of interest as a sum of parcels representing the additive genetic effects, environmental effects and unspecified sources of variability; as required in quantitative genetic...

  15. [Corneal transplant in a second level hospital. A survival analysis].

    Science.gov (United States)

    Hernández-Da Mota, Sergio E; Paniagua Jacobo, Margarita; Gómez Revuelta, Gustavo; Páez Martínez, Raymundo Mauricio

    2013-01-01

    To determine the long-term corneal graft survival in patients of General Hospital Dr. Miguel Silva. This was a retrospective cohort study. Records from patients who underwent corneal transplant surgery at General Hospital Dr. Miguel Silva were analyzed. The percentages of graft failure were obtained. Kaplan-Meier survival analysis was performed to evaluate the long-term cumulative probability of graft non-rejection in all patients according to diagnosis. Overall, 71.9% (CI 95%: 64.8-78.9) of the patients did not have any graft rejections, and 12.5% (CI 95%: 7-18) required a regraft and were considered graft failures. Patients with posttraumatic leucoma had a cumulative probability of non-rejection of 100%. Subjects with keratoconus had a 65% likelihood of non-rejection after 40 months of follow-up. The likelihood of non-rejection was greater than 80% at 100 months of follow-up in pseudophakic bullous keratopathy patients and 60% at 20 months of follow-up in inactive herpetic leucoma patients. Posttraumatic leucoma patients had the greatest cumulative survival probability compared with postherpetic leucoma patients and other patient groups.

  16. Demographic and Socio-economic Determinants of Birth Interval Dynamics in Manipur: A Survival Analysis

    Directory of Open Access Journals (Sweden)

    Sanajaoba Singh N,

    2011-01-01

    Full Text Available The birth interval is a major determinant of levels of fertility in high fertility populations. A house-to-house survey of 1225 women in Manipur, a tiny state in North Eastern India was carried out to investigate birth interval patterns and its determinants. Using survival analysis, among the nine explanatory variables of interest, only three factors – infant mortality, Lactation and use of contraceptive devices have highly significant effect (P<0.01 on the duration of birth interval and only three factors – age at marriage of wife, parity and sex of child are found to be significant (P<0.05 on the duration variable.

  17. THE POSITION OF INTEREST IN SPORTS AND RECREATION OF 7th GRADE ELEMENTARY SCHOOL STUDENTS IN THE FACTOR ANALYSIS OF DIFFERENT INTEREST

    Directory of Open Access Journals (Sweden)

    Vladimir Milošević

    2013-07-01

    Full Text Available Personal interests carry a great potential and are usually a drive to act. Therefore they usually point towards the activity of an individual in his interest area. An insight into the position of the interest in sports and recreation among other interests can be obtained by inspecting the interests of 7th grade elementary school students from Sremska Mitrovica and Jagodina. The sample consisted of 736 7th grade elementary school students of both genders. A non-experimental study of the students’ interests was done using a questionnaire that consisted of 5 interest indicators: job preference, self-estimation of affinity, use of free time, direct self-estimation of interests and reaction to key words-stimuli. Each indicator had 30 items that asses 30 interests. A t test was used to inspect the level of interest in sports and recreation. Also, factor analysis was done for each indicator separately. The reason for this approach is that there is no real confirmation that these 5 indicators are well suited for assessing the interests of young persons in the time we live in. Students’ interest in sports and recreation is about 4 on the scale of 1 to 5, on each of the indicators. The data shows that the interest of 7th grade elementary school students in sports and recreation is closely linked to interest in military, these two interests belong to the same factor regardless of the way the interests are assessed, that is, they belong to the same factor on each of the 5 indicators. The interest in adventure belongs to the same factor as the interest in sports and recreation on 4 out of 5 indicators, and interest in humor, interest in travel and hedonistic interest on 3 out of 5 indicators. These results might indicate that the motives for engaging in sports and recreation are unstable, because this composition of relatedness of the interests can be interpreted as the factor of fun. If that is so, these findings alert to the importance of building a

  18. SURVIVAL ANALYSIS OF CANCER PATIENTS USING PARAMETRIC AND NON-PARAMETRIC APPROACHES

    Directory of Open Access Journals (Sweden)

    M. AKRAM, M. AMAN ULLAH AND R. TAJ

    2007-10-01

    Full Text Available Exploring the health related quality of life is usually the focus of the survival studies. Using the health data of cancer registry in Multan, Pakistan, an investigation about the survival pattern of cancer patients was explored, using the non-parametric and parametric modeling strategies. The Kaplan-Meier method and Weibull model based on Anderson-Darling test were applied to the real life time data. Findings suggested different sex-superiority of survival pattern among different groups of cancer patients. Interestingly, Kaplan-Meier and Weibul model provided a very close estimate of the survival function and other characteristics of interest.

  19. Survival analysis and classification methods for forest fire size.

    Directory of Open Access Journals (Sweden)

    Pier-Olivier Tremblay

    Full Text Available Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene and the size at "being held" (a state when no further increase in size is expected. We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at "being held" exceeds the size at initial assessment. Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.

  20. Survival analysis and classification methods for forest fire size.

    Science.gov (United States)

    Tremblay, Pier-Olivier; Duchesne, Thierry; Cumming, Steven G

    2018-01-01

    Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at "being held" (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at "being held" exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.

  1. Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves

    National Research Council Canada - National Science Library

    Guyot, Patricia; Ades, A E; Ouwens, Mario J N M; Welton, Nicky J

    2012-01-01

    .... In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient...

  2. Estimation of Survival Probabilities for Use in Cost-effectiveness Analyses: A Comparison of a Multi-state Modeling Survival Analysis Approach with Partitioned Survival and Markov Decision-Analytic Modeling.

    Science.gov (United States)

    Williams, Claire; Lewsey, James D; Mackay, Daniel F; Briggs, Andrew H

    2017-05-01

    Modeling of clinical-effectiveness in a cost-effectiveness analysis typically involves some form of partitioned survival or Markov decision-analytic modeling. The health states progression-free, progression and death and the transitions between them are frequently of interest. With partitioned survival, progression is not modeled directly as a state; instead, time in that state is derived from the difference in area between the overall survival and the progression-free survival curves. With Markov decision-analytic modeling, a priori assumptions are often made with regard to the transitions rather than using the individual patient data directly to model them. This article compares a multi-state modeling survival regression approach to these two common methods. As a case study, we use a trial comparing rituximab in combination with fludarabine and cyclophosphamide v. fludarabine and cyclophosphamide alone for the first-line treatment of chronic lymphocytic leukemia. We calculated mean Life Years and QALYs that involved extrapolation of survival outcomes in the trial. We adapted an existing multi-state modeling approach to incorporate parametric distributions for transition hazards, to allow extrapolation. The comparison showed that, due to the different assumptions used in the different approaches, a discrepancy in results was evident. The partitioned survival and Markov decision-analytic modeling deemed the treatment cost-effective with ICERs of just over £16,000 and £13,000, respectively. However, the results with the multi-state modeling were less conclusive, with an ICER of just over £29,000. This work has illustrated that it is imperative to check whether assumptions are realistic, as different model choices can influence clinical and cost-effectiveness results.

  3. Survival analysis under cross-sectional sampling : length bias and multiplicative censoring

    NARCIS (Netherlands)

    van Es, Bert; Klaassen, Chris A.J.; Oudshoorn, Karin

    2000-01-01

    Consider a parametric, nonparametric or semiparametric model for survival times. Interest is in estimation of Euclidean and Banach parameters for these models. However, not the survival times themselves will be observed, since this might be quite time consuming. Instead, cross-sectional sampling is

  4. Financial conflicts of interest and conclusions about neuraminidase inhibitors for influenza: an analysis of systematic reviews.

    Science.gov (United States)

    Dunn, Adam G; Arachi, Diana; Hudgins, Joel; Tsafnat, Guy; Coiera, Enrico; Bourgeois, Florence T

    2014-10-07

    Industry funding and financial conflicts of interest may contribute to bias in the synthesis and interpretation of scientific evidence. To examine the association between financial conflicts of interest and characteristics of systematic reviews of neuraminidase inhibitors. Retrospective analysis. Reviews that examined the use of neuraminidase inhibitors in the prophylaxis or treatment of influenza, were published between January 2005 and May 2014, and used a systematic search protocol. Two investigators blinded to all information regarding the review authors independently assessed the presentation of evidence on the use of neuraminidase inhibitors as favorable or not favorable. Financial conflicts of interest were identified using the index reviews, other publications, and Web-based searches. Associations between financial conflicts of interest, favorability assessments, and presence of critical appraisals of evidence quality were analyzed. Twenty-six systematic reviews were identified, of which 13 examined prophylaxis and 24 examined treatment, accounting for 37 distinct assessments. Among assessments associated with a financial conflict of interest, 7 of 8 (88%) were classified as favorable, compared with 5 of 29 (17%) among those without a financial conflict of interest. Reviewers without financial conflicts of interest were more likely to include statements about the quality of the primary studies than those with financial conflicts of interest. The heterogeneity in populations and outcomes examined in the reviews precluded analysis of the contribution of selective inclusion of evidence on the discordance of the assessments made in the reviews. Many of the systematic reviews had overlapping authorship. Reviewers with financial conflicts of interest may be more likely to present evidence about neuraminidase inhibitors in a favorable manner and recommend the use of these drugs than reviewers without financial conflicts of interest. Australian National Health and

  5. Survival analysis of preweaning piglet survival in a dry-cured ham-producing crossbred line.

    Science.gov (United States)

    Cecchinato, A; Bonfatti, V; Gallo, L; Carnier, P

    2008-10-01

    The aim of this study was to investigate piglet preweaning survival and its relationship with a total merit index (TMI) used for selection of Large White terminal boars for dry-cured ham production. Data on 13,924 crossbred piglets (1,347 litters), originated by 189 Large White boars and 328 Large White-derived crossbred sows, were analyzed under a frailty proportional hazards model, assuming different baseline hazard functions and including sire and nursed litter as random effects. Estimated hazard ratios (HR) indicated that sex, cross-fostering, year-month of birth, parity of the nurse sow, size of the nursed litter, and class of TMI were significant effects for piglet preweaning survival. Female piglets had less risk of dying than males (HR = 0.81), as well as cross-fostered piglets (HR = 0.60). Survival increased when piglets were nursed by sows of third (HR = 0.85), fourth (HR = 0.76), and fifth (HR = 0.79) parity in comparison with first and second parity sows. Piglets of small (HR = 3.90) or very large litters (HR >1.60) had less chance of surviving in comparison with litters of intermediate size. Class of TMI exhibited an unfavorable relationship with survival (HR = 1.20 for the TMI top class). The modal estimates of sire variance under different baseline hazard functions were 0.06, whereas the variance for the nursed litter was close to 0.7. The estimate of the nursed litter effect variance was greater than that of the sire, which shows the importance of the common environment generated by the nurse sow. Relationships between sire rankings obtained from different survival models were high. The heritability estimate in equivalent scale was low and reached a value of 0.03. Nevertheless, the exploitable genetic variation for this trait justifies the inclusion of piglet preweaning survival in the current breeding program for selection of Large White terminal boars for dry-cured ham production.

  6. Survival analysis of HIV-infected patients under antiretroviral ...

    African Journals Online (AJOL)

    admin

    Abstract. Background: The introduction of ART dramatically improved the survival and health quality of HIV-infected patients in the industrialized world; and the survival benefit of ART has been well studied too. However, in resource-poor settings, where such treatment was started only recently, limited data exist on treatment ...

  7. FACTORS OF INFLUENCE ON THE ENTREPRENEURIAL INTEREST: AN ANALYSIS WITH STUDENTS OF INFORMATION TECHNOLOGY RELATED COURSES

    Directory of Open Access Journals (Sweden)

    Diego Guilherme Bonfim

    2009-10-01

    Full Text Available The purpose of the research was to analyze the entrepreneurial interest of students in information technology related courses. A literature review was performed, from which four hypotheses were announced, affirming that the student interest in entrepreneurial activity is influenced by (1 the perceived vocation of the area, (2 the ownership of a company, (3 the perceived social support from friends and family, and (4 the entrepreneurial skills mastery. A field study was developed, with data collected from the 171 students of higher education institutions from Fortaleza. The data were analyzed by using statistical techniques of descriptive analysis, analysis of variance, and multiple regression analysis. It was found that: (1 students, in general, have a moderate predisposition to engage in entrepreneurial activities; (2 the entrepreneurial interest is influenced by the perceived entrepreneurial vocation of the area, the social support, and the perceived strategic entrepreneurial skills mastery.

  8. Influencing factors to be interested in entrepreneurial activities: an analysis with tourism students

    Directory of Open Access Journals (Sweden)

    Francisco José Costa

    2008-10-01

    Full Text Available This research intends to analyze the interest students attending Tourism Programmes have in entrepreneurial activities. A bibliographical research was conducted and four hypotheses were announced. Data were collected during a field study with 149 students of higher education institutions located at Fortaleza (Ceara State, Brazil. Data were analyzed using three statistical techniques: descriptive analysis, multiple regression analysis, and analysis of variance. It was found that: (1 students, in general, have an intermediary predisposition to engage in entrepreneurial activities; (2 entrepreneurial interest is influenced by the perceived entrepreneurial vocation of the area, support of friends and family, ownership of a firm (individual or family business, and the perceived mastership of entrepreneurial strategic skills. Even results have limitations due to non-probabilistic sampling, they may help to improve the actions developed to encourage entrepreneurial interest in tourism students.

  9. LONG TERM SURVIVAL FOLLOWING TRAUMATIC BRAIN INJURY: A POPULATION BASED PARAMETRIC SURVIVAL ANALYSIS

    Science.gov (United States)

    Fuller, Gordon Ward; Ransom, Jeanine; Mandrekar, Jay; Brown, Allen W

    2017-01-01

    Background Long term mortality may be increased following traumatic brain injury (TBI); however the degree to which survival could be reduced is unknown. We aimed to model life expectancy following post-acute TBI to provide predictions of longevity and quantify differences in survivorship with the general population. Methods A population based retrospective cohort study using data from the Rochester Epidemiology Project (REP) was performed. A random sample of patients from Olmsted County, Minnesota with a confirmed TBI between 1987 and 2000 was identified and vital status determined in 2013. Parametric survival modelling was then used to develop a model to predict life expectancy following TBI conditional on age at injury. Survivorship following TBI was also compared with the general population and age and gender matched non-head injured REP controls. Results 769 patients were included in complete case analyses. Median follow up time was 16.1 years (IQR 9.0–20.4) with 120 deaths occurring in the cohort during the study period. Survival after acute TBI was well represented by a Gompertz distribution. Victims of TBI surviving for at least 6 months post-injury demonstrated a much higher ongoing mortality rate compared to the US general population and non-TBI controls (hazard ratio 1·47, 95% CI 1·15–1·87). US general population cohort life table data was used to update the Gompertz model’s shape and scale parameters to account for cohort effects and allow prediction of life expectancy in contemporary TBI. Conclusions Survivors of TBI have decreased life expectancy compared to the general population. This may be secondary to the head injury itself or result from patient characteristics associated with both the propensity for TBI and increased early mortality. Post-TBI life expectancy estimates may be useful to guide prognosis, in public health planning, for actuarial applications and in the extrapolation of outcomes for TBI economic models. PMID:27165161

  10. When do we need competing risks methods for survival analysis in nephrology?

    NARCIS (Netherlands)

    Noordzij, Marlies; Leffondré, Karen; van Stralen, Karlijn J.; Zoccali, Carmine; Dekker, Friedo W.; Jager, Kitty J.

    2013-01-01

    Survival analyses are commonly applied to study death or other events of interest. In such analyses, so-called competing risks may form an important problem. A competing risk is an event that either hinders the observation of the event of interest or modifies the chance that this event occurs. For

  11. Integrative analysis of survival-associated gene sets in breast cancer.

    Science.gov (United States)

    Varn, Frederick S; Ung, Matthew H; Lou, Shao Ke; Cheng, Chao

    2015-03-12

    Patient gene expression information has recently become a clinical feature used to evaluate breast cancer prognosis. The emergence of prognostic gene sets that take advantage of these data has led to a rich library of information that can be used to characterize the molecular nature of a patient's cancer. Identifying robust gene sets that are consistently predictive of a patient's clinical outcome has become one of the main challenges in the field. We inputted our previously established BASE algorithm with patient gene expression data and gene sets from MSigDB to develop the gene set activity score (GSAS), a metric that quantitatively assesses a gene set's activity level in a given patient. We utilized this metric, along with patient time-to-event data, to perform survival analyses to identify the gene sets that were significantly correlated with patient survival. We then performed cross-dataset analyses to identify robust prognostic gene sets and to classify patients by metastasis status. Additionally, we created a gene set network based on component gene overlap to explore the relationship between gene sets derived from MSigDB. We developed a novel gene set based on this network's topology and applied the GSAS metric to characterize its role in patient survival. Using the GSAS metric, we identified 120 gene sets that were significantly associated with patient survival in all datasets tested. The gene overlap network analysis yielded a novel gene set enriched in genes shared by the robustly predictive gene sets. This gene set was highly correlated to patient survival when used alone. Most interestingly, removal of the genes in this gene set from the gene pool on MSigDB resulted in a large reduction in the number of predictive gene sets, suggesting a prominent role for these genes in breast cancer progression. The GSAS metric provided a useful medium by which we systematically investigated how gene sets from MSigDB relate to breast cancer patient survival. We used

  12. Mediation analysis for survival data using semiparametric probit models.

    Science.gov (United States)

    Huang, Yen-Tsung; Cai, Tianxi

    2016-06-01

    Causal mediation modeling has become a popular approach for studying the effect of an exposure on an outcome through mediators. Currently, the literature on mediation analyses with survival outcomes largely focused on settings with a single mediator and quantified the mediation effects on the hazard, log hazard and log survival time (Lange and Hansen 2011; VanderWeele 2011). In this article, we propose a multi-mediator model for survival data by employing a flexible semiparametric probit model. We characterize path-specific effects (PSEs) of the exposure on the outcome mediated through specific mediators. We derive closed form expressions for PSEs on a transformed survival time and the survival probabilities. Statistical inference on the PSEs is developed using a nonparametric maximum likelihood estimator under the semiparametric probit model and the functional Delta method. Results from simulation studies suggest that our proposed methods perform well in finite sample. We illustrate the utility of our method in a genomic study of glioblastoma multiforme survival. © 2015, The International Biometric Society.

  13. Study of Hip Fracture Risk using Tree Structured Survival Analysis

    Directory of Open Access Journals (Sweden)

    Lu Y

    2003-01-01

    Full Text Available In dieser Studie wird das Hüftfraktur-Risiko bei postmenopausalen Frauen untersucht, indem die Frauen in verschiedene Subgruppen hinsichtlich dieses Risikos klassifiziert werden. Frauen in einer gemeinsamen Subgruppe haben ein ähnliches Risiko, hingegen in verschiedenen Subgruppen ein unterschiedliches Hüftfraktur-Risiko. Die Subgruppen wurden mittels der Tree Structured Survival Analysis (TSSA aus den Daten von 7.665 Frauen der SOF (Study of Osteoporosis Fracture ermittelt. Bei allen Studienteilnehmerinnen wurde die Knochenmineraldichte (BMD von Unterarm, Oberschenkelhals, Hüfte und Wirbelsäule gemessen. Die Zeit von der BMD-Messung bis zur Hüftfraktur wurde als Endpunkt notiert. Eine Stichprobe von 75% der Teilnehmerinnen wurde verwendet, um die prognostischen Subgruppen zu bilden (Trainings-Datensatz, während die anderen 25% als Bestätigung der Ergebnisse diente (Validierungs-Datensatz. Aufgrund des Trainings-Datensatzes konnten mittels TSSA 4 Subgruppen identifiziert werden, deren Hüftfraktur-Risiko bei einem Follow-up von im Mittel 6,5 Jahren bei 19%, 9%, 4% und 1% lag. Die Einteilung in die Subgruppen erfolgte aufgrund der Bewertung der BMD des Ward'schen Dreiecks sowie des Oberschenkelhalses und nach dem Alter. Diese Ergebnisse konnten mittels des Validierungs-Datensatzes reproduziert werden, was die Sinnhaftigkeit der Klassifizierungregeln in einem klinischen Setting bestätigte. Mittels TSSA war eine sinnvolle, aussagekräftige und reproduzierbare Identifikation von prognostischen Subgruppen, die auf dem Alter und den BMD-Werten beruhen, möglich. In this paper we studied the risk of hip fracture for post-menopausal women by classifying women into different subgroups based on their risk of hip fracture. The subgroups were generated such that all the women in a particular subgroup had relatively similar risk while women belonging to two different subgroups had rather different risks of hip fracture. We used the Tree Structured

  14. Survival analysis of cervical cancer using stratified Cox regression

    Science.gov (United States)

    Purnami, S. W.; Inayati, K. D.; Sari, N. W. Wulan; Chosuvivatwong, V.; Sriplung, H.

    2016-04-01

    Cervical cancer is one of the mostly widely cancer cause of the women death in the world including Indonesia. Most cervical cancer patients come to the hospital already in an advanced stadium. As a result, the treatment of cervical cancer becomes more difficult and even can increase the death's risk. One of parameter that can be used to assess successfully of treatment is the probability of survival. This study raises the issue of cervical cancer survival patients at Dr. Soetomo Hospital using stratified Cox regression based on six factors such as age, stadium, treatment initiation, companion disease, complication, and anemia. Stratified Cox model is used because there is one independent variable that does not satisfy the proportional hazards assumption that is stadium. The results of the stratified Cox model show that the complication variable is significant factor which influent survival probability of cervical cancer patient. The obtained hazard ratio is 7.35. It means that cervical cancer patient who has complication is at risk of dying 7.35 times greater than patient who did not has complication. While the adjusted survival curves showed that stadium IV had the lowest probability of survival.

  15. Interesting Interest Points

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Dahl, Anders Lindbjerg; Pedersen, Kim Steenstrup

    2012-01-01

    Not all interest points are equally interesting. The most valuable interest points lead to optimal performance of the computer vision method in which they are employed. But a measure of this kind will be dependent on the chosen vision application. We propose a more general performance measure based...... position. The LED illumination provides the option for artificially relighting the scene from a range of light directions. This data set has given us the ability to systematically evaluate the performance of a number of interest point detectors. The highlights of the conclusions are that the fixed scale...

  16. Interest Rate Variations and Stock Market Capitalization in Nigeria: An Empirical Analysis

    Directory of Open Access Journals (Sweden)

    Edirin Jeroh

    2012-10-01

    Full Text Available In most economies, variations in interest rates have become a prominent feature both in the long-run and short-run. This study thus examines by means of robust analysis, the effect of the variations in interest rates on the level of stock market capitalization in Nigeria for a period of 29 years (1981 – 2009. Data was obtained from the statistical bulletin of the Central Bank of Nigeria (CBN for the relevant years. The analysis of the data obtained was done with the Ordinary Least Square (OLS method. The results from the study showed that variations in interest rate significantly affect the level of stock market capitalization, thereby suggesting that there is a significant relationship between interest rate variation and the level of stock market capitalization in Nigeria for the period under study. Based on the above, it was recommended that the Government of Nigeria and the appropriate monetary authorities should continue to give serious attention to policies geared towards lending rate in the country, if a desired level of market capitalization must be achieved.

  17. Policies on Conflicts of Interest in Health Care Guideline Development: A Cross-Sectional Analysis

    Science.gov (United States)

    Morciano, Cristina; Basevi, Vittorio; Faralli, Carla; Hilton Boon, Michele; Tonon, Sabina; Taruscio, Domenica

    2016-01-01

    Objective To assess whether organisations that develop health care guidelines have conflict of interest (COI) policies and to review the content of the available COI policies. Methods Survey and content analysis of COI policies available in English, French, Spanish, and Italian conducted between September 2014 and June 2015. A 24-item data abstraction instrument was created on the basis of guideline development standards. Results The survey identified 29 organisations from 19 countries that met the inclusion criteria. From these organisations, 19 policies were eligible for inclusion in the content analysis. Over one-third of the policies (7/19, 37%) did not report or did not clearly report whether disclosure was a prerequisite for membership of the guideline panel. Strategies for the prevention of COI such as divestment were mentioned by only two organisations. Only 21% of policies (4/19) used criteria to determine whether an interest constitutes a COI and to assess the severity of the risk imposed. Conclusions The finding that some organisations, in contradiction of widely available standards, still do not have COI policies publicly available is concerning. Also troubling were the findings that some policies did not clearly report critical steps in obtaining, managing and communicating disclosure of relationships of interest. This in addition to the variability encountered in content and accessibility of COI policies may cause confusion and distrust among guideline users. It is in the interest of guideline users and developers to design an agreed-upon, comprehensive, clear, and accessible COI policy. PMID:27846255

  18. Statistical Survival Analysis of Fish and Wildlife Tagging Studies; SURPH.1 Manual - Analysis of Release-Recapture Data for Survival Studies, 1994 Technical Manual.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven G.; Skalski, John R.; Schelechte, J. Warren [Univ. of Washington, Seattle, WA (United States). Center for Quantitative Science

    1994-12-01

    Program SURPH is the culmination of several years of research to develop a comprehensive computer program to analyze survival studies of fish and wildlife populations. Development of this software was motivated by the advent of the PIT-tag (Passive Integrated Transponder) technology that permits the detection of salmonid smolt as they pass through hydroelectric facilities on the Snake and Columbia Rivers in the Pacific Northwest. Repeated detections of individually tagged smolt and analysis of their capture-histories permits estimates of downriver survival probabilities. Eventual installation of detection facilities at adult fish ladders will also permit estimation of ocean survival and upstream survival of returning salmon using the statistical methods incorporated in SURPH.1. However, the utility of SURPH.1 far exceeds solely the analysis of salmonid tagging studies. Release-recapture and radiotelemetry studies from a wide range of terrestrial and aquatic species have been analyzed using SURPH.1 to estimate discrete time survival probabilities and investigate survival relationships. The interactive computing environment of SURPH.1 was specifically developed to allow researchers to investigate the relationship between survival and capture processes and environmental, experimental and individual-based covariates. Program SURPH.1 represents a significant advancement in the ability of ecologists to investigate the interplay between morphologic, genetic, environmental and anthropogenic factors on the survival of wild species. It is hoped that this better understanding of risk factors affecting survival will lead to greater appreciation of the intricacies of nature and to improvements in the management of wild resources. This technical report is an introduction to SURPH.1 and provides a user guide for both the UNIX and MS-Windows{reg_sign} applications of the SURPH software.

  19. Advanced Online Survival Analysis Tool for Predictive Modelling in Clinical Data Science.

    Science.gov (United States)

    Montes-Torres, Julio; Subirats, José Luis; Ribelles, Nuria; Urda, Daniel; Franco, Leonardo; Alba, Emilio; Jerez, José Manuel

    2016-01-01

    One of the prevailing applications of machine learning is the use of predictive modelling in clinical survival analysis. In this work, we present our view of the current situation of computer tools for survival analysis, stressing the need of transferring the latest results in the field of machine learning to biomedical researchers. We propose a web based software for survival analysis called OSA (Online Survival Analysis), which has been developed as an open access and user friendly option to obtain discrete time, predictive survival models at individual level using machine learning techniques, and to perform standard survival analysis. OSA employs an Artificial Neural Network (ANN) based method to produce the predictive survival models. Additionally, the software can easily generate survival and hazard curves with multiple options to personalise the plots, obtain contingency tables from the uploaded data to perform different tests, and fit a Cox regression model from a number of predictor variables. In the Materials and Methods section, we depict the general architecture of the application and introduce the mathematical background of each of the implemented methods. The study concludes with examples of use showing the results obtained with public datasets.

  20. Survival analysis using S analysis of time-to-event data

    CERN Document Server

    Tableman, Mara

    2003-01-01

    Survival Analysis Using S: Analysis of Time-to-Event Data is designed as a text for a one-semester or one-quarter course in survival analysis for upper-level or graduate students in statistics, biostatistics, and epidemiology. Prerequisites are a standard pre-calculus first course in probability and statistics, and a course in applied linear regression models. No prior knowledge of S or R is assumed. A wide choice of exercises is included, some intended for more advanced students with a first course in mathematical statistics. The authors emphasize parametric log-linear models, while also detailing nonparametric procedures along with model building and data diagnostics. Medical and public health researchers will find the discussion of cut point analysis with bootstrap validation, competing risks and the cumulative incidence estimator, and the analysis of left-truncated and right-censored data invaluable. The bootstrap procedure checks robustness of cut point analysis and determines cut point(s). In a chapter ...

  1. Epidemiology and Survival Analysis of Jordanian Female Breast Cancer Patients Diagnosed from 1997 to 2002

    Directory of Open Access Journals (Sweden)

    Ghazi Sharkas

    2011-04-01

    Full Text Available Background: Breast cancer is the most common cancer among Jordanian women, yet survival data are scarce. This study aims to assess the observed five-year survival rate of breast cancer in Jordan from 1997 to 2002 and to determine factors that may influence survival. Methods: Data were obtained from the Jordan Cancer Registry (JCR, which is a population-based registry. From 1997-2002, 2121 patients diagnosed with breast cancer were registered in JCR. Relevant data were collected from JCR files, hospital medical records and histopathology reports. Patient's status, whether alive or dead, wasascertained from the Department of Civil Status using patients’ national numbers (ID. Statistical analysis was carried out using SPSS (version 10. Survival probabilities by age, morphology, grade, stage and other relevant variables were obtained with the Kaplan Meier method. Results: The overall five-year survival for breast cancer in Jordan, regardless of the stage or grade was 64.2%, meanwhile it was 58% in the group aged less than 30 years. The best survival was in the age group 40-49 years (69.3%. The survival for adenocarcinoma was 57.4% and for medullary carcinoma, it was 82%. The survival rate approximated 73.8% for well-differentiated, 55.6% for anaplastic, and 58% for poorly differentiated cancers. The five-year survival rate was 82.7% for stage I, 72.2% for stage II, 58.7% for stage III, and 34.6% for stage IV cancers.Conclusion: According to univariate analysis, stage, grade, age and laterality of breast cancer significantly influenced cancer survival. Cox regression analysis revealed that stage, grade and age factors correlated with prognosis, while laterality showed no significant effect on survival. Results demonstrated that overall survival was relatively poor. We hypothesized that this was due to low levels of awareness and lack of screening programs.

  2. Using Survival Analysis to Describe Developmental Achievements of Early Intervention Recipients at Kindergarten

    Science.gov (United States)

    Scarborough, Anita A.; Hebbeler, Kathleen M.; Spiker, Donna; Simeonsson, Rune J.

    2011-01-01

    Survival analysis was used to document the developmental achievements of 2298 kindergarten children who participated in the National Early Intervention Longitudinal Study, a study that followed children from entry to Part C early intervention (EI) through kindergarten. Survival functions were produced depicting the percentage of children at…

  3. High-dimensional, massive sample-size Cox proportional hazards regression for survival analysis.

    Science.gov (United States)

    Mittal, Sushil; Madigan, David; Burd, Randall S; Suchard, Marc A

    2014-04-01

    Survival analysis endures as an old, yet active research field with applications that spread across many domains. Continuing improvements in data acquisition techniques pose constant challenges in applying existing survival analysis methods to these emerging data sets. In this paper, we present tools for fitting regularized Cox survival analysis models on high-dimensional, massive sample-size (HDMSS) data using a variant of the cyclic coordinate descent optimization technique tailored for the sparsity that HDMSS data often present. Experiments on two real data examples demonstrate that efficient analyses of HDMSS data using these tools result in improved predictive performance and calibration.

  4. Analysis of breath samples for lung cancer survival

    Energy Technology Data Exchange (ETDEWEB)

    Schmekel, Birgitta [Division of of Clinical Physiology, County Council of Östergötland, Linköping (Sweden); Clinical Physiology, Department of Medicine and Health, Faculty of Health Sciences, Linköping University, Linköping (Sweden); Winquist, Fredrik, E-mail: frw@ifm.liu.se [Department of Physics, Chemistry and Biology, Linköping University, Linköping SE-581 83 (Sweden); Vikström, Anders [Department of Pulmonary Medicine, University hospital of Linköping, County Council of Östergötland, Linköping (Sweden)

    2014-08-20

    Graphical abstract: Predictions of survival days for lung cancer patients. - Highlights: • Analyses of exhaled air offer a large diagnostic potential. • Patientswith diagnosed lung cancer were studied using an electronic nose. • Excellent predictions and stable models of survival day were obtained. • Consecutive measurements were very important. - Abstract: Analyses of exhaled air by means of electronic noses offer a large diagnostic potential. Such analyses are non-invasive; samples can also be easily obtained from severely ill patients and repeated within short intervals. Lung cancer is the most deadly malignant tumor worldwide, and monitoring of lung cancer progression is of great importance and may help to decide best therapy. In this report, twenty-two patients with diagnosed lung cancer and ten healthy volunteers were studied using breath samples collected several times at certain intervals and analysed by an electronic nose. The samples were divided into three sub-groups; group d for survivor less than one year, group s for survivor more than a year and group h for the healthy volunteers. Prediction models based on partial least square and artificial neural nets could not classify the collected groups d, s and h, but separated well group d from group h. Using artificial neural net, group d could be separated from group s. Excellent predictions and stable models of survival day for group d were obtained, both based on partial least square and artificial neural nets, with correlation coefficients 0.981 and 0.985, respectively. Finally, the importance of consecutive measurements was shown.

  5. Public Interest in Breast Augmentation: Analysis and Implications of Google Trends Data.

    Science.gov (United States)

    Wilson, Stelios C; Daar, David A; Sinno, Sammy; Levine, Steven M

    2017-12-21

    Breast augmentation is the most common aesthetic surgery performed in the United States (US) annually. Analysis of Google Trends (GT) data may give plastic surgeons useful information regarding worldwide, national, and regional interest for breast augmentation and other commonly performed aesthetic surgeries. Data were collected using GT for breast augmentation and associated search terms from January 2004 to May 2017. Case volume was obtained from the American Society of Plastic Surgeons (ASPS) annual reports for the calendar year 2005-2016. Trend analysis showed that total search term volume for breast augmentation and breast implants gradually decreased worldwide and in the US over the study period while the search term boob job slowly increased. Univariate linear regression demonstrated a statistically significant positive correlation between average annual Google search volume of "breast augmentation" and the annual volume of breast augmentations performed in the US according to ASPS data (R 2  = 0.44, p = 0.018). There was no significant correlation between national volume of breast augmentations performed and search volume using the terms "breast implants" or "boob job" over time (p = 0.84 and p = 0.07, respectively). In addition, there appears to be country specific variation in interest based on time of year and peaks in interest following specific policies. To our knowledge, this is the first and only analysis of GT data in the plastic surgery literature to date. To that end, this study highlights this large and potentially powerful data set for plastic surgeons both in the US and around the world. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  6. Reporting and methodological quality of survival analysis in articles published in Chinese oncology journals.

    Science.gov (United States)

    Zhu, Xiaoyan; Zhou, Xiaobin; Zhang, Yuan; Sun, Xiao; Liu, Haihua; Zhang, Yingying

    2017-12-01

    Survival analysis methods have gained widespread use in the filed of oncology. For achievement of reliable results, the methodological process and report quality is crucial. This review provides the first examination of methodological characteristics and reporting quality of survival analysis in articles published in leading Chinese oncology journals.To examine methodological and reporting quality of survival analysis, to identify some common deficiencies, to desirable precautions in the analysis, and relate advice for authors, readers, and editors.A total of 242 survival analysis articles were included to be evaluated from 1492 articles published in 4 leading Chinese oncology journals in 2013. Articles were evaluated according to 16 established items for proper use and reporting of survival analysis.The application rates of Kaplan-Meier, life table, log-rank test, Breslow test, and Cox proportional hazards model (Cox model) were 91.74%, 3.72%, 78.51%, 0.41%, and 46.28%, respectively, no article used the parametric method for survival analysis. Multivariate Cox model was conducted in 112 articles (46.28%). Follow-up rates were mentioned in 155 articles (64.05%), of which 4 articles were under 80% and the lowest was 75.25%, 55 articles were100%. The report rates of all types of survival endpoint were lower than 10%. Eleven of 100 articles which reported a loss to follow-up had stated how to treat it in the analysis. One hundred thirty articles (53.72%) did not perform multivariate analysis. One hundred thirty-nine articles (57.44%) did not define the survival time. Violations and omissions of methodological guidelines included no mention of pertinent checks for proportional hazard assumption; no report of testing for interactions and collinearity between independent variables; no report of calculation method of sample size. Thirty-six articles (32.74%) reported the methods of independent variable selection. The above defects could make potentially inaccurate

  7. Predicting secondary school dropout among South African adolescents: A survival analysis approach

    National Research Council Canada - National Science Library

    Xie, Hui (Jimmy); Caldwell, Linda L; Smith, Edward A; Weybright, Elizabeth H; Wegner, Lisa

    2017-01-01

    ...% of the age appropriate population remain enrolled. Survival analysis was used to identify the risk of dropping out of secondary school for male and female adolescents and examine the influence of substance use and leisure experience predictors...

  8. Application of survival analysis methodology to the quantitative analysis of LC-MS proteomics data

    KAUST Repository

    Tekwe, C. D.

    2012-05-24

    MOTIVATION: Protein abundance in quantitative proteomics is often based on observed spectral features derived from liquid chromatography mass spectrometry (LC-MS) or LC-MS/MS experiments. Peak intensities are largely non-normal in distribution. Furthermore, LC-MS-based proteomics data frequently have large proportions of missing peak intensities due to censoring mechanisms on low-abundance spectral features. Recognizing that the observed peak intensities detected with the LC-MS method are all positive, skewed and often left-censored, we propose using survival methodology to carry out differential expression analysis of proteins. Various standard statistical techniques including non-parametric tests such as the Kolmogorov-Smirnov and Wilcoxon-Mann-Whitney rank sum tests, and the parametric survival model and accelerated failure time-model with log-normal, log-logistic and Weibull distributions were used to detect any differentially expressed proteins. The statistical operating characteristics of each method are explored using both real and simulated datasets. RESULTS: Survival methods generally have greater statistical power than standard differential expression methods when the proportion of missing protein level data is 5% or more. In particular, the AFT models we consider consistently achieve greater statistical power than standard testing procedures, with the discrepancy widening with increasing missingness in the proportions. AVAILABILITY: The testing procedures discussed in this article can all be performed using readily available software such as R. The R codes are provided as supplemental materials. CONTACT: ctekwe@stat.tamu.edu.

  9. PROGNOSTIC FACTORS AND SURVIVAL ANALYSIS IN ESOPHAGEAL CARCINOMA.

    Science.gov (United States)

    Tustumi, Francisco; Kimura, Cintia Mayumi Sakurai; Takeda, Flavio Roberto; Uema, Rodrigo Hideki; Salum, Rubens Antônio Aissar; Ribeiro-Junior, Ulysses; Cecconello, Ivan

    2016-01-01

    Despite recent advances in diagnosis and treatment, esophageal cancer still has high mortality. Prognostic factors associated with patient and with disease itself are multiple and poorly explored. Assess prognostic variables in esophageal cancer patients. Retrospective review of all patients with esophageal cancer in an oncology referral center. They were divided according to histological diagnosis (444 squamous cell carcinoma patients and 105 adenocarcinoma), and their demographic, pathological and clinical characteristics were analyzed and compared to clinical stage and overall survival. No difference was noted between squamous cell carcinoma and esophageal adenocarcinoma overall survival curves. Squamous cell carcinoma presented 22.8% survival after five years against 20.2% for adenocarcinoma. When considering only patients treated with curative intent resection, after five years squamous cell carcinoma survival rate was 56.6 and adenocarcinoma, 58%. In patients with squamous cell carcinoma, poor differentiation histology and tumor size were associated with worse oncology stage, but this was not evidenced in adenocarcinoma. Weight loss (kg), BMI variation (kg/m²) and percentage of weight loss are factors that predict worse stage at diagnosis in the squamous cell carcinoma. In adenocarcinoma, these findings were not statistically significant. Apesar dos avanços recentes nos métodos diagnósticos e tratamento, o câncer de esôfago mantém alta mortalidade. Fatores prognósticos associados ao paciente e ao câncer propriamente dito são pouco conhecidos. Investigar variáveis prognósticas no câncer esofágico. Pacientes diagnosticados entre 2009 e 2012 foram analisados e subdivididos de acordo com tipo histológico (444 carcinomas espinocelulares e 105 adenocarcinomas), e então características demográficas, anatomopatológicas e clínicas foram analisadas. Não houve diferença entre os dois tipos histológicos na sobrevida global. Carcinoma espinocelular

  10. Individual patient data meta-analysis of survival data using Poisson regression models

    Directory of Open Access Journals (Sweden)

    Crowther Michael J

    2012-03-01

    Full Text Available Abstract Background An Individual Patient Data (IPD meta-analysis is often considered the gold-standard for synthesising survival data from clinical trials. An IPD meta-analysis can be achieved by either a two-stage or a one-stage approach, depending on whether the trials are analysed separately or simultaneously. A range of one-stage hierarchical Cox models have been previously proposed, but these are known to be computationally intensive and are not currently available in all standard statistical software. We describe an alternative approach using Poisson based Generalised Linear Models (GLMs. Methods We illustrate, through application and simulation, the Poisson approach both classically and in a Bayesian framework, in two-stage and one-stage approaches. We outline the benefits of our one-stage approach through extension to modelling treatment-covariate interactions and non-proportional hazards. Ten trials of hypertension treatment, with all-cause death the outcome of interest, are used to apply and assess the approach. Results We show that the Poisson approach obtains almost identical estimates to the Cox model, is additionally computationally efficient and directly estimates the baseline hazard. Some downward bias is observed in classical estimates of the heterogeneity in the treatment effect, with improved performance from the Bayesian approach. Conclusion Our approach provides a highly flexible and computationally efficient framework, available in all standard statistical software, to the investigation of not only heterogeneity, but the presence of non-proportional hazards and treatment effect modifiers.

  11. Individual patient data meta-analysis of survival data using Poisson regression models.

    Science.gov (United States)

    Crowther, Michael J; Riley, Richard D; Staessen, Jan A; Wang, Jiguang; Gueyffier, Francois; Lambert, Paul C

    2012-03-23

    An Individual Patient Data (IPD) meta-analysis is often considered the gold-standard for synthesising survival data from clinical trials. An IPD meta-analysis can be achieved by either a two-stage or a one-stage approach, depending on whether the trials are analysed separately or simultaneously. A range of one-stage hierarchical Cox models have been previously proposed, but these are known to be computationally intensive and are not currently available in all standard statistical software. We describe an alternative approach using Poisson based Generalised Linear Models (GLMs). We illustrate, through application and simulation, the Poisson approach both classically and in a Bayesian framework, in two-stage and one-stage approaches. We outline the benefits of our one-stage approach through extension to modelling treatment-covariate interactions and non-proportional hazards. Ten trials of hypertension treatment, with all-cause death the outcome of interest, are used to apply and assess the approach. We show that the Poisson approach obtains almost identical estimates to the Cox model, is additionally computationally efficient and directly estimates the baseline hazard. Some downward bias is observed in classical estimates of the heterogeneity in the treatment effect, with improved performance from the Bayesian approach. Our approach provides a highly flexible and computationally efficient framework, available in all standard statistical software, to the investigation of not only heterogeneity, but the presence of non-proportional hazards and treatment effect modifiers.

  12. Up-to-date and precise estimates of cancer patient survival: model-based period analysis.

    Science.gov (United States)

    Brenner, Hermann; Hakulinen, Timo

    2006-10-01

    Monitoring of progress in cancer patient survival by cancer registries should be as up-to-date as possible. Period analysis has been shown to provide more up-to-date survival estimates than do traditional methods of survival analysis. However, there is a trade-off between up-to-dateness and the precision of period estimates, in that increasing the up-to-dateness of survival estimates by restricting the analysis to a relatively short, recent time period, such as the most recent calendar year for which cancer registry data are available, goes along with a loss of precision. The authors propose a model-based approach to maximize the up-to-dateness of period estimates at minimal loss of precision. The approach is illustrated for monitoring of 5-year relative survival of patients diagnosed with one of 20 common forms of cancer in Finland between 1953 and 2002 by use of data from the nationwide Finnish Cancer Registry. It is shown that the model-based approach provides survival estimates that are as up-to-date as the most up-to-date conventional period estimates and at the same time much more precise than the latter. The modeling approach may further enhance the use of period analysis for deriving up-to-date cancer survival rates.

  13. Parametric and semiparametric models with applications to reliability, survival analysis, and quality of life

    CERN Document Server

    Nikulin, M; Mesbah, M; Limnios, N

    2004-01-01

    Parametric and semiparametric models are tools with a wide range of applications to reliability, survival analysis, and quality of life. This self-contained volume examines these tools in survey articles written by experts currently working on the development and evaluation of models and methods. While a number of chapters deal with general theory, several explore more specific connections and recent results in "real-world" reliability theory, survival analysis, and related fields.

  14. Acute Myeloid Leukemia: analysis of epidemiological profile and survival rate.

    Science.gov (United States)

    de Lima, Mariana Cardoso; da Silva, Denise Bousfield; Freund, Ana Paula Ferreira; Dacoregio, Juliana Shmitz; Costa, Tatiana El Jaick Bonifácio; Costa, Imaruí; Faraco, Daniel; Silva, Maurício Laerte

    2016-01-01

    To describe the epidemiological profile and the survival rate of patients with acute myeloid leukemia (AML) in a state reference pediatric hospital. Clinical-epidemiological, observational, retrospective, descriptive study. The study included new cases of patients with AML, diagnosed between 2004 and 2012, younger than 15 years. Of the 51 patients studied, 84% were white; 45% were females and 55%, males. Regarding age, 8% were younger than 1 year, 47% were aged between 1 and 10 years, and 45% were older than 10 years. The main signs/symptoms were fever (41.1%), asthenia/lack of appetite (35.2%), and hemorrhagic manifestations (27.4%). The most affected extra-medullary site was the central nervous system (14%). In 47% of patients, the white blood cell (WBC) count was below 10,000/mm(3) at diagnosis. The minimal residual disease (MRD) was less than 0.1%, on the 15th day of treatment in 16% of the sample. Medullary relapse occurred in 14% of cases. When comparing the bone marrow MRD with the vital status, it was observed that 71.42% of the patients with type M3 AML were alive, as were 54.05% of those with non-M3 AML. The death rate was 43% and the main proximate cause was septic shock (63.6%). In this study, the majority of patients were male, white, and older than 1 year. Most patients with WBC count <10,000/mm(3) at diagnosis lived. Overall survival was higher in patients with MRD <0.1%. The prognosis was better in patients with AML-M3. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  15. Network-based survival analysis reveals subnetwork signatures for predicting outcomes of ovarian cancer treatment.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available Cox regression is commonly used to predict the outcome by the time to an event of interest and in addition, identify relevant features for survival analysis in cancer genomics. Due to the high-dimensionality of high-throughput genomic data, existing Cox models trained on any particular dataset usually generalize poorly to other independent datasets. In this paper, we propose a network-based Cox regression model called Net-Cox and applied Net-Cox for a large-scale survival analysis across multiple ovarian cancer datasets. Net-Cox integrates gene network information into the Cox's proportional hazard model to explore the co-expression or functional relation among high-dimensional gene expression features in the gene network. Net-Cox was applied to analyze three independent gene expression datasets including the TCGA ovarian cancer dataset and two other public ovarian cancer datasets. Net-Cox with the network information from gene co-expression or functional relations identified highly consistent signature genes across the three datasets, and because of the better generalization across the datasets, Net-Cox also consistently improved the accuracy of survival prediction over the Cox models regularized by L(2 or L(1. This study focused on analyzing the death and recurrence outcomes in the treatment of ovarian carcinoma to identify signature genes that can more reliably predict the events. The signature genes comprise dense protein-protein interaction subnetworks, enriched by extracellular matrix receptors and modulators or by nuclear signaling components downstream of extracellular signal-regulated kinases. In the laboratory validation of the signature genes, a tumor array experiment by protein staining on an independent patient cohort from Mayo Clinic showed that the protein expression of the signature gene FBN1 is a biomarker significantly associated with the early recurrence after 12 months of the treatment in the ovarian cancer patients who are

  16. Trend Analysis of Worldwide FDI Flows in the Context of Promoting Sustainable Development and National Interest

    Directory of Open Access Journals (Sweden)

    Alina Georgeta Ailincă

    2016-10-01

    Full Text Available About FDI there are numerous studies, some of them have mostly theoretical character and others mostly practical. This article aims at capturing and analyzing the most important trends in the short, medium and long term on FDI flows worldwide, thus this study has a rather practical approach. Also, the paper aims to discern how FDI flows may influence the sustainable development and the national interest. The analysis starts from studying the past in the most significant developments of the world economy in terms of inflows of investment attraction, drawing marginally some advantages or disadvantages of joining a political entity with regional vocation (e.g. European Union or a currency area (e.g. E.M.U.. It should also be noted that, beyond the analysis of past trends, the direction towards which worldwide foreign direct investment (FDI should be considered in relationship with the ability to infer certain areas which in future can attract FDI for a sustainable and balanced national economy development, serving to the national interest. Thus, the article aims, through a broad set of indicators, to seize these structural or cyclical advantages of world economies and, to the extent that can be applied to the Romanian economy, to contribute to the restructuring of objectives of macroeconomic policies in order to mobilize the country's potential to attract FDI.

  17. Functional MRI Preprocessing in Lesioned Brains: Manual Versus Automated Region of Interest Analysis

    Science.gov (United States)

    Garrison, Kathleen A.; Rogalsky, Corianne; Sheng, Tong; Liu, Brent; Damasio, Hanna; Winstein, Carolee J.; Aziz-Zadeh, Lisa S.

    2015-01-01

    Functional magnetic resonance imaging (fMRI) has significant potential in the study and treatment of neurological disorders and stroke. Region of interest (ROI) analysis in such studies allows for testing of strong a priori clinical hypotheses with improved statistical power. A commonly used automated approach to ROI analysis is to spatially normalize each participant’s structural brain image to a template brain image and define ROIs using an atlas. However, in studies of individuals with structural brain lesions, such as stroke, the gold standard approach may be to manually hand-draw ROIs on each participant’s non-normalized structural brain image. Automated approaches to ROI analysis are faster and more standardized, yet are susceptible to preprocessing error (e.g., normalization error) that can be greater in lesioned brains. The manual approach to ROI analysis has high demand for time and expertise, but may provide a more accurate estimate of brain response. In this study, commonly used automated and manual approaches to ROI analysis were directly compared by reanalyzing data from a previously published hypothesis-driven cognitive fMRI study, involving individuals with stroke. The ROI evaluated is the pars opercularis of the inferior frontal gyrus. Significant differences were identified in task-related effect size and percent-activated voxels in this ROI between the automated and manual approaches to ROI analysis. Task interactions, however, were consistent across ROI analysis approaches. These findings support the use of automated approaches to ROI analysis in studies of lesioned brains, provided they employ a task interaction design. PMID:26441816

  18. The national public's values and interests related to the Arctic National Wildlife Refuge: A computer content analysis

    Science.gov (United States)

    David N. Bengston; David P. Fan; Roger. Kaye

    2010-01-01

    This study examined the national public's values and interests related to the Arctic National Wildlife Refuge. Computer content analysis was used to analyze more than 23,000 media stories about the refuge from 1995 through 2007. Ten main categories of Arctic National Wildlife Refuge values and interests emerged from the analysis, reflecting a diversity of values,...

  19. Automated detection of regions of interest for tissue microarray experiments: an image texture analysis

    Directory of Open Access Journals (Sweden)

    Tözeren Aydin

    2007-03-01

    Full Text Available Abstract Background Recent research with tissue microarrays led to a rapid progress toward quantifying the expressions of large sets of biomarkers in normal and diseased tissue. However, standard procedures for sampling tissue for molecular profiling have not yet been established. Methods This study presents a high throughput analysis of texture heterogeneity on breast tissue images for the purpose of identifying regions of interest in the tissue for molecular profiling via tissue microarray technology. Image texture of breast histology slides was described in terms of three parameters: the percentage of area occupied in an image block by chromatin (B, percentage occupied by stroma-like regions (P, and a statistical heterogeneity index H commonly used in image analysis. Texture parameters were defined and computed for each of the thousands of image blocks in our dataset using both the gray scale and color segmentation. The image blocks were then classified into three categories using the texture feature parameters in a novel statistical learning algorithm. These categories are as follows: image blocks specific to normal breast tissue, blocks specific to cancerous tissue, and those image blocks that are non-specific to normal and disease states. Results Gray scale and color segmentation techniques led to identification of same regions in histology slides as cancer-specific. Moreover the image blocks identified as cancer-specific belonged to those cell crowded regions in whole section image slides that were marked by two pathologists as regions of interest for further histological studies. Conclusion These results indicate the high efficiency of our automated method for identifying pathologic regions of interest on histology slides. Automation of critical region identification will help minimize the inter-rater variability among different raters (pathologists as hundreds of tumors that are used to develop an array have typically been evaluated

  20. Permanent teeth pulpotomy survival analysis: retrospective follow-up.

    Science.gov (United States)

    Kunert, Gustavo Golgo; Kunert, Itaborai Revoredo; da Costa Filho, Luiz Cesar; de Figueiredo, José Antônio Poli

    2015-09-01

    The aim of the present study is to evaluate risk factors influencing the success rates of pulpotomies both in young and adult populations. Pulpotomies (n=273) performed by a single endodontic specialist were analyzed, and data on success rates were collected. Additionally, possible explanatory variables were noted such as: age, gender, clinical findings (teeth, type of restoration after pulpotomy), radiographic findings (dentin bridge formation) and systemic conditions. The follow-up period varied from 1 to 29 years, and the results were analyzed by Kaplan-Meier survival curves and also by Cox regression. Age at the time of pulpotomy ranged from 8 to 79 and had not influenced the success rates (p=0.35). The formation of dentin bridge had a strong protective effect (hazard ratio-HR=0.16, ppulpotomy had the smallest failure rate, and amalgam has not increased the risk of failure significantly in relation to prosthesis. Resin composite restorations following pulpotomy increased in 263% the risk of failure (HR=3.63, ppulpotomy may be a successful treatment at any age, and not only for young permanent teeth. It was also possible to conclude that the use of direct composite restorations following pulpotomies is associated with higher failure rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. THE POSITION OF INTEREST IN SPORTS AND RECREATION OF 7th GRADE ELEMENTARY SCHOOL STUDENTS IN THE FACTOR ANALYSIS OF DIFFERENT INTEREST

    National Research Council Canada - National Science Library

    Vladimir Milošević; Adam Petrović; Nikola Stevanović

    2013-01-01

    .... An insight into the position of the interest in sports and recreation among other interests can be obtained by inspecting the interests of 7th grade elementary school students from Sremska Mitrovica and Jagodina...

  2. Tutorial: survival analysis--a statistic for clinical, efficacy, and theoretical applications.

    Science.gov (United States)

    Gruber, F A

    1999-04-01

    Current demands for increased research attention to therapeutic efficacy, efficiency, and also for improved developmental models call for analysis of longitudinal outcome data. Statistical treatment of longitudinal speech and language data is difficult, but there is a family of statistical techniques in common use in medicine, actuarial science, manufacturing, and sociology that has not been used in speech or language research. Survival analysis is introduced as a method that avoids many of the statistical problems of other techniques because it treats time as the outcome. In survival analysis, probabilities are calculated not just for groups but also for individuals in a group. This is a major advantage for clinical work. This paper provides a basic introduction to nonparametric and semiparametric survival analysis using speech outcomes as examples. A brief discussion of potential conflicts between actuarial analysis and clinical intuition is also provided.

  3. Socioeconomic deprivation and cancer survival in Germany: an ecological analysis in 200 districts in Germany.

    Science.gov (United States)

    Jansen, Lina; Eberle, Andrea; Emrich, Katharina; Gondos, Adam; Holleczek, Bernd; Kajüter, Hiltraud; Maier, Werner; Nennecke, Alice; Pritzkuleit, Ron; Brenner, Hermann

    2014-06-15

    Although socioeconomic inequalities in cancer survival have been demonstrated both within and between countries, evidence on the variation of the inequalities over time past diagnosis is sparse. Furthermore, no comprehensive analysis of socioeconomic differences in cancer survival in Germany has been conducted. Therefore, we analyzed variations in cancer survival for patients diagnosed with one of the 25 most common cancer sites in 1997-2006 in ten population-based cancer registries in Germany (covering 32 million inhabitants). Patients were assigned a socioeconomic status according to the district of residence at diagnosis. Period analysis was used to derive 3-month, 5-year and conditional 1-year and 5-year age-standardized relative survival for 2002-2006 for each deprivation quintile in Germany. Relative survival of patients living in the most deprived district was compared to survival of patients living in all other districts by model-based period analysis. For 21 of 25 cancer sites, 5-year relative survival was lower in the most deprived districts than in all other districts combined. The median relative excess risk of death over the 25 cancer sites decreased from 1.24 in the first 3 months to 1.16 in the following 9 months to 1.08 in the following 4 years. Inequalities persisted after adjustment for stage. These major regional socioeconomic inequalities indicate a potential for improving cancer care and survival in Germany. Studies on individual-level patient data with access to treatment information should be conducted to examine the reasons for these socioeconomic inequalities in cancer survival in more detail. © 2013 UICC.

  4. Bayesian linear regression with skew-symmetric error distributions with applications to survival analysis

    KAUST Repository

    Rubio, Francisco J.

    2016-02-09

    We study Bayesian linear regression models with skew-symmetric scale mixtures of normal error distributions. These kinds of models can be used to capture departures from the usual assumption of normality of the errors in terms of heavy tails and asymmetry. We propose a general noninformative prior structure for these regression models and show that the corresponding posterior distribution is proper under mild conditions. We extend these propriety results to cases where the response variables are censored. The latter scenario is of interest in the context of accelerated failure time models, which are relevant in survival analysis. We present a simulation study that demonstrates good frequentist properties of the posterior credible intervals associated with the proposed priors. This study also sheds some light on the trade-off between increased model flexibility and the risk of over-fitting. We illustrate the performance of the proposed models with real data. Although we focus on models with univariate response variables, we also present some extensions to the multivariate case in the Supporting Information.

  5. Application of LC-MS to the analysis of dyes in objects of historical interest

    Science.gov (United States)

    Zhang, Xian; Laursen, Richard

    2009-07-01

    High-performance liquid chromatography (HPLC) with photodiode array and mass spectrometric detection permits dyes extracted from objects of historical interest or from natural plant or animal dyestuffs to be characterized on the basis of three orthogonal properties: HPLC retention time, UV-visible spectrum and molecular mass. In the present study, we have focused primarily on yellow dyes, the bulk of which are flavonoid glycosides that would be almost impossible to characterize without mass spectrometric detection. Also critical for this analysis is a method for mild extraction of the dyes from objects (e.g., textiles) without hydrolyzing the glycosidic linkages. This was accomplished using 5% formic acid in methanol, rather than the more traditional 6 M HCl. Mass spectroscopy, besides providing the molecular mass of the dye molecule, sometimes yields additional structural data based on fragmentation patterns. In addition, coeluting compounds can often be detected using extracted ion chromatography. The utility of mass spectrometry is illustrated by the analysis of historical specimens of silk that had been dyed yellow with flavonoid glycosides from Sophora japonica (pagoda tree) and curcumins from Curcuma longa (turmeric). In addition, we have used these techniques to identify the dye type, and sometimes the specific dyestuff, in a variety of objects, including a yellow varnish from a 19th century Tibetan altar and a 3000-year-old wool mortuary textiles, from Xinjiang, China. We are using HPLC with diode array and mass spectrometric detection to create a library of analyzed dyestuffs (>200 so far; mostly plants) to serve as references for identification of dyes in objects of historical interest.

  6. MethSurv: a web tool to perform multivariable survival analysis using DNA methylation data.

    Science.gov (United States)

    Modhukur, Vijayachitra; Iljasenko, Tatjana; Metsalu, Tauno; Lokk, Kaie; Laisk-Podar, Triin; Vilo, Jaak

    2017-12-21

    To develop a web tool for survival analysis based on CpG methylation patterns. We utilized methylome data from 'The Cancer Genome Atlas' and used the Cox proportional-hazards model to develop an interactive web interface for survival analysis. MethSurv enables survival analysis for a CpG located in or around the proximity of a query gene. For further mining, cluster analysis for a query gene to associate methylation patterns with clinical characteristics and browsing of top biomarkers for each cancer type are provided. MethSurv includes 7358 methylomes from 25 different human cancers. The MethSurv tool is a valuable platform for the researchers without programming skills to perform the initial assessment of methylation-based cancer biomarkers.

  7. Racist Parenting and the Best Interests of the Child: A Legal and Ethical Analysis

    Science.gov (United States)

    Clarke, Paul T.; Heavin, Heather; Walker, Keith

    2010-01-01

    In this article, we use a recent Manitoba child custody case to provide a legal and ethical account of the notion of the best interests of the child. We explore the tension between the best interests of the child and parental rights to expression of a racist nature. We consider how the interests of different actors--the state, parents and…

  8. Oral rehabilitation with dental implants in irradiated patients: a meta-analysis on implant survival.

    Science.gov (United States)

    Schiegnitz, E; Al-Nawas, B; Kämmerer, P W; Grötz, K A

    2014-04-01

    The aim of this comprehensive literature review is to provide recommendations and guidelines for dental implant therapy in patients with a history of radiation in the head and neck region. For the first time, a meta-analysis comparing the implant survival in irradiated and non-irradiated patients was performed. An extensive electronic search in the electronic databases of the National Library of Medicine was conducted for articles published between January 1990 and January 2013 to identify literature presenting survival data on the topic of dental implants in patients receiving radiotherapy for head and neck cancer. Review and meta-analysis were performed according to Preferred Reporting Items for Systematic Review and Meta-Analyses statement. For meta-analysis, only studies with a mean follow-up of at least 5 years were included. After screening 529 abstracts from the electronic database, we included 31 studies in qualitative and 8 in quantitative synthesis. The mean implant survival rate of all examined studies was 83 % (range, 34-100 %). Meta-analysis of the current literature (2007-2013) revealed no statistically significant difference in implant survival between non-irradiated native bone and irradiated native bone (odds ratio [OR], 1.44; confidence interval [CI], 0.67-3.1). In contrast, meta-analysis of the literature of the years 1990-2006 showed a significant difference in implant survival between non-irradiated and irradiated patients ([OR], 2.12; [CI], 1.69-2.65) with a higher implant survival in the non-irradiated bone. Meta-analysis of the implant survival regarding bone origin indicated a statistically significant higher implant survival in the irradiated native bone compared to the irradiated grafted bone ([OR], 1.82; [CI], 1.14-2.90). Within the limits of this meta-analytic approach to the literature, this study describes for the first time a comparable implant survival in non-irradiated and irradiated native bone in the current literature. Grafted

  9. Dynamic Game Analysis of Coal Electricity Market Involving Multi-Interests

    Directory of Open Access Journals (Sweden)

    Yu Xiaobao

    2016-01-01

    Full Text Available The coal consumption of China reached 2.75 billion tons of standard coal in 2013, which accounted for 67.5% of total energy consumption and more than 50% of global coal consumption. Therefore, the impact of coal price is huge on coal market and even energy market in China. As a large consumer of coal, thermal power enterprise has a strong sensitivity to coal price. In order to balance the rising cost of enterprises due to coal price, we need to analyze the interests of multiple stakeholders. Firstly, this paper combined the Nash equilibrium and cobweb model and proposed the characteristics in different cobweb model. Then, for coal, power, and energy companies, the dynamic game analysis model is constructed. This model gives a game analysis in four scenarios and quantifies the decision of each stakeholder in different coal prices. Finally, the impact figure of different coal prices on each stakeholder has been drawn. The impacts of different coal or thermal power prices on different markets have been put forward, so relevant policy recommendations have been proposed combined with the cobweb model.

  10. Region of interest extraction based on multiscale visual saliency analysis for remote sensing images

    Science.gov (United States)

    Zhang, Yinggang; Zhang, Libao; Yu, Xianchuan

    2015-01-01

    Region of interest (ROI) extraction is an important component of remote sensing image processing. However, traditional ROI extraction methods are usually prior knowledge-based and depend on classification, segmentation, and a global searching solution, which are time-consuming and computationally complex. We propose a more efficient ROI extraction model for remote sensing images based on multiscale visual saliency analysis (MVS), implemented in the CIE L*a*b* color space, which is similar to visual perception of the human eye. We first extract the intensity, orientation, and color feature of the image using different methods: the visual attention mechanism is used to eliminate the intensity feature using a difference of Gaussian template; the integer wavelet transform is used to extract the orientation feature; and color information content analysis is used to obtain the color feature. Then, a new feature-competition method is proposed that addresses the different contributions of each feature map to calculate the weight of each feature image for combining them into the final saliency map. Qualitative and quantitative experimental results of the MVS model as compared with those of other models show that it is more effective and provides more accurate ROI extraction results with fewer holes inside the ROI.

  11. Solitary plasmacytoma: population-based analysis of survival trends and effect of various treatment modalities in the USA.

    Science.gov (United States)

    Thumallapally, Nishitha; Meshref, Ahmed; Mousa, Mohammed; Terjanian, Terenig

    2017-01-05

    Solitary plasmacytoma (SP) is a localized neoplastic plasma cell disorder with an annual incidence of less than 450 cases. Given the rarity of this disorder, it is difficult to conduct large-scale population studies. Consequently, very limited information on the disorder is available, making it difficult to estimate the incidence and survival rates. Furthermore, limited information is available on the efficacy of various treatment modalities in relation to primary tumor sites. The data for this retrospective study were drawn from the Surveillance, Epidemiology and End Results (SEER) database, which comprises 18 registries; patient demographics, treatment modalities and survival rates were obtained for those diagnosed with SP from 1998 to 2007. Various prognostic factors were analyzed via Kaplan-Meier analysis and log-rank test, with 5-year relative survival rate defined as the primary outcome of interest. Cox regression analysis was employed in the multivariate analysis. The SEER search from 1998 to 2007 yielded records for 1691 SP patients. The median age at diagnosis was 63 years. The patient cohort was 62.4% male, 37.6% female, 80% Caucasian, 14.6% African American and 5.4% other races. Additionally, 57.8% had osseous plasmacytoma, and 31.9% had extraosseous involvement. Unspecified plasmacytoma was noted in 10.2% of patients. The most common treatment modalities were radiotherapy (RT) (48.8%), followed by combination surgery with RT (21.2%) and surgery alone (11.6%). Univariate analysis of prognostic factors revealed that the survival outcomes were better for younger male patients who received RT with surgery (p multiple myeloma (MM) was noted in 551 patients. Age >60 years was associated with a lower 5-year survival in patients who progressed to MM compared to those who were diagnosed initially with MM (15.1 vs 16.6%). Finally, those who received RT and progressed to MM still had a higher chance of survival than those who were diagnosed with MM initially and

  12. Semi-automated region of interest generation for the analysis of optically recorded neuronal activity.

    Science.gov (United States)

    Mellen, Nicholas M; Tuong, Chi-Minh

    2009-10-01

    Bath-applied membrane-permeant Ca(2+) indicators offer access to network function with single-cell resolution. A barrier to wider and more efficient use of this technique is the difficulty of extracting fluorescence signals from the active constituents of the network under study. Here we present a method for semi-automatic region of interest (ROI) detection that exploits the spatially compact, slowly time-varying character of the somatic signals that these indicators typically produce. First, the image series is differenced to eliminate static and very slowly varying fluorescence values, and then the differenced image series undergoes low-pass filtering in the spatial domain, to eliminate temporally isolated fluctuations in brightness. This processed image series is then thresholded so that pixel regions of fluctuating brightness are set to white, while all other regions are set to black. Binary images are averaged, and then subjected to iterative thresholding to extract ROIs associated with both dim and bright cells. The original image series is then analyzed using the generated ROIs, after which the end-user rejects spurious signals. These methods are applied to respiratory networks in the neonate rat tilted sagittal slab preparation, and to simulations with signal-to-noise ratios ranging between 1.0-0.2. Simulations established that algorithm performance degraded gracefully with increasing noise. Because signal extraction is the necessary first step in the analysis of time-varying Ca(2+) signals, semi-automated ROI detection frees the researcher to focus on the next step: selecting traces of interest from the relatively complete set generated using these methods.

  13. Handling incomplete smoking history data in survival analysis.

    Science.gov (United States)

    Furukawa, Kyoji; Preston, Dale L; Misumi, Munechika; Cullings, Harry M

    2017-04-01

    While data are unavoidably missing or incomplete in most observational studies, consequences of mishandling such incompleteness in analysis are often overlooked. When time-varying information is collected irregularly and infrequently over a long period, even precisely obtained data may implicitly involve substantial incompleteness. Motivated by an analysis to quantitatively evaluate the effects of smoking and radiation on lung cancer risks among Japanese atomic-bomb survivors, we provide a unique application of multiple imputation to incompletely observed smoking histories under the assumption of missing at random. Predicting missing values for the age of smoking initiation and, given initiation, smoking intensity and cessation age, analyses can be based on complete, though partially imputed, smoking histories. A simulation study shows that multiple imputation appropriately conditioned on the outcome and other relevant variables can produce consistent estimates when data are missing at random. Our approach is particularly appealing in large cohort studies where a considerable amount of time-varying information is incomplete under a mechanism depending in a complex manner on other variables. In application to the motivating example, this approach is expected to reduce estimation bias that might be unavoidable in naive analyses, while keeping efficiency by retaining known information.

  14. The mechanism of influence of interest groups in the European Union: political and sociological analysis

    Directory of Open Access Journals (Sweden)

    P. S. Kanevsky

    2016-01-01

    Full Text Available Interaction between interest groups and political institutions is one of the cornerstones of the European Union policy making process. Although majority of Russian and foreign works dedicated to lobbying and decision making in the EU, concentrate on a governmental stadial system and normative procedures that regulate interest groups access to policy making centers. Such institutional approach doesn’t clarify why the EU has concrete policies, why not all interest groups are able to win, who sets the agenda and in whose interests decisions are made. Current article, using contemporary theories and research, analyzes process of interaction between interest groups and governmental structures in the EU. It also proposes explanations of wins and losses in the policy making process, trying to answer how interest groups interacts with each other and what patterns can be identified in the process of interest aggregation by governmental structures.

  15. 30-Day Survival Probabilities as a Quality Indicator for Norwegian Hospitals: Data Management and Analysis.

    Science.gov (United States)

    Hassani, Sahar; Lindman, Anja Schou; Kristoffersen, Doris Tove; Tomic, Oliver; Helgeland, Jon

    2015-01-01

    The Norwegian Knowledge Centre for the Health Services (NOKC) reports 30-day survival as a quality indicator for Norwegian hospitals. The indicators have been published annually since 2011 on the website of the Norwegian Directorate of Health (www.helsenorge.no), as part of the Norwegian Quality Indicator System authorized by the Ministry of Health. Openness regarding calculation of quality indicators is important, as it provides the opportunity to critically review and discuss the method. The purpose of this article is to describe the data collection, data pre-processing, and data analyses, as carried out by NOKC, for the calculation of 30-day risk-adjusted survival probability as a quality indicator. Three diagnosis-specific 30-day survival indicators (first time acute myocardial infarction (AMI), stroke and hip fracture) are estimated based on all-cause deaths, occurring in-hospital or out-of-hospital, within 30 days counting from the first day of hospitalization. Furthermore, a hospital-wide (i.e. overall) 30-day survival indicator is calculated. Patient administrative data from all Norwegian hospitals and information from the Norwegian Population Register are retrieved annually, and linked to datasets for previous years. The outcome (alive/death within 30 days) is attributed to every hospital by the fraction of time spent in each hospital. A logistic regression followed by a hierarchical Bayesian analysis is used for the estimation of risk-adjusted survival probabilities. A multiple testing procedure with a false discovery rate of 5% is used to identify hospitals, hospital trusts and regional health authorities with significantly higher/lower survival than the reference. In addition, estimated risk-adjusted survival probabilities are published per hospital, hospital trust and regional health authority. The variation in risk-adjusted survival probabilities across hospitals for AMI shows a decreasing trend over time: estimated survival probabilities for AMI in

  16. 30-Day Survival Probabilities as a Quality Indicator for Norwegian Hospitals: Data Management and Analysis.

    Directory of Open Access Journals (Sweden)

    Sahar Hassani

    Full Text Available The Norwegian Knowledge Centre for the Health Services (NOKC reports 30-day survival as a quality indicator for Norwegian hospitals. The indicators have been published annually since 2011 on the website of the Norwegian Directorate of Health (www.helsenorge.no, as part of the Norwegian Quality Indicator System authorized by the Ministry of Health. Openness regarding calculation of quality indicators is important, as it provides the opportunity to critically review and discuss the method. The purpose of this article is to describe the data collection, data pre-processing, and data analyses, as carried out by NOKC, for the calculation of 30-day risk-adjusted survival probability as a quality indicator.Three diagnosis-specific 30-day survival indicators (first time acute myocardial infarction (AMI, stroke and hip fracture are estimated based on all-cause deaths, occurring in-hospital or out-of-hospital, within 30 days counting from the first day of hospitalization. Furthermore, a hospital-wide (i.e. overall 30-day survival indicator is calculated. Patient administrative data from all Norwegian hospitals and information from the Norwegian Population Register are retrieved annually, and linked to datasets for previous years. The outcome (alive/death within 30 days is attributed to every hospital by the fraction of time spent in each hospital. A logistic regression followed by a hierarchical Bayesian analysis is used for the estimation of risk-adjusted survival probabilities. A multiple testing procedure with a false discovery rate of 5% is used to identify hospitals, hospital trusts and regional health authorities with significantly higher/lower survival than the reference. In addition, estimated risk-adjusted survival probabilities are published per hospital, hospital trust and regional health authority. The variation in risk-adjusted survival probabilities across hospitals for AMI shows a decreasing trend over time: estimated survival probabilities

  17. Impact of Interstitial Pneumonia on the Survival and Risk Factors Analysis of Patients with Hematological Malignancy

    Directory of Open Access Journals (Sweden)

    Wei-Liang Chen

    2013-01-01

    Full Text Available Background. The emergence of interstitial pneumonia (IP in patients with hematological malignancy (HM is becoming a challenging scenario in current practice. However, detailed characterization and investigation of outcomes and risk factors on survival have not been addressed. Methods. We conducted a retrospective study of 42,584 cancer patients covering the period between 1996 and 2008 using the institutional cancer registry system. Among 816 HM patients, 61 patients with IP were recognized. The clinical features, laboratory results, and histological types were studied to determine the impact of IP on survival and identify the profile of prognostic factors. Results. HM patients with IP showed a significant worse survival than those without IP in the 5-year overall survival (P=0.027. The overall survival showed no significant difference between infectious pneumonia and noninfectious interstitial pneumonia (IIP versus nIIP (P=0.323. In a multivariate Cox regression model, leukocyte and platelet count were associated with increased risk of death. Conclusions. The occurrence of IP in HM patients is associated with increased mortality. Of interest, nIIP is a prognostic indicator in patients with lymphoma but not in patients with leukemia. However, aggressive management of IP in patients with HM is strongly advised, and further prospective survey is warranted.

  18. Definition of the thermographic regions of interest in cycling by using a factor analysis

    Science.gov (United States)

    Priego Quesada, Jose Ignacio; Lucas-Cuevas, Angel Gabriel; Salvador Palmer, Rosario; Pérez-Soriano, Pedro; Cibrián Ortiz de Anda, Rosa M.a.

    2016-03-01

    Research in exercise physiology using infrared thermography has increased in the last years. However, the definition of the Regions of Interest (ROIs) varies strongly between studies. Therefore, the aim of this study was to use a factor analysis approach to define highly correlated groups of thermographic ROIs during a cycling test. Factor analyses were performed based on the moment of measurement and on the variation of skin temperatures as a result of the cycling exercise. 19 male participants cycled during 45 min at 50% of their individual peak power output with a cadence of 90 rpm. Infrared thermography was used to measure skin temperatures in sixteen ROIs of the trunk and lower limbs at three moments: before, immediately after and 10 min after the cycling test. Factor analyses were used to identify groups of ROIs based on the skin absolute temperatures at each moment of measurement as well as on skin temperature variations between moments. All the factor analyses performed for each moment and skin temperature variation explained more than the 80% of the variance. Different groups of ROIs were obtained when the analysis was based on the moment of measurement or on the effect of exercise on the skin temperature. Furthermore, some ROIs were grouped in the same way in both analyses (e.g. the ROIs of the trunk), whereas other regions (legs and their joints) were grouped differently in each analysis. Differences between groups of ROIs are related to their tissue composition, muscular activity and capacity of sweating. In conclusion, the resultant groups of ROIs were coherent and could help researchers to define the ROIs in future thermal studies.

  19. The impact of psychosocial intervention on survival in cancer: a meta-analysis.

    Science.gov (United States)

    Fu, Wayne W; Popovic, Marko; Agarwal, Arnav; Milakovic, Milica; Fu, Terence S; McDonald, Rachel; Fu, Gordon; Lam, Michael; Chow, Ronald; Cheon, Stephanie; Pulenzas, Natalie; Lam, Henry; DeAngelis, Carlo; Chow, Edward

    2016-04-01

    The impact of psychosocial interventions on survival remains controversial in patients with cancer. A meta-analysis of the recent literature was conducted to evaluate the potential survival benefit associated with psychosocial interventions for cancer patients. MEDLINE, EMBASE, and Cochrane Central were searched from January 2004 to May 2015 for all randomized controlled trials (RCTs) that compared survival outcomes between cancer patients receiving a psychosocial intervention and those receiving other, or no interventions. Endpoints included one-, two-, and four-year overall survival. Subgroup analyses were performed to compare group-versus individually-delivered interventions, and to assess breast cancer-only trials. Of 5,080 identified articles, thirteen trials were included for analysis. There was a significant survival benefit for the intervention group at one year [risk ratio (RR) =0.82; 95% confidence interval (CI), 0.67-1.00; P=0.04] and two years (RR =0.86; 95% CI, 0.78-0.95; P=0.003). However, no significant difference was detected at four years (RR =0.94; 95% CI, 0.85-1.04; P=0.24). Among patients with breast cancer, there was a significant survival benefit of psychosocial interventions at one year (RR =0.59; 95% CI, 0.42-0.82; P=0.002), but no difference at two years (RR =0.82; 95% CI, 0.67-1.02; P=0.07) or four years (RR =0.95; 95% CI, 0.73-1.23; P=0.68). Group-delivered interventions had a significant survival benefit favouring the intervention group at one year (RR =0.57; 95% CI, 0.41-0.79; P=0.0008), but no difference at two years (RR =0.84; 95% CI, 0.68-1.02; P=0.08) or four years (RR =0.94; 95% CI, 0.75-1.20; P=0.64). Individually-delivered interventions had no significant survival benefit at one year (RR =0.92; 95% CI, 0.79-1.08; P=0.32), two years (RR =0.87; 95% CI, 0.75-1.00; P=0.05), or four years (RR =0.93; 95% CI, 0.84-1.04; P=0.21). For the main analysis and group-delivered treatments, psychosocial interventions demonstrated only short

  20. Revisit of 1997 TNM staging system--survival analysis of 1112 lung cancer patients in Taiwan.

    Science.gov (United States)

    Perng, Reury-Perng; Chen, Chih-Yi; Chang, Gee-Chen; Hsia, Te-Chun; Hsu, Nan-Yung; Tsai, Ying-Huang; Tsai, Chun-Ming; Yang, Chih-Hsin; Chen, Yuh-Min; Yu, Chong-Jen; Lee, Jen-Jyh; Hsu, Han-Shui; Yu, Chih-Teng; Kao, Eing-Long; Chiu, Chao-Hua

    2007-01-01

    There is neither a nation-wide nor a large-scale, multi-institutional lung cancer database available for stage-by-stage survival analysis in Taiwan at present. Using the data element provided by the International Association for the Study of Lung Cancer, the Taiwan Lung Cancer Society initiated a project to include native lung cancer patients into a global database. A total of 1112 Taiwan lung cancer patients treated in 7 medical centers were enrolled. In small cell lung cancer, patients with ipsilateral pleural effusion had a survival between those with locoregional disease alone and those with distant metastasis; however, the difference was not statistically significant (P = 0.204). In non-small cell lung cancer, tumor size had significant survival influence for patients as a whole (P < 0.001) but it did not support the further division of stage IA according to tumor size (P = 0.122). The survival was compatible in stage IIIB and IV patients and therefore, the survival impact of pleural effusion cannot be determined. In patients with pIIIA-N2 disease, those who had station 8 nodal metastasis had inferior survival (P = 0.020) and station 5 superior survival (P = 0.010). In patients with distant metastasis, bone, liver, or distant lymph node metastasis predicted an inferior survival (all P values < 0.05). The present study provides for comparison in this area a stage-by-stage reference for the survival of lung cancer patients. Some factors other than current TNM descriptors need to be further investigated in constructing the next version of the staging system.

  1. Interest rate changes and stock returns in Spain: A wavelet analysis

    Directory of Open Access Journals (Sweden)

    Pablo Moya-Martínez

    2015-04-01

    Full Text Available This paper investigates the relationship between changes in interest rates and the Spanish stock market at the industry level over the period from January 1993 to December 2012 using a wavelet-based approach. The empirical results indicate that Spanish industries exhibit, in general, a significant interest rate sensitivity, although the degree of interest rate exposure differs considerably across industries and depending on the time horizon under consideration. In particular, regulated industries such as Utilities, highly indebted industries such as Real Estate, Utilities or Technology and Telecommunications, and the Banking industry emerge as the most vulnerable to interest rates. Further, the link between movements in interest rates and industry equity returns is stronger at the coarsest scales. This finding is consistent with the idea that investors with long-term horizons are more likely to follow macroeconomic fundamentals, such as interest rates, in their investment decisions.

  2. Meta-Analysis of Studies Incorporating the Interests of Young Children with Autism Spectrum Disorders into Early Intervention Practices

    Directory of Open Access Journals (Sweden)

    Carl J. Dunst

    2012-01-01

    Full Text Available Incorporating the interests and preferences of young children with autism spectrum disorders into interventions to promote prosocial behavior and decrease behavior excesses has emerged as a promising practice for addressing the core features of autism. The efficacy of interest-based early intervention practices was examined in a meta-analysis of 24 studies including 78 children 2 to 6 years of age diagnosed with autism spectrum disorders. Effect size analyses of intervention versus nonintervention conditions and high-interest versus low-interest contrasts indicated that interest-based intervention practices were effective in terms of increasing prosocial and decreasing aberrant child behavior. Additionally, interest-based interventions that focused on two of the three core features of autism spectrum disorders (poor communication, poor interpersonal relationships were found most effective in influencing child outcomes. Implications for very early intervention are discussed in terms addressing the behavior markers of autism spectrum disorders before they become firmly established.

  3. Survival trees: an alternative non-parametric multivariate technique for life history analysis.

    Science.gov (United States)

    De Rose, A; Pallara, A

    1997-01-01

    "In this paper an extension of tree-structured methodology to cover censored survival analysis is discussed.... The tree-shaped diagram...can be used to draw meaningful patterns of behaviour throughout the individual life history.... The fundamentals of tree methodology are outlined; [then] an application of the technique to real data from a survey on the progression to marriage among adult women in Italy is illustrated; [and] some comments are presented on the main advantages and problems related to tree-structured methodology for censored survival analysis." (EXCERPT)

  4. [Epidemiological analysis of leukemia survival in Cracow for cases registered in 1980-1990].

    Science.gov (United States)

    Fornal, Maria; Janicki, Kazimierz; Grodzicki, Tomasz

    2003-01-01

    The aim of the study was epidemiological analysis of survival from all types of leukemia occurring in Cracow in the years 1980-1990. The study was focused on survival times in patients according to a) cytologico-clinical type of leukemia, b) timeframe in which treatment was initiated (between 1980-1985 and 1986-1090). All patients diagnosed of leukemia between the years 1980-1990, living in Cracow and whose cytologico-clinical picture was determined had their survival times and censored survival times established. Survival until 1997 was taken into account. For each cytologico-clinical type of leukemia survival function according to Kaplan-Meier was calculated. The Cox model was implemented to analyze the risk of death depending on the period in which the disease appeared--two time frames were established 1980-1985 and 1986-1990. Other parameters considered were; age, sex and area in which the patient lived (suburb). Practically in all types of leukemia a higher probability of survival was found in patients in whom leukemia was diagnosed (and consequently treated) in the second period i.e., 1986-1990. The highest achievement was observed in acute lymphoblastic leukemia in children, in which the relative 5-year survival probability rose from 35% in the years 1980-1985 to 78% in the years 1986-1990, thus achieving the level of well developed countries. A similar picture was seen in chronic lymphocytic leukemia where the relative 5 year survival probability rose from 57% to 77%, and in chronic granulocytic leukemia where the 5 year survival probabilities were accordingly 23% and 39%. All cited values for the second period of analysis are at the levels noted in the United States and in Europe. The positive changes in the survival times observed in patients with leukemia seen in the second half of the 80-ies (in comparison to the period 1980-1985) has been interpreted as the result of advancements in therapy of the disease in Cracow.

  5. Reproducibility of myelin water fraction analysis: a comparison of region of interest and voxel-based analysis methods.

    Science.gov (United States)

    Meyers, Sandra M; Laule, Cornelia; Vavasour, Irene M; Kolind, Shannon H; Mädler, Burkhard; Tam, Roger; Traboulsee, Anthony L; Lee, Jimmy; Li, David K B; MacKay, Alex L

    2009-10-01

    This study compared region of interest (ROI) and voxel-based analysis (VBA) methods to determine the optimal method of myelin water fraction (MWF) analysis. Twenty healthy controls were scanned twice using a multi-echo T(2) relaxation sequence and ROIs were drawn in white and grey matter. MWF was defined as the fractional signal from 15 to 40 ms in the T(2) distribution. For ROI analysis, the mean intensity of voxels within an ROI was fit using non-negative least squares. For VBA, MWF was obtained for each voxel and the mean and median values within an ROI were calculated. There was a slightly higher correlation between Scan 1 and 2 for the VBA method (R(2)=0.98) relative to the ROI method (R(2)=0.95), and the VBA mean square difference between scans was 300% lower, indicating VBA was the most consistent between scans. For the VBA method, mean MWF was found to be more reproducible than median MWF. As the VBA method is more reproducible and gives more options for visualization and analysis of MWF, it is recommended over the ROI method of MWF analysis.

  6. An empirical analysis of the German long-term interest rat

    NARCIS (Netherlands)

    den Butter, F.A.G.; Jansen, P.W.

    2004-01-01

    The short run and long run influences of the main determinants of the German long-term interest rate are estimated using quarterly data for the period 1982-2001. A major reason for the focus on the German interest rate is that this rate, and hence its determinants, will be dominant in explaining the

  7. A study into students' interests in industrial design engineering using a gender pattern analysis

    NARCIS (Netherlands)

    Stilma, Margot; van Oost, Elizabeth C.J.; Reinders, Angelina H.M.E.; Eger, Arthur O.; Rogers, Paul; Brodhurst, Libby; Hepburn, Duncan

    2005-01-01

    This paper describes first year students’ interest and motivation towards the field of Industrial Design Engineering (IDE) at the University of Twente during three years (2002-2004). Data was gathered systematically based on students’ interest to aspects of IDE: technology, styling, ergonomics and

  8. Conflicts of interest in randomised controlled surgical trials: systematic review and qualitative and quantitative analysis

    Directory of Open Access Journals (Sweden)

    Probst Pascal

    2016-09-01

    Full Text Available Conflicts of interest may lead to biased trial designs and unbalanced interpretation of study results. We aimed to evaluate the reporting of potential conflicts of interest in full publications of surgical randomised controlled trials (RCTs. A systematic literature search was performed in CENTRAL, MEDLINE and EMBASE (1985–2014 to find all surgical RCTs of medical devices and perioperative pharmacological or nutritional interventions. The information on conflicts of interest was evaluated both quantitatively and qualitatively, and the development of stated conflicts over time was studied. Of 7934 articles, 444 met the inclusion criteria. In 93 of 444 trials (20.9%, conflicts of interest were disclosed. In half of the cases, the information provided was insufficient to permit conclusions regarding possible influence on the trials. Information about conflicts of interest has increased continuously during the last decades (1985–1994: 0%, 1995–2004: 2.8% and 2005–2014: 33.0%; p<0.001. Among the 115 industry-funded trials, industry participation was considered as a potential conflict of interest in 24 cases (20.9%. Over the past three decades, only every 10th trial has provided appropriate information on conflicts of interest. However, transparency is crucial for the reliability of evidence-based medicine. There is an urgent need for the full disclosure of all conflicts of interest in surgical publishing and for transparency regarding cooperation between academia and industry.

  9. SURVIVAL ANALYSIS AND GROWTH OF Cordia trichotoma, BORAGINACEAE, LAMIALES, IN MATO GROSSO DO SUL STATE, BRAZIL

    Directory of Open Access Journals (Sweden)

    Sergio Luiz Salvadori

    2013-12-01

    Full Text Available http://dx.doi.org/10.5902/1980509812357The evaluation of a plant survival percentage and growth may reflect its competitive ability in plantcommunity. Cordia trichotoma is a common native tree in Mato Grosso do Sul State and one of the mostpromising for planting. This study monitored the survival percentage and growth of Cordia trichotomaunder different conditions such as weeding and receiving or not fertilization. The experiment started inSeptember 2008 and it was concluded in March 2010. The seeds collection and sowing were held in urbanarea of Mundo Novo Municipality and the area for permanent planting to measure seedlings survival andgrowth was set at Japorã Municipality, Fazenda Santa Clara. Seedlings were planted in two categories: theuse or not of fertilizer and crowing resulting in four distinct groups: block fertilizer bare earth (ATN, bareland block without fertilizer (BTN, fertilizer and crown block (AC and without fertilizer and crownedblock (BC. The results indicated high survival of Cordia trichotoma in the seedling transplant system from bed to bags. The BC block showed the highest percentage of survival, but the smaller increments in height.The AC, ATN and BTN blocks presented the same survival pattern and similar average growth. However,there may be differences in nutritional and chemical composition of the soil suggesting sector analysis forfuture studies.

  10. A Paired Kidney Analysis of Multiorgan Transplantation: Implications for Allograft Survival.

    Science.gov (United States)

    Choudhury, Rashikh A; Reese, Peter P; Goldberg, David S; Bloom, Roy D; Sawinski, Deirdre L; Abt, Peter L

    2017-02-01

    United Network for Organ Sharing multiorgan transplantation allocation policy allows sequestration of a kidney by another solid organ regardless of the priority of the candidate for the kidney allograft. The implications of this policy for kidney allograft survival are not well understood. We conducted a retrospective cohort analysis of pairs of deceased donor kidney transplants where 1 kidney was allocated to a simultaneous liver-kidney (SLK) or simultaneous heart-kidney (SHK) recipient and the contralateral kidney to a kidney transplant alone (KTA) recipient (cohort from February 2002 to December 2010). Graft and patient survivals were assessed with Cox regression models. There were 1998 SLK and 276 SHK transplants with matching KTA transplants. Five-year kidney graft (64% [SLK] vs 75% [KTA], P transplant was 115 years, and by 5 years, the difference increased to 1062 years. Among the SHK arm of our study, 5-year graft survival (72% [SHK] vs 73% [KTA], P = 0.71) did not significantly differ, although patient survival (75% [SHK] vs 84% [KTA], P = 0.02) was higher in KTA recipients. Kidney graft survival is inferior among SLK relative to KTA, but not SHK. Multiorgan transplantation allocation may not be congruent with the intention of new kidney allocation policies that attempt to maximize survival after kidney transplantation.

  11. Microcomputer-assisted univariate survival data analysis using Kaplan-Meier life table estimators.

    Science.gov (United States)

    Campos-Filho, N; Franco, E L

    1988-01-01

    We describe a microcomputer program (KMSURV) for exploratory univariate statistical analysis of survival data which is directly applicable to the evaluation of clinical trials and to retrospective epidemiological studies of hospital registry-based data. The program calculates life-table-like information based on Kaplan-Meier's product-limit estimators of the survivorship function S(t) and provides summary measures of average survival times. In addition, two non-parametric tests for the comparison of survival distributions are performed. A report-quality, high resolution plot of the S(t) estimates for all groups being compared complements each set of analyses. KMSURV is not a simple adaptation of a mainframe statistical analysis package and, thus, it utilizes efficiently the interactive environment which is inherent in microcomputing.

  12. Rurality and survival differences in lung cancer: a large population-based multivariate analysis.

    Science.gov (United States)

    Pozet, Astrid; Westeel, Virginie; Berion, Pascal; Danzon, Arlette; Debieuvre, Didier; Breton, Jean-Luc; Monnier, Alain; Lahourcade, Jean; Dalphin, Jean-Charles; Mercier, Mariette

    2008-03-01

    Several studies have suggested rural health disadvantages. In France, studies on rural-urban patterns of lung cancer survival have yielded conflicting results. The aim of this analysis was to determine whether rural residence was associated with poor survival in three French counties. The database consisted of all primary lung cancer cases diagnosed in 2000 and 2001 collected through the Doubs cancer registry. A degree of rurality, obtained from socio-demographic and farming parameters of the 1999 French census treated with factor analysis, was attributed to each patient according to his/her place of residence. Among the 802 patients, 21% resided in rural areas, 11% were semi-urban inhabitants and 68% were urban residents. Survival differed significantly between these three rurality categories (p=0.04), with 2-year survival rates of 18, 29 and 24%, respectively. Using a Cox model, rural areas were significantly correlated with poor survival as compared with semi-urban areas (OR=1.42; 95% confidence interval=1.06-1.90; p=0.02). There was no survival difference between semi-urban and urban patients (OR=1.18; 95% confidence interval=0.91-1.53; p=0.21). Patient and tumour characteristics, especially stage and staging procedures, as well as first line treatment, did not vary with the degree of rurality. In conclusion, rurality has to be considered as a strong prognostic factor. Several intricate factors might be hypothesized such as increasing time to diagnosis leading to heavier tumour burden, worse treatment compliance and socioeconomic status. Before practical interventions can be proposed, prospective studies are warranted with further definition of rural risk factors for decreased survival in rural lung cancer patients.

  13. TP53 Mutations and Survival in Osteosarcoma Patients: A Meta-Analysis of Published Data

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    2016-01-01

    Full Text Available Several research groups have examined the association between TP53 mutations and prognosis in human osteosarcoma. However, the results were controversial. The purpose of this study was to evaluate the prognostic value of TP53 mutations in osteosarcoma patients. A meta-analysis was conducted with all eligible studies which quantitatively evaluated the relationship between TP53 mutations and clinical outcome of osteosarcoma patients. Eight studies with a total of 210 patients with osteosarcoma were included in this meta-analysis. The risk ratio (RR with a 95% confidence interval (95% CI was calculated to assess the effect of TP53 mutations on 2-year overall survival. The quantitative synthesis of 8 published studies showed that TP53 mutations were associated with 2-year overall survival in osteosarcoma patients. These data suggested that TP53 mutations had an unfavorable impact on 2-year overall survival when compared to the counterparts with wild type (WT TP53 (RR: 1.79; 95% CI: 1.12 to 2.84; P=0.01; I2=0%. There was no between-study heterogeneity. TP53 mutations are an effective prognostic marker for survival of patients with osteosarcoma. However, further large-scale prospective trials should be performed to clarify the prognostic value of TP53 mutations on 3- or 5-year survival in osteosarcoma patients.

  14. Multiparametric analysis of magnetic resonance images for glioma grading and patient survival time prediction

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, Benjamin (Dept. of Circulation and Medical Imaging, NTNU, Trondheim (Norway)), email: benjamin.garzon@ntnu.no; Emblem, Kyrre E. (The Interventional Center, Rikshospitalet, Oslo Univ. Hospital, Oslo (Norway); Dept. of Radiology, MGH-HST AA Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston (United States)); Mouridsen, Kim (Center of Functionally Integrative Neuroscience, Aarhus Univ., Aarhus (Denmark)); Nedregaard, Baard; Due-Toennessen, Paulina; Nome, Terje; Hald, John K. (Dept. of Radiology and Nuclear Medicine, Rikshospitalet, Oslo Univ. Hospital, Oslo (Norway)); Bjoernerud, Atle (The Interventional Center, Rikshospitalet, Oslo Univ. Hospital, Oslo (Norway)); Haaberg, Asta K. (Dept. of Circulation and Medical Imaging, NTNU, Trondheim (Norway); Dept. of Medical Imaging, St Olav' s Hospital, Trondheim (Norway)); Kvinnsland, Yngve (NordicImagingLab, Bergen (Norway))

    2011-11-15

    Background. A systematic comparison of magnetic resonance imaging (MRI) options for glioma diagnosis is lacking. Purpose. To investigate multiple MR-derived image features with respect to diagnostic accuracy in tumor grading and survival prediction in glioma patients. Material and Methods. T1 pre- and post-contrast, T2 and dynamic susceptibility contrast scans of 74 glioma patients with histologically confirmed grade were acquired. For each patient, a set of statistical features was obtained from the parametric maps derived from the original images, in a region-of-interest encompassing the tumor volume. A forward stepwise selection procedure was used to find the best combinations of features for grade prediction with a cross-validated logistic model and survival time prediction with a cox proportional-hazards regression. Results. Presence/absence of enhancement paired with kurtosis of the FM (first moment of the first-pass curve) was the feature combination that best predicted tumor grade (grade II vs. grade III-IV; median AUC 0.96), with the main contribution being due to the first of the features. A lower predictive value (median AUC = 0.82) was obtained when grade IV tumors were excluded. Presence/absence of enhancement alone was the best predictor for survival time, and the regression was significant (P < 0.0001). Conclusion. Presence/absence of enhancement, reflecting transendothelial leakage, was the feature with highest predictive value for grade and survival time in glioma patients

  15. Random-effects regression analysis of correlated grouped-time survival data.

    Science.gov (United States)

    Hedeker, D; Siddiqui, O; Hu, F B

    2000-04-01

    Random-effects regression modelling is proposed for analysis of correlated grouped-time survival data. Two analysis approaches are considered. The first treats survival time as an ordinal outcome, which is either right-censored or not. The second approach treats survival time as a set of dichotomous indicators of whether the event occurred for time periods up to the period of the event or censor. For either approach both proportional hazards and proportional odds versions of the random-effects model are developed, while partial proportional hazards and odds generalizations are described for the latter approach. For estimation, a full-information maximum marginal likelihood solution is implemented using numerical quadrature to integrate over the distribution of multiple random effects. The quadrature solution allows some flexibility in the choice of distributions for the random effects; both normal and rectangular distributions are considered in this article. An analysis of a dataset where students are clustered within schools is used to illustrate features of random-effects analysis of clustered grouped-time survival data.

  16. It's Deja Vu All over Again: Using Multiple-Spell Discrete-Time Survival Analysis.

    Science.gov (United States)

    Willett, John B.; Singer, Judith D.

    1995-01-01

    The multiple-spell discrete-time survival analysis method is introduced and illustrated using longitudinal data on exit from and reentry into the teaching profession. The method is applicable to many educational problems involving the sequential occurrence of disparate events or episodes. (SLD)

  17. Mortality and survival in systemic sclerosis: systematic review and meta-analysis.

    Science.gov (United States)

    Rubio-Rivas, Manuel; Royo, Cristina; Simeón, Carmen Pilar; Corbella, Xavier; Fonollosa, Vicent

    2014-10-01

    To determine the mortality, survival, and causes of death in patients with systemic sclerosis (SSc) through a meta-analysis of the observational studies published up to 2013. We performed a systematic review and meta-analysis of the observational studies in patients with SSc and mortality data from entire cohorts published in MEDLINE and SCOPUS up to July 2013. A total of 17 studies were included in the mortality meta-analysis from 1964 to 2005 (mid-cohort years), with data from 9239 patients. The overall SMR was 2.72 (95% CI: 1.93-3.83). A total of 43 studies have been included in the survival meta-analysis, reporting data from 13,529 patients. Cumulative survival from onset (first Raynaud's symptom) has been estimated at 87.6% at 5 years and 74.2% at 10 years, from onset (non-Raynaud's first symptom) 84.1% at 5 years and 75.5% at 10 years, and from diagnosis 74.9% at 5 years and 62.5% at 10 years. Pulmonary involvement represented the main cause of death. SSc presents a larger mortality than general population (SMR = 2.72). Cumulative survival from diagnosis has been estimated at 74.9% at 5 years and 62.5% at 10 years. Pulmonary involvement represented the main cause of death. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. When will I succeed in my first-year diploma? Survival analysis in Dutch higher education

    NARCIS (Netherlands)

    Bruinsma, Marjon; Jansen, Ellen P. W. A.

    2009-01-01

    The goal of this study was to illustrate survival analysis with higher education data and gain insight into a limited set of factors that predict when students passed their first-year examination at a Dutch university. Study participants consisted of 565 first-year students in four departments. Data

  19. Predicting Secondary School Dropout among South African Adolescents: A Survival Analysis Approach

    Science.gov (United States)

    Weybright, Elizabeth H.; Caldwell, Linda L.; Xie, Hui; Wegner, Lisa; Smith, Edward A.

    2017-01-01

    Education is one of the strongest predictors of health worldwide. In South Africa, school dropout is a crisis where by Grade 12, only 52% of the age appropriate population remain enrolled. Survival analysis was used to identify the risk of dropping out of secondary school for male and female adolescents and examine the influence of substance use…

  20. Survival analysis of postoperative nausea and vomiting in patients receiving patient-controlled epidural analgesia

    Directory of Open Access Journals (Sweden)

    Shang-Yi Lee

    2014-11-01

    Conclusion: Survival analysis using Cox regression showed that the average consumption of opioids played an important role in postoperative nausea and vomiting, a result not found by logistic regression. Therefore, the incidence of postoperative nausea and vomiting in patients cannot be reliably determined on the basis of a single visit at one point in time.

  1. Interdependent multi-layer networks: modeling and survivability analysis with applications to space-based networks.

    Science.gov (United States)

    Castet, Jean-Francois; Saleh, Joseph H

    2013-01-01

    This article develops a novel approach and algorithmic tools for the modeling and survivability analysis of networks with heterogeneous nodes, and examines their application to space-based networks. Space-based networks (SBNs) allow the sharing of spacecraft on-orbit resources, such as data storage, processing, and downlink. Each spacecraft in the network can have different subsystem composition and functionality, thus resulting in node heterogeneity. Most traditional survivability analyses of networks assume node homogeneity and as a result, are not suited for the analysis of SBNs. This work proposes that heterogeneous networks can be modeled as interdependent multi-layer networks, which enables their survivability analysis. The multi-layer aspect captures the breakdown of the network according to common functionalities across the different nodes, and it allows the emergence of homogeneous sub-networks, while the interdependency aspect constrains the network to capture the physical characteristics of each node. Definitions of primitives of failure propagation are devised. Formal characterization of interdependent multi-layer networks, as well as algorithmic tools for the analysis of failure propagation across the network are developed and illustrated with space applications. The SBN applications considered consist of several networked spacecraft that can tap into each other's Command and Data Handling subsystem, in case of failure of its own, including the Telemetry, Tracking and Command, the Control Processor, and the Data Handling sub-subsystems. Various design insights are derived and discussed, and the capability to perform trade-space analysis with the proposed approach for various network characteristics is indicated. The select results here shown quantify the incremental survivability gains (with respect to a particular class of threats) of the SBN over the traditional monolith spacecraft. Failure of the connectivity between nodes is also examined, and the

  2. Interdependent multi-layer networks: modeling and survivability analysis with applications to space-based networks.

    Directory of Open Access Journals (Sweden)

    Jean-Francois Castet

    Full Text Available This article develops a novel approach and algorithmic tools for the modeling and survivability analysis of networks with heterogeneous nodes, and examines their application to space-based networks. Space-based networks (SBNs allow the sharing of spacecraft on-orbit resources, such as data storage, processing, and downlink. Each spacecraft in the network can have different subsystem composition and functionality, thus resulting in node heterogeneity. Most traditional survivability analyses of networks assume node homogeneity and as a result, are not suited for the analysis of SBNs. This work proposes that heterogeneous networks can be modeled as interdependent multi-layer networks, which enables their survivability analysis. The multi-layer aspect captures the breakdown of the network according to common functionalities across the different nodes, and it allows the emergence of homogeneous sub-networks, while the interdependency aspect constrains the network to capture the physical characteristics of each node. Definitions of primitives of failure propagation are devised. Formal characterization of interdependent multi-layer networks, as well as algorithmic tools for the analysis of failure propagation across the network are developed and illustrated with space applications. The SBN applications considered consist of several networked spacecraft that can tap into each other's Command and Data Handling subsystem, in case of failure of its own, including the Telemetry, Tracking and Command, the Control Processor, and the Data Handling sub-subsystems. Various design insights are derived and discussed, and the capability to perform trade-space analysis with the proposed approach for various network characteristics is indicated. The select results here shown quantify the incremental survivability gains (with respect to a particular class of threats of the SBN over the traditional monolith spacecraft. Failure of the connectivity between nodes is also

  3. Survival Analysis of 1,742 Patients with Stage IV Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Hong PENG

    2011-04-01

    Full Text Available Background and objective At present non-small cell lung cancer (NSCLC is still the leading cause of death induced by cancer. The aim of this study is to investigate the prognostic factors of advanced NSCLC. Methods Total 1,742 cases of stage IV NSCLC data from Jan 4, 2000 to Dec 25, 2008 in Shanghai Chest Hospital were collected, confirmed by pathological examinations. Analysis was made to observe the impact of treatment on prognosis in gender, age, smoking history, pathology, classification, clinical TNM stage. Survival rate, survival difference were evaluated by Kaplan-Meire method and Logrank test respectively. The prognosis were analyzed by Cox multivariate regression. Results The median survival time of 1,742 patients was 10.0 months (9.5 months-10.5 months. One, two, three, four, and five-year survival rates were 44%, 22%, 13%, 9%, 6% respectively. The median survivals of single or multiple metastasis were 11 months vs 7 months (P < 0.001. Survival time were different in metastasic organs, with the median survival time as follows: lung for about 12 months (11.0 months-12.9 months, bone for 9 months (8.3 months-9.6 months, brain for 8 months (6.8 months-9.1 months, liver, adrenal gland, distannt lymph node metastasis for 5 months (3.8 months-6.1 months, and subcutaneous for 3 months (1.7 months-4.3 months. The median survival times of adenocarcinoma (n=1,086, 62% and squamous cell carcinoma cases (n=305, 17.5% were 12 months vs 8 months (P < 0.001. The median survival time of chemotherapy and best supportive care were 11 months vs 6 months (P < 0.001; the median survival times of with and without radiotherapy were 11 months vs 9 months (P=0.017. Conclusion Gender, age, gross type, pathological type, clinical T stage, N stage, numbers of metastatic organ, smoking history, treatment of advanced non-small cell lung cancer were independent prognostic factors.

  4. Mechanisms and mediation in survival analysis: towards an integrated analytical framework.

    LENUS (Irish Health Repository)

    Haase, Trutz

    2016-02-29

    A wide-ranging debate has taken place in recent years on mediation analysis and causal modelling, raising profound theoretical, philosophical and methodological questions. The authors build on the results of these discussions to work towards an integrated approach to the analysis of research questions that situate survival outcomes in relation to complex causal pathways with multiple mediators. The background to this contribution is the increasingly urgent need for policy-relevant research on the nature of inequalities in health and healthcare.

  5. Post-surgery radiation in early breast cancer: survival analysis of registry data

    OpenAIRE

    Vinh-Hung, Vincent; BURZYKOWSKI, Tomasz; Van de Steene, Jan; Storme, Guy; Soete, Guy

    2002-01-01

    BACKGROUND AND PURPOSE: Overviews of randomized trials have shown a small survival advantage with post-surgery radiation in early breast cancer. The present study attempts to extend this observation through a systematic analysis of population data.Materials and METHODS: This retrospective cohort study used the Surveillance, Epidemiology, and End Results (SEER) data on 83,776 women with breast cancer diagnosed between 1988 and 1997, stage T1-T2, node negative or node positive. The analysis was...

  6. Multimodality treatment of brain metastases: an institutional survival analysis of 275 patients

    Directory of Open Access Journals (Sweden)

    Demakas John J

    2011-07-01

    Full Text Available Abstract Background Whole brain radiation therapy (WBRT, surgical resection, stereotactic radiosurgery (SRS, and combinations of the three modalities are used in the management of patients with metastatic brain tumors. We present the previously unreported survival outcomes of 275 patients treated for newly diagnosed brain metastases at Cancer Care Northwest and Gamma Knife of Spokane between 1998 and 2008. Methods The effects treatment regimen, age, Eastern Cooperative Oncology Group-Performance Status (ECOG-PS, primary tumor histology, number of brain metastases, and total volume of brain metastases have on patient overall survival were analyzed. Statistical analysis was performed using Kaplan-Meier survival curves, Andersen 95% confidence intervals, approximate confidence intervals for log hazard-ratios, and multivariate Cox proportional hazard models. Results The median clinical follow up time was 7.2 months. On multivariate analysis, survival statistically favored patients treated with SRS alone when compared to patients treated with WBRT alone (p Conclusions In our analysis, patients benefited from a combined modality treatment approach and physicians must consider patient age, performance status, and primary tumor histology when recommending specific treatments regimens.

  7. Survival in patients with primary Dermatofibrosarcoma Protuberans: National Cancer Data Base analysis.

    Science.gov (United States)

    Trofymenko, Oleksandr; Bordeaux, Jeremy S; Zeitouni, Nathalie C

    2017-11-23

    The predictors of mortality, second surgery, and postoperative radiation therapy for treating Dermatofibrosarcoma protuberans (DFSP) are not well described. We sought to determine the impact of patient demographics, tumor characteristics, and treatment site and modality on survival after primary DFSP. A retrospective analysis of data from the National Cancer Data Base program was performed for patients diagnosed with DFSP from 2003 to 2012. A total of 5249 cases were identified. Of these, 3.1% of patients died during an average of 51.4 months of follow up. After adjusting for relevant factors, uninsured and/or Medicaid/Medicare insurance, anaplastic histology, and positive postoperative margins predicted mortality, while treatment at Integrated Network Cancer programs predicted survival (P data was not cancer-specific. Better understanding of factors affecting survival outcomes may help improve management of DFSP and delineate other potential causes of increased morbidity and mortality. Copyright © 2017. Published by Elsevier Inc.

  8. Effect of birth spacing on infant survival in Thailand: two-stage logit analysis.

    Science.gov (United States)

    Park, C B; Siasakul, S; Saengtienchai, C

    1994-03-01

    We formulated a two-stage causal model for infant survival and applied it to data drawn from the 1987 Thai Demographic and Health Survey covering the fate of 5,074 index children. The following six variables were considered as the explanatory variables: maternal age, maternal education, birth order, preceding birth interval, survival of the preceding child, and place of residence. The analysis suggests that the birth interval not only directly affected the chance of infant survival but it played the role of the filtering factor through which other variables indirectly operate on infant mortality. The effect of preceding child's death was very strong, the odds ratios for the following infant's death and short birth interval both exceeding three.

  9. Factors affecting interest in orthopedics among female medical students: a prospective analysis.

    Science.gov (United States)

    Baldwin, Keith; Namdari, Surena; Bowers, Andrea; Keenan, Mary Ann; Levin, L Scott; Ahn, Jaimo

    2011-12-06

    The field of orthopedics has a limited ability to recruit high-quality female applicants. The purpose of this study was to determine whether early exposure to the field affects a woman's decision to pursue orthopedics. We performed a prospective, nonrandomized cohort study between academic years 2005 and 2009 and compared interest in orthopedic surgery among female (n=271) and male (n=71) medical students at 2 urban teaching institutions. Elective lectures and orthopedic literature were distributed via e-mail to the study participants. These materials included articles published in the medical literature, materials produced and distributed by the American Academy of Orthopaedic Surgeons, and Web sites providing educational materials. The primary outcome was the likelihood of application for orthopedic residency. We studied the influence of demographics, exposure, and attitudes on interest in pursuing an orthopedic career. Men had a significantly higher baseline level of interest in orthopedic surgery than women (P=.005). Younger age (Porthopedics were significantly related to interest among women. At final follow-up, total personal exposures (P=.003) and total independent exposures (Porthopedic educational resources may be useful in generating female interest. Perceptions and attitudes regarding orthopedic surgery must to be changed to attract the best and brightest minds, regardless of sex. Copyright © 2011, SLACK Incorporated.

  10. Predicting survival of Salmonella in low-water activity foods: an analysis of literature data.

    Science.gov (United States)

    Santillana Farakos, Sofia M; Schaffner, Donald W; Frank, Joseph F

    2014-09-01

    Factors such as temperature, water activity (aw), substrate, culture media, serotype, and strain influence the survival of Salmonella in low-aw foods. Predictive models for Salmonella survival in low-aw foods at temperatures ranging from 21 to 80(u) C and water activities below 0.6 were previously developed. Literature data on survival of Salmonella in low-aw foods were analyzed in the present study to validate these predictive models and to determine global influencing factors. The results showed the Weibull model provided suitable fits to the data in 75% of the curves as compared with the log-linear model. The secondary models predicting the time required for log-decimal reduction (log δ) and shape factor (log β) values were useful in predicting the survival of Salmonella in low-aw foods. Statistical analysis indicated overall fail-safe secondary models, with 88% of the residuals in the acceptable and safe zones (survival kinetics of Salmonella in low-aw foods and its influencing factors.

  11. Evaluation of parametric models by the prediction error in colorectal cancer survival analysis.

    Science.gov (United States)

    Baghestani, Ahmad Reza; Gohari, Mahmood Reza; Orooji, Arezoo; Pourhoseingholi, Mohamad Amin; Zali, Mohammad Reza

    2015-01-01

    The aim of this study is to determine the factors influencing predicted survival time for patients with colorectal cancer (CRC) using parametric models and select the best model by predicting error's technique. Survival models are statistical techniques to estimate or predict the overall time up to specific events. Prediction is important in medical science and the accuracy of prediction is determined by a measurement, generally based on loss functions, called prediction error. A total of 600 colorectal cancer patients who admitted to the Cancer Registry Center of Gastroenterology and Liver Disease Research Center, Taleghani Hospital, Tehran, were followed at least for 5 years and have completed selected information for this study. Body Mass Index (BMI), Sex, family history of CRC, tumor site, stage of disease and histology of tumor included in the analysis. The survival time was compared by the Log-rank test and multivariate analysis was carried out using parametric models including Log normal, Weibull and Log logistic regression. For selecting the best model, the prediction error by apparent loss was used. Log rank test showed a better survival for females, BMI more than 25, patients with early stage at diagnosis and patients with colon tumor site. Prediction error by apparent loss was estimated and indicated that Weibull model was the best one for multivariate analysis. BMI and Stage were independent prognostic factors, according to Weibull model. In this study, according to prediction error Weibull regression showed a better fit. Prediction error would be a criterion to select the best model with the ability to make predictions of prognostic factors in survival analysis.

  12. Gene expression meta-analysis identifies chromosomal regions involved in ovarian cancer survival

    DEFF Research Database (Denmark)

    Thomassen, Mads; Jochumsen, Kirsten M; Mogensen, Ole

    2009-01-01

    Ovarian cancer cells exhibit complex karyotypic alterations causing deregulation of numerous genes. Some of these genes are probably causal for cancer formation and local growth, whereas others are causal for metastasis and recurrence. By using publicly available data sets, we have investigated...... the relation of gene expression and chromosomal position to identify chromosomal regions of importance for early recurrence of ovarian cancer. By use of *Gene Set Enrichment Analysis*, we have ranked chromosomal regions according to their association to survival. Over-representation analysis including 1...... summarized mutation load in these regions by a combined mutation score that is statistical significantly associated to survival by analysis in the data sets used for identification of the regions. Furthermore, the prognostic value of the combined mutation score was validated in an independent large data set...

  13. Modelling p-value distributions to improve theme-driven survival analysis of cancer transcriptome datasets

    Directory of Open Access Journals (Sweden)

    Brors Benedikt

    2010-01-01

    Full Text Available Abstract Background Theme-driven cancer survival studies address whether the expression signature of genes related to a biological process can predict patient survival time. Although this should ideally be achieved by testing two separate null hypotheses, current methods treat both hypotheses as one. The first test should assess whether a geneset, independent of its composition, is associated with prognosis (frequently done with a survival test. The second test then verifies whether the theme of the geneset is relevant (usually done with an empirical test that compares the geneset of interest with random genesets. Current methods do not test this second null hypothesis because it has been assumed that the distribution of p-values for random genesets (when tested against the first null hypothesis is uniform. Here we demonstrate that such an assumption is generally incorrect and consequently, such methods may erroneously associate the biology of a particular geneset with cancer prognosis. Results To assess the impact of non-uniform distributions for random genesets in such studies, an automated theme-driven method was developed. This method empirically approximates the p-value distribution of sets of unrelated genes based on a permutation approach, and tests whether predefined sets of biologically-related genes are associated with survival. The results from a comparison with a published theme-driven approach revealed non-uniform distributions, suggesting a significant problem exists with false positive rates in the original study. When applied to two public cancer datasets our technique revealed novel ontological categories with prognostic power, including significant correlations between "fatty acid metabolism" with overall survival in breast cancer, as well as "receptor mediated endocytosis", "brain development", "apical plasma membrane" and "MAPK signaling pathway" with overall survival in lung cancer. Conclusions Current methods of theme

  14. Andrzej Pekalski networks of scientific interests with integral degrees of freedom through self-citation analysis

    NARCIS (Netherlands)

    Ausloos, M.; Lambiotte, R.; Scharnhorst, A.; Hellsten, I.R.

    2008-01-01

    Old and recent theoretical works by Andrzej P̧kalski (APE) are recalled as possible sources of interest for describing network formation and clustering in complex (scientific) communities, through self-organization and percolation processes. Emphasis is placed on APE self-citation network over four

  15. A Critical-Holistic Analysis of Nursing Faculty and Student Interest in International Health.

    Science.gov (United States)

    Wright, Maria da Gloria Miotto; Korniewicz, Denise M.; Zerbe, Melissa

    2001-01-01

    Responses from 211 undergraduate and 23 graduate nursing students and 38 faculty revealed substantial interest in international health. Faculty had numerous international experiences; many students had traveled abroad and one-third considered international health a career priority. The need for a broad interdisciplinary framework rather than…

  16. Effects of temperature on development, survival and reproduction of insects: experimental design, data analysis and modeling.

    Science.gov (United States)

    Régnière, Jacques; Powell, James; Bentz, Barbara; Nealis, Vincent

    2012-05-01

    The developmental response of insects to temperature is important in understanding the ecology of insect life histories. Temperature-dependent phenology models permit examination of the impacts of temperature on the geographical distributions, population dynamics and management of insects. The measurement of insect developmental, survival and reproductive responses to temperature poses practical challenges because of their modality, variability among individuals and high mortality near the lower and upper threshold temperatures. We address this challenge with an integrated approach to the design of experiments and analysis of data based on maximum likelihood. This approach expands, simplifies and unifies the analysis of laboratory data parameterizing the thermal responses of insects in particular and poikilotherms in general. This approach allows the use of censored observations (records of surviving individuals that have not completed development after a certain time) and accommodates observations from temperature transfer treatments in which individuals pass only a portion of their development at an extreme (near-threshold) temperature and are then placed in optimal conditions to complete their development with a higher rate of survival. Results obtained from this approach are directly applicable to individual-based modeling of insect development, survival and reproduction with respect to temperature. This approach makes possible the development of process-based phenology models that are based on optimal use of available information, and will aid in the development of powerful tools for analyzing eruptive insect population behavior and response to changing climatic conditions. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  17. A Gradient Boosting Algorithm for Survival Analysis via Direct Optimization of Concordance Index

    Directory of Open Access Journals (Sweden)

    Yifei Chen

    2013-01-01

    statistical models have been proposed for survival analysis. They often impose strong assumptions on hazard functions, which describe how the risk of an event changes over time depending on covariates associated with each individual. In particular, the prevalent proportional hazards model assumes that covariates are multiplicatively related to the hazard. Here we propose a nonparametric model for survival analysis that does not explicitly assume particular forms of hazard functions. Our nonparametric model utilizes an ensemble of regression trees to determine how the hazard function varies according to the associated covariates. The ensemble model is trained using a gradient boosting method to optimize a smoothed approximation of the concordance index, which is one of the most widely used metrics in survival model performance evaluation. We implemented our model in a software package called GBMCI (gradient boosting machine for concordance index and benchmarked the performance of our model against other popular survival models with a large-scale breast cancer prognosis dataset. Our experiment shows that GBMCI consistently outperforms other methods based on a number of covariate settings. GBMCI is implemented in R and is freely available online.

  18. Renal cell carcinoma in end-stage renal disease: Multi-institutional comparative analysis of survival.

    Science.gov (United States)

    Song, Cheryn; Hong, Sung Hoo; Chung, Jin Soo; Byun, Seok Soo; Kwak, Cheol; Jeong, Chang Wook; Seo, Seong Il; Jeon, Hwang Gyun; Seo, Ill Young

    2016-06-01

    To describe the clinical features of renal cell carcinoma arising in end-stage renal disease and to compare survival outcomes after definitive treatment with non-end-stage renal disease renal cell carcinoma. Data of 181 consecutive patients with end-stage renal disease renal cell carcinoma who had received surgical treatment between 1995 and 2011 at seven institutions were reviewed. Data of 362 non-end-stage renal disease renal cell carcinoma patients matched for clinicopathological parameters who received surgery at Asan Medical Center during the same study period were also reviewed. The two study groups were compared with respect to recurrence-free, cancer-specific, and overall survival by Kaplan-Meier analysis and Cox proportional hazards method. Mean follow up was 40 ± 34.2 months after surgery. Median tumor size was 2.5 cm (interquartile range 1.5-4.5), and pathological tumor stage was T1 in 78%, T2 in 7.1% and T3 and higher in 14.9%. Tumor histological type was clear cell in 63%, papillary in 17%, chromophobe in 5%, clear cell papillary in 2.8% and acquired cystic disease-related in 6.1%. Compared with the controls, the stage-specific 5-year recurrence-free survival was similar (87.6 vs 88.5%), but cancer-specific and overall survival was significantly lower. On multivariate analysis, end-stage renal disease renal cell carcinoma was not a predictor for recurrence-free survival, but a significant predictor for cancer-specific (hazard ratio 4.07, 95% confidence interval 2.08-7.94) and overall survival (hazard ratio 3.13, 95% confidence interval 1.66-5.96). End-stage renal disease renal cell carcinoma seems to have comparable stage-specific recurrence-free, but poorer cancer-specific and overall survival compared with non-end-stage renal disease renal cell carcinoma. As patients with end-stage renal disease are a high-risk population for renal cell carcinoma, routine radiographic screening to improve survival outcomes should be further investigated. © 2016

  19. Influence of Androgen Receptor Expression on the Survival Outcomes in Breast Cancer: A Meta-Analysis.

    Science.gov (United States)

    Kim, Yoonseok; Jae, Eunae; Yoon, Myunghee

    2015-06-01

    Despite the fact that the androgen receptor (AR) is known to be involved in the pathogenesis of breast cancer, its prognostic effect remains controversial. In this meta-analysis, we explored AR expression and its impact on survival outcomes in breast cancer. We searched PubMed, EMBASE, Cochrane Library, ScienceDirect, SpringerLink, and Ovid databases and references of articles to identify studies reporting data until December 2013. Disease-free survival (DFS) and overall survival (OS) were analyzed by extracting the number of patients with recurrence and survival according to AR expression. There were 16 articles that met the criteria for inclusion in our meta-analysis. DFS and OS were significantly longer in patients with AR expression compared with patients without AR expression (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.40-0.90; OR, 0.53; 95% CI, 0.38-0.73, respectively). In addition, hormone receptor (HR) positive patients had a longer DFS when AR was also expressed (OR, 0.63; 95% CI, 0.41-0.98). For patients with triple negative breast cancer (TNBC), AR expression was also associated with longer DFS and OS (OR, 0.44, 95% CI, 0.26-0.75; OR, 0.26, 95% CI, 0.12-0.55, respectively). Furthermore, AR expression was associated with a longer DFS and OS in women (OR, 0.42, 95% CI, 0.27-0.64; OR, 0.47, 95% CI, 0.38-0.59, respectively). However, in men, AR expression was associated with a worse DFS (OR, 6.00; 95% CI, 1.46-24.73). Expression of AR in breast cancer might be associated with better survival outcomes, especially in patients with HR-positive tumors and TNBC, and women. Based on this meta-analysis, we propose that AR expression might be related to prognostic features and contribute to clinical outcomes.

  20. Factors Influencing the Cure Rate in the Corneal Graft Rejection with Survival Analysis

    Directory of Open Access Journals (Sweden)

    Feizi S.

    2009-11-01

    Full Text Available AbstractBackground and Objectives: Immunologic rejection of the transplanted cornea is the major cause of human allograft failure with several risk factors contributing to it. Since in the corneal graft, most individuals do not reject the graft, we used the survival analysis with cure rate for the assessment of the factors influencing the cure rate at the time of data analysis. The main aim of this study was to evaluate the cure rate and assess the risk factors for corneal graft rejection in the keratoconus disease in Labafinejad Hospital, Tehran, Iran. Methods: This was a routine data base study in which the data were gathered from keratoconus patients’ files that had undergone penetrating keratoplasty operation. In the survival analysis, individuals who didn’t reject corneal were considered cured. To study the factors influencing the cure rate, we used the Weibull distribution for survival function and the logistic link function for the cure rate because of their tractability and accuracy.Results: Out of 119 patients 31 patients (26% rejected grafts. Among the factors influencing cure rate, only in vascularization and in persons older than 25 years of age was ameaningful effect on decreasing cure rate. With this cure model, the expected cure rate in the non-vascularization and less than 25 year- old patients was 81, in non-vascularization and more than 25 year- olds it is 64, in the vascularization and less than 25 year- olds, the cure rate is 19 and in the vascularization and more than 25 years of age, the cure rate is 9 percent and the observed cure rate for Kaplan-Meier product limit estimator was 79, 61, 27 and 0 percent, respectively. The results showed that the estimate of cure rate in the survival analysis was near the Kaplan-Meier product-limits estimator.Conclusion: One of the benefits of modeling is its ability to generalize the results; using them in the prediction. According to the results obtained from the fitting cure model

  1. [An analysis of cancer survival narratives using computerized text analysis program].

    Science.gov (United States)

    Kim, Dal Sook; Park, Ah Hyun; Kang, Nam Jun

    2014-06-01

    This study was done to explore experiences of persons living through the periods of cancer diagnosis, treatment, and self-care. With permission, texts of 29 cancer survival narratives (8 men and 21 women, winners in contests sponsored by two institutes), were analyzed using Kang's Korean-Computerized-Text-Analysis-Program where the commonly used Korean-Morphological-Analyzer and the 21st-century-Sejong-Modern-Korean-Corpora representing laymen's Korean-language-use are connected. Experiences were explored based on words included in 100 highly-used-morphemes. For interpretation, we used 'categorizing words by meaning', 'comparing use-rate by periods and to the 21st-century-Sejong-Modern-Korean-Corpora', and highly-used-morphemes that appeared only in a specific period. The most highly-used-word-morpheme was first-person-pronouns followed by, diagnosis·treatment-related-words, mind-expression-words, cancer, persons-in-meaningful-interaction, living and eating, information-related-verbs, emotion-expression-words, with 240 to 0.8 times for layman use-rate. 'Diagnosis-process', 'cancer-thought', 'things-to-come-after-diagnosis', 'physician·husband', 'result-related-information', 'meaningful-things before diagnosis-period', and 'locus-of-cause' dominated the life of the diagnosis-period. 'Treatment', 'unreliable-body', 'husband · people · mother · physician', 'treatment-related-uncertainty', 'hard-time', and 'waiting-time represented experiences in the treatment-period. Themes of living in the self-care-period were complex and included 'living-as-a-human', 'self-managing-of-diseased-body', 'positive-emotion', and 'connecting past · present · future'. The results show that the experience of living for persons with cancer is influenced by each period's own situational-characteristics. Experiences of the diagnosis and treatment-period are negative disease-oriented while that of the self-care period is positive present-oriented.

  2. Survival analysis of female dogs with mammary tumors after mastectomy: epidemiological, clinical and morphological aspects

    Directory of Open Access Journals (Sweden)

    Maria Luíza de M. Dias

    2016-03-01

    Full Text Available Abstract: Mammary gland tumors are the most common type of tumors in bitches but research on survival time after diagnosis is scarce. The purpose of this study was to investigate the relationship between survival time after mastectomy and a number of clinical and morphological variables. Data was collected retrospectively on bitches with mammary tumors seen at the Small Animal Surgery Clinic Service at the University of Brasília. All subjects had undergone mastectomy. Survival analysis was conducted using Cox's proportional hazard method. Of the 139 subjects analyzed, 68 died and 71 survived until the end of the study (64 months. Mean age was 11.76 years (SD=2.71, 53.84% were small dogs. 76.92% of the tumors were malignant, and 65.73% had both thoracic and inguinal glands affected. Survival time in months was associated with age (hazard rate ratios [HRR] =1.23, p-value =1.4x10-4, animal size (HRR between giant and small animals =2.61, p-value =0.02, nodule size (HRR =1.09, p-value =0.03, histological type (HRR between solid carcinoma and carcinoma in a mixed tumor =2.40, p-value =0.02, time between diagnosis and surgery (TDS, with HRR =1.21, p-value =2.7x10-15, and the interaction TDS*follow-up time (HRR =0.98, p-value =1.6x10-11. The present study is one of the few on the subject matter. Several important covariates were evaluated and age, animal size, nodule size, histological type, TDS and TDS*follow up time were identified as significantly associated to survival time.

  3. Lung cancer associated hypercalcemia: An analysis of factors influencing survival and prognosis in 34 cases

    Directory of Open Access Journals (Sweden)

    Su-jie ZHANG

    2012-06-01

    Full Text Available Objectives  To explore the factors influencing survival time in lung cancer associated hypercalcemia patients. Methods  Thirty-four patients with pathologically confirmed lung cancer complicated with hypercalcemia, who were treated at the Department of Oncology in General Hospital of PLA from Jan. 2001 to Dec. 2010, were enrolled in this study. The clinical data analyzed included sex, age, pathological type of the malignancies, organ metastasis (bone, lung, liver, kidney, brain, number of distal metastatic site, mental status, interval between final diagnosis of lung cancer and of hypercalcemia, peak value of blood calcium during the disease course, treatment methods and so on. Survival analysis was performed with the Kaplan-Meier method and Cox analysis with statistic software SPSS 18.0 to identify the potential prognostic factors. Results  The highest blood calcium level ranged from 2.77 to 4.87mmol/L, and the median value was 2.94mmol/L. The patients' survival time after diagnosis of hypercalcemia varied from 1 day to 1067 days, and the median survival time was 92 days. With the log-rank test, age above 50 years old, hypercalcemia occurring over 90 days after diagnosis of cancer, central nervous system symptoms and renal metastasis were predictors for poor survival (P=0.048, P=0.001, P=0.000, P=0.003. In the COX proportional hazard model analysis, age above 50 years old, hypercalcemia occurring over 90 days after cancer diagnosis, central nervous system symptoms and renal metastasis were significant prognostic factors for poor survival (HR=11.483, P=0.006; HR=4.371, P=0.002; HR=6.064, P=0.026; HR=8.502, P=0.011. Conclusions  Patients with lung cancer associated hypercalcemia have a shorter survival time and poor prognosis. Age above 50 years old, hypercalcemia occurring over 90 days after cancer diagnosis, central nervous system symptoms and renal metastasis are significant factors of poor prognosis.

  4. Does Students' Interest in a Mathematical Problem Depend on the Problem's Connection to Reality? An Analysis of Students' Interest and Pre-Service Teachers' Judgments of Students' Interest in Problems with and without a Connection to Reality

    Science.gov (United States)

    Rellensmann, Johanna; Schukajlow, Stanislaw

    2017-01-01

    Students' interest in mathematics is important for their learning of mathematics, and the ability to accurately judge students' motivational orientation is important for mathematics teachers. The aim of this study was to answer the following research questions: (1) Is there a difference in students' interest in solving problems with and without a…

  5. Analysis of Overnight ROBOR Interbank Interest Rate Recorded in October 2008 Using a Correlational Mathematical Model

    Directory of Open Access Journals (Sweden)

    Ramona Mariana CALINICA

    2013-08-01

    Full Text Available Information about possible manipulation of the overnight Robor interbank interest rates appeared in the press in late June 2012 when the British bank Barclays was fined for manipulating Libor. Suspicion of manipulation of interest rates has not spared Romania.The purpose of this paper is to provide mathematical support persons or authorities concerned in finding out whether the overnight ROBOR reference rates from October 2008 were the result of an agreement between banks or is a natural reaction to the difficult conditions prevailing at that time, and why not, decision support to establish a intervention policies when deviations of the interbank money market parameters, in relation to a specific goal, above a certain value.

  6. Needs analysis in developing the entrepreneurial interest of vocational education students

    Science.gov (United States)

    Widiyanti

    2017-09-01

    Vocational education aims to graduates have the ability to work independently. To make it happen, in addition to entrepreneurship education is required also the explicit understanding of factors that can increase entrepreneurial interest. These factors are more dominant in external conditions, which means that to be entrepreneurship can be learned and formed on a person's person start early. The introduction of entrepreneurship can begin with the giving of entrepreneurial materials, which can then be spelled out in the form of concrete actions. In this article is briefly described but detailed about factors that can increase entrepreneurship interest in vocational education students, which can be applied at the secondary level as well as at the level of further education.

  7. Equilibrium real interest rates and secular stagnation: An empirical analysis for euro area member countries

    OpenAIRE

    Belke, Ansgar; Klose, Jens

    2016-01-01

    Is secular stagnation a valid concern for Euro Area countries? We tackle this question using the well-established Laubach-Williams model to estimate the unobservable equilibrium real interest rate and compare it to the actual real rate. We apply our approach to twelve Euro Area countries, since heterogeneity among member countries has become considerably extensive since the beginning of the financial crisis. Hence, the question of secular stagnation has to be answered at the country level. Ou...

  8. Optical vibration detection spectral analysis assembly and method for detecting vibration in an object of interest

    Science.gov (United States)

    Hale, Thomas C.; Telschow, Kenneth L.

    1998-01-01

    A vibration detection assembly is described which includes an emitter of light which has object and reference beams, the object beam reflected off of a vibrating object of interest; and a photorefractive substance having a given response time and which passes the reflected object beam and the reference beam, the reference beam and the object beam interfering within the photorefractive substance to create a space charge field which develops within the response time of the photorefractive substance.

  9. CONFLICT OF INTEREST AND INTEGRITY IN PUBLIC ADMINISTRATION IN CEE COUNTRIES. COMPARATIVE ANALYSIS

    Directory of Open Access Journals (Sweden)

    POPA Florin Marius

    2013-12-01

    Full Text Available Corruption is a threat to democracy, to the law’s supremacy, to social equity and justice, it erodes the principles of efficient administration, undermines the market economy and endanger the stability of state institutions. Research on corruption has particularly focused on the classification of its various forms in order to operationalize the concept of analytical judgment and practical reasoning. In this context, conflict of interest represent one of the main form of manifestation of corruption in public administration

  10. CONFLICT OF INTEREST AND INTEGRITY IN PUBLIC ADMINISTRATION IN CEE COUNTRIES. COMPARATIVE ANALYSIS

    OpenAIRE

    POPA Florin Marius

    2013-01-01

    Corruption is a threat to democracy, to the law’s supremacy, to social equity and justice, it erodes the principles of efficient administration, undermines the market economy and endanger the stability of state institutions. Research on corruption has particularly focused on the classification of its various forms in order to operationalize the concept of analytical judgment and practical reasoning. In this context, conflict of interest represent one of the main form of manifestation of corru...

  11. A Quantitative Analysis of Undisclosed Conflicts of Interest in Pharmacology Textbooks

    OpenAIRE

    Piper, Brian J.; Telku, Hassenet M.; Lambert, Drew A.

    2015-01-01

    Background Disclosure of potential conflicts of interest (CoI) is a standard practice for many biomedical journals but not for educational materials. The goal of this investigation was to determine whether the authors of pharmacology textbooks have undisclosed financial CoIs and to identify author characteristics associated with CoIs. Methods and Findings The presence of potential CoIs was evaluated by submitting author names (N = 403; 36.3% female) to a patent database (Google Scholar) as we...

  12. INTEREST ON EQUITY: AN ANALYSIS OF THE IMPACT FOR THE PAYER AND THE RECEIVER

    Directory of Open Access Journals (Sweden)

    Maria Heloisa Bisca

    2012-12-01

    Full Text Available With the publication of law 9.249/95 the use of interest on capital becomes an option for the compensation of shareholders and stakeholders in the companies. Once this alternative is chosen, the company gains the rights to deduct the value of the JSCP as the basis for calculating income tax and social contribution. This study demonstrates the impact results of this choice for the company and for the shareholders. The company will have a fiscal tax advantage with the use of JSCP, as the tax base for income and social contribution is reduced after the deduction of interest on capital as a financial expense. The shareholders, as natural person, will benefit because they will have a tax liability on the JSCP taxes hold, and still will Keyreceive a larger portion of dividends -words: Interest on capital; distribution of profits; tax; JSCP; Dividends.because with the spending cuts the amount to be distributed by the company increases. For the artificial person, this method may not be the most INTRODUÇÃO attractive one because the JSCP are considered financial revenue which results in higher taxation for the corporation.

  13. Scientific Interests of 21st Century Clinical Oral Implant Research: Topical Trend Analysis.

    Science.gov (United States)

    Pommer, Bernhard; Valkova, Vesela; Ubaidha Maheen, Ceeneena; Fürhauser, Lukas; Rausch-Fan, Xiaohui; Seeman, Rudolf

    2016-08-01

    Discrimination between ongoing and solved research questions may help to distinguish established dogmas from evidence-based implant dentistry. The purpose of this study was to investigate topics of interest in the field of oral implant science and evolving thematic trends in clinical studies during the last decade. Electronic and manual searches of English literature were performed to identify clinical studies on oral implants. Out of 15,695 publications screened, 2,875 clinical investigations were included. Among the most prevalent topics were immediate loading (14.3%), bone substitutes (11.6%), lateral sinus grafting (10.7%), implant overdentures (10.5%), single-tooth implant crowns (8.8%), cross-arch implant bridges (8.0%), immediate implant placement (7.5%), implant surfaces (7.0%), simultaneous implant placement and augmentation (6.4%) as well as guided bone regeneration (5.3%). Significant increase of scientific interest was seen in immediate loading (+6.3%, p research on implant overdentures (-6.6%, p = .033) and tooth-to-implant connection (-2.5%, p = .010) was on the decline. Literature coverage, since the beginning of the 21st century, has seen greater focus on surgical topics compared to prosthodontic issues (p = .005) while only few topics experienced decrease of interest indicating scientific consensus. © 2015 Wiley Periodicals, Inc.

  14. Analysis of Tax-deductible Interest Payments for Re-advanceable Canadian Mortgages

    Science.gov (United States)

    Naseem, Almas; Reesor, Mark

    2011-11-01

    According to Canadian tax law the interest on loans used for investment purposes is tax deductible while interest on personal mortgage loans is not. One way of transforming from non-tax deductible to tax deductible interest expenses is to borrow against home equity to make investments. A re-advanceable mortgage is a product specifically designed to take advantage of this tax discrepancy. Using simulation we study the risk associated with the re-advanceable mortgage strategy to provide a better description of the mortgagor's position. We assume that the mortgagor invests the borrowings secured by home equity into a single risky asset (e.g., stock or mutual fund) whose evolution is described by geometric Brownian motion (GBM). With a re-advanceable mortgage we find that the average mortgage payoff time is less than the original mortgage term. However, there is considerable variation in the payoff times with a significant probability of a payoff time exceeding the original mortgage term. Higher income homeowners enjoy a payoff time distribution with both a lower average and a lower standard deviation than low-income homeowners. Thus this strategy is most beneficial to those with the highest income. We also find this strategy protects the homeowner in the event of job loss. This work is important to lenders, financial planners and homeowners to more fully understand the benefits and risk associated with this strategy.

  15. Estimating Probability of Default on Peer to Peer Market – Survival Analysis Approach

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    Đurović Andrija

    2017-05-01

    Full Text Available Arguably a cornerstone of credit risk modelling is the probability of default. This article aims is to search for the evidence of relationship between loan characteristics and probability of default on peer-to-peer (P2P market. In line with that, two loan characteristics are analysed: 1 loan term length and 2 loan purpose. The analysis is conducted using survival analysis approach within the vintage framework. Firstly, 12 months probability of default through the cycle is used to compare riskiness of analysed loan characteristics. Secondly, log-rank test is employed in order to compare complete survival period of cohorts. Findings of the paper suggest that there is clear evidence of relationship between analysed loan characteristics and probability of default. Longer term loans are more risky than the shorter term ones and the least risky loans are those used for credit card payoff.

  16. Chemoembolization With Doxorubicin-Eluting Beads for Unresectable Hepatocellular Carcinoma: Five-Year Survival Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Malagari, Katerina, E-mail: kmalag@otonet.gr [University of Athens, Second Department of Radiology (Greece); Pomoni, Mary [University of Athens, Imaging and Research Unit (Greece); Moschouris, Hippocrates, E-mail: hipmosch@gmail.com [Tzanion Hospital, Department of Radiology (Greece); Bouma, Evanthia [University of Athens, Imaging and Research Unit (Greece); Koskinas, John [Ippokration Hospital, University of Athens, Department of Internal Medicine and Hepatology (Greece); Stefaniotou, Aspasia [University of Athens, Imaging and Research Unit (Greece); Marinis, Athanasios [Tzanion Hospital, Department of Surgery (Greece); Kelekis, Alexios; Alexopoulou, Efthymia [University of Athens, Second Department of Radiology (Greece); Chatziioannou, Achilles [University of Athens, First Department of Radiology (Greece); Chatzimichael, Katerina [University of Athens, Second Department of Radiology (Greece); Dourakis, Spyridon [Ippokration Hospital, University of Athens, Department of Internal Medicine and Hepatology (Greece); Kelekis, Nikolaos [University of Athens, Second Department of Radiology (Greece); Rizos, Spyros [Tzanion Hospital, Department of Surgery (Greece); Kelekis, Dimitrios [University of Athens, Imaging and Research Unit (Greece)

    2012-10-15

    Purpose: The purpose of this study was to report on the 5-year survival of hepatocellular carcinoma (HCC) patients treated with DC Bead loaded with doxorubicin (DEB-DOX) in a scheduled scheme in up to three treatments and thereafter on demand. Materials and Methods: 173 HCC patients not suitable for curable treatments were prospectively enrolled (mean age 70.4 {+-} 7.4 years). Child-Pugh (Child) class was A/B (102/71 [59/41 %]), Okuda stage was 0/1/2 (91/61/19 [53.2/35.7/11.1 %]), and mean lesion diameter was 7.6 {+-} 2.1 cm. Lesion morphology was one dominant {<=}5 cm (22 %), one dominant >5 cm (41.6 %), multifocal {<=}5 (26 %), and multifocal >5 (10.4 %). Results: Overall survival at 1, 2, 3, 4, and 5 years was 93.6, 83.8, 62, 41.04, and 22.5 %, with higher rates achieved in Child class A compared with Child class B patients (95, 88.2, 61.7, 45, and 29.4 % vs. 91.5, 75, 50.7, 35.2, and 12.8 %). Mean overall survival was 43.8 months (range 1.2-64.8). Cumulative survival was better for Child class A compared with Child class B patients (p = 0.029). For patients with dominant lesions {<=}5 cm 1-, 2-, 3-, 4-, and 5-year survival rates were 100, 95.2, 71.4, 66.6, and 47.6 % for Child class A and 94.1, 88.2, 58.8, 41.2, 29.4, and 23.5 % for Child class B patients. Regarding DEB-DOX treatment, multivariate analysis identified number of lesions (p = 0.033), lesion vascularity (p < 0.0001), initially achieved complete response (p < 0.0001), and objective response (p = 0.046) as significant and independent determinants of 5-year survival. Conclusion: DEB-DOX results, with high rates of 5-year survival for patients, not amenable to curative treatments. Number of lesions, lesion vascularity, and local response were significant independent determinants of 5-year survival.

  17. Analysis of an Interactive Technology Supported Problem-Based Learning STEM Project Using Selected Learning Sciences Interest Areas (SLSIA)

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    Kumar, David Devraj

    2017-01-01

    This paper reports an analysis of an interactive technology-supported, problem-based learning (PBL) project in science, technology, engineering and mathematics (STEM) from a Learning Sciences perspective using the Selected Learning Sciences Interest Areas (SLSIA). The SLSIA was adapted from the "What kinds of topics do ISLS [International…

  18. Lipid emulsion improves survival in animal models of local anesthetic toxicity: a meta-analysis.

    Science.gov (United States)

    Fettiplace, Michael R; McCabe, Daniel J

    2017-08-01

    The Lipid Emulsion Therapy workgroup, organized by the American Academy of Clinical Toxicology, recently conducted a systematic review, which subjectively evaluated lipid emulsion as a treatment for local anesthetic toxicity. We re-extracted data and conducted a meta-analysis of survival in animal models. We extracted survival data from 26 publications and conducted a random-effect meta-analysis based on odds ratio weighted by inverse variance. We assessed the benefit of lipid emulsion as an independent variable in resuscitative models (16 studies). We measured Cochran's Q for heterogeneity and I2 to determine variance contributed by heterogeneity. Finally, we conducted a funnel plot analysis and Egger's test to assess for publication bias in studies. Lipid emulsion reduced the odds of death in resuscitative models (OR =0.24; 95%CI: 0.1-0.56, p = .0012). Heterogeneity analysis indicated a homogenous distribution. Funnel plot analysis did not indicate publication bias in experimental models. Meta-analysis of animal data supports the use of lipid emulsion (in combination with other resuscitative measures) for the treatment of local anesthetic toxicity, specifically from bupivacaine. Our conclusion differed from the original review. Analysis of outliers reinforced the need for good life support measures (securement of airway and chest compressions) along with prompt treatment with lipid.

  19. Survival analysis of colorectal cancer patients with tumor recurrence using global score test methodology

    Science.gov (United States)

    Zain, Zakiyah; Aziz, Nazrina; Ahmad, Yuhaniz; Azwan, Zairul; Raduan, Farhana; Sagap, Ismail

    2014-12-01

    Colorectal cancer is the third and the second most common cancer worldwide in men and women respectively, and the second in Malaysia for both genders. Surgery, chemotherapy and radiotherapy are among the options available for treatment of patients with colorectal cancer. In clinical trials, the main purpose is often to compare efficacy between experimental and control treatments. Treatment comparisons often involve several responses or endpoints, and this situation complicates the analysis. In the case of colorectal cancer, sets of responses concerned with survival times include: times from tumor removal until the first, the second and the third tumor recurrences, and time to death. For a patient, the time to recurrence is correlated to the overall survival. In this study, global score test methodology is used in combining the univariate score statistics for comparing treatments with respect to each survival endpoint into a single statistic. The data of tumor recurrence and overall survival of colorectal cancer patients are taken from a Malaysian hospital. The results are found to be similar to those computed using the established Wei, Lin and Weissfeld method. Key factors such as ethnic, gender, age and stage at diagnose are also reported.

  20. Survival analysis of colorectal cancer patients with tumor recurrence using global score test methodology

    Energy Technology Data Exchange (ETDEWEB)

    Zain, Zakiyah, E-mail: zac@uum.edu.my; Ahmad, Yuhaniz, E-mail: yuhaniz@uum.edu.my [School of Quantitative Sciences, Universiti Utara Malaysia, UUM Sintok 06010, Kedah (Malaysia); Azwan, Zairul, E-mail: zairulazwan@gmail.com, E-mail: farhanaraduan@gmail.com, E-mail: drisagap@yahoo.com; Raduan, Farhana, E-mail: zairulazwan@gmail.com, E-mail: farhanaraduan@gmail.com, E-mail: drisagap@yahoo.com; Sagap, Ismail, E-mail: zairulazwan@gmail.com, E-mail: farhanaraduan@gmail.com, E-mail: drisagap@yahoo.com [Surgery Department, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, 56000 Bandar Tun Razak, Kuala Lumpur (Malaysia); Aziz, Nazrina, E-mail: nazrina@uum.edu.my

    2014-12-04

    Colorectal cancer is the third and the second most common cancer worldwide in men and women respectively, and the second in Malaysia for both genders. Surgery, chemotherapy and radiotherapy are among the options available for treatment of patients with colorectal cancer. In clinical trials, the main purpose is often to compare efficacy between experimental and control treatments. Treatment comparisons often involve several responses or endpoints, and this situation complicates the analysis. In the case of colorectal cancer, sets of responses concerned with survival times include: times from tumor removal until the first, the second and the third tumor recurrences, and time to death. For a patient, the time to recurrence is correlated to the overall survival. In this study, global score test methodology is used in combining the univariate score statistics for comparing treatments with respect to each survival endpoint into a single statistic. The data of tumor recurrence and overall survival of colorectal cancer patients are taken from a Malaysian hospital. The results are found to be similar to those computed using the established Wei, Lin and Weissfeld method. Key factors such as ethnic, gender, age and stage at diagnose are also reported.

  1. A panel-data analysis of interest rates and dollarization in Brazil

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    Edmar L. Bacha

    2009-12-01

    Full Text Available We investigate the role of financial dollarization and systemic risks in the determination of real interest rates in Brazil. In a simple currency-choice portfolio model, we show that a strategy of reducing dollarization, if it fails to address fundamental macroeconomic risks, leads to higher domestic real interest rates. We confirm this prediction in an empirical panel-based model, involving systemic risk variables, but find that the effect is small after controlling for the risks of dilution and default. We apply our empirical estimates to the case of Brazil - a natural case study given its low degree of financial dollarization and very high real interest rates. The estimated model is unable to explain the high interest rate levels in the aftermath of Brazil's 1994 inflation stabilization. However, since the adoption in 1999 of inflation targeting and floating exchange rates, Brazil's real interest rates are found to be gradually converging to the model's predicted values. The estimation also shows that further reductions in Brazil's real interest rates could be achieved through sound fundamentals that led to investment-grade status rather than financial dollarization.Analisamos o papel da dolarização financeira e do risco sistêmico na determinação da taxa real de juros no Brasil. Em um modelo simples de portfólio, nós mostramos que a estratégia de reduzir a dolarização da economia, se ainda persistirem riscos macroeconômicos, leva a uma maior taxa real de juros doméstica. Nós confirmamos essa assertiva a partir de um modelo em painel, envolvendo variáveis de risco sistêmico; contudo, os efeitos são pequenos quando controlados por riscos de inflação e de default. Em seguida, aplicamos nossas estimações para o caso do Brasil - um caso natural dado seu baixo nível de dolarização financeira e altas taxas reais de juros. O modelo estimado é incapaz de explicar os elevados níveis de taxas de juros no Brasil após a

  2. Publication analysis of the contact lens field: what are the current topics of interest?

    Science.gov (United States)

    Cardona, Genís; Sanz, Joan P

    2015-01-01

    To determine the main current research interests of scientists working in the contact lens field. All articles published in the 2011 issues of all journals included in the Journal Citation Reports subject category Ophthalmology were inspected to expose those papers related to the contact lens field. Information regarding source journal was obtained and authorship details were recorded to determine the top most prolific authors, institutions and countries. A comprehensive list of key words was compiled to generate a two-dimensional term map in which the frequency of occurrence of a particular term is defined by label size and the distance between two terms is an indication of the relatedness of these terms, based on their co-occurrences within groups of key words. Clusters of related terms were also identified. Visual examination of all articles uncovered a total of 156 papers, published in 28 different journals. Contact Lens & Anterior Eye, Eye & Contact Lens and Optometry and Vision Science had 27 articles each. The most prolific authors and institutions revealed the predominance of countries with long research tradition in the contact lens field. Ten different word clusters or areas of interest were identified, including both traditional, yet unresolved issues (e.g., comfort or dry eye), and the latest research efforts (e.g., myopia control). These findings, which revealed contact lenses to be a fertile area of research, may be of relevance to new researchers as well as to those interested in exploring the latest research trends in this scientific discipline. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  3. Survival analysis of irish amyotrophic lateral sclerosis patients diagnosed from 1995-2010.

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    James Rooney

    Full Text Available INTRODUCTION: The Irish ALS register is a valuable resource for examining survival factors in Irish ALS patients. Cox regression has become the default tool for survival analysis, but recently new classes of flexible parametric survival analysis tools known as Royston-Parmar models have become available. METHODS: We employed Cox proportional hazards and Royston-Parmar flexible parametric modeling to examine factors affecting survival in Irish ALS patients. We further examined the effect of choice of timescale on Cox models and the proportional hazards assumption, and extended both Cox and Royston-Parmar models with time varying components. RESULTS: On comparison of models we chose a Royston-Parmar proportional hazards model without time varying covariates as the best fit. Using this model we confirmed the association of known survival markers in ALS including age at diagnosis (Hazard Ratio (HR 1.34 per 10 year increase; 95% CI 1.26-1.42, diagnostic delay (HR 0.96 per 12 weeks delay; 95% CI 0.94-0.97, Definite ALS (HR 1.47 95% CI 1.17-1.84, bulbar onset disease (HR 1.58 95% CI 1.33-1.87, riluzole use (HR 0.72 95% CI 0.61-0.85 and attendance at an ALS clinic (HR 0.74 95% CI 0.64-0.86. DISCUSSION: Our analysis explored the strengths and weaknesses of Cox proportional hazard and Royston-Parmar flexible parametric methods. By including time varying components we were able to gain deeper understanding of the dataset. Variation in survival between time periods appears to be due to missing data in the first time period. The use of age as timescale to account for confounding by age resolved breaches of the proportional hazards assumption, but in doing so may have obscured deficiencies in the data. Our study demonstrates the need to test for, and fully explore, breaches of the Cox proportional hazards assumption. Royston-Parmar flexible parametric modeling proved a powerful method for achieving this.

  4. [Conflicts of interest in clinical practice. Ethical analysis of some relationships with the pharmaceutical industry].

    Science.gov (United States)

    Salas, Sofía P; Osorio F, Marcial; Vial C, Pablo; Rehbein V, Ana María; Salas A, Camila; Beca I, Juan Pablo

    2006-12-01

    Sometimes, the prescription practice of physicians can be influenced by factors that are not related to scientific evidence due to the appearance of several conflicts of interest. These conflicts cause social concern and have prompted actions to regulate the ethics of individual and corporative activities related to healthcare. We analyzed the ethical problems involved in the physician-industry relationship. For this purpose, we considered as the main actors related to this problem, the pharmaceutical industry and their marketing strategies, medical doctors and the independence and objectivity that should guide prescriptions and, finally, patients and their right to receive prescriptions based on scientific evidence. From the point of view of the Bioethics principles, Beneficence would not be respected when gifts or other donations received from the industry affect doctor's independence. Non Maleficence principle could be jeopardized if there is an increased risk of treatment failure and finally Justice could be altered if there is a cost increase for either patients or health institutions. As a conclusion, we consider that the presence of conflicts of interest in the relationship of physicians with the pharmaceutical industry is an important ethical problem. In consequence, this group endorses the recommendations of the Chilean Association of Medical Scientific Societies and advices to include ethical guidelines on this topic in the curriculum of medical schools.

  5. Landscape transformation analysis employing compound interest formula in the Nun Nadi Watershed, India

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    Hasan Raja Naqvi

    2014-12-01

    Full Text Available The Nun Nadi watershed is close to the Dehradun city and some settlements are spread over the Mussoorie hills. Landsat TM images of the year 2000 and 2009 were used to analyze the changes in Land Use/Land Cover (LULC data employing compound interest formula. The main reason to choose the time period is that Dehradun was declared capital of Uttrakhand state of India in the year 2001. We observed rapid changes in the LULC data in the time period studied. This is primarily due to urban growth that increased exponentially after 2001 near Dehradun city and Mussoorie hills. The highest positive change rate was observed in the built-up and agricultural land which increased 8.39 and 9.92 percent, respectively. Interestingly we noticed that the dense and sparse vegetation shrunk in terms of land coverage, on the other hand, drastic negative change was observed in the bare/barren soil class. Taken together, these results indicate significant changes in various land use categories.

  6. Meta-analysis of the effects of beta blocker on survival time in cancer patients.

    Science.gov (United States)

    Choi, Chel Hun; Song, Taejong; Kim, Tae Hyun; Choi, Jun Kuk; Park, Jin-Young; Yoon, Aera; Lee, Yoo-Young; Kim, Tae-Joong; Bae, Duk-Soo; Lee, Jeong-Won; Kim, Byoung-Gie

    2014-07-01

    This study was to elucidate the potential benefit of beta blockers on cancer survival. We comprehensively searched PubMed, Embase, and the Cochrane Library from their inception to April 2013. Two authors independently screened and reviewed the eligibility of each study and coded the participants, treatment, and outcome characteristics. The primary outcomes were overall survival (OS) and disease-free survival (DFS). Twelve studies published between 1993 and 2013 were included in the final analysis. Four papers reported results from 10 independent groups, resulting in a total of 18 comparisons based on data obtained from 20,898 subjects. Effect sizes (hazard ratios, HR) were heterogeneous, and random-effects models were used in the analyses. The meta-analysis demonstrated that beta blocker use is associated with improved OS (HR 0.79; 95 % CI 0.67-0.93; p = 0.004) and DFS (HR 0.69; 95 % CI 0.53-0.91; p = 0.009). Although statistically not significant, the effect size was greater in patients with low-stage cancer or cancer treated primarily with surgery than in patients with high-stage cancer or cancer treated primarily without surgery (HR 0.60 vs. 0.78, and 0.60 vs. 0.80, respectively). Although only two study codes were analyzed, the studies using nonselective beta blockers showed that there was no overall effect on OS (HR 0.52, 95 % CI 0.09-3.04). This meta-analysis provides evidence that beta blocker use can be associated with the prolonged survival of cancer patients, especially patients with early-stage cancer treated primarily with surgery.

  7. Analysis on Lung Cancer Survival from 2001 to 2007 in Qidong, China

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    Jian ZHU

    2011-01-01

    Full Text Available Background and objective Lung cancer is one of the most important malignancies in China. Survival rates of lung cancer on the population-based cancer registry for the years 2001-2007 in Qidong were analysed in order to provide the basis for the prognosis assessment and the control of this cancer. Methods Total 4,451 registered lung cancer cases was followed up to December 31st, 2009. Death certificates only (DCO cases were excluded, leaving 4,382 cases for survival analysis. Cumulative observed survival rate (OS and relative survival rate (RS were calculated using Hakulinen’s method performed by the SURV 3.01 software developed at the Finnish Cancer Registry. Results The 1-, 3-, and 5-year OS rates were 23.73%, 11.89%, 10.01%, and the RS rates were 24.86%, 13.69%, 12.73%, respectively. The 1-, 3-, and 5-year RS of males vs females were 23.70% vs 27.89%, 12.58% vs 16.53%, and 11.73% vs 15.21%, respectively, with statisitically significant differences (χ2=13.77, P=0.032. RS of age groups of 15-34, 35-44, 45-54, 55-64, 65-74 and 75+ were 35.46%, 17.66%, 11.97%, 13.49%, 10.61%, 15.14%, respectively. Remarkable improvement could be seen for the 5-year RS in this setting if compared with that for the years 1972-2000. Conclusion The lung cancer survival outcomes in Qidong have been improved gradually for the past decades. Further measures on the prevention, diagnosis and treatment of lung cancer should be taken.

  8. Exploratory analysis of ERCC2 DNA methylation in survival among pediatric medulloblastoma patients.

    Science.gov (United States)

    Banfield, Emilyn; Brown, Austin L; Peckham, Erin C; Rednam, Surya P; Murray, Jeffrey; Okcu, M Fatih; Mitchell, Laura E; Chintagumpala, Murali M; Lau, Ching C; Scheurer, Michael E; Lupo, Philip J

    2016-10-01

    Medulloblastoma is the most frequent malignant pediatric brain tumor. While survival rates have improved due to multimodal treatment including cisplatin-based chemotherapy, there are few prognostic factors for adverse treatment outcomes. Notably, genes involved in the nucleotide excision repair pathway, including ERCC2, have been implicated in cisplatin sensitivity in other cancers. Therefore, this study evaluated the role of ERCC2 DNA methylation profiles on pediatric medulloblastoma survival. The study population included 71 medulloblastoma patients (age DNA methylation profiles were generated from peripheral blood samples using the Illumina Infinium Human Methylation 450 Beadchip. Sixteen ERCC2-associated CpG sites were evaluated in this analysis. Multivariable regression models were used to determine the adjusted association between DNA methylation and survival. Cox regression and Kaplan-Meier curves were used to compare 5-year overall survival between hyper- and hypo-methylation at each CpG site. In total, 12.7% (n=9) of the patient population died within five years of diagnosis. In our population, methylation of the cg02257300 probe (Hazard Ratio=9.33; 95% Confidence Interval: 1.17-74.64) was associated with death (log-rank p=0.01). This association remained suggestive after correcting for multiple comparisons (FDR pDNA methylation within the promoter region of the ERCC2 gene may be associated with survival in pediatric medulloblastoma. If confirmed in future studies, this information may lead to improved risk stratification or promote the development of novel, targeted therapeutics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Functional Regions of Interest in Electrical Impedance Tomography: A Secondary Analysis of Two Clinical Studies.

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    Tobias Becher

    Full Text Available Patients with acute respiratory distress syndrome (ARDS typically show a high degree of ventilation inhomogeneity, which is associated with morbidity and unfavorable outcomes. Electrical impedance tomography (EIT is able to detect ventilation inhomogeneity, but it is unclear which method for defining the region of interest (ROI should be used for this purpose. The aim of our study was to compare the functional region of interest (fROI method to both the lung area estimation method (LAEM and no ROI when analysing global parameters of ventilation inhomogeneity. We assumed that a good method for ROI determination would lead to a high discriminatory power for ventilation inhomogeneity, as defined by the area under the receiver operating characteristics curve (AUC, comparing patients suffering from ARDS and control patients without pulmonary pathologies.We retrospectively analysed EIT data from 24 ARDS patients and 12 control patients without pulmonary pathology. In all patients, a standardized low-flow-pressure volume maneuver had been performed and was used for EIT image generation. We compared the AUC for global inhomogeneity (GI index and coefficient of variation (CV between ARDS and control patients using all EIT image pixels, the fROI method and the LAEM for ROI determination.When analysing all EIT image pixels, we found an acceptable AUC both for the GI index (AUC = 0.76; 95% confidence interval (CI 0.58-0.94 and the CV (AUC = 0.74; 95% CI 0.55-0.92. With the fROI method, we found a deteriorating AUC with increasing threshold criteria. With the LAEM, we found the best AUC both for the GI index (AUC = 0.89; 95% CI 0.78-1.0 and the CV (AUC = 0.89; 95% CI 0.78-1.0 using a threshold criterion of 50% of the maximum tidal impedance change.In the assessment of ventilation inhomogeneity with EIT, functional regions of interest obscure the difference between patients with ARDS and control patients without pulmonary pathologies. The LAEM is preferable

  10. Discovery analysis of TCGA data reveals association between germline genotype and survival in ovarian cancer patients.

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    Rosemary Braun

    Full Text Available Ovarian cancer remains a significant public health burden, with the highest mortality rate of all the gynecological cancers. This is attributable to the late stage at which the majority of ovarian cancers are diagnosed, coupled with the low and variable response of advanced tumors to standard chemotherapies. To date, clinically useful predictors of treatment response remain lacking. Identifying the genetic determinants of ovarian cancer survival and treatment response is crucial to the development of prognostic biomarkers and personalized therapies that may improve outcomes for the late-stage patients who comprise the majority of cases.To identify constitutional genetic variations contributing to ovarian cancer mortality, we systematically investigated associations between germline polymorphisms and ovarian cancer survival using data from The Cancer Genome Atlas Project (TCGA. Using stage-stratified Cox proportional hazards regression, we examined >650,000 SNP loci for association with survival. We additionally examined whether the association of significant SNPs with survival was modified by somatic alterations.Germline polymorphisms at rs4934282 (AGAP11/C10orf116 and rs1857623 (DNAH14 were associated with stage-adjusted survival (p= 1.12e-07 and 1.80e-07, FDR q= 1.2e-04 and 2.4e-04, respectively. A third SNP, rs4869 (C10orf116, was additionally identified as significant in the exome sequencing data; it is in near-perfect LD with rs4934282. The associations with survival remained significant when somatic alterations.Discovery analysis of TCGA data reveals germline genetic variations that may play a role in ovarian cancer survival even among late-stage cases. The significant loci are located near genes previously reported as having a possible relationship to platinum and taxol response. Because the variant alleles at the significant loci are common (frequencies for rs4934282 A/C alleles = 0.54/0.46, respectively; rs1857623 A/G alleles = 0

  11. Molecular Genetic Analysis of Human Endometrial Mesenchymal Stem Cells That Survived Sublethal Heat Shock

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    A. E. Vinogradov

    2017-01-01

    Full Text Available High temperature is a critical environmental and personal factor. Although heat shock is a well-studied biological phenomenon, hyperthermia response of stem cells is poorly understood. Previously, we demonstrated that sublethal heat shock induced premature senescence in human endometrial mesenchymal stem cells (eMSC. This study aimed to investigate the fate of eMSC-survived sublethal heat shock (SHS with special emphasis on their genetic stability and possible malignant transformation using methods of classic and molecular karyotyping, next-generation sequencing, and transcriptome functional analysis. G-banding revealed random chromosome breakages and aneuploidy in the SHS-treated eMSC. Molecular karyotyping found no genomic imbalance in these cells. Gene module and protein interaction network analysis of mRNA sequencing data showed that compared to untreated cells, SHS-survived progeny revealed some difference in gene expression. However, no hallmarks of cancer were found. Our data identified downregulation of oncogenic signaling, upregulation of tumor-suppressing and prosenescence signaling, induction of mismatch, and excision DNA repair. The common feature of heated eMSC is the silence of MYC, AKT1/PKB oncogenes, and hTERT telomerase. Overall, our data indicate that despite genetic instability, SHS-survived eMSC do not undergo transformation. After long-term cultivation, these cells like their unheated counterparts enter replicative senescence and die.

  12. Survival benefit with capecitabine/docetaxel versus docetaxel alone: analysis of therapy in a randomized phase III trial.

    Science.gov (United States)

    Miles, David; Vukelja, Svetislava; Moiseyenko, Vladimir; Cervantes, Guadalupe; Mauriac, Louis; Van Hazel, Guy; Liu, Wing-Yiu; Ayoub, Jean-Pierre; O'Shaughnessy, Joyce A

    2004-10-01

    In a large phase III trial of 511 patients with anthracycline-pretreated advanced/metastatic breast cancer, capecitabine/docetaxel combination therapy was shown to have significantly superior efficacy compared with single-agent docetaxel, including superior progression-free and overall survival and objective response rate. An updated survival analysis with >/= 27 months follow-up shows that patients receiving combination therapy maintained significantly superior survival (hazard ratio [HR], 0.777 [95% CI, 0.645-0.942]; P < 0.01; median survival, 14.5 months vs. 11.5 months) compared with those receiving single-agent docetaxel. Following the failure of docetaxel monotherapy, 35% of patients did not receive additional cytotoxic chemotherapy. Among patients randomized to single-agent docetaxel, only those given poststudy single-agent capecitabine had significantly prolonged survival compared with those given any other poststudy chemotherapy (HR, 0.500; P = 0.0046; median survival, 21.0 months vs. 12.3 months, respectively). By contrast, poststudy vinorelbine-containing chemotherapy did not affect survival following progression on single-agent docetaxel compared with other poststudy chemotherapy regimens (HR, 1.014; P = 0.94; median survival, 13.5 months vs. 12.6 months, respectively). Among patients randomized to combination therapy, discontinuing docetaxel of capecitabine has a similar effect on survival (HR, 0.720; P = 0.20; median survival, 15.8 months vs. 18.3 months, respectively). Median survival was 18.3 months in patients who discontinued docetaxel and continued to receive capecitabine versus 15.8 months in patients who discontinued capecitabine and continued to receive docetaxel, with a trend toward improved survival in patients continuing to receive capecitabine. Although this is a retrospective analysis, these data suggest that the sequential administration of docetaxel followed by capecitabine is associated with prolonged survival in patients who are

  13. Demographic analysis of dormancy and survival in the terrestrial orchid Cypripedium reginae

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    Kery, Marc; Gregg, Katharine B.

    2004-01-01

    1. We use capture-recapture models to estimate the fraction of dormant ramets, survival and state transition rates, and to identify factors affecting these rates, for the terrestrial orchid Cypripedium reginae. We studied two populations in West Virginia, USA, for 11 years and investigated relationships between grazing and demography. Abe Run's population was small, with moderate herbivory by deer and relatively constant population size. The population at Big Draft was of medium size, with heavy deer grazing, and a sharply declining number of flowering plants up to the spring before our study started, when the population was fenced. 2. We observed dormant episodes lasting from 1 to 4 years. At Abe Run and Big Draft, 32.5% and 7.4% of ramets, respectively, were dormant at least once during the study period for an average of 1.6 and 1.3 years, respectively. We estimated the annual fraction of ramets in the dormant state at 12.3% (95% CI 9.5-15.8%) at Abe Run and at 1.8% (95% CI 1.2-2.6%) at Big Draft. Transition rates between the dormant, vegetative and flowering life-states did not vary between years in either population. Most surviving ramets remained in the same state from one year to the next. Survival rates were constant at Abe Run (0.96, 95% CI 0.93-0.97), but varied between years at Big Draft (0.89-0.99, mean 0.95). 3. At Big Draft, we found neither a temporal trend in survival after cessation of grazing, nor relationships between survival and the number of spring frost days or cumulative precipitation during the current or the previous 12 months. However, analysis of precipitation on a 3-month basis revealed a positive relationship between survival and precipitation during the spring (March-May) of the previous year. 4. Relationship between climate and the population dynamics of orchids may have to be studied with a fine temporal resolution, and considering possible time lags. Capture-recapture modelling provides a comprehensive and flexible framework for

  14. Survival rates of porcelain laminate restoration based on different incisal preparation designs: An analysis

    Science.gov (United States)

    Shetty, Ashish; Kaiwar, Anjali; Shubhashini, N; Ashwini, P; Naveen, DN; Adarsha, MS; Shetty, Mitha; Meena, N

    2011-01-01

    Background: Veneer restorations provide a valid conservative alternative to complete coverage as they avoid aggressive dental preparation; thus, maintaining tooth structure. Initially, laminates were placed on the unprepared tooth surface. Although there is as yet no consensus as to whether or not teeth should be prepared for laminate veneers, currently, more conservative preparations have been advocated. Because of their esthetic appeal, biocompatibility and adherence to the physiology of minimal-invasive dentistry, porcelain laminate veneers have now become a restoration of choice. Currently, there is a lack of clinical consensus regarding the type of design preferred for laminates. Widely varying survival rates and methods for its estimation have been reported for porcelain veneers over approximately 2–10 years. Relatively few studies have been reported in the literature that use survival estimates, which allow for valid study comparisons between the types of preparation designs used. No survival analysis has been undertaken for the designs used. The purpose of this article is to attempt to review the survival rates of veneers based on different incisal preparation designs from both clinical and non-clinical studies. Aims and Objectives: The purpose of this study is to review both clinical and non-clinical studies to determine the survival rates of veneers based on different incisal preparation designs. A further objective of the study is to understand which is the most successful design in terms of preparation. Materials and Methods This study evaluated the existing literature – survival rates of veneers based on incisal preparation designs. The search strategy involved MEDLINE, BITTORRENT and other databases. Statistical Analysis Data were tabulated. Because of variability in the follow-up period in different studies, the follow-up period was extrapolated to 10 years in common for all of them. Accordingly, the failure rate was then estimated and The

  15. Analysis of error-prone survival data under additive hazards models: measurement error effects and adjustments.

    Science.gov (United States)

    Yan, Ying; Yi, Grace Y

    2016-07-01

    Covariate measurement error occurs commonly in survival analysis. Under the proportional hazards model, measurement error effects have been well studied, and various inference methods have been developed to correct for error effects under such a model. In contrast, error-contaminated survival data under the additive hazards model have received relatively less attention. In this paper, we investigate this problem by exploring measurement error effects on parameter estimation and the change of the hazard function. New insights of measurement error effects are revealed, as opposed to well-documented results for the Cox proportional hazards model. We propose a class of bias correction estimators that embraces certain existing estimators as special cases. In addition, we exploit the regression calibration method to reduce measurement error effects. Theoretical results for the developed methods are established, and numerical assessments are conducted to illustrate the finite sample performance of our methods.

  16. Survival Analysis of Breast Cancer Subtypes in Patients With Spinal Metastases

    DEFF Research Database (Denmark)

    Wang, Miao; Jensen, Anders Bonde; Morgen, Soeren Smith

    2014-01-01

    hazards regression model unadjusted and adjusted by age were used. RESULTS: Patients with ER-negative (-) breast cancer had 11 months shorter median survival duration (10.6 vs. 21.5 mo) and 48% higher mortality risk (P=0.03) than those with ER-positive (+) breast cancer. Patients with PgR (-) status had...... in determining breast cancer subtypes and predicting patients' response to adjuvant treatments. METHODS: Until August 2013, we retrieved 151 surgically treated patients with breast cancer spinal metastases and followed up all the patients for at least 2 years. Survival duration analysis and Cox proportional...... from score "5" to "3" in Tokuhashi scoring system and from "slow growth" to "moderate growth" in Tomita scoring system. Spine surgeons should be critical before performing high-risk extensive surgery in patients with ER/HR (-) status, and especially, in those with triple-negative status. LEVEL...

  17. Hypofractionated radiation therapy for invasive thyroid carcinoma in dogs: a retrospective analysis of survival.

    Science.gov (United States)

    Brearley, M J; Hayes, A M; Murphy, S

    1999-05-01

    Thirteen dogs with invasive thyroid carcinoma (WHO classification T2b or T3b) seen between January 1991 and October 1997 were treated by external beam irradiation. Four once-weekly fractions of 9 gray of 4 MeV X-rays were administered. Four of the dogs died of progression of the primary disease and four from metastatic spread. Of the remaining dogs, three died of unrelated problems, although two were still alive at the time of the censor. Kaplan-Meier analysis of the survival time from first dose to death from either primary or metastatic disease gave a median survival time of 96 weeks (mean 85 weeks, range six to 247 weeks). Radiographic evidence of pulmonary metastatic disease at presentation had no prognostic value whereas crude growth rate was a highly significant factor. The present series indicates that radiation therapy should be considered an important modality for the control of invasive thyroid carcinoma in the dog.

  18. Survival analysis of a critical resource for cavity-nesting communities: patterns of tree cavity longevity.

    Science.gov (United States)

    Edworthy, Amanda B; Wiebe, Karen L; Martin, Kathy

    2012-09-01

    Tree cavities are a vital multi-annual resource used by cavity-nesting birds and mammals for nesting and shelter. The abundance of this resource will be influenced by the rates at which cavities are created and destroyed. We applied the demographic concepts of survival and longevity to populations of tree holes to investigate rates of loss for cavities in three tree species, as well as how characteristics of nest trees, habitat type, and species of excavator affected the persistence of tree cavities in trembling aspen, Populus tremuloides (95% of cavities were in aspen trees), in interior British Columbia, Canada. By modeling survival of 1635 nesting cavities in aspen over a time span of 16 years, we found that the decay stage of the nest tree was the most important factor determining cavity longevity. Cavities in trees with advanced decay had a relatively short median longevity of 7 years (95% CI 6-9 years), whereas those in living trees had a median longevity of more than 15 years. We found that cavity longevity was greater in continuous forest than in aspen grove habitat. Interestingly, cavities formed by weak excavators survived as long as those created by Northern Flickers (Colaptes auratus), despite occurring in more decayed tree stems. Thus, weak excavators may be selecting for characteristics that make a tree persistent, such as a broken top. Our results indicate that retention of cavities in large, live aspen trees is necessary to conserve persistent cavities, and that cavity longevity will have a large effect on the structure and function of cavity-using vertebrate communities.

  19. Multiple regions-of-interest analysis of setup uncertainties for head-and-neck cancer radiotherapy.

    Science.gov (United States)

    Zhang, Lifei; Garden, Adam S; Lo, Justin; Ang, K Kian; Ahamad, Anesa; Morrison, William H; Rosenthal, David I; Chambers, Mark S; Zhu, X Ronald; Mohan, Radhe; Dong, Lei

    2006-04-01

    To analyze three-dimensional setup uncertainties for multiple regions of interest (ROIs) in head-and-neck region. In-room computed tomography (CT) scans were acquired using a CT-on-rails system for 14 patients. Three separate bony ROIs were defined: C2 and C6 vertebral bodies and the palatine process of the maxilla. Translational shifts of 3 ROIs were calculated relative to the marked isocenter on the immobilization mask. The shifts for all 3 ROIs were highly correlated. However, noticeable differences on the order of 2-6 mm existed between any 2 ROIs, indicating the flexibility and/or rotational effect in the head-and-neck region. The palatine process of the maxilla had the smallest right-left shifts because of the tight lateral fit in the face mask, but the largest superior-inferior movement because of in-plane rotation and variations in jaw positions. The neck region (C6) had the largest right-left shifts. The positioning mouthpiece was found effective in reducing variations in the superior-inferior direction. There was no statistically significant improvement for using the S-board (8 out of 14 patients) vs. the short face mask. We found variability in setup corrections for different regions of head-and-neck anatomy. These relative positional variations should be considered when making setup corrections or designing treatment margins.

  20. A Quantitative Analysis of Undisclosed Conflicts of Interest in Pharmacology Textbooks.

    Science.gov (United States)

    Piper, Brian J; Telku, Hassenet M; Lambert, Drew A

    2015-01-01

    Disclosure of potential conflicts of interest (CoI) is a standard practice for many biomedical journals but not for educational materials. The goal of this investigation was to determine whether the authors of pharmacology textbooks have undisclosed financial CoIs and to identify author characteristics associated with CoIs. The presence of potential CoIs was evaluated by submitting author names (N = 403; 36.3% female) to a patent database (Google Scholar) as well as a database that reports on the compensation ($USD) received from 15 pharmaceutical companies (ProPublica's Dollars for Docs). All publications (N = 410) of the ten highest compensated authors from 2009 to 2013 and indexed in Pubmed were also examined for disclosure of additional companies that the authors received research support, consulted, or served on speaker's bureaus. A total of 134 patents had been awarded (Maximum = 18/author) to textbook authors. Relative to DiPiro's Pharmacotherapy: A Pathophysiologic Approach, contributors to Goodman and Gilman's Pharmacological Basis of Therapeutics and Katzung's Basic and Clinical Pharmacology were more frequently patent holders (OR = 6.45, P 1 patent (OR = 0.15, P textbooks. Full transparency of potential CoIs, particularly patents, should become standard procedure for future editions of educational materials in pharmacology.

  1. Intelligent topical sentiment analysis for the classification of e-learners and their topics of interest.

    Science.gov (United States)

    Ravichandran, M; Kulanthaivel, G; Chellatamilan, T

    2015-01-01

    Every day, huge numbers of instant tweets (messages) are published on Twitter as it is one of the massive social media for e-learners interactions. The options regarding various interesting topics to be studied are discussed among the learners and teachers through the capture of ideal sources in Twitter. The common sentiment behavior towards these topics is received through the massive number of instant messages about them. In this paper, rather than using the opinion polarity of each message relevant to the topic, authors focus on sentence level opinion classification upon using the unsupervised algorithm named bigram item response theory (BIRT). It differs from the traditional classification and document level classification algorithm. The investigation illustrated in this paper is of threefold which are listed as follows: (1) lexicon based sentiment polarity of tweet messages; (2) the bigram cooccurrence relationship using naïve Bayesian; (3) the bigram item response theory (BIRT) on various topics. It has been proposed that a model using item response theory is constructed for topical classification inference. The performance has been improved remarkably using this bigram item response theory when compared with other supervised algorithms. The experiment has been conducted on a real life dataset containing different set of tweets and topics.

  2. Survival rates of porcelain laminate restoration based on different incisal preparation designs: An analysis.

    Science.gov (United States)

    Shetty, Ashish; Kaiwar, Anjali; Shubhashini, N; Ashwini, P; Naveen, Dn; Adarsha, Ms; Shetty, Mitha; Meena, N

    2011-01-01

    Veneer restorations provide a valid conservative alternative to complete coverage as they avoid aggressive dental preparation; thus, maintaining tooth structure. Initially, laminates were placed on the unprepared tooth surface. Although there is as yet no consensus as to whether or not teeth should be prepared for laminate veneers, currently, more conservative preparations have been advocated. Because of their esthetic appeal, biocompatibility and adherence to the physiology of minimal-invasive dentistry, porcelain laminate veneers have now become a restoration of choice. Currently, there is a lack of clinical consensus regarding the type of design preferred for laminates. Widely varying survival rates and methods for its estimation have been reported for porcelain veneers over approximately 2-10 years. Relatively few studies have been reported in the literature that use survival estimates, which allow for valid study comparisons between the types of preparation designs used. No survival analysis has been undertaken for the designs used. The purpose of this article is to attempt to review the survival rates of veneers based on different incisal preparation designs from both clinical and non-clinical studies. The purpose of this study is to review both clinical and non-clinical studies to determine the survival rates of veneers based on different incisal preparation designs. A further objective of the study is to understand which is the most successful design in terms of preparation. This study evaluated the existing literature - survival rates of veneers based on incisal preparation designs. The search strategy involved MEDLINE, BITTORRENT and other databases. Data were tabulated. Because of variability in the follow-up period in different studies, the follow-up period was extrapolated to 10 years in common for all of them. Accordingly, the failure rate was then estimated and The weighted mean was computed. The study found that the window preparation was of the

  3. Comparison of a radiomic biomarker with volumetric analysis for decoding tumour phenotypes of lung adenocarcinoma with different disease-specific survival

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Mei; Zhang, Yu-Dong; Pu, Xue-Hui; Zhong, Yan; Yu, Tong-Fu [First Affiliated Hospital of Nanjing Medical University, Department of Radiology, Nanjing, Jiangsu Province (China); Li, Hai [First Affiliated Hospital of Nanjing Medical University, Department of Pathology, Nanjing (China); Wu, Jiang-Fen [GE Healthcare, Shanghai (China)

    2017-11-15

    To compare a multi-feature-based radiomic biomarker with volumetric analysis in discriminating lung adenocarcinomas with different disease-specific survival on computed tomography (CT) scans. This retrospective study obtained institutional review board approval and was Health Insurance Portability and Accountability Act (HIPAA) compliant. Pathologically confirmed lung adenocarcinoma (n = 431) manifested as subsolid nodules on CT were identified. Volume and percentage solid volume were measured by using a computer-assisted segmentation method. Radiomic features quantifying intensity, texture and wavelet were extracted from the segmented volume of interest (VOI). Twenty best features were chosen by using the Relief method and subsequently fed to a support vector machine (SVM) for discriminating adenocarcinoma in situ (AIS)/minimally invasive adenocarcinoma (MIA) from invasive adenocarcinoma (IAC). Performance of the radiomic signatures was compared with volumetric analysis via receiver-operating curve (ROC) analysis and logistic regression analysis. The accuracy of proposed radiomic signatures for predicting AIS/MIA from IAC achieved 80.5% with ROC analysis (Az value, 0.829; sensitivity, 72.1%; specificity, 80.9%), which showed significantly higher accuracy than volumetric analysis (69.5%, P = 0.049). Regression analysis showed that radiomic signatures had superior prognostic performance to volumetric analysis, with AIC values of 81.2% versus 70.8%, respectively. The radiomic tumour-phenotypes biomarker exhibited better diagnostic accuracy than traditional volumetric analysis in discriminating lung adenocarcinoma with different disease-specific survival. (orig.)

  4. Thermal analysis of ice and glass transitions in insects that do and do not survive freezing.

    Science.gov (United States)

    Rozsypal, Jan; Moos, Martin; Šimek, Petr; Koštál, Vladimír

    2018-03-01

    Some insects rely on the strategy of freeze tolerance for winter survival. During freezing, extracellular body water transitions from the liquid to solid phase and cells undergo freeze-induced dehydration. Here we present results of a thermal analysis (from differential scanning calorimetry) of ice fraction dynamics during gradual cooling after inoculative freezing in variously acclimated larvae of two drosophilid flies, Drosophila melanogaster and Chymomyza costata. Although the species and variants ranged broadly between 0 and close to 100% survival of freezing, there were relatively small differences in ice fraction dynamics. For instance, the maximum ice fraction (IF max ) ranged between 67.9 and 77.7% total body water (TBW). The C. costata larvae showed statistically significant phenotypic shifts in parameters of ice fraction dynamics (melting point and IF max ) upon entry into diapause, cold-acclimation, and feeding on a proline-augmented diet. These differences were mostly driven by colligative effects of accumulated proline (ranging between 6 and 487 mmol.kg -1 TBW) and other metabolites. Our data suggest that these colligative effects per se do not represent a sufficient mechanistic explanation for high freeze tolerance observed in diapausing, cold-acclimated C. costata larvae. Instead, we hypothesize that accumulated proline exerts its protective role via a combination of mechanisms. Specifically, we found a tight association between proline-induced stimulation of glass transition in partially-frozen body liquids (vitrification) and survival of cryopreservation in liquid nitrogen. © 2018. Published by The Company of Biologists Ltd.

  5. Squamous cell carcinoma of the pancreas: A systematic review and pooled survival analysis.

    Science.gov (United States)

    Ntanasis-Stathopoulos, Ioannis; Tsilimigras, Diamantis I; Georgiadou, Despoina; Kanavidis, Prodromos; Riccioni, Olga; Salla, Charitini; Psaltopoulou, Theodora; Sergentanis, Theodoros N

    2017-07-01

    The diagnosis and treatment of squamous cell carcinoma of the pancreas pose dilemmas in the clinical practice. The present study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eligible articles were sought in MEDLINE up to 30th April 2016. A pooled Cox regression analysis was performed to evaluate factors potentially associated with overall survival (OS) and relapse-free survival (RFS). Fifty-four cases of pure squamous cell pancreatic carcinomas were identified in total. The mean age was 61.9 years, and most patients were males (61.1%). The median OS was 7 months. Resectability (p = 0.003) and more recent publication year (p < 0.001) were associated with better OS, as was low/intermediate tumour grade (p = 0.032) with RFS. Despite its poor prognosis, survival rates of pancreatic squamous cell carcinoma seem improved during the recent years; resectability and low/intermediate grade emerged as favourable prognostic factors. Collaborative epidemiological studies are deemed necessary to further validate the results stemming from the published case reports of this rare entity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Pan-cancer analysis of intratumor heterogeneity as a prognostic determinant of survival

    Science.gov (United States)

    Desrichard, Alexis; Şenbabaoğlu, Yasin; Hakimi, A. Ari; Makarov, Vladimir; Reis-Filho, Jorge S.; Chan, Timothy A.

    2016-01-01

    As tumors accumulate genetic alterations, an evolutionary process occurs in which genetically distinct subclonal populations of cells co-exist, resulting in intratumor genetic heterogeneity (ITH). The clinical implications of ITH remain poorly defined. Data are limited with respect to whether ITH is an independent determinant of patient survival outcomes, across different cancer types. Here, we report the results of a pan-cancer analysis of over 3300 tumors, showing a varied landscape of ITH across 9 cancer types. While some gene mutations are subclonal, the majority of driver gene mutations are clonal events, present in nearly all cancer cells. Strikingly, high levels of ITH are associated with poorer survival across diverse types of cancer. The adverse impact of high ITH is independent of other clinical, pathologic and molecular factors. High ITH tends to be associated with lower levels of tumor-infiltrating immune cells, but this association is not able to explain the observed survival differences. Together, these data show that ITH is a prognostic marker in multiple cancers. These results illuminate the natural history of cancer evolution, indicating that tumor heterogeneity represents a significant obstacle to cancer control. PMID:26840267

  7. Turnover of new graduate nurses in their first job using survival analysis.

    Science.gov (United States)

    Cho, Sung-Hyun; Lee, Ji Yun; Mark, Barbara A; Yun, Sung-Cheol

    2012-03-01

    To examine factors related to turnover of new graduate nurses in their first job. Data were obtained from a 3-year panel survey (2006-2008) of the Graduates Occupational Mobility Survey that followed-up college graduates in South Korea. The sample consisted of 351 new graduates whose first job was as a full-time registered nurse in a hospital. Survival analysis was conducted to estimate survival curves and related factors, including individual and family, nursing education, hospital, and job dissatisfaction (overall and 10 specific job aspects). The estimated probabilities of staying in their first job for 1, 2, and 3 years were 0.823, 0.666, and 0.537, respectively. Nurses reporting overall job dissatisfaction had significantly lower survival probabilities than those who reported themselves to be either neutral or satisfied. Nurses were more likely to leave if they were married or worked in small (vs. large), nonmetropolitan, and nonunionized hospitals. Dissatisfaction with interpersonal relationships, work content, and physical work environment was associated with a significant increase in the hazards of leaving the first job. Hospital characteristics as well as job satisfaction were significantly associated with new graduates' turnover. The high turnover of new graduates could be reduced by improving their job satisfaction, especially with interpersonal relationships, work content, and the physical work environment. © 2012 Sigma Theta Tau International.

  8. Young patients with colorectal cancer have poor survival in the first twenty months after operation and predictable survival in the medium and long-term: Analysis of survival and prognostic markers

    Directory of Open Access Journals (Sweden)

    Wickramarachchi RE

    2010-09-01

    Full Text Available Abstract Objectives This study compares clinico-pathological features in young (50 years with colorectal cancer, survival in the young and the influence of pre-operative clinical and histological factors on survival. Materials and methods A twelve year prospective database of colorectal cancer was analysed. Fifty-three young patients were compared with forty seven consecutive older patients over fifty years old. An analysis of survival was undertaken in young patients using Kaplan Meier graphs, non parametric methods, Cox's Proportional Hazard Ratios and Weibull Hazard models. Results Young patients comprised 13.4 percent of 397 with colorectal cancer. Duration of symptoms and presentation in the young was similar to older patients (median, range; young patients; 6 months, 2 weeks to 2 years, older patients; 4 months, 4 weeks to 3 years, p > 0.05. In both groups, the majority presented without bowel obstruction (young - 81%, older - 94%. Cancer proximal to the splenic flexure was present more in young than in older patients. Synchronous cancers were found exclusively in the young. Mucinous tumours were seen in 16% of young and 4% of older patients (p Conclusion If patients, who are less than 40 years old with colorectal cancer, survive twenty months after operation, the prognosis improves and their survival becomes predictable.

  9. Partial lateral facetectomy plus Insall's procedure for the treatment of isolated patellofemoral osteoarthritis: survival analysis.

    Science.gov (United States)

    Montserrat, Ferran; Alentorn-Geli, Eduard; León, Vicente; Ginés-Cespedosa, Alberto; Rigol, Pau

    2014-01-01

    The purpose of this study was to report the survival analysis of partial lateral facetectomy and Insall's procedure in patients with isolated patellofemoral osteoarthritis, and to assess the risk and protective factors for failure of this procedure. From 1992 to 2004, all subjects with isolated patellofemoral osteoarthritis who met the inclusion criteria and underwent this procedure were enrolled. Risk and protective factors for failure (failure considered as the need for total knee arthroplasty) were assessed by comparing obtained baseline data between failed and non-failed cases. Eighty-seven cases (mean (SD) age 61.8 (7.7) years, mean (SD) follow-up 9.6 (3.2) years) were included. Twenty-three failed cases were found. Mean (SD) survival time was 13.6 (0.5) years. At 13 years (last failure case), the cumulative survival was 59.3 %. Baseline medial tibiofemoral pain, genu flexum, and worst grade of tibiofemoral osteoarthritis were significant risk factors for failure (p < 0.0001, p = 0.02, p < 0.0001, respectively). In contrast, higher anatomical (p = 0.02) and total (p = 0.03) knee society score (KSS) scores, absence of knee effusion (p = 0.03), higher value of the Caton-Deschamps index (p = 0.03), and lateral position of the patella (p = 0.01) were all protective factors against failure. The treatment for isolated patellofemoral osteoarthritis through partial lateral facetectomy and Insall's procedure demonstrated good long-term survival. The presence of preoperative medial tibiofemoral pain, genu flexum, and incipient tibiofemoral osteoarthritis increased the risk of failure of this procedure. In contrast, higher anatomical and total KSS scores, absence of knee effusion, higher value of the Caton-Deschamps index, and lateral position of the patella were found to protect against failure.

  10. Survival Analysis in Patients with Non- metastatic Squamous Cell Carcinoma of the Urinary Bladder

    Directory of Open Access Journals (Sweden)

    Ahmed M. Abdel-Rahim

    2011-04-01

    Full Text Available Background: We conducted a retrospective analysis to evaluate overall survival(OAS and disease free survival (DFS rates in patients with squamous cell carcinoma of the urinary bladder according to different prognostic factors. Methods: This retrospective study analyzed the medical records of patients with non-metastatic squamous cell carcinoma of the urinary bladder. All men underwent radical cystectomy and women underwent anterior pelvic exentration. Most patients had postoperative radiation therapy. The log-rank test examined differences in OASand DFS rates. Results: The medical records of 106 patients were analyzed. The median follow-up from the date of enrollment was 30 months and ranged from 2 to 73 months. For the entire group, three-year OAS rates were 46.9% and DFS rates were 44%. For patients with P2 (tumor invasion into the muscularis propria the three-year OAS rate was 53%, for P3 (tumor invasion into perivesical fat it was 45% and 9% for P4 (tumor invasion into adjacent organs, pelvic wall or abdominal wall The OAS rate was statistically significant in favor of P2 disease (P=0.0041. The three-year DFS rate was 50% for P2, 45% for P3 and 9% for P4 disease (P=0.0125. Administration of post-operative radiotherapy did not result in statistically significant improvement in three-year OASand DFS rates. Conclusion: Survival rates were statistically significant and higher in patients with P2 and P3 disease compared to P4 disease. Adjuvant radiotherapy did not result in statistically significant survival improvement.

  11. Analysis of Survival After Initiation of Continuous Renal Replacement Therapy in a Surgical Intensive Care Unit.

    Science.gov (United States)

    Tatum, James M; Barmparas, Galinos; Ko, Ara; Dhillon, Navpreet; Smith, Eric; Margulies, Daniel R; Ley, Eric J

    2017-10-01

    Continuous renal replacement therapy (CRRT) benefits patients with renal failure who are too hemodynamically unstable for intermittent hemodialysis. The duration of therapy beyond which continued use is futile, particularly in a population of patients admitted to and primarily cared for by a surgical service (hereinafter referred to as surgical patients), is unclear. To analyze proportions of and independent risk factors for survival to discharge after initiation of CRRT among patients in a surgical intensive care unit (SICU). This retrospective cohort study included all patients undergoing CRRT from July 1, 2012, through January 31, 2016, in an SICU of an urban tertiary medical center. The population included patients treated before or after general surgery and patients admitted to a surgical service during inpatient evaluation and care before liver transplant. The pretransplant population was censored from further survival analysis on receipt of a transplant. Continuous renal replacement therapy. Hospital mortality among patients in an SICU after initiation of CRRT. Of 108 patients (64 men [59.3%] and 44 women [40.7%]; mean [SD] age, 62.0 [12.7] years) admitted to the SICU, 53 were in the general surgical group and 55 in the pretransplant group. Thirteen of the 22 patients in the pretransplant group who required 7 or more days of CRRT died (in-hospital mortality, 59.1%); among the 12 patients in the general surgery group who required 7 or more days of CRRT, 12 died (in-hospital mortality, 100%). In the general surgical group, each day of CRRT was associated with an increased adjusted odds ratio of death of 1.39 (95% CI, 1.01-1.90; P = .04). Continuous renal replacement therapy is valuable for surgical patients with an acute and correctable indication; however, survival decreases significantly with increasing duration of CRRT. Duration of CRRT does not correlate with survival among patients awaiting liver transplant.

  12. Sex ratio estimation and survival analysis for Orthetrum coerulescens (Odonata, Libellulidae)

    Science.gov (United States)

    Kery, M.; Juillerat, L.

    2004-01-01

    There is controversy over whether uneven sex ratios observed in mature dragonfly populations are a mere artifact resulting from the higher observability of males. Previous studies have at best made indirect inference about sex ratios by analysis of survival or recapture rates. Here, we obtain direct estimates of sex ratio from capture?recapture data based on the Cormack?Jolly?Seber model. We studied Orthetrum coerulescens (Fabricius, 1798) at three sites in the Swiss Jura Mountains over an entire activity period. Recapture rates per 5-day interval were 3.5 times greater for males (0.67, SE 0.02) than for females (0.19, SE 0.02). At two sites, recapture rate increased over the season for males and was constant for females, and at one site it decreased with precipitation for both sexes. In addition, recapture rate was higher with higher temperature for males only. We found no evidence for higher male survival rates in any population. Survival per 5-day interval for both sexes was estimated to be 0.77 (95% CI 0.75?0.79) without significant site or time-specific variation. There were clear effects of temperature (positive) and precipitation (negative) on survival rate at two sites. Direct estimates of sex ratios were not significantly different from 1 for any time interval. Hence, the observed male-biased sex ratio in adult O. coerulescens was an artifact resulting from the better observability of males. The method presented in this paper is applicable to sex ratio estimation in any kind of animal.

  13. Survival of melanoma patients treated with novel drugs: retrospective analysis of real-world data.

    Science.gov (United States)

    Polkowska, Marta; Ekk-Cierniakowski, Paweł; Czepielewska, Edyta; Wysoczański, Wojciech; Matusewicz, Wojciech; Kozłowska-Wojciechowska, Małgorzata

    2017-10-01

    Recently, several new drugs have been licensed for advanced melanoma therapy, significantly changing the therapeutic landscape. Ipilimumab and vemurafenib were the first drugs that demonstrated a survival benefit over the long-standing standard therapy with dacarbazine. However, the comparative efficacy of these novel drugs has not been properly assessed yet. We conducted a retrospective analysis of all the Polish population treated between January 2012 and October 2016 with one of the following agents: ipilimumab (IPI), vemurafenib (VEM), dabrafenib (DAB), and classic chemotherapy (CTH). The main objective was to assess the overall survival of melanoma patients treated in real-world conditions, taking into account sequences of treatment. We identified 3397 patients with malignant melanoma treated for the first line and the second line. Patients receiving CTH were significantly older than those treated with the novel drugs. At the same time, the population treated with immunotherapy and targeted therapy was well balanced. Overall survival was significantly better for the novel drugs compared to classic chemotherapy in both lines (for the first line, VEM vs CTH HR = 0.72, 95% CI 0.65-0.81; p melanoma provide a significant advantage in survival over classic chemotherapy. Comparative assessment of IPI and VEM indicated no difference, but only immunotherapy-treated patients achieved long-lasting results. Our data on sequential treatment indicate that immunotherapy might be a better option for the first line rather than targeted therapy, but that conclusion requires further studies of the best way to manage the treatment of melanoma patients.

  14. Radiogenomic analysis of hypoxia pathway reveals computerized MRI descriptors predictive of overall survival in glioblastoma

    Science.gov (United States)

    Beig, Niha; Patel, Jay; Prasanna, Prateek; Partovi, Sasan; Varadan, Vinay; Madabhushi, Anant; Tiwari, Pallavi

    2017-03-01

    Glioblastoma Multiforme (GBM) is a highly aggressive brain tumor with a median survival of 14 months. Hypoxia is a hallmark trait in GBM that is known to be associated with angiogenesis, tumor growth, and resistance to conventional therapy, thereby limiting treatment options for GBM patients. There is thus an urgent clinical need for non-invasively capturing tumor hypoxia in GBM towards identifying a subset of patients who would likely benefit from anti-angiogenic therapies (bevacizumab) in the adjuvant setting. In this study, we employed radiomic descriptors to (a) capture molecular variations of tumor hypoxia on routine MRI that are otherwise not appreciable; and (b) employ the radiomic correlates of hypoxia to discriminate patients with short-term survival (STS, overall survival (OS) 16 months). A total of 97 studies (25 STS, 36 MTS, 36 LTS) with Gadolinium T1-contrast (Gd-T1c), T2w, and FLAIR protocols with their corresponding gene expression profiles were obtained from the cancer genome atlas (TCGA) database. For each MRI study, necrotic, enhancing tumor, and edematous regions were segmented by an expert. A total of 30 radiomic descriptors (i.e. Haralick, Laws energy, Gabor) were extracted from every region across all three MRI protocols. By performing unsupervised clustering of the expression profile of hypoxia associated genes, a "low", "medium", or "high" index was defined for every study. Spearman correlation was then used to identify the most significantly correlated MRI features with the hypoxia index for every study. These features were further used to categorize each study as STS, MTS, and LTS using Kaplan-Meier (KM) analysis. Our results revealed that the most significant features (p < 0.05) were identified as Laws energy and Haralick features that capture image heterogeneity on FLAIR and Gd-T1w sequences. We also found these radiomic features to be significantly associated with survival, distinguishing MTS from LTS (p=.005) and STS from LTS (p=.0008).

  15. Pathway analysis reveals common pro-survival mechanisms of metyrapone and carbenoxolone after traumatic brain injury.

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    Helen L Hellmich

    Full Text Available Developing new pharmacotherapies for traumatic brain injury (TBI requires elucidation of the neuroprotective mechanisms of many structurally and functionally diverse compounds. To test our hypothesis that diverse neuroprotective drugs similarly affect common gene targets after TBI, we compared the effects of two drugs, metyrapone (MT and carbenoxolone (CB, which, though used clinically for noncognitive conditions, improved learning and memory in rats and humans. Although structurally different, both MT and CB inhibit a common molecular target, 11β hydroxysteroid dehydrogenase type 1, which converts inactive cortisone to cortisol, thereby effectively reducing glucocorticoid levels. We examined injury-induced signaling pathways to determine how the effects of these two compounds correlate with pro-survival effects in surviving neurons of the injured rat hippocampus. We found that treatment of TBI rats with MT or CB acutely induced in hippocampal neurons transcriptional profiles that were remarkably similar (i.e., a coordinated attenuation of gene expression across multiple injury-induced cell signaling networks. We also found, to a lesser extent, a coordinated increase in cell survival signals. Analysis of injury-induced gene expression altered by MT and CB provided additional insight into the protective effects of each. Both drugs attenuated expression of genes in the apoptosis, death receptor and stress signaling pathways, as well as multiple genes in the oxidative phosphorylation pathway such as subunits of NADH dehydrogenase (Complex1, cytochrome c oxidase (Complex IV and ATP synthase (Complex V. This suggests an overall inhibition of mitochondrial function. Complex 1 is the primary source of reactive oxygen species in the mitochondrial oxidative phosphorylation pathway, thus linking the protective effects of these drugs to a reduction in oxidative stress. The net effect of the drug-induced transcriptional changes observed here indicates that

  16. Survival analysis of pure seminoma at post-chemotherapy retroperitoneal lymph node dissection.

    Science.gov (United States)

    Rice, Kevin R; Beck, Stephen D W; Bihrle, Richard; Cary, K Clint; Einhorn, Lawrence H; Foster, Richard S

    2014-11-01

    Viable seminoma encountered at post-chemotherapy retroperitoneal lymph node dissection for pure testicular seminoma is rare due to the chemosensitivity of this germ cell tumor. In this study we define the natural history of viable seminoma at post-chemotherapy retroperitoneal lymph node dissection. The Indiana University testis cancer database was queried from 1988 to 2011 to identify all patients with primary testicular or retroperitoneal pure seminoma and who were found to have pure seminoma at post-chemotherapy retroperitoneal lymph node dissection. Clinical characteristics were reviewed and survival analysis was performed. A total of 36 patients met the study inclusion criteria. All patients received standard first line cisplatin based chemotherapy and 17 received salvage chemotherapy. The decision to proceed to retroperitoneal lymph node dissection was based on enlarging retroperitoneal mass and/or positron emission positivity in the majority of cases. Seven patients had undergone previous retroperitoneal lymph node dissection. Additional surgical procedures were required in 19 patients to achieve a complete resection. The 5-year cancer specific survival rate was 54%. However, only 9 of 36 patients remained continuously free of disease and of these patients 4 received adjuvant chemotherapy. Mean time from post-chemotherapy retroperitoneal lymph node dissection to death was 6.9 months. Second line chemotherapy, reoperative retroperitoneal lymph node dissection and earlier era of treatment were associated with poorer cancer specific survival. A total of 36 patients with pure seminoma were found to have viable pure seminoma at post-chemotherapy retroperitoneal lymph node dissection. While 5-year cancer specific survival was 54%, these surgeries are technically demanding and only a minority of patients achieves a durable cure from surgery alone. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights

  17. Integrated analysis of multiple microarray datasets identifies a reproducible survival predictor in ovarian cancer.

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    Panagiotis A Konstantinopoulos

    Full Text Available BACKGROUND: Public data integration may help overcome challenges in clinical implementation of microarray profiles. We integrated several ovarian cancer datasets to identify a reproducible predictor of survival. METHODOLOGY/PRINCIPAL FINDINGS: Four microarray datasets from different institutions comprising 265 advanced stage tumors were uniformly reprocessed into a single training dataset, also adjusting for inter-laboratory variation ("batch-effect". Supervised principal component survival analysis was employed to identify prognostic models. Models were independently validated in a 61-patient cohort using a custom array genechip and a publicly available 229-array dataset. Molecular correspondence of high- and low-risk outcome groups between training and validation datasets was demonstrated using Subclass Mapping. Previously established molecular phenotypes in the 2(nd validation set were correlated with high and low-risk outcome groups. Functional representational and pathway analysis was used to explore gene networks associated with high and low risk phenotypes. A 19-gene model showed optimal performance in the training set (median OS 31 and 78 months, p < 0.01, 1(st validation set (median OS 32 months versus not-yet-reached, p = 0.026 and 2(nd validation set (median OS 43 versus 61 months, p = 0.013 maintaining independent prognostic power in multivariate analysis. There was strong molecular correspondence of the respective high- and low-risk tumors between training and 1(st validation set. Low and high-risk tumors were enriched for favorable and unfavorable molecular subtypes and pathways, previously defined in the public 2(nd validation set. CONCLUSIONS/SIGNIFICANCE: Integration of previously generated cancer microarray datasets may lead to robust and widely applicable survival predictors. These predictors are not simply a compilation of prognostic genes but appear to track true molecular phenotypes of good- and poor-outcome.

  18. Effect of Body Mass Index on Overall Survival of Pancreatic Cancer: A Meta-Analysis.

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    Shi, Yu-Qi; Yang, Jing; Du, Peng; Xu, Ting; Zhuang, Xiao-Hui; Shen, Jia-Qing; Xu, Chun-Fang

    2016-04-01

    Although obesity has been identified as a risk factor for pancreatic cancer, the important question of whether obesity influences the prognosis of pancreatic cancer has not been explicated thoroughly. We therefore performed a meta-analysis to investigate the association between body mass index (BMI) and survival outcomes of patients with pancreatic cancer.Studies that described the relationship between BMI and overall survival (OS) of pancreatic cancer were searched in PubMed, Embase, Ovid, and Cochrane Library Databases from the earliest available date to May 12, 2015. Hazard ratios (HRs) for OS in each BMI category from individual studies were extracted and pooled by a random-effect model. Dose-response meta-analysis was also performed to estimate summary HR and 95% confidence interval (CI) for every 5-unit increment. Publication bias was evaluated by Begg funnel plot and Egger linear regression test.Ten relevant studies involving 6801 patients were finally included in the meta-analysis. Results showed that obesity in adulthood significantly shortened OS of pancreatic cancer patients (HR: 1.29, 95% CI: 1.17-1.41), whereas obesity at diagnosis was not associated with any increased risk of death (HR: 1.10, 95% CI: 0.78-1.42). For every 5-kg/m increment in adult BMI, the summary HR was 1.11 (95% CI: 1.05-1.18) for death risk of pancreatic cancer. However, no dose-response relationship was found in the BMI at diagnosis. Egger regression test and Begg funnel plot both revealed no obvious risk of publication bias.In conclusion, increased adult BMI is associated with increased risk of death for pancreatic cancer patients, which suggested that obesity in adulthood may be an important prognostic factor that indicates an abbreviated survival from pancreatic cancer. More studies are needed to validate this finding, and the mechanism behind the observation should be evaluated in further studies.

  19. Survival analysis using primary care electronic health record data: A systematic review of the literature.

    Science.gov (United States)

    Hodgkins, Adam Jose; Bonney, Andrew; Mullan, Judy; Mayne, Darren John; Barnett, Stephen

    2017-01-01

    An emerging body of research involves observational studies in which survival analysis is applied to data obtained from primary care electronic health records (EHRs). This systematic review of these studies examined the utility of using this approach. An electronic literature search of the Scopus, PubMed, Web of Science, CINAHL, and Cochrane databases was conducted. Search terms and exclusion criteria were chosen to select studies where survival analysis was applied to the data extracted wholly from EHRs used in primary care medical practice. A total of 46 studies that met the inclusion criteria for the systematic review were examined. All were published within the past decade (2005-2014) with a majority ( n = 26, 57%) being published between 2012 and 2014. Even though citation rates varied from nil to 628, over half ( n = 27, 59%) of the studies were cited 10 times or more. The median number of subjects was 18,042 with five studies including over 1,000,000 patients. Of the included studies, 35 (76%) were published in specialty journals and 11 (24%) in general medical journals. The many conditions studied largely corresponded well with conditions important to general practice. Survival analysis applied to primary care electronic medical data is a research approach that has been frequently used in recent times. The utility of this approach was demonstrated by the ability to produce research with large numbers of subjects, across a wide range of conditions and with the potential of a high impact. Importantly, primary care data were thus available to inform primary care practice.

  20. Public-Private Interests and Conflicts in Ports: A Content Analysis Approach

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    Cassia Bömer Galvao

    2016-03-01

    Full Text Available Various levels of private sector involvement such as changes to incentives, capital utilization, flexible finance schemes, and the infrastructure investment has occurred as consequences of port devolution and reform processes. Our investigation uses a basic content analysis across both academic literature and maritime specialized media with research appropriate selected keywords to identify potential conflict within the changing institutional processes. Two major ports, New York/New Jersey (USA and Santos (Brazil, with different characteristics in institutional background, are studied aiming to identify these conflicts. The results presented offer a contribution that enhances the academic debate and potentially enlightens solution formulation for those active in the port management.

  1. Estimation of failure criteria in multivariate sensory shelf life testing using survival analysis.

    Science.gov (United States)

    Giménez, Ana; Gagliardi, Andrés; Ares, Gastón

    2017-09-01

    For most food products, shelf life is determined by changes in their sensory characteristics. A predetermined increase or decrease in the intensity of a sensory characteristic has frequently been used to signal that a product has reached the end of its shelf life. Considering all attributes change simultaneously, the concept of multivariate shelf life allows a single measurement of deterioration that takes into account all these sensory changes at a certain storage time. The aim of the present work was to apply survival analysis to estimate failure criteria in multivariate sensory shelf life testing using two case studies, hamburger buns and orange juice, by modelling the relationship between consumers' rejection of the product and the deterioration index estimated using PCA. In both studies, a panel of 13 trained assessors evaluated the samples using descriptive analysis whereas a panel of 100 consumers answered a "yes" or "no" question regarding intention to buy or consume the product. PC1 explained the great majority of the variance, indicating all sensory characteristics evolved similarly with storage time. Thus, PC1 could be regarded as index of sensory deterioration and a single failure criterion could be estimated through survival analysis for 25 and 50% consumers' rejection. The proposed approach based on multivariate shelf life testing may increase the accuracy of shelf life estimations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Persistence of interest in science, technology, engineering and mathematics: An analysis of persisting and non-persisting students

    Science.gov (United States)

    White, Jeffry L.

    While there has been an increase in enrollment, interest in science, technology, engineering, and mathematics (STEM) has been declining on college campuses since 1967. Higher enrollment does not transfer to an increase in the number of minorities in the STEM fields. The majority-minority enrollment ratio is nearly 2:1 but the gap widens to 4:1 when it comes to graduation. In fact, underrepresented minorities (URM) earned only 12% of the STEM degrees awarded in 1998. When the higher attrition and lower graduation rates of URM are scrutinized, upwards of 60% changed majors or dropped out of STEM. Further investigation reveals the most frequently cited reasons for departure were loss of initial interest, developed a greater interest in another field, or were turned off by the STEM disciplines. A primarily exploratory study was conducted into the conditions necessary for academic interest in the STEM fields to persist. A model based on student engagement (Astin, 1977) and interest operations (Prenzel, 1988a) theories was used with a random sample of URM at universities participating in the Ohio Science and Engineering Alliance. Survey research was employed to investigate interest development and the effect of student retention programs and activities on such interest. The latter part of the study could not be fully examined when 95% reported not utilizing retention services. For the section on interest, an online survey using a 5-point Likert scale was validated using principal components analysis. A binominal logistic regression was used to predict membership in one of two possible groups: persisters and students at-risk for not persisting. The major conclusions are: (1) While 3 variables (feelings, learning and difficulty) were statistically significant only one, feelings was substantively significant. (2) Persistence increased 80.9% for each 1-unit increase in feelings and 9.9% for learning. (3) Persistence decreased 19.8% for each one-unit increase in difficulty

  3. Analysis of polycyclic aromatic hydrocarbons adsorbed on particles of atmospheric interest using pressurised fluid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Perraudin, Emilie [Universite Bordeaux I, Laboratoire de Physico et Toxico-Chimie des Systemes Naturels, UMR 5472 CNRS, Talence Cedex (France); Universite Bordeaux I, Laboratoire de Physico-Chimie Moleculaire, UMR 5803 CNRS, Talence Cedex (France); Budzinski, Helene [Universite Bordeaux I, Laboratoire de Physico et Toxico-Chimie des Systemes Naturels, UMR 5472 CNRS, Talence Cedex (France); Villenave, Eric [Universite Bordeaux I, Laboratoire de Physico-Chimie Moleculaire, UMR 5803 CNRS, Talence Cedex (France)

    2005-09-01

    Pressurised fluid extraction (PFE) was used for the measurement of 13 polycyclic aromatic hydrocarbons (PAHs) adsorbed on different types of particles: two model particles (PAH-coated silica, PAH-coated graphite) and two natural atmospheric particles (urban dust and diesel exhaust, from NIST reference materials). Samples were analysed by gas chromatography coupled to mass spectrometry. Extraction efficiency was evaluated with internal standard recovery yields and was shown to depend on the nature of the particle, on the structure of the analytes and on the PAH concentration. Extraction conditions (toluene, 130 C, 130 bar, 2 x 8-min static cycles) were optimised to extract PAHs when strongly interacting with solid matrices and were validated by the analysis of two PAH-certified materials. (orig.)

  4. Improving cervical region of interest by eliminating vaginal walls and cotton-swabs for automated image analysis

    Science.gov (United States)

    Venkataraman, Sankar; Li, Wenjing

    2008-03-01

    Image analysis for automated diagnosis of cervical cancer has attained high prominence in the last decade. Automated image analysis at all levels requires a basic segmentation of the region of interest (ROI) within a given image. The precision of the diagnosis is often reflected by the precision in detecting the initial region of interest, especially when some features outside the ROI mimic the ones within the same. Work described here discusses algorithms that are used to improve the cervical region of interest as a part of automated cervical image diagnosis. A vital visual aid in diagnosing cervical cancer is the aceto-whitening of the cervix after the application of acetic acid. Color and texture are used to segment acetowhite regions within the cervical ROI. Vaginal walls along with cottonswabs sometimes mimic these essential features leading to several false positives. Work presented here is focused towards detecting in-focus vaginal wall boundaries and then extrapolating them to exclude vaginal walls from the cervical ROI. In addition, discussed here is a marker-controlled watershed segmentation that is used to detect cottonswabs from the cervical ROI. A dataset comprising 50 high resolution images of the cervix acquired after 60 seconds of acetic acid application were used to test the algorithm. Out of the 50 images, 27 benefited from a new cervical ROI. Significant improvement in overall diagnosis was observed in these images as false positives caused by features outside the actual ROI mimicking acetowhite region were eliminated.

  5. Some Interesting Applications of Probabilistic Techiques in Structural Dynamic Analysis of Rocket Engines

    Science.gov (United States)

    Brown, Andrew M.

    2014-01-01

    Numerical and Analytical methods developed to determine damage accumulation in specific engine components when speed variation included. Dither Life Ratio shown to be well over factor of 2 for specific example. Steady-State assumption shown to be accurate for most turbopump cases, allowing rapid calculation of DLR. If hot-fire speed data unknown, Monte Carlo method developed that uses speed statistics for similar engines. Application of techniques allow analyst to reduce both uncertainty and excess conservatism. High values of DLR could allow previously unacceptable part to pass HCF criteria without redesign. Given benefit and ease of implementation, recommend that any finite life turbomachine component analysis adopt these techniques. Probability Values calculated, compared, and evaluated for several industry-proposed methods for combining random and harmonic loads. Two new excel macros written to calculate combined load for any specific probability level. Closed form Curve fits generated for widely used 3(sigma) and 2(sigma) probability levels. For design of lightweight aerospace components, obtaining accurate, reproducible, statistically meaningful answer critical.

  6. Cloud solution for histopathological image analysis using region of interest based compression.

    Science.gov (United States)

    Kanakatte, Aparna; Subramanya, Rakshith; Delampady, Ashik; Nayak, Rajarama; Purushothaman, Balamuralidhar; Gubbi, Jayavardhana

    2017-07-01

    Recent technological gains have led to the adoption of innovative cloud based solutions in medical imaging field. Once the medical image is acquired, it can be viewed, modified, annotated and shared on many devices. This advancement is mainly due to the introduction of Cloud computing in medical domain. Tissue pathology images are complex and are normally collected at different focal lengths using a microscope. The single whole slide image contains many multi resolution images stored in a pyramidal structure with the highest resolution image at the base and the smallest thumbnail image at the top of the pyramid. Highest resolution image will be used for tissue pathology diagnosis and analysis. Transferring and storing such huge images is a big challenge. Compression is a very useful and effective technique to reduce the size of these images. As pathology images are used for diagnosis, no information can be lost during compression (lossless compression). A novel method of extracting the tissue region and applying lossless compression on this region and lossy compression on the empty regions has been proposed in this paper. The resulting compression ratio along with lossless compression on tissue region is in acceptable range allowing efficient storage and transmission to and from the Cloud.

  7. Foster Care Reentry: A survival analysis assessing differences across permanency type.

    Science.gov (United States)

    Goering, Emily Smith; Shaw, Terry V

    2017-06-01

    Foster care reentry is an important factor for evaluating the overall success of permanency. Rates of reentry are typically only measured for 12-months and are often evaluated only for children who exit foster care to reunification and not across exit types, also known as 'permanency types'. This study examined the odds of reentry across multiple common permanency types for a cohort of 8107 children who achieved permanency between 2009 and 2013. Overall, 14% of children reentered care within 18-months with an average time to reentry of 6.36 months. A Kaplan-Meier survival analysis was used to assess differences in reentry across permanency types (including reunification, relative guardianship and non-relative guardianship). Children who achieved guardianship with kin had the lowest odds of reentry overall, followed by guardianship with non-kin, and reunification with family of origin. Children reunifying against the recommendations of Children and Family Services had the highest odds of reentry. A Cox regression survival analysis was conducted to assess odds of reentry across permanency type while controlling for demographics, services, and other risk factors. In the final model, only permanency type and cumulative risk were found to have a statistically significant impact on odds of reentry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Time trend analysis of primary tumor resection for stage IV colorectal cancer: less surgery, improved survival.

    Science.gov (United States)

    Hu, Chung-Yuan; Bailey, Christina E; You, Y Nancy; Skibber, John M; Rodriguez-Bigas, Miguel A; Feig, Barry W; Chang, George J

    2015-03-01

    With the advent of effective modern chemotherapeutic and biologic agents, primary tumor resection for patients with stage IV colorectal cancer (CRC) may not be routinely necessary. To evaluate the secular patterns of primary tumor resection use in stage IV CRC in the United States. A retrospective cohort study using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results CRC registry. Demographic and clinical factors were compared for 64,157 patients diagnosed with stage IV colon or rectal cancer from January 1, 1988, through December 31, 2010, who had undergone primary tumor resection and those who had not. Rates of primary tumor resection and median relative survival were calculated for each year. Joinpoint regression analysis was used to determine when a significant change in trend in the primary tumor resection rate had occurred. Logistic regression analysis was used to assess factors associated with primary tumor resection. Difference in primary tumor resection rates over time. Of the 64,157 patients with stage IV CRC, 43,273 (67.4%) had undergone primary tumor resection. The annual rate of primary tumor resection decreased from 74.5% in 1988 to 57.4% in 2010 (Ptrend toward fewer primary tumor resections was seen. Despite the decreasing primary tumor resection rate, patient survival rates improved. However, primary tumor resection may still be overused, and current treatment practices lag behind evidence-based treatment guidelines.

  9. Primary myelofibrosis: a detailed statistical analysis of the clinicopathological variables influencing survival.

    Science.gov (United States)

    Rupoli, S; Da Lio, L; Sisti, S; Campanati, G; Salvi, A; Brianzoni, M F; D'Amico, S; Cinciripini, A; Leoni, P

    1994-04-01

    In the present study we analyzed the prognostic significance of several clinical, hematological, and histological parameters recorded at diagnosis in a consecutive series of 72 patients with primary myelofibrosis (PMF). Univariate analysis showed that the most significant indicators of poor survival were the following: age greater than 60, splenomegaly, anemia (hemoglobin > 10 g/dl), leukopenia (WBC 14 x 10(9)/l), and any of these histological features: adipose tissue and megakaryocyte reduction, prominent osteoblastic rims along the trabecular bone, presence of peritrabecular megakaryocytes (Mk), absence of normal or giant Mk. The multivariate analysis showed that only the level of hemoglobin and the presence of both normal Mk and fever independently influenced the prognosis. These parameters were used to set up a prognostic scoring system, allowing a feasible prognosis to be made for each patient at the time of diagnosis and identifying those patients in urgent need of new therapeutic approaches.

  10. Acute lymphoblastic leukemia in children and adolescents: prognostic factors and analysis of survival

    Directory of Open Access Journals (Sweden)

    Daniel Willian Lustosa de Sousa

    2015-08-01

    Full Text Available OBJECTIVE: To describe the clinical and laboratory features of children and adolescents with acute lymphoblastic leukemia treated at three referral centers in Ceará and evaluate prognostic factors for survival, including age, gender, presenting white blood cell count, immunophenotype, DNA index and early response to treatment.METHODS: Seventy-six under 19-year-old patients with newly diagnosed acute lymphoblastic leukemia treated with the Grupo Brasileiro de Tratamento de Leucemia da Infância - acute lymphoblastic leukemia-93 and -99 protocols between September 2007 and December 2009 were analyzed. The diagnosis was based on cytological, immunophenotypic and cytogenetic criteria. Associations between variables, prognostic factors and response to treatment were analyzed using the chi-square test and Fisher's exact test. Overall and event-free survival were estimated by Kaplan-Meier analysis and compared using the log-rank test. A Cox proportional hazards model was used to identify independent prognostic factors.RESULTS: The average age at diagnosis was 6.3 ± 0.5 years and males were predominant (65%. The most frequently observed clinical features were hepatomegaly, splenomegaly and lymphadenopathy. Central nervous system involvement and mediastinal enlargement occurred in 6.6% and 11.8%, respectively. B-acute lymphoblastic leukemia was more common (89.5% than T-acute lymphoblastic leukemia. A DNA index >1.16 was found in 19% of patients and was associated with favorable prognosis. On Day 8 of induction therapy, 95% of the patients had lymphoblast counts <1000/µL and white blood cell counts <5.0 Ã- 109/L. The remission induction rate was 95%, the induction mortality rate was 2.6% and overall survival was 72%.CONCLUSION: The prognostic factors identified are compatible with the literature. The 5-year overall and event-free survival rates were lower than those reported for developed countries. As shown by the multivariate analysis, age

  11. Acute lymphoblastic leukemia in children and adolescents: prognostic factors and analysis of survival

    Science.gov (United States)

    Lustosa de Sousa, Daniel Willian; de Almeida Ferreira, Francisco Valdeci; Cavalcante Félix, Francisco Helder; de Oliveira Lopes, Marcos Vinicios

    2015-01-01

    Objective To describe the clinical and laboratory features of children and adolescents with acute lymphoblastic leukemia treated at three referral centers in Ceará and evaluate prognostic factors for survival, including age, gender, presenting white blood cell count, immunophenotype, DNA index and early response to treatment. Methods Seventy-six under 19-year-old patients with newly diagnosed acute lymphoblastic leukemia treated with the Grupo Brasileiro de Tratamento de Leucemia da Infância – acute lymphoblastic leukemia-93 and -99 protocols between September 2007 and December 2009 were analyzed. The diagnosis was based on cytological, immunophenotypic and cytogenetic criteria. Associations between variables, prognostic factors and response to treatment were analyzed using the chi-square test and Fisher's exact test. Overall and event-free survival were estimated by Kaplan–Meier analysis and compared using the log-rank test. A Cox proportional hazards model was used to identify independent prognostic factors. Results The average age at diagnosis was 6.3 ± 0.5 years and males were predominant (65%). The most frequently observed clinical features were hepatomegaly, splenomegaly and lymphadenopathy. Central nervous system involvement and mediastinal enlargement occurred in 6.6% and 11.8%, respectively. B-acute lymphoblastic leukemia was more common (89.5%) than T-acute lymphoblastic leukemia. A DNA index >1.16 was found in 19% of patients and was associated with favorable prognosis. On Day 8 of induction therapy, 95% of the patients had lymphoblast counts <1000/μL and white blood cell counts <5.0 × 109/L. The remission induction rate was 95%, the induction mortality rate was 2.6% and overall survival was 72%. Conclusion The prognostic factors identified are compatible with the literature. The 5-year overall and event-free survival rates were lower than those reported for developed countries. As shown by the multivariate analysis, age and baseline white

  12. Bisphosphonates in the adjuvant setting of breast cancer therapy--effect on survival: a systematic review and meta-analysis.

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    Irit Ben-Aharon

    Full Text Available The role of bisphosphonates (BP in early breast cancer (BC has been considered controversial. We performed a meta-analysis of all randomized controlled trials (RCTs that appraised the effects of BP on survival in early BC.RCTs were identified by searching the Cochrane Library, MEDLINE databases and conference proceedings. Hazard ratios (HRs of overall survival (OS, disease-free survival (DFS and relative risks of adverse events were estimated and pooled.Thirteen trials met the inclusion criteria, evaluating a total of 15,762 patients. Meta-analysis of ten trials which reported OS revealed no statistically significant benefit in OS for BP (HR 0.89, 95% CI = 0.79 to 1.01. Meta-analysis of nine trials which reported the DFS revealed no benefit in DFS (HR 0.95 (0.81-1.12. Meta-analysis upon menopausal status showed a statistically significant better DFS in the BP-treated patients (HR 0.81(0.69-0.95. In meta-regression, chemotherapy was negatively associated with HR of survival.Our meta-analysis indicates a positive effect for adjuvant BP on survival only in postmenopausal patients. Meta-regression demonstrated a negative association between chemotherapy use BP effect on survival. Further large scale RCTs are warranted to unravel the specific subgroups that would benefit from the addition of BP in the adjuvant setting.

  13. Liver recurrence in endometrial cancer: a multi-institutional analysis of factors predictive of postrecurrence survival.

    Science.gov (United States)

    Toptas, Tayfun; Karalok, Alper; Ureyen, Isin; Tasci, Tolga; Erol, Onur; Bozkurt, Selen; Tulunay, Gokhan; Simsek, Tayup; Turan, Taner

    2016-10-01

    Predictive factors for survival following liver metastasis in endometrial cancer (EC) have not been studied to date. It is expected that patients who initially presented with liver metastasis or developed liver metastasis as the subsequent metastatic site of progressive disease are likely to have poor outcomes. However, patients developing liver metastasis as the first site of recurrence may have a chance of benefiting from the salvage therapies. Therefore, we aimed to determine factors influencing postrecurrence survival in EC patients who developed liver metastasis as the first site of recurrence. Patients with EC who underwent primary surgery at three centers between 1993 and 2013 were reviewed. Liver recurrence was defined as documentation of parenchymal liver metastasis either by radiologically or biopsy, after a disease-free interval of ≥3 months. Patients with liver metastasis at presentation, or liver metastasis as the subsequent metastatic site of progressive disease were excluded. Forty-six patients were identified. Median time to liver recurrence was 12 months, with 91.3 % of recurrences detected within 3 years. Most patients (73.9 %) had liver recurrence concomitant with extra-hepatic disease. Median survival after the diagnosis of liver recurrence was 9 months. While in univariate analysis, time to liver recurrence (p liver recurrence (p < 0.001) was the only independent predictor. This criterion may be used as a marker for stratifying patients into different prognostic risk groups and for selection of patients for salvage therapies.

  14. Tooth Loss and Survival Analysis after Traumatic Injuries in Primary Dentition

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    Galovic Jelena

    2017-11-01

    Full Text Available Background/Aim: The aim of the present study was to investigate the treatment options, survival rate of traumatized primary teeth and evaluate the factors influencing the outcome. Material and Methods: The sample consisted of all dental trauma cases treated over a 14 years period at the Department of Pediatric and Preventive Dentistry, Dental Clinic of Vojvodina, Novi Sad. Criteria for inclusion in this study were: dental trauma to primary teeth and age in the moment of injury up to seven years. Dental trauma records were analyzed in order to obtain the following: gender and age of the child at the time of trauma, type of trauma, as well as the type and timing of treatment received. After data analysis a survival rate of traumatized primary teeth was evaluated. Results: The study was designed as retrospective and it included 225 children, with 346 traumatized primary teeth. The occurrence of trauma was higher in male patients (60,4% and in children up to 4 years of age. Luxations were more frequent (72.8% compared to isolated teeth fractures (20.8%, while the two types of injury combined were rare (6,3%. One year following dental trauma 231 teeth (0.67% developed complications. Falls were the main cause of trauma (68.9% and the presence of more than one traumatized tooth was frequent. A percentage of 48.8 children received dental care during first 24 h after the injury. Conclusions: Survival of injured primary teeth is relatively low, regardless of trauma type, time interval between injury and treatment and the type of provided treatment.

  15. Healthy eating index/alternative healthy eating index and breast cancer mortality and survival: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Makan Pourmasoumi

    2016-01-01

    Full Text Available Objective: Breast cancer is the most common cancer in women worldwide. The effects of overall diet quality instead of single nutrients after breast cancer diagnosis on mortality have been a growing area of research interest. The aim of this systematic review was to investigate the relationship between the Healthy Eating Index (HEI/the Alternative Healthy Eating Index (AHEI and risk of breast cancer mortality or survival rates as a primary outcome, and some related inflammatory factors, as secondary outcomes among postdiagnosed women. Methods: This study methodology was performed based on the Preferred Reporting Item for Systematic Review and Meta-analysis statement recommendation and had been registered at PROSPERO (registration number: CRD42015015605. The systematic search was conducted in the electronic databases including PubMed, ISI, Scopus, Cochrane, and Google before July 2016. Researches that had not reported risk of breast cancer mortality or survival rates separately were excluded from the study. Similarly, this review excluded studies which only had examined the HEI or AHEI without reporting their association with the risk of mortality or survival rates. Results: After primary search, of 643 studies identified, 4 studies including eligible criteria were selected for the final assessment. All selected studies had been conducted in the USA and used self-report food-frequency questionnaire for diet quality assessment. In two studies HEI-2005, in one study AHEI, and in another study AHEI-2010 were applied. Meta-analysis result showed no significant association between these indexes and risk of breast cancer mortality/survival among women with this malignancy [relative risk: (RR 1.04; 95% confidence interval (CI: 0.69–1.56; P = 0.87]. Conclusions: Regarding the adherence HEI/AHEI, we found no association between mentioned indexes and risk of mortality or survival from breast cancer in women with breast cancer. However, evidence in this

  16. An Analysis of Differences in Terms of Professional Interests Based on the Project to Replace IAS 39

    Directory of Open Access Journals (Sweden)

    Cláudia Daniela Ferreira da Mota Carvalho

    2015-08-01

    Full Text Available The professional interests of the various stakeholders groups are often seen as obstacles to full accounting harmonization. Studying different professional interests in the accounting domain is significant for organizations involved in the international accounting harmonization process, insofar as it enables them to identify the main obstacles to face in order to achieve full harmonization. Thus, this article is aimed at analyzing the differences in terms of professional interests by addressing the participation of various stakeholders groups in the process of issuing/modifying standards of the International Accounting Standards Board (IASB. Based on content analysis, we examined the comment letters sent to the IASB in the context of the first part of the first phase of the project to replace the International Accounting Standard (IAS 39, entitled "Financial Instruments - Recognition and Measurement", by the International Financial Reporting Standard (IFRS 9, on its turn entitled "Financial Instruments". Respondents were identified according to the stakeholders group, and, later, the collected data underwent a nonparametric chi-square test. The results of this study indicate there are significant differences between the answers obtained from the various stakeholders groups involved in the process of issuing or reviewing a standard of the IASB, above all made clear between the group of financial preparers and the regulatory and/or standard-setting agencies and the professional associations related to accounting.

  17. Meta-analysis of gene expression profiles associated with histological classification and survival in 829 ovarian cancer samples.

    Science.gov (United States)

    Fekete, Tibor; Rásó, Erzsébet; Pete, Imre; Tegze, Bálint; Liko, István; Munkácsy, Gyöngyi; Sipos, Norbert; Rigó, János; Györffy, Balázs

    2012-07-01

    Transcriptomic analysis of global gene expression in ovarian carcinoma can identify dysregulated genes capable to serve as molecular markers for histology subtypes and survival. The aim of our study was to validate previous candidate signatures in an independent setting and to identify single genes capable to serve as biomarkers for ovarian cancer progression. As several datasets are available in the GEO today, we were able to perform a true meta-analysis. First, 829 samples (11 datasets) were downloaded, and the predictive power of 16 previously published gene sets was assessed. Of these, eight were capable to discriminate histology subtypes, and none was capable to predict survival. To overcome the differences in previous studies, we used the 829 samples to identify new predictors. Then, we collected 64 ovarian cancer samples (median relapse-free survival 24.5 months) and performed TaqMan Real Time Polimerase Chain Reaction (RT-PCR) analysis for the best 40 genes associated with histology subtypes and survival. Over 90% of subtype-associated genes were confirmed. Overall survival was effectively predicted by hormone receptors (PGR and ESR2) and by TSPAN8. Relapse-free survival was predicted by MAPT and SNCG. In summary, we successfully validated several gene sets in a meta-analysis in large datasets of ovarian samples. Additionally, several individual genes identified were validated in a clinical cohort. Copyright © 2011 UICC.

  18. Prospective postmarket device studies versus returned product analysis as a predictor of system survival.

    Science.gov (United States)

    Pratt, T R; Pulling, C C; Stanton, M S

    2000-07-01

    Monitoring and reporting mechanisms are vital tools for clinicians to assess ICD system performance over time for optimal patient care. This article explores the various reporting mechanisms available to the clinician, both historical and current, and compares and contrasts two such methods. The lead survival rates obtained by return product analysis (RPA) are compared with those from an ongoing prospective chronic study that actively follows patients for clinical ICD system failures (Tachyarrhythmia Chronic Systems Study [TCSS]). Examination of available data shows that a prospective study such as the TCSS is capable of detecting clinically significant adverse events in 2.2% of the 3,958 leads followed. By comparison, RPA-based monitoring of the same leads detects "out of specification" events in 0.5% of the 78,571 leads followed. Statistical analyses of two separate families of leads (RV leads and SQ Patch leads) show that survival rates obtained by the two methods begin to differ at approximately 2 years of implant experience, with 95% confidence intervals no longer overlapping at 3 years. The authors conclude that prospective chronic device studies are a superior tool for the ongoing monitoring of implanted device performance compared to RPA-based reports.

  19. Time-Dependent Tree-Structured Survival Analysis with Unbiased Variable Selection through Permutation Tests

    Science.gov (United States)

    Wallace, M. L.

    2014-01-01

    Incorporating time-dependent covariates into tree-structured survival analysis (TSSA) may result in more accurate prognostic models than if only baseline values are used. Available time-dependent TSSA methods exhaustively test every binary split on every covariate; however, this approach may result in selection bias towards covariates with more observed values. We present a method that uses unbiased significance levels from newly proposed permutation tests to select the time-dependent or baseline covariate with the strongest relationship with the survival outcome. The specific splitting value is identified using only the selected covariate. Simulation results show that the proposed time-dependent TSSA method produces tree models of equal or greater accuracy as compared to baseline TSSA models, even with high censoring rates and large within-subject variability in the time-dependent covariate. To illustrate, the proposed method is applied to data from a cohort of bipolar youth to identify subgroups at risk for self-injurious behavior. PMID:25043382

  20. Analysis of survival in breast cancer patients by using different parametric models

    Science.gov (United States)

    Enera Amran, Syahila; Asrul Afendi Abdullah, M.; Kek, Sie Long; Afiqah Muhamad Jamil, Siti

    2017-09-01

    In biomedical applications or clinical trials, right censoring was often arising when studying the time to event data. In this case, some individuals are still alive at the end of the study or lost to follow up at a certain time. It is an important issue to handle the censoring data in order to prevent any bias information in the analysis. Therefore, this study was carried out to analyze the right censoring data with three different parametric models; exponential model, Weibull model and log-logistic models. Data of breast cancer patients from Hospital Sultan Ismail, Johor Bahru from 30 December 2008 until 15 February 2017 was used in this study to illustrate the right censoring data. Besides, the covariates included in this study are the time of breast cancer infection patients survive t, age of each patients X1 and treatment given to the patients X2 . In order to determine the best parametric models in analysing survival of breast cancer patients, the performance of each model was compare based on Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC) and log-likelihood value using statistical software R. When analysing the breast cancer data, all three distributions were shown consistency of data with the line graph of cumulative hazard function resembles a straight line going through the origin. As the result, log-logistic model was the best fitted parametric model compared with exponential and Weibull model since it has the smallest value in AIC and BIC, also the biggest value in log-likelihood.

  1. Systematic genetic analysis identifies Cis-eQTL target genes associated with glioblastoma patient survival.

    Directory of Open Access Journals (Sweden)

    Qing-Rong Chen

    Full Text Available Prior expression quantitative trait locus (eQTL studies have demonstrated heritable variation determining differences in gene expression. The majority of eQTL studies were based on cell lines and normal tissues. We performed cis-eQTL analysis using glioblastoma multiforme (GBM data sets obtained from The Cancer Genome Atlas (TCGA to systematically investigate germline variation's contribution to tumor gene expression levels. We identified 985 significant cis-eQTL associations (FDR<0.05 mapped to 978 SNP loci and 159 unique genes. Approximately 57% of these eQTLs have been previously linked to the gene expression in cell lines and normal tissues; 43% of these share cis associations known to be associated with functional annotations. About 25% of these cis-eQTL associations are also common to those identified in Breast Cancer from a recent study. Further investigation of the relationship between gene expression and patient clinical information identified 13 eQTL genes whose expression level significantly correlates with GBM patient survival (p<0.05. Most of these genes are also differentially expressed in tumor samples and organ-specific controls (p<0.05. Our results demonstrated a significant relationship of germline variation with gene expression levels in GBM. The identification of eQTLs-based expression associated survival might be important to the understanding of genetic contribution to GBM cancer prognosis.

  2. Incidence of acute pulmonary embolism, related comorbidities and survival; analysis of a Swedish national cohort.

    Science.gov (United States)

    Andersson, Therese; Söderberg, Stefan

    2017-06-14

    The aim of the study was to determine the incidence of acute pulmonary embolism (PE) in Sweden and any regional differences. To assess short- and long-term survival analysis after an episode of PE, before and after excluding patients with known malignancies, and to determine the most common comorbidities prior to the PE event. All in-hospital patients, including children, diagnosed with acute PE in 2005 were retrieved from the Swedish National Patient Registry (NPR) and incidence rates were calculated. All registered comorbidities from 1998 until the index events were collected and survival up to 4 years after the event were calculated and compared to matched controls. There were 5793 patients of all ages diagnosed with acute PE in 2005 resulting in a national incidence of 0.6/1000/year. The mean age was 70 years and 52% were women. The most frequent comorbidities were cardiac-, vascular-, infectious- and gastrointestinal diseases, injuries and malignancies. The mortality rates were more than doubled in patients with recent PE compared to that in a matched control group (49.1% vs 21.9%), and the excess mortality remained after exclusion of deaths occurring within one year and after exclusion of patients with any malignancy prior to the event. PE is associated with high age as well as with multiple comorbidities, and with an increased short- and long-term mortality. This study highlights the importance of a proper follow-up after an acute PE.

  3. [A survival analysis approach to assess the association between maternal smoking during pregnancy and childhood obesity].

    Science.gov (United States)

    Suzuki, Kohta; Sato, Miri; Ando, Daisuke; Kondo, Naoki; Yamagata, Zentaro

    2012-08-01

    It has been suggested that maternal smoking during pregnancy has an effect on childhood obesity. We previously clarified the association between maternal lifestyle habits practiced during pregnancy, including smoking, and childhood obesity and overweight at 9-10 years of age. In this study, we aimed to demonstrate this association through survival analysis. This study was based on an on-going community-based prospective cohort study initiated in the fetal stage called Project Koshu. The study population comprised of the participants of Project Koshu, who were children born in a rural Japanese area between 1991 and 1999 and their mothers. In this project, maternal smoking status during pregnancy was collected through a questionnaire and childhood anthropometric data were measured at annual medical check-ups from 3 years of age to 9-10 years of age. Using these data, we performed a survival analysis using the Kaplan-Meier method to compare the cumulative rate of childhood obesity and overweight between those with mothers who smoked during pregnancy and those who did not. Subsequently, we calculated the hazard ratio (HR) of the effect of maternal smoking during pregnancy on childhood obesity using the Cox proportional hazard model. In the survival analysis of childhood obesity, we analyzed the data of 1428 children and their mothers (follow-up rate: 87.7%). Of these, 290 children (20.3%) became overweight and 92 children (6.4%) became obese between 3 years of age and 9-10 years of age. This shows that the cumulative rate of childhood obesity was significantly different between mothers with and without smoking habits (P obese between 3 years of age and 9-10 years of age. Maternal smoking during pregnancy was found to be associated with childhood obesity (HR, 2.0; 95% confidence interval (CI): 1.04-4.0). However, there was no significant association between maternal smoking during pregnancy and childhood overweight. Our results suggest that the effect of fetal

  4. Survival Analysis of Occipital Nerve Stimulator Leads Placed under Fluoroscopic Guidance with and without Ultrasonography.

    Science.gov (United States)

    Jones, James H; Brown, Alison; Moyse, Daniel; Qi, Wenjing; Roy, Lance

    2017-11-01

    Electrical stimulation of the greater occipital nerves is performed to treat pain secondary to chronic daily headaches and occipital neuralgia. The use of fluoroscopy alone to guide the surgical placement of electrodes near the greater occipital nerves disregards the impact of tissue planes on lead stability and stimulation efficacy. We hypothesized that occipital neurostimulator (ONS) leads placed with ultrasonography combined with fluoroscopy would demonstrate increased survival rates and times when compared to ONS leads placed with fluoroscopy alone. A 2-arm retrospective chart review. A single academic medical center. This retrospective chart review analyzed the procedure notes and demographic data of patients who underwent the permanent implant of an ONS lead between July 2012 and August 2015. Patient data included the diagnosis (reason for implant), smoking tobacco use, disability, and age. ONS lead data included the date of permanent implant, the imaging modality used during permanent implant (fluoroscopy with or without ultrasonography), and, if applicable, the date and reason for lead removal. A total of 21 patients (53 leads) were included for the review. Chi-squared tests, Fishers exact tests, 2-sample t-tests, and Wilcoxon rank-sum tests were used to compare fluoroscopy against combined fluoroscopy and ultrasonography as implant methods with respect to patient demographics. These tests were also used to evaluate the primary aim of this study, which was to compare the survival rates and times of ONS leads placed with combined ultrasonography and fluoroscopy versus those placed with fluoroscopy alone. Survival analysis was used to assess the effect of implant method, adjusted for patient demographics (age, smoking tobacco use, and disability), on the risk of lead explant. Data from 21 patients were collected, including a total of 53 ONS leads. There was no statistically significant difference in the lead survival rate or time, disability, or patient age

  5. A systematic review and meta-analysis of the influence of peritoneal dialysis catheter type on complication rate and catheter survival.

    Science.gov (United States)

    Hagen, Sander M; Lafranca, Jeffrey A; IJzermans, Jan N M; Dor, Frank J M F

    2014-04-01

    Peritoneal dialysis (PD) is an effective treatment for end-stage renal disease. There are several configurations of PD catheter design that may impact catheter function, such as the shape of the intraperitoneal segment, the number of cuffs, and the subcutaneous configuration. This review and meta-analysis was carried out to determine whether there is a clinical advantage for one of the catheter types or configurations. Comprehensive searches were conducted in MEDLINE, Embase, and CENTRAL (the Cochrane Library 2012, issue 10). The methodology was in accordance with the Cochrane Handbook for Interventional Systematic Reviews and written based on the PRISMA statement. The initial search yielded 682 hits from which 13 randomized controlled trials were identified. Outcomes of interest were as follows: catheter survival, drainage dysfunction, migration, leakage, exit-site infections, peritonitis, and catheter removal. Comparing straight vs. swan neck and single vs. double-cuffed catheters, no differences were found when results were pooled. Comparison of straight vs. coiled-tip catheters demonstrated that survival was significantly different in favor of straight catheters (hazard ratio 2.05; confidence interval 1.10-3.79, P=0.02). For surgically inserted catheters, the removal rate and survival at 1 year after insertion were significantly in favor of straight catheters. Our meta-analysis clearly demonstrates benefits for catheters with a straight intraperitoneal segment.

  6. Mediation analysis of the relationship between institutional research activity and patient survival

    DEFF Research Database (Denmark)

    Rochon, Justine; du Bois, Andreas; Lange, Theis

    2014-01-01

    BACKGROUND: Recent studies have suggested that patients treated in research-active institutions have better outcomes than patients treated in research-inactive institutions. However, little attention has been paid to explaining such effects, probably because techniques for mediation analysis exis......, we have shown that the research activity of a hospital contributes to superior patient survival through better use of surgery and chemotherapy. This methodology may be applied to analyze direct and indirect natural effects for almost any combination of variable types....... the 133 patients treated in non-trial hospitals. Taking into account baseline confounders, the overall adjusted hazard ratio of death was 0.58 (95% confidence interval: 0.42 to 0.79). This effect was decomposed into a direct effect of research activity of 0.67 and two indirect effects of 0.93 each...

  7. Breastfeeding practices in a public health field practice area in Sri Lanka: a survival analysis

    Directory of Open Access Journals (Sweden)

    Agampodi Thilini C

    2007-10-01

    Full Text Available Abstract Background Exclusive breastfeeding up to the completion of the sixth month of age is the national infant feeding recommendation for Sri Lanka. The objective of the present study was to collect data on exclusive breastfeeding up to six months and to describe the association between exclusive breastfeeding and selected socio-demographic factors. Methods A clinic based cross-sectional study was conducted in the Medical Officer of Health area, Beruwala, Sri Lanka in June 2006. Mothers with infants aged 4 to 12 months, attending the 19 child welfare clinics in the area were included in the study. Infants with specific feeding problems (cleft lip and palate and primary lactose intolerance were excluded. Cluster sampling technique was used and consecutive infants fulfilling the inclusion criteria were enrolled. A total of 219 mothers participated in the study. The statistical tests used were survival analysis (Kaplan-Meier survival curves and Cox proportional Hazard model. Results All 219 mothers had initiated breastfeeding. The median duration of exclusive breastfeeding was four months (95% CI 3.75, 4.25. The rates of exclusive breastfeeding at 4 and 6 months were 61.6% (135/219 and 15.5% (24/155 respectively. Bivariate analysis showed that the Muslim ethnicity (p = 0.004, lower levels of parental education (p Conclusion The rate of breastfeeding initiation and exclusive breastfeeding up to the fourth month is very high in Medical Officer of Health area, Beruwala, Sri Lanka. However exclusive breastfeeding up to six months is still low and the prevalence of inappropriate feeding practices is high.

  8. Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees.

    Science.gov (United States)

    Kenah, Eben; Britton, Tom; Halloran, M Elizabeth; Longini, Ira M

    2016-04-01

    Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology.

  9. Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees

    Science.gov (United States)

    Kenah, Eben; Britton, Tom; Halloran, M. Elizabeth; Longini, Ira M.

    2016-01-01

    Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology. PMID:27070316

  10. Results after replantation of avulsed permanent teeth. III. Tooth loss and survival analysis.

    Science.gov (United States)

    Pohl, Yango; Wahl, Gerhard; Filippi, Andreas; Kirschner, Horst

    2005-04-01

    Avulsed permanent teeth were replanted following immediate extraoral endodontic treatment by insertion of posts from a retrograde direction. Some teeth were rescued in a physiologic environment (tissue culture medium contained in a tooth rescue box), and in some cases antiresorptive-regenerative therapy (ART) was used. The aim of the study was to identify variables that influence the incidence of tooth loss and the survival of avulsed and replanted permanent incisors. Twenty-eight permanent teeth in 24 patients aged 7-17 years were investigated. In all teeth extraoral endodontic treatment by retrograde insertion of posts was performed. All nine teeth with functional healing (FH) were in situ. Of the 19 teeth with non-FH, seven were removed to allow transplantations. Two teeth were removed due to severe infrapositions. One tooth was lost following a new trauma. No tooth was lost due to acute infections. In descriptive statistics the incidence of tooth loss was significantly related to healing (P = 0.0098, Fisher's exact test), to treatment planning, i.e. consecutive replantation of premolars and primary canines (P = 0.0001, Fisher's exact test) and to immediate physiologic rescue (P = 0.0394). ART was related to tooth loss when tested in teeth with a compromised periodontal ligament (P = 0.0389). No influence could be found for the parameters maturity, age and all other factors. In a regression analysis treatment planning was the only factor left which had a significant influence (P = 0.0002). The estimated mean survival time (Kaplan-Meier analysis) for all teeth was 57.3 months. The survival was significantly reduced (P = 0.0002, log rank test) when consecutive transplantations were intended and performed. No influence could be found for maturity, age and all other factors. The different findings to previous studies can be explained by the prevention of complications related to conventional endodontic treatment approaches. Statistics have to be carefully

  11. Survival benefit of postoperative radiation in papillary meningioma: Analysis of the National Cancer Data Base.

    Science.gov (United States)

    Sumner, Whitney A; Amini, Arya; Hankinson, Todd C; Foreman, Nicholas K; Gaspar, Laurie E; Kavanagh, Brian D; Karam, Sana D; Rusthoven, Chad G; Liu, Arthur K

    2017-01-01

    Papillary meningioma represents a rare subset of World Health Organization (WHO) Grade III meningioma that portends an overall poor prognosis. There is relatively limited data regarding the benefit of postoperative radiation therapy (PORT). We used the National Cancer Data Base (NCDB) to compare overall survival (OS) outcomes of surgically resected papillary meningioma cases undergoing PORT compared to post-operative observation. The NCDB was queried for patients with papillary meningioma, diagnosed between 2004 and 2013, who underwent upfront surgery with or without PORT. Overall survival (OS) was determined using the Kaplan-Meier method. Univariate (UVA) and multivariate (MVA) analyses were performed. In total, 190 patients were identified; 89 patients underwent PORT, 101 patients were observed. Eleven patients received chemotherapy (6 with PORT, 5 without). 2-Year OS was significantly improved with PORT vs. no PORT (93.0% vs. 74.4%), as was 5-year OS (78.5% vs. 62.5%) (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.27-0.85; p = 0.01). On MVA, patients receiving PORT had improved OS compared to observation (HR, 0.41; 95% CI, 0.22-0.76; p = 0.005). On subset analysis by age group, the benefit of PORT vs. no PORT was significant in patients ≤18 years (n = 13), with 2-year OS of 85.7% vs. 50.0% (HR, 0.08; 95% CI, 0.01-0.80; p = 0.032) and for patients >18 years (n = 184), with 2-year OS of 94.7% vs. 76.1% (HR, 0.55; 95% CI, 0.31-1.00; p = 0.049), respectively. In this large contemporary analysis, PORT was associated with improved survival for both adult and pediatric patients with papillary meningioma. PORT should be considered in those who present with this rare, aggressive tumor.

  12. Establishing the change in antibiotic resistance of Enterococcus faecium strains isolated from Dutch broilers by logistic regression and survival analysis

    NARCIS (Netherlands)

    Stegeman, J.A.; Vernooij, J.C.M.; Khalifa, O.A.; Broek, van den J.; Mevius, D.J.

    2006-01-01

    In this study, we investigated the change in the resistance of Enterococcus faecium strains isolated from Dutch broilers against erythromycin and virginiamycin in 1998, 1999 and 2001 by logistic regression analysis and survival analysis. The E. faecium strains were isolated from caecal samples that

  13. STXMPy: a new software package for automated region of interest selection and statistical analysis of XANES data

    Directory of Open Access Journals (Sweden)

    Grunze Michael

    2010-06-01

    Full Text Available Abstract Background Soft X-ray spectromicroscopy based absorption near-edge structure analysis, is a spectroscopic technique useful for investigating sample composition at a nanoscale of resolution. While the technique holds great promise for analysis of biological samples, current methodologies are challenged by a lack of automatic analysis software e. g. for selection of regions of interest and statistical comparisons of sample variability. Results We have implemented a set of functions and scripts in Python to provide a semiautomatic treatment of data obtained using scanning transmission X-ray microscopy. The toolkit includes a novel line-by-line absorption conversion and data filtering automatically identifying image components with significant absorption. Results are provided to the user by direct graphical output to the screen and by output images and data files, including the average and standard deviation of the X-ray absorption spectrum. Using isolated mouse melanosomes as a sample biological tissue, application of STXMPy in analysis of biological tissues is illustrated. Conclusion The STXMPy package allows both interactive and automated batch processing of scanning transmission X-ray microscopic data. It is open source, cross platform, and offers rapid script development using the interpreted Python language.

  14. Survival analysis: A consumer-friendly method to estimate the optimum sucrose level in probiotic petit suisse.

    Science.gov (United States)

    Esmerino, E A; Paixão, J A; Cruz, A G; Garitta, L; Hough, G; Bolini, H M A

    2015-11-01

    For years, just-about-right (JAR) scales have been among the most used techniques to obtain sensory information about consumer perception, but recently, some researchers have harshly criticized the technique. The present study aimed to apply survival analysis to estimate the optimum sucrose concentration in probiotic petit suisse cheese and compare the survival analysis to JAR scales to verify which technique more accurately predicted the optimum sucrose concentration according to consumer acceptability. Two panels of consumers (total=170) performed affective tests to determine the optimal concentration of sucrose in probiotic petit suisse using 2 different methods of analysis: JAR scales (n=85) and survival analysis (n=85). Then an acceptance test was conducted using naïve consumers (n=100) between 18 and 60 yr old, with 2 samples of petit suisse, one with the ideal sucrose determined by JAR scales and the other with the ideal sucrose content determined by survival analysis, to determine which formulation was in accordance with consumer acceptability. The results indicate that the 2 sensory methods were equally effective in predicting the optimum sucrose level in probiotic petit suisse cheese, and no significant differences were detected in any of the characteristics related to liking evaluated. However, survival analysis has important advantages over the JAR scales. Survival analysis has shown the potential to be an advantageous tool for dairy companies because it was able to accurately predict the optimum sucrose content in a consumer-friendly way and was also practical for researchers because experimental sensory work is simpler and has been shown to be more cost effective than JAR scales without losses of consumer acceptability. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Rethinking plant functional types in Earth System Models: pan-tropical analysis of tree survival across environmental gradients

    Science.gov (United States)

    Johnson, D. J.; Needham, J.; Xu, C.; Davies, S. J.; Bunyavejchewin, S.; Giardina, C. P.; Condit, R.; Cordell, S.; Litton, C. M.; Hubbell, S.; Kassim, A. R. B.; Shawn, L. K. Y.; Nasardin, M. B.; Ong, P.; Ostertag, R.; Sack, L.; Tan, S. K. S.; Yap, S.; McDowell, N. G.; McMahon, S.

    2016-12-01

    Terrestrial carbon cycling is a function of the growth and survival of trees. Current model representations of tree growth and survival at a global scale rely on coarse plant functional traits that are parameterized very generally. In view of the large biodiversity in the tropical forests, it is important that we account for the functional diversity in order to better predict tropical forest responses to future climate changes. Several next generation Earth System Models are moving towards a size-structured, trait-based approach to modelling vegetation globally, but the challenge of which and how many traits are necessary to capture forest complexity remains. Additionally, the challenge of collecting sufficient trait data to describe the vast species richness of tropical forests is enormous. We propose a more fundamental approach to these problems by characterizing forests by their patterns of survival. We expect our approach to distill real-world tree survival into a reasonable number of functional types. Using 10 large-area tropical forest plots that span geographic, edaphic and climatic gradients, we model tree survival as a function of tree size for hundreds of species. We found surprisingly few categories of size-survival functions emerge. This indicates some fundamental strategies at play across diverse forests to constrain the range of possible size-survival functions. Initial cluster analysis indicates that four to eight functional forms are necessary to describe variation in size-survival relations. Temporal variation in size-survival functions can be related to local environmental variation, allowing us to parameterize how demographically similar groups of species respond to perturbations in the ecosystem. We believe this methodology will yield a synthetic approach to classifying forest systems that will greatly reduce uncertainty and complexity in global vegetation models.

  16. Long-Term Survival Outcomes of Cancer-Directed Surgery for Malignant Pleural Mesothelioma: Propensity Score Matching Analysis.

    Science.gov (United States)

    Nelson, David B; Rice, David C; Niu, Jiangong; Atay, Scott; Vaporciyan, Ara A; Antonoff, Mara; Hofstetter, Wayne L; Walsh, Garrett L; Swisher, Stephen G; Roth, Jack A; Tsao, Anne; Gomez, Daniel; Giordano, Sharon H; Mehran, Reza; Sepesi, Boris

    2017-10-10

    Purpose Small observational studies have shown a survival advantage to undergoing cancer-directed surgery for malignant pleural mesothelioma (MPM); however, it is unclear if these results are generalizable. Our purpose was to evaluate survival after treatment of MPM with cancer-directed surgery and to explore the effect surgery interaction with chemotherapy or radiation therapy on survival by using the National Cancer Database. Patients and Methods Patients with microscopically proven MPM were identified within the National Cancer Database (2004 to 2014). Propensity score matching was performed 1:2 and among this cohort, a Cox proportional hazards regression model was used to identify predictors of survival. Median survival was calculated by using the Kaplan-Meier method. Results Of 20,561 patients with MPM, 6,645 were identified in the matched cohort, among whom 2,166 underwent no therapy, 2,015 underwent chemotherapy alone, 850 underwent cancer-directed surgery alone, 988 underwent surgery with chemotherapy, and 274 underwent trimodality therapy. The remaining 352 patients underwent another combination of surgery, radiation, or chemotherapy. Thirty-day and 90-day mortality rates were 6.3% and 15.5%. Cancer-directed surgery, chemotherapy, and radiation therapy were independently associated with improved survival (hazard ratio, 0.77, 0.74, and 0.88, respectively). Stratified analysis revealed that surgery-based multimodality therapy demonstrated an improved survival compared with surgery alone, with no significant difference between surgery-based multimodality therapies; however, the largest estimated effect was when cancer-directed surgery, chemotherapy, and radiation therapy were combined (hazard ratio, 0.52). For patients with the epithelial subtype who underwent trimodality therapy, median survival was extended from 14.5 months to 23.4 months. Conclusion MPM is an aggressive and rapidly fatal disease. Surgery-based multimodality therapy was associated with

  17. Transnational tobacco company interests in smokeless tobacco in Europe: analysis of internal industry documents and contemporary industry materials.

    Directory of Open Access Journals (Sweden)

    Silvy Peeters

    Full Text Available European Union (EU legislation bans the sale of snus, a smokeless tobacco (SLT which is considerably less harmful than smoking, in all EU countries other than Sweden. To inform the current review of this legislation, this paper aims to explore transnational tobacco company (TTC interests in SLT and pure nicotine in Europe from the 1970s to the present, comparing them with TTCs' public claims of support for harm reduction.Internal tobacco industry documents (in total 416 documents dating from 1971 to 2009, obtained via searching the online Legacy Tobacco Documents Library, were analysed using a hermeneutic approach. This library comprises documents obtained via litigation in the US and does not include documents from Imperial Tobacco, Japan Tobacco International, or Swedish Match. To help overcome this limitation and provide more recent data, we triangulated our documentary findings with contemporary documentation including TTC investor presentations. The analysis demonstrates that British American Tobacco explored SLT opportunities in Europe from 1971 driven by regulatory threats and health concerns, both likely to impact cigarette sales negatively, and the potential to create a new form of tobacco use among those no longer interested in taking up smoking. Young people were a key target. TTCs did not, however, make SLT investments until 2002, a time when EU cigarette volumes started declining, smoke-free legislation was being introduced, and public health became interested in harm reduction. All TTCs have now invested in snus (and recently in pure nicotine, yet both early and recent snus test markets appear to have failed, and little evidence was found in TTCs' corporate materials that snus is central to their business strategy.There is clear evidence that BAT's early interest in introducing SLT in Europe was based on the potential for creating an alternative form of tobacco use in light of declining cigarette sales and social restrictions on

  18. Transnational tobacco company interests in smokeless tobacco in Europe: analysis of internal industry documents and contemporary industry materials.

    Science.gov (United States)

    Peeters, Silvy; Gilmore, Anna B

    2013-01-01

    European Union (EU) legislation bans the sale of snus, a smokeless tobacco (SLT) which is considerably less harmful than smoking, in all EU countries other than Sweden. To inform the current review of this legislation, this paper aims to explore transnational tobacco company (TTC) interests in SLT and pure nicotine in Europe from the 1970s to the present, comparing them with TTCs' public claims of support for harm reduction. Internal tobacco industry documents (in total 416 documents dating from 1971 to 2009), obtained via searching the online Legacy Tobacco Documents Library, were analysed using a hermeneutic approach. This library comprises documents obtained via litigation in the US and does not include documents from Imperial Tobacco, Japan Tobacco International, or Swedish Match. To help overcome this limitation and provide more recent data, we triangulated our documentary findings with contemporary documentation including TTC investor presentations. The analysis demonstrates that British American Tobacco explored SLT opportunities in Europe from 1971 driven by regulatory threats and health concerns, both likely to impact cigarette sales negatively, and the potential to create a new form of tobacco use among those no longer interested in taking up smoking. Young people were a key target. TTCs did not, however, make SLT investments until 2002, a time when EU cigarette volumes started declining, smoke-free legislation was being introduced, and public health became interested in harm reduction. All TTCs have now invested in snus (and recently in pure nicotine), yet both early and recent snus test markets appear to have failed, and little evidence was found in TTCs' corporate materials that snus is central to their business strategy. There is clear evidence that BAT's early interest in introducing SLT in Europe was based on the potential for creating an alternative form of tobacco use in light of declining cigarette sales and social restrictions on smoking, with

  19. Integrated survival analysis using an event-time approach in a Bayesian framework

    Science.gov (United States)

    Walsh, Daniel P.; Dreitz, VJ; Heisey, Dennis M.

    2015-01-01

    Event-time or continuous-time statistical approaches have been applied throughout the biostatistical literature and have led to numerous scientific advances. However, these techniques have traditionally relied on knowing failure times. This has limited application of these analyses, particularly, within the ecological field where fates of marked animals may be unknown. To address these limitations, we developed an integrated approach within a Bayesian framework to estimate hazard rates in the face of unknown fates. We combine failure/survival times from individuals whose fates are known and times of which are interval-censored with information from those whose fates are unknown, and model the process of detecting animals with unknown fates. This provides the foundation for our integrated model and permits necessary parameter estimation. We provide the Bayesian model, its derivation, and use simulation techniques to investigate the properties and performance of our approach under several scenarios. Lastly, we apply our estimation technique using a piece-wise constant hazard function to investigate the effects of year, age, chick size and sex, sex of the tending adult, and nesting habitat on mortality hazard rates of the endangered mountain plover (Charadrius montanus) chicks. Traditional models were inappropriate for this analysis because fates of some individual chicks were unknown due to failed radio transmitters. Simulations revealed biases of posterior mean estimates were minimal (≤ 4.95%), and posterior distributions behaved as expected with RMSE of the estimates decreasing as sample sizes, detection probability, and survival increased. We determined mortality hazard rates for plover chicks were highest at weights and/or whose nest was within agricultural habitats. Based on its performance, our approach greatly expands the range of problems for which event-time analyses can be used by eliminating the need for having completely known fate data.

  20. The MicroRNAs as Prognostic Biomarkers for Survival in Esophageal Cancer: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Wenbo Fu

    2014-01-01

    Full Text Available Objectives. We performed this meta-analysis to summarize all the results from available studies, aiming delineating the prognostic role of miRNA in esophageal cancer. Design and Methods. We searched the electronic databases PubMed, EMBASE, and ISI Web of Science without time restrictions for the correlative literature to aggregate the survival results. Relevant data were extracted from studies investigating the relationship between miRNAs expression and survival in esophageal cancer patients. Pooled hazard ratios of miR-21and miR-375 for OS in ESCC were calculated. Results. A total of 25 studies involving 2,258 subjects analyzed the relationship between miRNA and prognosis of EC. In all, thirty-nine miRNAs associated with prognosis were reported in these studies. The pooled HR of higher miR-21 expression compared with lower miR-21 expression in ESCC was 1.84 (95% CI: 1.41–2.40, P<0.001, which could significantly predict poorer OS in ESCC. Besides, higher miR-375 was also a significant predictor for OS in ESCC, with a pooled HR of 0.55 (95% CI: 0.42–0.72, P<0.001. Conclusions. Our results support that miR-21 and miR-375 have a prognostic role in ESCC and may be useful therapeutic targets for the treatment of ESCC and meticulous follow-up for early detection of recurrence.

  1. Risk factors for dental caries in childhood: a five-year survival analysis.

    Science.gov (United States)

    Lee, Hyo-Jin; Kim, Jin-Bom; Jin, Bo-Hyoung; Paik, Dai-Il; Bae, Kwang-Hak

    2015-04-01

    The purpose of this study was to examine the risk factors of dental caries at the level of an individual person with survival analysis of the prospective data for 5 years. A total of 249 first-grade students participated in a follow-up study for 5 years. All participants responded to a questionnaire inquiring about socio-demographic variables and oral health behaviors. They also received an oral examination and were tested for Dentocult SM and LB. Over 5 years, the participants received yearly oral follow-up examinations to determine the incidence of dental caries. The incidence of one or more dental caries (DC1) and four or more dental caries (DC4) were defined as one or more and four or more decayed, missing, and filled permanent teeth increments, respectively. Socio-demographic variables, oral health behaviors, and status and caries activity tests were assessed as risk factors for DC1 and DC4. The adjusted hazard ratios (HRs) of risk factors for DC1 and DC4 were calculated using Cox proportional hazard regression models. During the 5-year follow-up period, DC1 and DC4 occurred in 87 and 25 participants, respectively. In multivariate hazard models, five or more decayed, missing, and filled primary molar teeth [HR 1.93, 95% confidence interval (CI) 1.19-3.13], and Dentocult LB of two or three (HR 2.21, 95% CI 1.37-3.56) were independent risk factors of DC1. For DC4, only Dentocult LB of two or three was an independent risk factor (HR 2.95, 95% CI 1.11-7.79). Our results suggest that dental caries incidence at an individual level can be associated with the experience of dental caries in primary teeth and Dentocult LB based on the survival models for the 5-year prospective data. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. HIV testing in the maternity ward and the start of breastfeeding: a survival analysis.

    Science.gov (United States)

    Possolli, Glaucia T; Carvalho, Márcia L de; Oliveira, Maria Inês C de

    2015-01-01

    The purpose of this study was to analyze the factors that influence of the time between birth and the beginning of breastfeeding, especially at the moment of the rapid HIV test results at hospital admission for delivery. Cohort study of 932 pregnant women who underwent rapid HIV test admitted in the hospital for delivery in Baby-Friendly Hospitals. The survival curves of time from birth to the first feeding were estimated by the Kaplan-Meier method and the joint effect of independent variables by the Cox model with a hierarchical analysis. As the survival curves were not homogeneous among the five hospitals, hindering the principle of proportionality of risks, the data were divided into two groups according to the median time of onset of breastfeeding at birth in women undergoing rapid HIV testing. Hospitals with median time to breastfeeding onset at birth of up to 60 min were considered as early breastfeeding onset and those with higher medians were considered as late breastfeeding onset at birth. Risk factors common to hospitals considered to be with early and late breastfeeding onset at birth were: cesarean section (RR=1.75 [95% CI: 1.38-2.22]; RR=3.83 [95% CI: 3.03-4.85]) and rapid test result after birth (RR=1.45 [95% CI: 1.12-1.89]; RR=1.65 [95% CI: 1.35-2.02]), respectively; and hospitals with late onset: starting prenatal care in the third trimester (RR=1.86 [95% CI: 1.16-2.97]). The onset of breastfeeding is postponed, even in Baby-Friendly Hospitals, when the results of the rapid HIV test requested in the maternity are not available at the time of delivery. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  3. HIV testing in the maternity ward and the start of breastfeeding: a survival analysis

    Directory of Open Access Journals (Sweden)

    Glaucia T. Possolli

    2015-08-01

    Full Text Available OBJECTIVE: The purpose of this study was to analyze the factors that influence of the time between birth and the beginning of breastfeeding, especially at the moment of the rapid HIV test results at hospital admission for delivery.METHODS: Cohort study of 932 pregnant women who underwent rapid HIV test admitted in the hospital for delivery in Baby-Friendly Hospitals. The survival curves of time from birth to the first feeding were estimated by the Kaplan-Meier method and the joint effect of independent variables by the Cox model with a hierarchical analysis. As the survival curves were not homogeneous among the five hospitals, hindering the principle of proportionality of risks, the data were divided into two groups according to the median time of onset of breastfeeding at birth in women undergoing rapid HIV testing.RESULTS: Hospitals with median time to breastfeeding onset at birth of up to 60 min were considered as early breastfeeding onset and those with higher medians were considered as late breastfeeding onset at birth. Risk factors common to hospitals considered to be with early and late breastfeeding onset at birth were: cesarean section (RR = 1.75 [95% CI: 1.38-2.22]; RR = 3.83 [95% CI: 3.03-4.85] and rapid test result after birth (RR = 1.45 [95% CI: 1.12-1.89]; RR = 1.65 [95% CI: 1.35-2.02], respectively; and hospitals with late onset: starting prenatal care in the third trimester (RR = 1.86 [95% CI: 1.16-2.97].CONCLUSIONS: The onset of breastfeeding is postponed, even in Baby-Friendly Hospitals, when the results of the rapid HIV test requested in the maternity are not available at the time of delivery.

  4. Texture analysis for survival prediction of pancreatic ductal adenocarcinoma patients with neoadjuvant chemotherapy

    Science.gov (United States)

    Chakraborty, Jayasree; Langdon-Embry, Liana; Escalon, Joanna G.; Allen, Peter J.; Lowery, Maeve A.; O'Reilly, Eileen M.; Do, Richard K. G.; Simpson, Amber L.

    2016-03-01

    Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death in the United States. The five-year survival rate for all stages is approximately 6%, and approximately 2% when presenting with distant disease.1 Only 10-20% of all patients present with resectable disease, but recurrence rates are high with only 5 to 15% remaining free of disease at 5 years. At this time, we are unable to distinguish between resectable PDAC patients with occult metastatic disease from those with potentially curable disease. Early classification of these tumor types may eventually lead to changes in initial management including the use of neoadjuvant chemotherapy or radiation, or in the choice of postoperative adjuvant treatments. Texture analysis is an emerging methodology in oncologic imaging for quantitatively assessing tumor heterogeneity that could potentially aid in the stratification of these patients. The present study derives several texture-based features from CT images of PDAC patients, acquired prior to neoadjuvant chemotherapy, and analyzes their performance, individually as well as in combination, as prognostic markers. A fuzzy minimum redundancy maximum relevance method with leave-one-image-out technique is included to select discriminating features from the set of extracted features. With a naive Bayes classifier, the proposed method predicts the 5-year overall survival of PDAC patients prior to neoadjuvant therapy and achieves the best results in terms of the area under the receiver operating characteristic curve of 0:858 and accuracy of 83:0% with four-fold cross-validation techniques.

  5. National interest to TLCAN

    OpenAIRE

    Witker Velásquez, Jorge

    2017-01-01

    In this article the author reflects on the concept of national interest, considering its basic referents: State, nation and power. His analysis describes and examines aspects related to the vulnerability of the Mexican national interest on informal policies of the North American Free Trade Agreement (NAFTA.). This article explores, through a series of antithetical elements, such Mexico’s national interest, in the context of NAFTA, producing chiaroscuro effects for the country. The author prov...

  6. Analysis of multilevel grouped survival data with time-varying regression coefficients.

    Science.gov (United States)

    Wong, May C M; Lam, K F; Lo, Edward C M

    2011-02-10

    Correlated or multilevel grouped survival data are common in medical and dental research. Two common approaches to analyze such data are the marginal and the random-effects approaches. Models and methods in the literature generally assume that the treatment effect is constant over time. A researcher may be interested in studying whether the treatment effects in a clinical trial vary over time, say fade out gradually. This is of particular clinical value when studying the long-term effect of a treatment. This paper proposed to extend the random effects grouped proportional hazards models by incorporating the possibly time-varying covariate effects into the model in terms of a state-space formulation. The proposed model is very flexible and the estimation can be performed using the MCMC approach with non-informative priors in the Bayesian framework. The method is applied to a data set from a prospective clinical trial investigating the effectiveness of silver diamine fluoride (SDF) and sodium fluoride (NaF) varnish in arresting active dentin caries in the Chinese preschool children. It is shown that the treatment groups with caries removal prior to the topical fluoride applications are most effective in shortening the arrest times in the first 6-month interval, but their effects fade out rapidly since then. The effects of treatment groups without caries removal prior to topical fluoride application drop at a very slow rate and can be considered as more or less constant over time. The applications of SDF solution is found to be more effective than the applications of NaF vanish. Copyright © 2010 John Wiley & Sons, Ltd.

  7. Comparing measurement error correction methods for rate-of-change exposure variables in survival analysis.

    Science.gov (United States)

    Veronesi, Giovanni; Ferrario, Marco M; Chambless, Lloyd E

    2013-12-01

    In this article we focus on comparing measurement error correction methods for rate-of-change exposure variables in survival analysis, when longitudinal data are observed prior to the follow-up time. Motivational examples include the analysis of the association between changes in cardiovascular risk factors and subsequent onset of coronary events. We derive a measurement error model for the rate of change, estimated through subject-specific linear regression, assuming an additive measurement error model for the time-specific measurements. The rate of change is then included as a time-invariant variable in a Cox proportional hazards model, adjusting for the first time-specific measurement (baseline) and an error-free covariate. In a simulation study, we compared bias, standard deviation and mean squared error (MSE) for the regression calibration (RC) and the simulation-extrapolation (SIMEX) estimators. Our findings indicate that when the amount of measurement error is substantial, RC should be the preferred method, since it has smaller MSE for estimating the coefficients of the rate of change and of the variable measured without error. However, when the amount of measurement error is small, the choice of the method should take into account the event rate in the population and the effect size to be estimated. An application to an observational study, as well as examples of published studies where our model could have been applied, are also provided.

  8. Bayesian Analysis for Dynamic Generalized Linear Latent Model with Application to Tree Survival Rate

    Directory of Open Access Journals (Sweden)

    Yu-sheng Cheng

    2014-01-01

    Full Text Available Logistic regression model is the most popular regression technique, available for modeling categorical data especially for dichotomous variables. Classic logistic regression model is typically used to interpret relationship between response variables and explanatory variables. However, in real applications, most data sets are collected in follow-up, which leads to the temporal correlation among the data. In order to characterize the different variables correlations, a new method about the latent variables is introduced in this study. At the same time, the latent variables about AR (1 model are used to depict time dependence. In the framework of Bayesian analysis, parameters estimates and statistical inferences are carried out via Gibbs sampler with Metropolis-Hastings (MH algorithm. Model comparison, based on the Bayes factor, and forecasting/smoothing of the survival rate of the tree are established. A simulation study is conducted to assess the performance of the proposed method and a pika data set is analyzed to illustrate the real application. Since Bayes factor approaches vary significantly, efficiency tests have been performed in order to decide which solution provides a better tool for the analysis of real relational data sets.

  9. Analysis of factors affecting hemorrhagic diathesis and overall survival in patients with acute promyelocytic leukemia.

    Science.gov (United States)

    Lee, Ho Jin; Kim, Dong Hyun; Lee, Seul; Koh, Myeong Seok; Kim, So Yeon; Lee, Ji Hyun; Lee, Suee; Oh, Sung Yong; Han, Jin Yeong; Kim, Hyo-Jin; Kim, Sung-Hyun

    2015-11-01

    This study investigated whether patients with acute promyelocytic leukemia (APL) truly fulfill the diagnostic criteria of overt disseminated intravascular coagulation (DIC), as proposed by the International Society on Thrombosis and Haemostasis (ISTH) and the Korean Society on Thrombosis and Hemostasis (KSTH), and analyzed which component of the criteria most contributes to bleeding diathesis. A single-center retrospective analysis was conducted on newly diagnosed APL patients between January 1995 and May 2012. A total of 46 newly diagnosed APL patients were analyzed. Of these, 27 patients (58.7%) showed initial bleeding. The median number of points per patient fulfilling the diagnostic criteria of overt DIC by the ISTH and the KSTH was 5 (range, 1 to 7) and 3 (range, 1 to 4), respectively. At diagnosis of APL, 22 patients (47.8%) fulfilled the overt DIC diagnostic criteria by either the ISTH or KSTH. In multivariate analysis of the ISTH or KSTH diagnostic criteria for overt DIC, the initial fibrinogen level was the only statistically significant factor associated with initial bleeding (p = 0.035), but it was not associated with overall survival (OS). Initial fibrinogen level is associated with initial presentation of bleeding of APL patients, but does not affect OS.

  10. Proximate cues for a short-distance migratory species: An application of survival analysis

    Science.gov (United States)

    Meunier, J.; Song, R.; Lutz, R.S.; Andersen, D.E.; Doherty, K.E.; Bruggink, J.G.; Oppelt, E.

    2008-01-01

    Investigation of bird migration has often highlighted the importance of external factors in determining timing of migration However, little distinction has been made between short- and long-distance migrants and between local and flight birds (passage migrants) in describing migration chronology. In addition, measures of food abundance as a proximate factor influencing timing of migration are lacking in studies of migration chronology. To address the relationship between environmental variables and timing of migration we quantified the relative importance of proximate external factors on migration chronology of local American woodcock (Scolopax minor), a short distance migrant, using event-time analysis methods (survival analysis). We captured 1,094 woodcock local to our study sites in Michigan, Minnesota and Wisconsin (USA) during autumn 2002-2004 and documented 786 departure dates for these birds. Photoperiod appeared to provide an initial proximate cue for timing of departure. Moon phase was important in modifying timing of departure, which may serve as a navigational aid in piloting and possibly orientation. Local synoptic weather variables also contributed to timing of departure by changing the rate of departure from our study sites. We found no evidence that food availability influenced timing of woodcock departure. Our results suggest that woodcock use a conservative photoperiod-controlled strategy with proximate modifiers for timing of migration rather than relying on abundance of their primary food, earthworms. Managing harvest pressure on local birds by adjusting season lengths may be an effective management tool with consistent migration patterns from year to year based on photoperiod.

  11. Auto-SCT improves survival in systemic light chain amyloidosis: a retrospective analysis with 14-year follow-up.

    Science.gov (United States)

    Parmar, S; Kongtim, P; Champlin, R; Dinh, Y; Elgharably, Y; Wang, M; Bashir, Q; Shah, J J; Shah, N; Popat, U; Giralt, S A; Orlowski, R Z; Qazilbash, M H

    2014-08-01

    Optimal treatment approach continues to remain a challenge for systemic light chain amyloidosis (AL). So far, Auto-SCT is the only modality associated with long-term survival. However, failure to show survival benefit in randomized study raises questions regarding its efficacy. We present a comparative outcome analysis of Auto-SCT to conventional therapies (CTR) in AL patients treated over a 14-year period at our institution. Out of the 145 AL amyloidosis patients, Auto-SCT was performed in 80 patients with 1-year non-relapse mortality rate of 12.5%. Novel agents were used as part of induction therapy in 56% of transplant recipients vs 46% of CTR patients. Hematological and organ responses were seen in 74.6% and 39% in the Auto-SCT arm vs 53% and 12% in the CTR arm, respectively. The projected 5-year survival for Auto-SCT vs CTR was 63% vs 38%, respectively. Landmark analysis of patients alive at 1-year after diagnosis showed improved 5-year OS of 72% with Auto-SCT vs 65% in the CTR arm. In the multivariate analysis, age Auto-SCT were associated with improved survival. In conclusion, Auto-SCT is associated with long-term survival for patients with AL amyloidosis.

  12. Managing Conflicting Stakeholder Interests: An Exploratory Case Analysis of the Formulation of Corporate Social Responsibility Standards in the Netherlands

    NARCIS (Netherlands)

    Ingenbleek, P.T.M.; Immink, V.M.

    2010-01-01

    The formulation of corporate social responsibility standards must deal with conflicting interests among stakeholders. The standards formulation process occurs at the junction between market stakeholders and special interest groups, which implies that it may help increase understanding of the

  13. Statin use and kidney cancer survival outcomes: A systematic review and meta-analysis.

    Science.gov (United States)

    Nayan, Madhur; Punjani, Nahid; Juurlink, David N; Finelli, Antonio; Austin, Peter C; Kulkarni, Girish S; Uleryk, Elizabeth; Hamilton, Robert J

    2017-01-01

    Statin use has been associated with improved survival outcomes in various malignancies. Randomized controlled trials are currently underway evaluating their utility as adjunctive cancer therapies. However, studies evaluating the association between statin use and outcomes in kidney cancer yield conflicting results. We searched MEDLINE and EMBASE to identify studies evaluating the association between statin use and kidney cancer survival outcomes. We evaluated risk of bias with the Newcastle-Ottawa Scale. We pooled hazard ratios for recurrence-free survival, progression-free survival, cancer-specific survival, and overall survival using random-effects models. We evaluated publication bias through Begg's and Egger's tests, and the trim and fill procedure. We identified 12 studies meeting inclusion criteria and summarized data from 18,105 patients. No study was considered to be at high risk of bias. Statin use was not significantly associated with recurrence-free survival (pooled HR 0.97, 95% CI 0.89-1.06) or progression-free survival (pooled HR 0.92, 95% CI 0.51-1.65); however, statin use was associated with marked improvements in cancer-specific survival (pooled HR 0.67, 95% CI 0.47-0.94) and overall survival (pooled HR 0.74, 95% CI 0.63-0.88). There was no strong evidence of publication bias for any outcome. Our results demonstrate that statin use among patients with kidney cancer is associated with significantly improved cancer-specific and overall survival. Further studies are needed to confirm the therapeutic role of statins in kidney cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. [Long term biochemical recurrence free survival after radical prostatectomy for cancer: comparative analysis according to surgical approach and clinicopathological stage].

    Science.gov (United States)

    Rizk, J; Ouzzane, A; Flamand, V; Fantoni, J-C; Puech, P; Leroy, X; Villers, A

    2015-03-01

    To assess long term biochemical recurrence free survival after radical prostatectomy according to open, laparoscopic and robot-assisted surgical approach and clinicopathological stage. A cohort study of 1313 consecutive patients treated by radical prostatectomy for localized or locally advanced prostate cancer between 2000 and 2013. Open surgery (63.7%), laparoscopy (10%) and robot-assisted laparoscopy (26.4%) were performed. Biochemical recurrence was defined by PSA>0,1ng/mL. The biochemical recurrence free survival was described by Kaplan Meier method and prognostic factors were analysed by multivariable Cox regression. Median follow-up was 57 months (IQR: 31-90). Ten years biochemical recurrence free survival was 88.5%, 71.6% and 53.5% respectively for low, intermediate and high-risk D'Amico groups. On multivariable analysis, the worse prognostic factor was Gleason score (PBiochemical recurrence free survival (P=0.06) and positive surgical margins rate (P=0.87) were not statistically different between the three surgical approaches. Biochemical recurrence free survival in our study does not differ according to surgical approach and is similar to published series. Ten years biochemical recurrence free survival for high-risk tumours without hormone therapy is 54% justifying the role of surgery in the therapeutic conversations in this group of tumours. 3. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  15. Associations between statin use and non-Hodgkin lymphoma (NHL) risk and survival: a meta-analysis.

    Science.gov (United States)

    Ye, Xibiao; Mneina, Ayat; Johnston, James B; Mahmud, Salaheddin M

    2017-06-01

    Evidence on the effect of statin use on non-Hodgkin lymphoma (NHL) is not clear. We conducted a systematic review and meta-analysis to examine the associations between statin use and NHL risk and survival. We searched multiple literature sources up to October 2014 and identified 10 studies on the risk of diagnosis with NHL and 9 studies on survival. Random effects model was used to calculate pooled odds ratio (PORs) for risk and pooled hazard ratio (PHR) for survival. Heterogeneity among studies was examined using the Tau-squared and the I-squared (I 2 ) tests. Statin use was associated with reduced risk for total NHL (POR = 0.82, 95% CI 0.69-0.99). Among statin users, there was a lower incidence risk for marginal zone lymphoma (POR = 0.54, 95% CI 0.31-0.94), but this was not observed for other types of NHL. However, statin use did not affect overall survival (PHR = 1.02, 95% CI 0.99-1.06) or event-free survival (PHR = 0.99, 95% CI 0.87-1.12) in diffuse large B-cell lymphoma. There is suggestive epidemiological evidence that statins decrease the risk of NHL, but they do not influence survival in NHL patients. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Factors associated with survival in pediatric adrenocortical carcinoma: An analysis of the National Cancer Data Base (NCDB).

    Science.gov (United States)

    Gulack, Brian C; Rialon, Kristy L; Englum, Brian R; Kim, Jina; Talbot, Lindsay J; Adibe, Obinna O; Rice, Henry E; Tracy, Elisabeth T

    2016-01-01

    Adrenocortical carcinoma (ACC) is a rare tumor in children with important distinctions from the adult disease. We reviewed the National Cancer Data Base (NCDB) to determine factors associated with long-term survival. The NCDB was queried for patients less than 18 years of age who were diagnosed with ACC between 1998 and 2011. Kaplan-Meier analysis was utilized to determine factors significantly associated with overall survival. A total of 111 patients were included (median age: 4 years, 69% female). ACC was more common in the youngest cohort, with 48% of cases occurring in children younger than the age of 3. Median tumor size was 9.5 cm (IQR: 6.5-13.0), and 87% of patients underwent some form of surgical resection. Among children with available data, 19 of 62 presented with metastases. Overall 1- and 3-year survival was 70% and 64%, respectively. Age, tumor size, extension of tumor into surrounding tissue, and metastatic disease were all found to be significantly associated with survival. Among patients who underwent a surgical procedure, margin status was also found to be significantly associated with survival. Age, tumor size, extension of tumor, metastatic disease, and margin status are significantly associated with long-term survival in children with adrenocortical carcinoma. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Contesting the 'national interest' and maintaining 'our lifestyle': a discursive analysis of political rhetoric around climate change.

    Science.gov (United States)

    Kurz, Tim; Augoustinos, Martha; Crabb, Shona

    2010-09-01

    The release of the fourth United Nations Intergovernmental Panel on Climate Change (IPCC) report in February 2007 prompted a flood of responses from political leaders around the globe. Perhaps nowhere was this more apparent than in Australia, where its release coincided with the first sitting week of the Australian Parliament, in an election year. The current study involves a discursive analysis of climate change rhetoric produced by politicians from the major Australian political parties in the period following the release of the IPCC leading up to the national election. Data include both transcripts of parliamentary debate and statements directly broadcast in the media. The analysis focuses on the various ways in which the issue of climate change was invoked and rhetorically managed by each of the two parties in the lead up to the election. In particular, it focuses on the ways in which appeals to the 'national interest' and 'lifestyle maintenance', both regular features of political rhetoric, were mobilized by both parties to discursively manage their positions on the climate change issue. Implications of the ways in which such appeals were constructed are discussed in relation to the discursive limits of the ways in which the issue of climate change is constructed in public debate.

  18. Bone texture analysis on dental radiographic images: results with several angulated radiographs on the same region of interest

    Science.gov (United States)

    Amouriq, Yves; Guedon, Jeanpierre; Normand, Nicolas; Arlicot, Aurore; Benhdech, Yassine; Weiss, Pierre

    2011-03-01

    Bone microarchitecture is the predictor of bone quality or bone disease. It can only be measured on a bone biopsy, which is invasive and not available for all clinical situations. Texture analysis on radiographs is a common way to investigate bone microarchitecture. But relationship between three-dimension histomorphometric parameters and two-dimension texture parameters is not always well known, with poor results. The aim of this study is to performed angulated radiographs of the same region of interest and see if a better relationship between texture analysis on several radiographs and histomorphometric parameters can be developed. Computed radiography images of dog (Beagle) mandible section in molar regions were compared with high-resolution micro-CT (Computed-Tomograph) volumes. Four radiographs with 27° angle (up, down, left, right, using Rinn ring and customized arm positioning system) were performed from initial radiograph position. Bone texture parameters were calculated on all images. Texture parameters were also computed from new images obtained by difference between angulated images. Results of fractal values in different trabecular areas give some caracterisation of bone microarchitecture.

  19. A mixture model for the joint analysis of latent developmental trajectories and survival

    NARCIS (Netherlands)

    Klein Entink, R.H.; Fox, J.P.; Hout, A. van den

    2011-01-01

    A general joint modeling framework is proposed that includes a parametric stratified survival component for continuous time survival data, and a mixture multilevel item response component to model latent developmental trajectories given mixed discrete response data. The joint model is illustrated in

  20. Analysis of DNA repair gene polymorphisms and survival in low-grade and anaplastic gliomas

    DEFF Research Database (Denmark)

    Berntsson, Shala Ghaderi; Wibom, Carl; Sjöström, Sara

    2011-01-01

    different DNA repair genes (ATM, NEIL1, NEIL2, ERCC6 and RPA4) which were associated with survival. Finally, these eight genetic variants were adjusted for treatment, malignancy grade, patient age and gender, leaving one variant, rs4253079, mapped to ERCC6, with a significant association to survival (OR 0...

  1. Openness to Experience and Night-Sky Watching Interest as Predictors of Reading for Pleasure: Path Analysis of a Mediation Model

    Science.gov (United States)

    Kelly, William E.

    2010-01-01

    The relation between reading for pleasure, night-sky watching interest, and openness to experience were examined in a sample of 129 college students. Results of a path analysis examining a mediation model indicated that the influence of night-sky interest on reading for pleasure was not mediated by the broad personality domain openness to…

  2. Attributing death to cancer: cause-specific survival estimation.

    Directory of Open Access Journals (Sweden)

    Mathew A

    2002-10-01

    Full Text Available Cancer survival estimation is an important part of assessing the overall strength of cancer care in a region. Generally, the death of a patient is taken as the end point in estimation of overall survival. When calculating the overall survival, the cause of death is not taken into account. With increasing demand for better survival of cancer patients it is important for clinicians and researchers to know about survival statistics due to disease of interest, i.e. net survival. It is also important to choose the best method for estimating net survival. Increase in the use of computer programmes has made it possible to carry out statistical analysis without guidance from a bio-statistician. This is of prime importance in third- world countries as there are a few trained bio-statisticians to guide clinicians and researchers. The present communication describes current methods used to estimate net survival such as cause-specific survival and relative survival. The limitation of estimation of cause-specific survival particularly in India and the usefulness of relative survival are discussed. The various sources for estimating cancer survival are also discussed. As survival-estimates are to be projected on to the population at large, it becomes important to measure the variation of the estimates, and thus confidence intervals are used. Rothman′s confidence interval gives the most satisfactory result for survival estimate.

  3. Topological Data Analysis of Escherichia coli O157:H7 and Non-O157 Survival in Soils

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    ABASIOFIOK MARK IBEKWE

    2014-09-01

    Full Text Available Shiga toxin-producing E. coli O157:H7 and non-O157 have been implicated in many foodborne illnesses caused by the consumption of contaminated fresh produce. However, data on their persistence in soils are limited due to the complexity in datasets generated from different environmental variables and bacterial taxa. There is a continuing need to distinguish the various environmental variables and different bacterial groups to understand the relationships among these factors and the pathogen survival. Using an approach called Topological Data Analysis (TDA; we reconstructed the relationship structure of E. coli O157 and non-O157 survival in 32 soils (16 organic and 16 conventionally managed soils from California (CA and Arizona (AZ with a multi-resolution output. In our study, we took a community approach based on total soil microbiome to study community level survival and examining the network of the community as a whole and the relationship between its topology and biological processes. TDA produces a geometric representation of complex data sets. Network analysis showed that Shiga toxin negative strain E. coli O157:H7 4554 survived significantly longer in comparison to E. coli O157:H7 EDL933, while the survival time of E. coli O157:NM was comparable to that of E. coli O157:H7 strain 933 in all of the tested soils. Two non-O157 strains, E. coli O26:H11 and E. coli O103:H2 survived much longer than E. coli O91:H21 and the three strains of E. coli O157. We show that there are complex interactions between E. coli strain survival, microbial community structures, and soil parameters.

  4. Arthritis and the Risk of Falling Into Poverty: A Survival Analysis Using Australian Data.

    Science.gov (United States)

    Callander, Emily J; Schofield, Deborah J

    2016-01-01

    Low income is known to be associated with having arthritis. However, no longitudinal studies have documented the relationship between developing arthritis and falling into poverty. The purpose of this study was to evaluate Australians who developed arthritis to determine if they had an elevated risk of falling into poverty. Survival analysis using Cox regression models was applied to nationally representative, longitudinal survey data obtained between January 1, 2007 and December 31, 2012 from Australian adults who were ages 21 years and older in 2007. The hazard ratio for falling into income poverty was 1.08 (95% confidence interval [95% CI] 1.06-1.09) in women who were diagnosed as having arthritis and 1.15 (95% CI 1.13-1.16) in men who were diagnosed as having arthritis, as compared to those who were never diagnosed as having arthritis. The hazard ratio for falling into multidimensional poverty was 1.15 (95% CI 1.14-1.17) in women who were diagnosed as having arthritis and 1.88 (95% CI 1.85-1.91) in men who were diagnosed as having arthritis. Developing arthritis increases the risk of falling into income poverty and multidimensional poverty. The risk of multidimensional poverty is greater than the risk of income poverty. Given the high prevalence of arthritis, the condition is likely an overlooked driver of poverty. © 2016, American College of Rheumatology.

  5. Survival Analysis of Faculty Retention and Promotion in the Social Sciences by Gender.

    Directory of Open Access Journals (Sweden)

    Janet M Box-Steffensmeier

    Full Text Available Recruitment and retention of talent is central to the research performance of universities. Existing research shows that, while men are more likely than women to be promoted at the different stages of the academic career, no such difference is found when it comes to faculty retention rates. Current research on faculty retention, however, focuses on careers in science, technology, engineering, and mathematics (STEM. We extend this line of inquiry to the social sciences.We follow 2,218 tenure-track assistant professors hired since 1990 in seven social science disciplines at nineteen U.S. universities from time of hire to time of departure. We also track their time to promotion to associate and full professor. Using survival analysis, we examine gender differences in time to departure and time to promotion. Our methods account for censoring and unobserved heterogeneity, as well as effect heterogeneity across disciplines and cohorts.We find no statistically significant differences between genders in faculty retention. However, we do find that men are more likely to be granted tenure than women. When it comes to promotion to full professor, the results are less conclusive, as the effect of gender is sensitive to model specification.The results corroborate previous findings about gender patterns in faculty retention and promotion. They suggest that advances have been made when it comes to gender equality in retention and promotion, but important differences still persist.

  6. Relationship between somatic cell count and functional longevity assessed using survival analysis in Italian Holstein-Friesian cows

    NARCIS (Netherlands)

    Samoré, A.B.; Schneider, M.D.P.; Canavesi, F.; Bagnato, A.; Groen, A.F.

    2003-01-01

    The relationship between somatic cell scores (SCS) and longevity was assessed for Italian Holstein–Friesian dairy cows using survival analysis. The data of somatic cell count (SCC) test day information of 512 979 cows were provided by nine provinces from Northern Italy. Pedigree information was

  7. Evaluating national pricing policies of innovative anti-cancer drugs: correlation analysis between costs and survival in 15 European countries

    Directory of Open Access Journals (Sweden)

    Daniele Mengato

    2016-11-01

    Full Text Available Evaluating national pricing policies of innovative anti-cancer drugs: correlation analysis between costs and survival in 15 European countriesIntroductionIn recent years, public health systems in Europe have faced the challenge of sustainability in different ways. The aim of this study is to analyse the pricing policies of 15 European countries by studying the correlation between cost and survival of a series of anti-cancer drugs.MethodsOur study assessed nine anti-cancer drugs licensed by EMA in the last decade. Clinical benefits, measured as overall survival (OS and progression free survival (PFS, were obtained from EPAR or randomized controlled trials, while nominal and real prices in the 15 different countries (including discounts were derived from a published study. We performed a correlation analysis between cost and OS for each indication of any given drug.ResultsOnly two countries (Hungary and Lithuania demonstrated a strong correlation coefficient in the OS analysis. The PFS analysis has shown better results with 12 countries, with R values higher than 0.20.DiscussionTo the best of our knowledge, this is the first study in which the correlation between costs and outcomes has been studied in a large number of countries. Our results showed that, in these countries, prices had generally a poor correlation with OS and a better correlation with PFS.

  8. Application of Survival Analysis to Study Timing and Probability of Outcome Attainment by a Community College Student Cohort

    Science.gov (United States)

    Mourad, Roger; Hong, Ji-Hee

    2008-01-01

    This study applies competing risks survival analysis to describe outcome attainment for an entire cohort of students who first attended a Midwestern community college in the Fall Semester 2001. Outcome attainment included transfer to a four-year institution, degree/ certificate attainment from the community college under study, and transfer to a…

  9. Effect of somatic cell count level on functional longevity in Valle del Belice dairy sheep assessed using survival analysis

    NARCIS (Netherlands)

    Riggio, V.; Maizon, D.O.; Portolano, B.; Bovenhuis, H.; Arendonk, van J.A.M.

    2009-01-01

    The objectives of this study were to evaluate the effect of somatic cell count (SCC) on functional longevity and to estimate the heritability of functional longevity using survival analysis in Valle del Belice dairy sheep. A total of 4,880 lactations of 2,190 ewes from 11 flocks were used. In this

  10. Examining the Influence of Campus Climate on Students' Time to Degree: A Multilevel Discrete-Time Survival Analysis

    Science.gov (United States)

    Zhou, Ji; Castellanos, Michelle

    2013-01-01

    Utilizing longitudinal data of 3477 students from 28 institutions, we examine the effects of structural diversity and quality of interracial relation on students' persistence towards graduation within six years. We utilize multilevel discrete-time survival analysis to account for the longitudinal persistence patterns as well as the nested…

  11. Relationships between mastitis and functional longevity in Danish Black and White dairy cattle estimated using survival analysis

    NARCIS (Netherlands)

    Neerhof, H.J.; Madsen, P.; Ducrucq, V.; Vollema, A.R.; Jensen, I.; Korsgaard, I.R.

    2000-01-01

    The relationship between mastitis and functional longevity was assessed with survival analysis on data of Danish Black and White dairy cows. Different methods of including the effect of mastitis treatment on the culling decision by a farmer in the model were compared. The model in which mastitis

  12. Utility of tree crown condition indicators to predict tree survival using remeasured Forest Inventory and Analysis data

    Science.gov (United States)

    Randall S. Morin; Jim Steinman; KaDonna C. Randolph

    2012-01-01

    The condition of tree crowns is an important indicator of tree and forest health. Crown conditions have been evaluated during surveys of Forest Inventory and Analysis (FIA) Phase 3 (P3) plots since 1999. In this study, remeasured data from 39,357 trees in the northern United States were used to assess the probability of survival among various tree species using the...

  13. Input Frequency and Lexical Variability in Phonological Development: A Survival Analysis of Word-Initial Cluster Production

    Science.gov (United States)

    Ota, Mitsuhiko; Green, Sam J.

    2013-01-01

    Although it has been often hypothesized that children learn to produce new sound patterns first in frequently heard words, the available evidence in support of this claim is inconclusive. To re-examine this question, we conducted a survival analysis of word-initial consonant clusters produced by three children in the Providence Corpus (0 ; 11-4 ;…

  14. Desiccation survival in an Antarctic nematode: molecular analysis using expressed sequenced tags

    Directory of Open Access Journals (Sweden)

    Wall Diana H

    2009-02-01

    Full Text Available Abstract Background Nematodes are the dominant soil animals in Antarctic Dry Valleys and are capable of surviving desiccation and freezing in an anhydrobiotic state. Genes induced by desiccation stress have been successfully enumerated in nematodes; however we have little knowledge of gene regulation by Antarctic nematodes which can survive multiple environmental stresses. To address this problem we investigated the genetic responses of a nematode species, Plectus murrayi, that is capable of tolerating Antarctic environmental extremes, in particular desiccation and freezing. In this study, we provide the first insight into the desiccation induced transcriptome of an Antarctic nematode through cDNA library construction and suppressive subtractive hybridization. Results We obtained 2,486 expressed sequence tags (ESTs from 2,586 clones derived from the cDNA library of desiccated P. murrayi. The 2,486 ESTs formed 1,387 putative unique transcripts of which 523 (38% had matches in the model-nematode Caenorhabditis elegans, 107 (7% in nematodes other than C. elegans, 153 (11% in non-nematode organisms and 605 (44% had no significant match to any sequences in the current databases. The 1,387 unique transcripts were functionally classified by using Gene Ontology (GO hierarchy and the Kyoto Encyclopedia of Genes and Genomes (KEGG database. The results indicate that the transcriptome contains a group of transcripts from diverse functional areas. The subtractive library of desiccated nematodes showed 80 transcripts differentially expressed during desiccation stress, of which 28% were metabolism related, 19% were involved in environmental information processing, 28% involved in genetic information processing and 21% were novel transcripts. Expression profiling of 14 selected genes by quantitative Real-time PCR showed 9 genes significantly up-regulated, 3 down-regulated and 2 continuously expressed in response to desiccation. Conclusion The establishment of a

  15. Donor Funding for Newborn Survival: An Analysis of Donor-Reported Data, 2002–2010

    Science.gov (United States)

    Pitt, Catherine; Lawn, Joy E.; Ranganathan, Meghna; Mills, Anne; Hanson, Kara

    2012-01-01

    Background Neonatal mortality accounts for 43% of global under-five deaths and is decreasing more slowly than maternal or child mortality. Donor funding has increased for maternal, newborn, and child health (MNCH), but no analysis to date has disaggregated aid for newborns. We evaluated if and how aid flows for newborn care can be tracked, examined changes in the last decade, and considered methodological implications for tracking funding for specific population groups or diseases. Methods and Findings We critically reviewed and categorised previous analyses of aid to specific populations, diseases, or types of activities. We then developed and refined key terms related to newborn survival in seven languages and searched titles and descriptions of donor disbursement records in the Organisation for Economic Co-operation and Development's Creditor Reporting System database, 2002–2010. We compared results with the Countdown to 2015 database of aid for MNCH (2003–2008) and the search strategy used by the Institute for Health Metrics and Evaluation. Prior to 2005, key terms related to newborns were rare in disbursement records but their frequency increased markedly thereafter. Only two mentions were found of “stillbirth” and only nine references were found to “fetus” in any spelling variant or language. The total value of non-research disbursements mentioning any newborn search terms rose from US$38.4 million in 2002 to US$717.1 million in 2010 (constant 2010 US$). The value of non-research projects exclusively benefitting newborns fluctuated somewhat but remained low, at US$5.7 million in 2010. The United States and the United Nations Children's Fund (UNICEF) provided the largest value of non-research funding mentioning and exclusively benefitting newborns, respectively. Conclusions Donor attention to newborn survival has increased since 2002, but it appears unlikely that donor aid is commensurate with the 3.0 million newborn deaths and 2.7 million

  16. Desiccation survival in an Antarctic nematode: molecular analysis using expressed sequenced tags.

    Science.gov (United States)

    Adhikari, Bishwo N; Wall, Diana H; Adams, Byron J

    2009-02-09

    Nematodes are the dominant soil animals in Antarctic Dry Valleys and are capable of surviving desiccation and freezing in an anhydrobiotic state. Genes induced by desiccation stress have been successfully enumerated in nematodes; however we have little knowledge of gene regulation by Antarctic nematodes which can survive multiple environmental stresses. To address this problem we investigated the genetic responses of a nematode species, Plectus murrayi, that is capable of tolerating Antarctic environmental extremes, in particular desiccation and freezing. In this study, we provide the first insight into the desiccation induced transcriptome of an Antarctic nematode through cDNA library construction and suppressive subtractive hybridization. We obtained 2,486 expressed sequence tags (ESTs) from 2,586 clones derived from the cDNA library of desiccated P. murrayi. The 2,486 ESTs formed 1,387 putative unique transcripts of which 523 (38%) had matches in the model-nematode Caenorhabditis elegans, 107 (7%) in nematodes other than C. elegans, 153 (11%) in non-nematode organisms and 605 (44%) had no significant match to any sequences in the current databases. The 1,387 unique transcripts were functionally classified by using Gene Ontology (GO) hierarchy and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The results indicate that the transcriptome contains a group of transcripts from diverse functional areas. The subtractive library of desiccated nematodes showed 80 transcripts differentially expressed during desiccation stress, of which 28% were metabolism related, 19% were involved in environmental information processing, 28% involved in genetic information processing and 21% were novel transcripts. Expression profiling of 14 selected genes by quantitative Real-time PCR showed 9 genes significantly up-regulated, 3 down-regulated and 2 continuously expressed in response to desiccation. The establishment of a desiccation EST collection for Plectus murrayi, a

  17. Trend analysis and survival of primary gallbladder cancer in the United States: a 1973-2009 population-based study.

    Science.gov (United States)

    Rahman, Rubayat; Simoes, Eduardo J; Schmaltz, Chester; Jackson, Christian S; Ibdah, Jamal A

    2017-04-01

    Primary gallbladder cancer is an aggressive and uncommon cancer with poor outcomes. Our study examines epidemiology, trend, and survival of gallbladder cancer in the United States from 1973 to 2009. We utilized the Surveillance Epidemiology and End Results database (SEER). Frequency and rate analyses on demographics, stage, and survival were compared among non-Hispanic whites, Hispanics, African American, and Asian/Pacific Islanders. A total of 18,124 cases were reported in SEER from 1973 to 2009 comprising 1.4% of all reported gastrointestinal cancers. Gallbladder cancer was more common in females than males (71 vs. 29%, respectively). The age-adjusted incidence rate was 1.4 per 100,000, significantly higher in females than males (1.7 vs. 1.0). Trend analysis showed that the incidence rate has been decreasing over the last three decades for males. However, among females, the incidence rate had decreased from 1973 to mid-90s but has remained stable since then. Trend analysis for stage at diagnosis showed that the proportion of late-stage cases has been increasing significantly since 2001 after a decreasing pattern since 1973. Survival has improved considerably over time, and survival is better in females than males and in Asian/Pacific Islanders than other racial groups. The highest survival was in patients who received both surgery and radiation. Trend analysis revealed a recent increase of the incidence of late-stage gallbladder cancer. Highest survival was associated with receiving both surgery and radiation. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  18. A systematic review and meta-analysis of the survival of feldspathic porcelain veneers over 5 and 10 years.

    Science.gov (United States)

    Layton, Danielle M; Clarke, Michael; Walton, Terry R

    2012-01-01

    This systematic review reports on the survival of feldspathic porcelain veneers. The Cochrane Library, MEDLINE (OVID), Embase, Web of Knowledge, selected journals, clinical trials registers, and conference proceedings were searched independently by two reviewers. Academic colleagues were also contacted to identify relevant research. Inclusion criteria were human cohort studies (prospective and retrospective) and controlled trials assessing outcomes of feldspathic porcelain veneers in more than 15 patients and with at least some of the veneers in situ for 5 years. Of 4,294 articles identified, 116 studies underwent full-text screenings and 69 were further reviewed for eligibility. Of these, 11 were included in the qualitative analysis and 6 (5 cohorts) were included in meta-analyses. Estimated cumulative survival and standard error for each study were assessed and used for meta-, sensitivity, and post hoc analyses. The I2 statistic and the Cochran Q test and its associated P value were used to evaluate statistical heterogeneity, with a random-effects meta-analysis used when the P value for heterogeneity was less than .1. Galbraith, forest, and funnel plots explored heterogeneity, publication patterns, and small study biases. The estimated cumulative survival for feldspathic porcelain veneers was 95.7% (95% confidence interval [CI]: 92.9% to 98.4%) at 5 years and ranged from 64% to 95% at 10 years across three studies. A post hoc meta-analysis indicated that the 10-year best estimate may approach 95.6% (95% CI: 93.8% to 97.5%). High levels of statistical heterogeneity were found. When bonded to enamel substrate, feldspathic porcelain veneers have a very high 10-year survival rate that may approach 95%. Clinical heterogeneity is associated with differences in reported survival rates. Use of clinically relevant survival definitions and careful reporting of tooth characteristics, censorship, clustering, and precise results in future research would improve metaanalytic

  19. Time trends in population-based breast cancer survival in Estonia: analysis by age and stage.

    Science.gov (United States)

    Baburin, Aleksei; Aareleid, Tiiu; Padrik, Peeter; Valvere, Vahur; Innos, Kaire

    2014-02-01

    Survival from breast cancer (BC) in Estonia has been consistently among the lowest in Europe. The aim of this study was to examine most recent trends in BC survival in Estonia by age and stage. The trends in overall BC incidence and mortality are also shown in the paper. Estonian Cancer Registry data on all cases of BC, diagnosed in women in Estonia during 1995-2007 (n = 7424) and followed up for vital status through 2009, were used to estimate relative survival ratios (RSR). Period hybrid approach was used to obtain the most recent estimates (2005-2009). Stage was classified as localized, local/regional spread or distant. BC incidence continued to rise throughout the study period, but mortality has been in steady decline since 2000. The distribution of patients shifted towards older age and earlier stage at diagnosis. Overall age-standardized five-year RSR increased from 63% in 1995-1999 to 74% in 2005-2009. Younger age groups experienced a more rapid improvement compared to women over 60. Significant survival increase was observed for both localized and locally/regionally spread BC with five-year RSRs reaching 96% and 70% in 2005-2009, respectively; the latest five-year RSR for distant BC was 11%. Survival for T4 tumors was poor and large age difference was seen for locally/regionally spread BC. Considerable improvement in BC survival was observed over the study period. Women under 60 benefited most from both earlier diagnosis and treatment advances of locally/regionally spread cancers. However, the survival gap with more developed countries persists. Further increase in survival, but also decline in BC mortality in Estonia could be achieved by facilitating early diagnosis in all age groups, but particularly among women over 60. Investigations should continue to clarify the underlying mechanisms of the stage-specific survival deficit in Estonia.

  20. Survival analysis and prognostic factors of timing of first childbirth among women in Nigeria.

    Science.gov (United States)

    Fagbamigbe, Adeniyi Francis; Idemudia, Erhabor Sunday

    2016-05-13

    First childbirth in a woman's life is one of the most important events in her life. It marks a turnaround when she might have to drop roles of career building and education, for motherhood and parenthood. The timing of the commencement of these roles affects the child bearing behavior of women as they progress in their reproductive ages. Prevalent early first childbirth in Nigeria has been reported as the main cause of high population growth and high  fertility, mortality and morbidity among women, but little has been documented on the progression into first birth as well as factors affecting it in Nigeria. This paper modelled timing of first birth among women in Nigeria and determined socio-demographic and other factors affecting its timing. We hypothesized that background characteristics of a woman will influence her progression into having first birth. We developed and fitted a survival analysis model to understand the timing of first birth among women in Nigeria using a national representative 2013 NDHS data. Women with no children were right censored as of the date of the survey. The Kaplan Meier survival function was used to estimate the probabilities of first birth not occurring until certain ages of women while Cox proportional hazard regression was used to model the timing of first births at 5 % significance level. About 75.7 % of the respondents had given birth in the Northern region of Nigerian compared with 63.8 % in the South. Half (50.1 %) of the first childbirth occurred within the 15-19 years age bracket and 38.1 % within 20-29 years. The overall median survival time to first birth was 20 years (North 19, South 22), 27 years among women with higher education and 18 years for those with no formal education. The adjusted hazard of first birth was higher in the Northern region of Nigeria than in the South (aHR = 1.24, 95 % CI: 1.20-1.27), and higher in rural areas than in urban areas (aHR = 1.15, 95 % CI: 1.12-1.19). Also, hazard of earlier first

  1. ESHRE special interest group for andrology basic semen analysis course: a continued focus on accuracy, quality, efficiency and clinical relevance.

    Science.gov (United States)

    Barratt, C L R; Björndahl, L; Menkveld, R; Mortimer, D

    2011-12-01

    ESHRE has been running courses for basic semen analysis since 1994 and course material has been updated regularly in response to new findings and publications. Following publication of the 5th edition of the WHO laboratory manual, entitled WHO Laboratory Manual for the Examination and Processing of Human Semen (WHO5), the Subcommittee for training of the ESHRE Special Interest Group for Andrology evaluated potential amendments to its course. In respect of the updated ESHRE course, there are eight particular areas of discourse that are reviewed (i) maintaining the four-class differential motility count allowing distinction between rapid and slow progressive sperm for assisted reproduction technology. (ii) Maintaining the four-category assessment for sperm morphology with calculation of the teratozoospermic index. (iii) Continuing to advocate the use of three categories of results: 'normal', 'borderline' and 'abnormal' with respect to the clinical interpretation of the data. (iv) Presenting clear and unequivocal methods for performing assessments e.g. morphology. (v) Correcting the inconsistencies in WHO5, some of which are actually erroneous. (vi) Reducing the requirements for substantial extra work for what are unestablished improvements in accuracy and/or precision in the final results. (vii) Presentation of logical methods of sperm preparation. (viii) Discussion of the suddenly changed limits between fertile and subfertile men.

  2. Preoperative risk factors predict survival following cardiac retransplantation: analysis of the United Network for Organ Sharing database.

    Science.gov (United States)

    Belli, Erol; Leoni Moreno, Juan Carlos; Hosenpud, Jeffrey; Rawal, Bhupendra; Landolfo, Kevin

    2014-06-01

    The aim of our study was to identify preoperative risk factors affecting overall survival after cardiac retransplantation (ReTX) in a contemporary era. The United Network for Organ Sharing database was used to identify patients undergoing ReTX between 1995 and 2012. Of the total 28,464 primary transplants performed, 987 (3.5%) were retransplants. The primary outcome investigated was overall survival. The influence of preoperative donor and recipient characteristics on survival were then tested with univariate logistic regression and multivariate Cox regression models. Of 987 patients who underwent ReTX, median survival was 9 years. Estimated survival at 1, 3, 5, 10, and 15 years following retransplant was 80% (95% confidence interval [CI], 78%-83%), 70% (95% CI, 67%-73%), 64% (95% CI, 61%-67%), 47% (95% CI, 43%-51%), and 30% (95% CI, 25%-37%), respectively. Clinical predictors of survival using multivariable analysis included donor age (relative risk [RR], 1.14; P = .004), ischemic time > 4 hours (RR, 1.48; P = .004); preoperative support with extracorporeal membrane oxygenator (RR, 3.91; P risk of death compared with patients undergoing primary transplant only (RR, 1.27; 95% CI, 1.13-1.42; P < .001). Patients who undergo cardiac ReTX can expect to have a 1-year survival less than a patient undergoing primary transplant with an acceptable median overall survival. Both donor and recipient preoperative factors contribute to overall survival following cardiac ReTx. Donor characteristics include age of the donor and ischemic time. Recipient factors include the need for extracorporeal membrane oxygenator and the number of days between the first and second transplant. Optimal survival following cardiac ReTX can best be predicted by choosing patients who are farther out from their initial transplant, not dependent upon preoperative extracorporeal support, and by choosing donor hearts younger in age and those likely to have shorter ischemic times. Copyright © 2014 The

  3. Impact of Celiac Plexus Neurolysis on Survival in Patients with Unresectable Pancreatic Cancer: A Retrospective, Propensity Score Matching Analysis.

    Science.gov (United States)

    Oh, Tak Kyu; Lee, Woo Jin; Woo, Sang Myung; Kim, Nam Woo; Yim, Jiyeon; Kim, Dae Hyun

    2017-03-01

    Pain caused by pancreatic cancer (PC) is difficult to control. Celiac plexus neurolysis (CPN) can effectively control the pain and reduce the use of opioids. However, the effect of CPN on survival for patients with unresectable PC remains controversial. To determine if CPN is associated with survival benefits for these patients. Retrospective, observational cohort study. National Cancer Center in Korea. The CPN group included patients who were diagnosed with unresectable PC and underwent fluoroscopically guided bilateral CPN (10 mL dehydrated alcohol each side) once between January 1, 2006, and December 31, 2013. Patients with PC who did not undergo CPN were in the control group; for the final control group, 1:1 propensity score (PS) matching was conducted with the CPN group. The main outcome was median survival (PC diagnosis to death) after PS matching, assessed using Kaplan-Meier curves. For the primary overall survival analysis, the CPN and control groups included 110 and 258 patients, respectively. The median survival period was not significantly different between the CPN and control groups (278 vs. 203 days, P = 0.246), even after PS matching (278 vs. 180 days, P = 0.127), or based on time to CPN from diagnosis (≤ 6 vs. > 6 months; 255 vs. 310 days, P = 0.147). Retrospective design, small sample size, and inconsistent timing of CPN after the diagnosis date. CPN did not affect survival for patients with unresectable PC. Considering the limitations of the retrospective design, a well-designed prospective design study should be conducted.Key words: Celiac plexus, pancreatic neoplasms, survival, neurolysis, pain, propensity score matching, opioids, cancer.

  4. Pre-arrest predictors of failure to survive after in-hospital cardiopulmonary resuscitation: a meta-analysis.

    Science.gov (United States)

    Ebell, Mark H; Afonso, Anna M

    2011-10-01

    Our objective was to perform a systematic review of pre-arrest predictors of the outcome of in-hospital cardiopulmonary resuscitation (CPR) in adults. We searched PubMed for studies published since 1985 and bibliographies of previous meta-analyses. We included studies with predominantly adult patients, limited to in-hospital arrest, using an explicit definition of cardiopulmonary arrest and CPR and reporting survival to discharge by at least one pre-arrest variable. A total of 35 studies were included in the final analysis. Inclusion criteria, design elements and results were abstracted in parallel by both investigators. Discrepancies were resolved by consensus. The rate of survival to discharge was 17.5%; we found a trend towards increasing survival in more recent studies. Metastatic malignancy [odds ratio (OR) 3.9] or haematologic malignancy (OR 3.9), age over 70, 75 or 80 years (OR 1.5, 2.8 and 2.7, respectively), black race (OR 2.1), altered mental status (OR 2.2), dependency for activities of daily living (range OR 3.2-7.0 depending on specific activity), impaired renal function (OR 1.9), hypotension on admission (OR 1.8) and admission for pneumonia (OR 1.7), trauma (OR 1.7) or medical non-cardiac diagnosis (OR 2.2) were significantly associated with failure to survive to discharge; cardiovascular diagnoses and co-morbidities were associated with improved survival (range OR 0.23-0.53). Elevated CPR risk scores predicted failure to survive but have not been validated consistently in different populations. We identified several pre-arrest variables associated with failure to survive to discharge. This information should be shared with patients as part of a shared decision-making process regarding the use of do not resuscitate orders.

  5. Analysis of individual- and time-specific covariate effects on survival of Serinus serinus in north-eastern Spain

    Science.gov (United States)

    Conroy, M.J.; Senar, J.C.; Domenech, J.

    2002-01-01

    We developed models for the analysis of recapture data for 2678 serins (Serinus serinus) ringed in north-eastern Spain since 1985. We investigated several time- and individual-specific factors as potential predictors of overall mortality and dispersal patterns, and of gender and age differences in these patterns. Time-specific covariates included minimum daily temperature, days below freezing, and abundance of a strong competitor, siskins (Carduelis spinus) during winter, and maximum temperature and rainfall during summer. Individual covariates included body mass (i.e. body condition), and wing length (i.e. flying ability), and interactions between body mass and environmental factors. We found little support of a predictive relationship between environmental factors and survival, but good evidence of relationships between body mass and survival, especially for juveniles. Juvenile survival appears to vary in a curvilinear manner with increasing mass, suggesting that there may exist an optimal mass beyond which increases are detrimental. The mass-survival relationship does seem to be influenced by at least one environmental factor, namely the abundance of wintering siskins. When siskins are abundant, increases in body mass appear to relate strongly to increasing survival. When siskin numbers are average or low the relationship is largely reversed, suggesting that the presence of strong competition mitigates the otherwise largely negative aspects of greater body mass. Wing length in juveniles also appears to be related positively to survival, perhaps largely due to the influence of a few unusually large juveniles with adult-like survival. Further work is needed to test these relationships, ideally under experimentation.

  6. Design and analysis methods for fish survival experiments based on release-recapture

    National Research Council Canada - National Science Library

    Burnham, Kenneth P

    1987-01-01

    .... The application of the methods developed here is more general, however, as it includes experiments to estimate survival of fish as they pass over spillways or through bypass systems and several dams...

  7. Organizational Survival within a Declining Industry: An Analysis of a Single Sex Boarding School.

    Science.gov (United States)

    Recker, Gene; Goldsby, Michael G.; Neck, Christopher P.

    2002-01-01

    Examines research on organizational and industry decline and provides survival guidelines for organizations within declining industries. Demonstrates how an organization can use the guidelines by examining a single-sex boarding school facing such a dilemma. (EV)

  8. Gene–gene interaction analysis for the survival phenotype based on the Cox model

    OpenAIRE

    Lee, Seungyeoun; Kwon, Min-Seok; Oh, Jung Mi; Park, Taesung

    2012-01-01

    Motivation: For the past few decades, many statistical methods in genome-wide association studies (GWAS) have been developed to identify SNP–SNP interactions for case-control studies. However, there has been less work for prospective cohort studies, involving the survival time. Recently, Gui et al. (2011) proposed a novel method, called Surv-MDR, for detecting gene–gene interactions associated with survival time. Surv-MDR is an extension of the multifactor dimensionality reduction (MDR) metho...

  9. Surviving at high elevations: an inter- and intra-specific analysis in a mountain bird community.

    Science.gov (United States)

    Bastianelli, G; Tavecchia, G; Meléndez, L; Seoane, J; Obeso, J R; Laiolo, P

    2017-06-01

    Elevation represents an important selection agent on self-maintenance traits and correlated life histories in birds, but no study has analysed whether life-history variation along this environmental cline is consistent among and within species. In a sympatric community of passerines, we analysed how the average adult survival of 25 open-habitat species varied with their elevational distribution and how adult survival varied with elevation at the intra-specific level. For such purpose, we estimated intra-specific variation in adult survival in two mountainous species, the Water pipit (Anthus spinoletta) and the Northern wheatear (Oenanthe oenanthe) in NW Spain, by means of capture-recapture analyses. At the inter-specific level, high-elevation species showed higher survival values than low elevation ones, likely because a greater allocation to self-maintenance permits species to persist in alpine environments. At the intra-specific level, the magnitude of survival variation was lower by far. Nevertheless, Water pipit survival slightly decreased at high elevations, while the proportion of transient birds increased. In contrast, no such relationships were found in the Northern wheatear. Intra-specific analyses suggest that living at high elevation may be costly, such as for the Water pipit in our case study. Therefore, it seems that a species can persist with viable populations in uplands, where extrinsic mortality is high, by increasing the investment in self-maintenance and prospecting behaviours.

  10. Oral cavity squamous cell carcinoma in never smokers: analysis of clinicopathologic characteristics and survival.

    Science.gov (United States)

    Durr, Megan L; Li, David; Wang, Steven J

    2013-01-01

    To examine the relationship between tobacco smoking history and the clinicopathologic and survival characteristics of patients with oral cavity squamous cell carcinoma (OCSCC). This is a retrospective review of 531 patients treated for OCSCC from January 1998 to December 2009 at a tertiary care medical center. Thirty-two percent of OCSCC patients were never smokers. There were significant differences in tumor location between ever smokers and never smokers (pnever smokers more likely to have oral tongue tumors. Smokers were significantly (pnever smokers to present with locally advanced (T3 or T4) disease (57.8% vs. 35.4%). Never smokers demonstrated improved overall survival (78.8 months in never smokers vs. 44.7 months in ever smokers, p=.03). However, there were no survival differences when the two groups were compared separately for locally early (T1/T2) or advanced (T3/T4) disease. For T1/T2 tumors, mean survival was 88.2 months for never smokers and 78.5 months for smokers (p=.10). For T3/T4 tumors, median survival was 29.1 months for never smokers and 23.8 months for smokers (p=.09). Primary tumor location and T-status in OCSCC differed between never smokers and smokers. Compared to smokers, never smokers had fewer locally advanced tumors and better overall survival. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Role of Metastasis in Hypertabastic Survival Analysis of Breast Cancer: Interaction with Clinical and Gene Expression Variables

    Directory of Open Access Journals (Sweden)

    Mohammad A. Tabatabai Ph.D.

    2012-01-01

    Full Text Available This paper analyzes the survival of breast cancer patients, exploring the role of a metastasis variable in combination with clinical and gene expression variables. We use the hypertabastic model in a detailed analysis of 295 breast cancer patients from the Netherlands Cancer Institute given in. 1 In comparison to Cox regression the increase in accuracy is complemented by the ability to analyze the time course of the disease progression using the explicitly described hazard and survival curves. We also demonstrate the ability to compute deciles for survival and probability of survival to a given time. Our primary concern in this article is the introduction of a variable representing the existence of metastasis and the effects on the other clinical and gene expression variables. In addition to making a quantitative assessment of the impact of metastasis on the prospects for survival, we are able to look at its interactions with the other prognostic variables. The estrogen receptor status increase in importance, while the significance of the gene expression variables used in the combined model diminishes. When considering only the subgroup of patients who experienced metastasis, the covariates in the model are only the clinical variables for estrogen receptor status and tumor grade.

  12. Statins and risk of diabetes: an analysis of electronic medical records to evaluate possible bias due to differential survival.

    Science.gov (United States)

    Danaei, Goodarz; García Rodríguez, Luis A; Fernandez Cantero, Oscar; Hernán, Miguel A

    2013-05-01

    Two meta-analyses of randomized trials of statins found increased risk of type 2 diabetes. One possible explanation is bias due to differential survival when patients who are at higher risk of diabetes survive longer under statin treatment. We used electronic medical records from 500 general practices in the U.K. and included data from 285,864 men and women aged 50-84 years from January 2000 to December 2010. We emulated the design and analysis of a hypothetical randomized trial of statins, estimated the observational analog of the intention-to-treat effect, and adjusted for differential survival bias using inverse-probability weighting. During 1.2 million person-years of follow-up, there were 13,455 cases of type 2 diabetes and 8,932 deaths. Statin initiation was associated with increased risk of type 2 diabetes. The hazard ratio (95% CI) of diabetes was 1.45 (1.39-1.50) before adjusting for potential confounders and 1.14 (1.10-1.19) after adjustment. Adjusting for differential survival did not change the estimates. Initiating atorvastatin and simvastatin was associated with increased risk of type 2 diabetes. In this sample of the general population, statin therapy was associated with 14% increased risk of type 2 diabetes. Differential survival did not explain this increased risk.

  13. Propranolol and survival from breast cancer: a pooled analysis of European breast cancer cohorts.

    Science.gov (United States)

    Cardwell, Chris R; Pottegård, Anton; Vaes, Evelien; Garmo, Hans; Murray, Liam J; Brown, Chris; Vissers, Pauline A J; O'Rorke, Michael; Visvanathan, Kala; Cronin-Fenton, Deirdre; De Schutter, Harlinde; Lambe, Mats; Powe, Des G; van Herk-Sukel, Myrthe P P; Gavin, Anna; Friis, Søren; Sharp, Linda; Bennett, Kathleen

    2016-12-01

    Preclinical studies have demonstrated that propranolol inhibits several pathways involved in breast cancer progression and metastasis. We investigated whether breast cancer patients who used propranolol, or other non-selective beta-blockers, had reduced breast cancer-specific or all-cause mortality in eight European cohorts. Incident breast cancer patients were identified from eight cancer registries and compiled through the European Cancer Pharmacoepidemiology Network. Propranolol and non-selective beta-blocker use was ascertained for each patient. Breast cancer-specific and all-cause mortality were available for five and eight cohorts, respectively. Cox regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CIs) for cancer-specific and all-cause mortality by propranolol and non-selective beta-blocker use. HRs were pooled across cohorts using meta-analysis techniques. Dose-response analyses by number of prescriptions were also performed. Analyses were repeated investigating propranolol use before cancer diagnosis. The combined study population included 55,252 and 133,251 breast cancer patients in the analysis of breast cancer-specific and all-cause mortality respectively. Overall, there was no association between propranolol use after diagnosis of breast cancer and breast cancer-specific or all-cause mortality (fully adjusted HR = 0.94, 95% CI, 0.77, 1.16 and HR = 1.09, 95% CI, 0.93, 1.28, respectively). There was little evidence of a dose-response relationship. There was also no association between propranolol use before breast cancer diagnosis and breast cancer-specific or all-cause mortality (fully adjusted HR = 1.03, 95% CI, 0.86, 1.22 and HR = 1.02, 95% CI, 0.94, 1.10, respectively). Similar null associations were observed for non-selective beta-blockers. In this large pooled analysis of breast cancer patients, use of propranolol or non-selective beta-blockers was not associated with improved survival.

  14. Association between pretreatment Glasgow prognostic score and gastric cancer survival and clinicopathological features: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Zhang CX

    2016-06-01

    Full Text Available Chun-Xiao Zhang,* Shu-Yi Wang,* Shuang-Qian Chen, Shuai-Long Yang, Lu Wan, Bin Xiong Department of Oncology, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors and Hubei Cancer Clinical Study Center, Wuhan, Hubei, People’s Republic of China *These authors contributed equally to this work Background: Glasgow prognostic score (GPS is widely known as a systemic inflammatory-based marker. The relationship between pretreatment GPS and gastric cancer (GC survival and clinicopathological features remains controversial. The aim of the study was to conduct a meta-analysis of published studies to evaluate the association between pretreatment GPS and survival and clinicopathological features in GC patients. Methods: We searched PubMed, Embase, MEDLINE, and BioMed databases for relevant studies. Combined analyses were used to assess the association between pretreatment GPS and overall survival, disease-free survival, and clinicopathological parameters by Stata Version 12.0. Results: A total of 14 studies were included in this meta-analysis, including 5,579 GC patients. The results indicated that pretreatment high GPS (HGPS predicted poor overall survival (hazard ratio =1.51, 95% CI: 1.37–1.66, P<0.01 and disease-free survival (hazard ratio =1.45, 95% CI: 1.26–1.68, P<0.01 in GC patients. Pretreatment HGPS was also significantly associated with advanced tumor–node–metastasis stage (odds ratio [OR] =3.09, 95% CI: 2.11–4.53, P<0.01, lymph node metastasis (OR =4.60, 95% CI: 3.23–6.56, P<0.01, lymphatic invasion (OR =3.04, 95% CI: 2.00–4.62, P<0.01, and venous invasion (OR =3.56, 95% CI: 1.81–6.99, P<0.01. Conclusion: Our meta-analysis indicated that pretreatment HGPS could be a predicative factor of poor survival outcome and clinicopathological features for GC patients. Keywords: Glasgow prognostic score, gastric cancer, survival, clinicopathological feature

  15. Impact of local treatment on overall survival of patients with metastatic prostate cancer: systematic review and meta-analysis

    Science.gov (United States)

    Carneiro, Arie; Baccaglini, Willy; Glina, Felipe P.A.; Kayano, Paulo P.; Nunes, Victor M.; Smaletz, Oren; Bernardo, Wanderley Marques; de Carvalho, Icaro Thiago; Lemos, Gustavo Caserta

    2017-01-01

    ABSTRACT Context Currently, standard treatment of metastatic prostatic cancer (MPCa) is androgen-deprivation therapy (ADT). Recent studies suggested that local treatment of MPCa is related to increase of survival of those patients, as observed in other tumors. Objective To evaluate the impact of local treatment on overall survival and cancer specific survival in 3 and 5 years in patients with MPCa. Materials and Methods Systematic review and meta-analysis of population studies published at PubMed, Scielo, Lilacs, Cochrane and EMBASE databases until June 2016. Several large cohorts and Post-Roc studies were included, that evaluated patients with MPCa submitted to local treatment (LT) using radiotherapy (RDT), surgery (RP) or brachytherapy (BCT) or not submitted to local treatment (NLT). Results 34.338 patients were analyzed in six included papers, 31.653 submitted to NLT and 2.685 to LT. Overall survival in three years was significantly higher in patients submitted to LT versus NLT (64.2% vs. 44.5%; RD 0.19, 95% CI, 0.17-0.21; p<0.00001; I2=0%), as well as in five years (51.9% vs. 23.6%; RD 0.30, 95% CI, 0.11-0.49; p<0.00001; I2=97%). Sensitive analysis according to type of local treatment showed that surgery (78.2% and 45.0%; RD 0.31, 95% CI, 0.26-0.35; p<0.00001; I2=50%) and radiotherapy (60.4% and 44.5%; RD 0.17, 95% CI, 0.12-0.22; p<0.00001; I2=67%) presented better outcomes. Conclusion LT using RDT, RP or BCT seems to significantly improve overall survival and cancer-specific survival of patients with metastatic prostatic cancer. Prospective and randomized studies must be performed in order to confirm our results. PMID:27802009

  16. Surviving blind decomposition: A distributional analysis of the time-course of complex word recognition.

    Science.gov (United States)

    Schmidtke, Daniel; Matsuki, Kazunaga; Kuperman, Victor

    2017-11-01

    The current study addresses a discrepancy in the psycholinguistic literature about the chronology of information processing during the visual recognition of morphologically complex words. Form-then-meaning accounts of complex word recognition claim that morphemes are processed as units of form prior to any influence of their meanings, whereas form-and-meaning models posit that recognition of complex word forms involves the simultaneous access of morphological and semantic information. The study reported here addresses this theoretical discrepancy by applying a nonparametric distributional technique of survival analysis (Reingold & Sheridan, 2014) to 2 behavioral measures of complex word processing. Across 7 experiments reported here, this technique is employed to estimate the point in time at which orthographic, morphological, and semantic variables exert their earliest discernible influence on lexical decision RTs and eye movement fixation durations. Contrary to form-then-meaning predictions, Experiments 1-4 reveal that surface frequency is the earliest lexical variable to exert a demonstrable influence on lexical decision RTs for English and Dutch derived words (e.g., badness; bad + ness), English pseudoderived words (e.g., wander; wand + er) and morphologically simple control words (e.g., ballad; ball + ad). Furthermore, for derived word processing across lexical decision and eye-tracking paradigms (Experiments 1-2; 5-7), semantic effects emerge early in the time-course of word recognition, and their effects either precede or emerge simultaneously with morphological effects. These results are not consistent with the premises of the form-then-meaning view of complex word recognition, but are convergent with a form-and-meaning account of complex word recognition. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. Vitamin C and survival among women with breast cancer: a meta-analysis.

    Science.gov (United States)

    Harris, Holly R; Orsini, Nicola; Wolk, Alicja

    2014-05-01

    The association between dietary vitamin C intake and breast cancer survival is inconsistent and few studies have specifically examined vitamin C supplement use among women with breast cancer. The purpose of this study was to summarise results from prospective studies on the association between vitamin C supplement use and dietary vitamin C intake and breast cancer-specific mortality and total mortality. Studies were identified using the PubMed database through February 6, 2014 and by examining the references of retrieved articles. Prospective studies were included if they reported relative risks (RR) with 95% confidence intervals (95% CIs) for at least two categories or as a continuous exposure. Random-effects models were used to combine study-specific results. The ten identified studies examined vitamin C supplement use (n=6) and dietary vitamin C intake (n=7) and included 17,696 breast cancer cases, 2791 total deaths, and 1558 breast cancer-specific deaths. The summary RR (95% CI) for post-diagnosis vitamin C supplement use was 0.81 (95% CI 0.72-0.91) for total mortality and 0.85 (95% CI 0.74-0.99) for breast cancer-specific mortality. The summary RR for a 100mg per day increase in dietary vitamin C intake was 0.73 (95% CI 0.59-0.89) for total mortality and 0.78 (95% CI 0.64-0.94) for breast cancer-specific mortality. Results from this meta-analysis suggest that post-diagnosis vitamin C supplement use may be associated with a reduced risk of mortality. Dietary vitamin C intake was also statistically significantly associated with a reduced risk of total mortality and breast cancer-specific mortality. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Bruxism and dental implant failures: a multilevel mixed effects parametric survival analysis approach.

    Science.gov (United States)

    Chrcanovic, B R; Kisch, J; Albrektsson, T; Wennerberg, A

    2016-11-01

    Recent studies have suggested that the insertion of dental implants in patients being diagnosed with bruxism negatively affected the implant failure rates. The aim of the present study was to investigate the association between the bruxism and the risk of dental implant failure. This retrospective study is based on 2670 patients who received 10 096 implants at one specialist clinic. Implant- and patient-related data were collected. Descriptive statistics were used to describe the patients and implants. Multilevel mixed effects parametric survival analysis was used to test the association between bruxism and risk of implant failure adjusting for several potential confounders. Criteria from a recent international consensus (Lobbezoo et al., J Oral Rehabil, 40, 2013, 2) and from the International Classification of Sleep Disorders (International classification of sleep disorders, revised: diagnostic and coding manual, American Academy of Sleep Medicine, Chicago, 2014) were used to define and diagnose the condition. The number of implants with information available for all variables totalled 3549, placed in 994 patients, with 179 implants reported as failures. The implant failure rates were 13·0% (24/185) for bruxers and 4·6% (155/3364) for non-bruxers (P bruxism was a statistically significantly risk factor to implant failure (HR 3·396; 95% CI 1·314, 8·777; P = 0·012), as well as implant length, implant diameter, implant surface, bone quantity D in relation to quantity A, bone quality 4 in relation to quality 1 (Lekholm and Zarb classification), smoking and the intake of proton pump inhibitors. It is suggested that the bruxism may be associated with an increased risk of dental implant failure. © 2016 John Wiley & Sons Ltd.

  19. Developing Interactive Plug-ins for tranSMART Using the SmartR Framework: The Case of Survival Analysis.

    Science.gov (United States)

    Knell, Christian; Sedlmayr, Martin; Christoph, Jan

    2017-01-01

    TranSMART has become an important and widely used platform for the translational research. Included features for analysing data have significant deficiencies concerning user interactivity with and export of the generated results. SmartR, a plugin for tranSMART, promises to close this gap with its interactive workflows. Test with a proof of concept whether an own SmartR workflow is possible. Improvement of the integrated survival analysis with a self-build workflow, taking specific user requirements into account. Analysis of existing SmartR workflows to understand the underlying SmartR architecture. Implementation of a SmartR workflow, which provides an improved survival analysis. Extension of SmartR and thus tranSMART is possible and could be successfully achieved with a prototype for survival analysis. The framework still lacks some functionality, like binning of continuous variables, and documentation. SmartR workflows are a good way for realising interactive analysis, but the SmartR framework still needs further improvements to become a full alternative to the already existing Rmodules.

  20. Challenges in the estimation of Net SURvival: The CENSUR working survival group.

    Science.gov (United States)

    Giorgi, R

    2016-10-01

    Net survival, the survival probability that would be observed, in a hypothetical world, where the cancer of interest would be the only possible cause of death, is a key indicator in population-based cancer studies. Accounting for mortality due to other causes, it allows cross-country comparisons or trends analysis and provides a useful indicator for public health decision-making. The objective of this study was to show how the creation and formalization of a network comprising established research teams, which already had substantial and complementary experience in both cancer survival analysis and methodological development, make it possible to meet challenges and thus provide more adequate tools, to improve the quality and the comparability of cancer survival data, and to promote methodological transfers in areas of emerging interest. The Challenges in the Estimation of Net SURvival (CENSUR) working survival group is composed of international researchers highly skilled in biostatistics, methodology, and epidemiology, from different research organizations in France, the United Kingdom, Italy, Slovenia, and Canada, and involved in French (FRANCIM) and European (EUROCARE) cancer registry networks. The expected advantages are an interdisciplinary, international, synergistic network capable of addressing problems in public health, for decision-makers at different levels; tools for those in charge of net survival analyses; a common methodology that makes unbiased cross-national comparisons of cancer survival feasible; transfer of methods for net survival estimations to other specific applications (clinical research, occupational epidemiology); and dissemination of results during an international training course. The formalization of the international CENSUR working survival group was motivated by a need felt by scientists conducting population-based cancer research to discuss, develop, and monitor implementation of a common methodology to analyze net survival in order

  1. A stochastic evolutionary model for survival dynamics

    Science.gov (United States)

    Fenner, Trevor; Levene, Mark; Loizou, George

    2014-09-01

    The recent interest in human dynamics has led researchers to investigate the stochastic processes that explain human behaviour in different contexts. Here we propose a generative model to capture the essential dynamics of survival analysis, traditionally employed in clinical trials and reliability analysis in engineering. In our model, the only implicit assumption made is that the longer an actor has been in the system, the more likely it is to have failed. We derive a power-law distribution for the process and provide preliminary empirical evidence for the validity of the model from two well-known survival analysis data sets.

  2. The role of LINE-1 methylation in predicting survival among colorectal cancer patients: a meta-analysis.

    Science.gov (United States)

    Ye, Ding; Jiang, Danjie; Li, Yingjun; Jin, Mingjuan; Chen, Kun

    2017-08-01

    The prognostic value of long interspersed nucleotide element-1 (LINE-1) methylation in patients with colorectal cancer (CRC) remains uncertain. We have therefore performed a meta-analysis to elucidate this issue. The PubMed and Web of Science databases were searched for studies published up to 30 June 2016 which reported on an association between LINE-1 methylation and overall survival (OS), disease-free survival (DFS), or cancer-specific survival (CSS) among CRC patients. The reference lists of the identified studies were also analyzed to identify additional eligible studies. Hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled using the fixed-effects or the random-effects model. Stratification analysis and meta-regression analysis were performed to detect the source of heterogeneity. Analyses of sensitivity and publication bias were also carried out. Thirteen independent studies involving 3620 CRC patients were recruited to the meta-analysis. LINE-1 hypomethylation was found to be significantly associated with shorter OS (HR 2.92, 95% CI 2.20-3.88, p LINE-1 hypomethylation and OS or DFS, with the exception being CSS. Moreover, meta-regression analysis suggested that one of the contributors to between-study heterogeneity on the association between LINE-1 methylation and CSS was statistical methodology. The subgroup analysis suggested that the association in studies using the Cox model statistical method (HR 2.76, 95% CI 1.90-4.01, p LINE-1 methylation is significantly associated with the survival of CRC patients and that it could be a predictive factor for CRC prognosis.

  3. Survival of patients with advanced pancreatic cancer after iodine125 seeds implantation brachytherapy: A meta-analysis.

    Science.gov (United States)

    Han, Quanli; Deng, Muhong; Lv, Yao; Dai, Guanghai

    2017-02-01

    Brachytherapy with iodine-labeled seeds (I-seeds) implantation is increasingly being used to treat tumors because of its positional precision, minimal invasion, least damage to noncancerous tissue due to slow and continuous release of radioactivity and facilitation with modern medical imaging technologies. This study evaluates the survival and pain relief outcomes of the I-seeds implantation brachytherapy in advanced pancreatic cancer patients. Literature search was carried out in multiple electronic databases (Google Scholar, Embase, Medline/PubMed, and Ovid SP) and studies reporting I seeds implantation brachytherapy in pancreatic cancer patients with unresectable tumor were selected by following predetermined eligibility criteria. Random effects meta-analysis was performed to achieve inverse variance weighted effect size of the overall survival rate after the intervention. Sensitivity and subgroups analyses were also carried out. Twenty-three studies (824 patients' data) were included in the meta-analysis. I-seeds implantation brachytherapy alone was associated with 8.98 [95% confidence interval (CI): 6.94, 11.03] months (P cancer patients, overall survival was 7.13 [95% CI: 4.75, 9.51] months (P cancer patients after I-seeds implantation brachytherapy is found to be 9 months, whereas a combined treatment with I-seeds brachytherapy and other therapies was associated with approximately 12 months' survival. The majority of patients who underwent I-seeds brachytherapy had their pain relieved.

  4. Long-term electrical survival analysis of Riata and Riata ST silicone leads: National Veterans Affairs experience.

    Science.gov (United States)

    Sung, Raphael K; Massie, Barry M; Varosy, Paul D; Moore, Hans; Rumsfeld, John; Lee, Byron K; Keung, Edmund

    2012-12-01

    A medical device advisory issued by St Jude Medical in November 2011 estimated 0.63% all-cause abrasion rate on their Riata and Riata ST silicone high-voltage lead families (Riata/ST), leading to Food and Drug Administration class I recall. We performed an independent comparative, long-term electrical survival analysis of Riata/ST and 3 other high-voltage lead families in a large national cohort of patients. To evaluate long-term electrical survival of Riata/ST leads relative to other commonly evaluated high-voltage leads. Failure rates of Riata/ST, Sprint Quattro Secure (Quattro), Sprint Fidelis (Fidelis), and Endotak Reliance G/SG (Endotak) leads from the Veterans Administration's National Cardiac Device Surveillance Center database, consisting of 24,145 patients with remote transmissions since 2003, were analyzed. Survival Probabilities were determined with Kaplan-Meier survival analysis and compared using the log-rank test. Of 1,403 Riata/ST, 6,091 Quattro, 5,073 Fidelis, and 2,401 Endotak leads identified, 5-year survival probability of Riata/ST leads (97.5%) was significantly lower than that of Quattro (99.3%) and Endotak (99.4%) leads (P leads (89.6%) (P leads showed a 5-year survival of 95.5% (95% confidence interval 92.4-97.4) compared to 98.4% (95% confidence interval 97.1-99.1) in Riata leads (P = .003). There is decreased survival probability of Riata/ST leads compared to other contemporary high-voltage leads, with decreased survival of Riata ST silicone compared to Riata lead series. Careful long-term follow-up should be maintained in patients with Riata/ST leads in order to prevent inappropriate shocks or failed device interventions. Our results were determined in advance of Food and Drug Administration class I recall, which suggested that large-scale remote monitoring may be an effective tool for continued implantable cardioverter-defibrillator system surveillance. Published by Elsevier Inc.

  5. The Association between Phase Angle of Bioelectrical Impedance Analysis and Survival Time in Advanced Cancer Patients: Preliminary Study.

    Science.gov (United States)

    Lee, So Yeon; Lee, Yong Joo; Yang, Jung-Hwa; Kim, Chul-Min; Choi, Whan-Seok

    2014-09-01

    A frequent manifestation of advanced cancer patients is malnutrition, which is correlated with poor prognosis and high mortality. Bioelectrical impedance analysis (BIA) is an easy-to-use and non-invasive technique to evaluate changes in body composition and nutritional status. We investigated BIA-derived phase angle as a prognostic indicator for survival in advanced cancer patients. Twenty-eight patients treated at the hospice center of Seoul St. Mary's Hospital underwent BIA measurements from January, 2013 to May, 2013. We also evaluated palliative prognostic index (PPI) and palliative performance scale to compare with the prognostic value of phase angle. Cox's proportional hazard models were constructed to evaluate the prognostic effect of phase angle. The Kaplan Meier method was used to calculate survival. Using univariate Cox analysis, phase angle (hazard ratio [HR], 0.61/per degree increase; 95% confidence interval [CI], 0.42 to 0.89; P = 0.010), PPI (HR, 1.21; 95% CI, 1.00 to 1.47; P = 0.048) were found to be significantly associated with survival. Adjusting age, PPI, body mass index, phase angle significantly showed association with survival in multivariate analysis (HR, 0.64/per degree increase; 95% CI, 0.42 to 0.95; P = 0.028). Survival time of patients with phase angle ≥ 4.4° was longer than patients with phase angle < 4.4° (log rank, 6.208; P-value = 0.013). Our data suggest BIA-derived phase angle may serve as an independent prognostic indicator in advanced cancer patients.

  6. Survival analysis and visual outcome in a large series of corneal transplants in India.

    Science.gov (United States)

    Dandona, L; Naduvilath, T J; Janarthanan, M; Ragu, K; Rao, G N

    1997-09-01

    The public health significance of corneal transplantation in dealing with corneal blindness in the developing world would depend upon the survival rate of transplants. This study was done to analyse the survival rate of corneal transplants in a large series in India, and to evaluate the influence of various risk factors on transplant survival. The records of a series of 1725 cases of corneal transplants carried out during 1987-95 at a tertiary eye care institution in India were reviewed. The Kaplan-Meier method was used to determine 5 year survival rates of corneal transplants performed for the various categories of preoperative diagnosis. Multivariate Cox proportional hazards regression was used to assess how preoperative diagnosis, socioeconomic status, age, sex, vascularisation of host cornea, quality of donor cornea, and training status of surgeon influenced transplant survival. The effect of these variables on visual outcome was assessed using multiple logistic regression. The survival rates at 1, 2, and 5 years for all corneal transplants performed for the first time in 1389 cases were 79.6% (95% confidence interval = 77.3-81.9%), 68.7% (65.7-71.7%) and 46.5% (41.7-51.3%). The 5 year survival rate was highest if the corneal transplant was done for keratoconus (95.1% (84.8-100%)) and lowest if carried out for previous transplant failure (21.2% (13.8-28.6%)). The relative risk of transplant failure was higher if the preoperative diagnosis was previous transplant failure (2.04 (1.62-2.55)), aphakic bullous keratopathy (1.78 (1.38-2.28)), corneal clouding due to miscellaneous causes including congenital conditions and glaucoma (1.63 (1.21-2.19)), or adherent leucoma (1.11 (0.81-1.51)) than for the other preoperative diagnoses. Patients with lower socioeconomic status had higher relative risk of transplant failure (1.28 (1.16-1.42)), as did patients corneal transplant 80.2% of the eyes were blind (visual acuity 6/18 were higher if the transplant was done for

  7. Trends of Incidence and Survival of Gastrointestinal Neuroendocrine Tumors in the United States: A Seer Analysis

    Directory of Open Access Journals (Sweden)

    Vassiliki L. Tsikitis, Betsy C. Wertheim, Marlon A. Guerrero

    2012-01-01

    Full Text Available OBJECTIVES: To examine trends in detection and survival of hollow viscus gastrointestinal neuroendocrine tumors (NETs across time and geographic regions of the U.S.METHODS: We used the Surveillance, Epidemiology and End Results (SEER database to investigate 19,669 individuals with newly diagnosed gastrointestinal NETs. Trends in incidence were tested using Poisson regression. Cox proportional hazards regression was used to examine survival.RESULTS: Incidence increased over time for NETs of all gastrointestinal sites (all P < 0.001, except appendix. Rates have risen faster for NETs of the small intestine and rectum than stomach and colon. Rectal NETs were detected at a faster pace among blacks than whites (P < 0.001 and slower in the East than other regions (P < 0.001. We observed that appendiceal and rectal NETs carry the best prognosis and survival of small intestinal and colon NETs has improved for both men and women. Colon NETs showed different temporal trends in survival according to geographic region (Pinteraction = 0.028. Improved prognosis was more consistent across the country for small intestinal NETs.CONCLUSIONS: Incidence of gastrointestinal NETs has increased, accompanied by inconsistently improved survival for different anatomic sites among certain groups defined by race and geographic region.

  8. Stadium IB - IIA cervical cancer patient’s survival rate after receiving definitive radiation and radical operation therapy followed by adjuvant radiation therapy along with analysis of factors affecting the patient’s survival rate

    Science.gov (United States)

    Ruslim, S. K.; Purwoto, G.; Widyahening, I. S.; Ramli, I.

    2017-08-01

    To evaluate the characteristics and overall survival rates of early stage cervical cancer (FIGO IB-IIA) patients who receive definitive radiation therapy and those who are prescribed adjuvant postoperative radiation and to conduct a factors analysis of the variables that affect the overall survival rates in both groups of therapy. The medical records of 85 patients with cervical cancer FIGO stages IB-IIA who were treated at the Department of Radiotherapy of Cipto Mangunkusumo Hospital were reviewed and analyzed to determine their overall survival and the factors that affected it between a definitive radiation group and an adjuvant postoperative radiation group. There were 25 patients in the definitive radiation and 60 patients in the adjuvant radiation group. The overall survival rates in the adjuvant radiation group at years one, two, and three were 96.7%, 95%, and 93.3%, respectively. Negative lymph node metastasis had an average association with overall survival (p 12 g/dl was a factor with an average association with the overall survival (p cervical cancer FIGO stage IB-IIA patients who received definitive radiation or adjuvant postoperative radiation. Negative lymph node metastasis had an effect on the overall survival rate in the adjuvant postoperative radiation group, while a preradiation Hb level >12 g/dl tended to affect the overall survival in the definitive radiation group patients.

  9. Cross-cultural analysis of teacher confirmation, student motivation, classroom emotion and emotional interest in China, Korea and Japan

    OpenAIRE

    Shen, Tingting

    2016-01-01

    This study investigates the relationship between teacher confirmation and student motivation across three cultures: China, Korea, and Japan and studies how classroom emotion and emotional interest influence this relationship in three different countries. Students in China (n=718), Korea (n=362), and Japan (n=350) completed questionnaires assessing their perceived teacher confirmation, student motivation, classroom emotion and emotional interest. Results of these samples indicate that teacher ...

  10. Cigarette smoking is associated with adverse survival among women with ovarian cancer: Results from a pooled analysis of 19 studies.

    Science.gov (United States)

    Praestegaard, Camilla; Jensen, Allan; Jensen, Signe M; Nielsen, Thor S S; Webb, Penelope M; Nagle, Christina M; DeFazio, Anna; Høgdall, Estrid; Rossing, Mary Anne; Doherty, Jennifer A; Wicklund, Kristine G; Goodman, Marc T; Modugno, Francesmary; Moysich, Kirsten; Ness, Roberta B; Edwards, Robert; Matsuo, Keitaro; Hosono, Satoyo; Goode, Ellen L; Winham, Stacey J; Fridley, Brooke L; Cramer, Daniel W; Terry, Kathryn L; Schildkraut, Joellen M; Berchuck, Andrew; Bandera, Elisa V; Paddock, Lisa E; Massuger, Leon F; Wentzensen, Nicolas; Pharoah, Paul; Song, Honglin; Whittemore, Alice; McGuire, Valerie; Sieh, Weiva; Rothstein, Joseph; Anton-Culver, Hoda; Ziogas, Argyrios; Menon, Usha; Gayther, Simon A; Ramus, Susan J; Gentry-Maharaj, Alexandra; Wu, Anna H; Pearce, Celeste L; Pike, Malcolm; Lee, Alice W; Sutphen, Rebecca; Chang-Claude, Jenny; Risch, Harvey A; Kjaer, Susanne K

    2017-06-01

    Cigarette smoking is associated with an increased risk of developing mucinous ovarian tumors but whether it is associated with ovarian cancer survival overall or for the different histotypes is unestablished. Furthermore, it is unknown whether the association between cigarette smoking and survival differs according to strata of ovarian cancer stage at diagnosis. In a large pooled analysis, we evaluated the association between various measures of cigarette smoking and survival among women with epithelial ovarian cancer. We obtained data from 19 case-control studies in the Ovarian Cancer Association Consortium (OCAC), including 9,114 women diagnosed with ovarian cancer. Cox regression models were used to estimate adjusted study-specific hazard ratios (HRs), which were combined into pooled hazard ratios (pHR) with corresponding 95% confidence intervals (CIs) under random effects models. Overall, 5,149 (57%) women died during a median follow-up period of 7.0 years. Among women diagnosed with ovarian cancer, both current (pHR = 1.17, 95% CI: 1.08-1.28) and former smokers (pHR = 1.10, 95% CI: 1.02-1.18) had worse survival compared with never smoking women. In histotype-stratified analyses, associations were observed for mucinous (current smoking: pHR = 1.91, 95% CI: 1.01-3.65) and serous histotypes (current smoking: pHR = 1.11, 95% CI: 1.00-1.23; former smoking: pHR = 1.12, 95% CI: 1.04-1.20). Further, our results suggested that current smoking has a greater impact on survival among women with localized than disseminated disease. The identification of cigarette smoking as a modifiable factor associated with survival has potential clinical importance as a focus area to improve ovarian cancer prognosis. © 2017 UICC.

  11. Treatment patterns and survival analysis in 9014 patients with malignant pleural mesothelioma from Belgium, the Netherlands and England.

    Science.gov (United States)

    Damhuis, R A; Khakwani, A; De Schutter, H; Rich, A L; Burgers, J A; van Meerbeeck, J P

    2015-08-01

    Pleural mesothelioma has a dismal prognosis and is refractory to local treatment. Combination chemotherapy can increase median survival by several months and was gradually introduced in the period 2003-2006. Elderly patients may be unfit for chemotherapy but little is known about age-related treatment practice. To determine treatment patterns and current survival outcome, three large population-based registries were queried in a uniform manner. Data from the Belgian Cancer Registry, the Netherlands Cancer Registry and the UK National Lung Cancer Audit were analyzed for patients diagnosed with pleural mesothelioma since 2007. Treatment patterns and survival rates were compared between countries and age-groups. The study included 900, 2306 and 5808 patients from Belgium, the Netherlands and England, respectively. Fifty-nine percent of patients were 70 years or older and 84% were men. Chemotherapy use decreased with advancing age and was used more often in Belgium (60%) than in the Netherlands (41%) and England (37%). For patients aged 70-79 years, chemotherapy use was 55%, 36% and 34% in the respective countries. Median survival was 10.7 months in Belgium versus 9.2 months for the Netherlands and 9.5 months for England. Survival rates decreased with advancing age. On average, median survival was 5.6 months longer for patients treated with chemotherapy, irrespective of age. Combined analysis of data from three countries with high mesothelioma rates demonstrates that chemotherapy has become standard treatment for younger patients. Elderly patients currently account for more than half of all cases and less toxic treatment options will be required to improve their prospects. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Analysis of bacterial survival after exposure to reactive oxygen species or antibiotics

    Directory of Open Access Journals (Sweden)

    Joris van der Heijden

    2016-06-01

    Full Text Available The redox balance in a variety of Gram-negative bacteria was explored using redox sensitive GFP (roGFP2, J. van der Heijden et al. doi:10.1016/j.freeradbiomed.2015.11.029 [1]. This data article provides Supporting material to further investigate the relationship between Salmonella typhimurium survival and oxidative stress. The first set of data presented in this article, shows the percentage of surviving bacteria after exposure to hydrogen peroxide. The second set of data shows the concentration of hydrogen peroxide that was produced by S. Typhimurium in different growth phases. The last set of data shows the percentage of surviving S. Typhimurium bacteria after exposure to different antibiotics.

  13. Analysis of tumor and endothelial cell viability and survival using sulforhodamine B and clonogenic assays.

    Science.gov (United States)

    Woolston, Caroline; Martin, Stewart

    2011-01-01

    A variety of assays, and rationales for their use, exist to monitor viability and/or survival following cellular exposure to insult. Two commonly used in vitro assays are the sulforhodamine B assay and the clonogenic survival assay which can be used to monitor the efficacy of anticancer agents, either via direct tumor cell cytotoxicity or antiangiogenic mechanisms. The techniques described are suitable for studying survival in a number of different cell types; however, this chapter describes how they may be used in the assessment of chemo-/radiosensitivity. The methods are uncomplicated and robust as long as attention is paid to key optimization steps. Except for a multiwell plate reader they do not require any specialized equipment other than that found in a typical tissue-culture laboratory.

  14. The effect of statins on average survival in randomised trials, an analysis of end point postponement

    DEFF Research Database (Denmark)

    Kristensen, Malene Lopez; Christensen, Palle Mark; Hallas, Jesper

    2015-01-01

    OBJECTIVE: To estimate the average postponement of death in statin trials. SETTING: A systematic literature review of all statin trials that presented all-cause survival curves for treated and untreated. INTERVENTION: Statin treatment compared to placebo. PRIMARY OUTCOME MEASURES: The average...... postponement of death as represented by the area between the survival curves. RESULTS: 6 studies for primary prevention and 5 for secondary prevention with a follow-up between 2.0 and 6.1 years were identified. Death was postponed between -5 and 19 days in primary prevention trials and between -10 and 27 days...... in secondary prevention trials. The median postponement of death for primary and secondary prevention trials were 3.2 and 4.1 days, respectively. CONCLUSIONS: Statin treatment results in a surprisingly small average gain in overall survival within the trials' running time. For patients whose life expectancy...

  15. Survival Impact of Adjuvant Radiation Therapy in Masaoka Stage II to IV Thymomas: A Systematic Review and Meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Yu Jin; Kim, Eunji [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Hak Jae, E-mail: khjae@snu.ac.kr [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Wu, Hong-Gyun [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul (Korea, Republic of); Yan, Jinchun [Department of Radiation Oncology, Dalian Medical University, Liaoning (China); Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China); Liu, Qin [The Wistar Institute, Philadelphia, Pennsylvania (United States); Patel, Shilpen [Department of Radiation Oncology, University of Washington Medical Center, Seattle, Washington (United States)

    2016-04-01

    Purpose: To evaluate the survival impact of postoperative radiation therapy (PORT) in stage II to IV thymomas, using systematic review and meta-analysis. Methods and Materials: A database search was conducted with EMBASE, PubMed, Web of Science, Cochrane Library, and Ovid from inception to August 2015. Thymic carcinomas were excluded, and studies comparing overall survival (OS) with and without PORT in thymomas were included. The hazard ratios (HRs) of OS were extracted, and a random-effects model was used in the pooled analysis. Results: Seven retrospective series with a total of 1724 patients were included and analyzed. Almost all of the patients underwent macroscopically complete resection, and thymoma histology was confirmed by the World Health Organization criteria. In the overall analysis of stage II to IV thymomas, OS was not altered with the receipt of PORT (HR 0.79, 95% confidence interval [CI] 0.58-1.08). Although PORT was not associated with survival difference in Masaoka stage II disease (HR 1.45, 95% CI 0.83-2.55), improved OS was observed with the addition of PORT in the discrete pooled analysis of stage III to IV (HR 0.63, 95% CI 0.40-0.99). Significant heterogeneity and publication bias were not found in the analyses. Conclusions: From the present meta-analysis of sole primary thymomas, we suggest the potential OS benefit of PORT in locally advanced tumors with macroscopically complete resection, but not in stage II disease. Further investigations with sufficient survival data are needed to establish detailed treatment indications.

  16. Survival analysis of patients with interval cancer undergoing gastric cancer screening by endoscopy.

    Science.gov (United States)

    Hamashima, Chisato; Shabana, Michiko; Okamoto, Mikizo; Osaki, Yoneatsu; Kishimoto, Takuji

    2015-01-01

    Interval cancer is a key factor that influences the effectiveness of a cancer screening program. To evaluate the impact of interval cancer on the effectiveness of endoscopic screening, the survival rates of patients with interval cancer were analyzed. We performed gastric cancer-specific and all-causes survival analyses of patients with screen-detected cancer and patients with interval cancer in the endoscopic screening group and radiographic screening group using the Kaplan-Meier method. Since the screening interval was 1 year, interval cancer was defined as gastric cancer detected within 1 year after a negative result. A Cox proportional hazards model was used to investigate the risk factors associated with gastric cancer-specific and all-causes death. A total of 1,493 gastric cancer patients (endoscopic screening group: n = 347; radiographic screening group: n = 166; outpatient group: n = 980) were identified from the Tottori Cancer Registry from 2001 to 2008. The gastric cancer-specific survival rates were higher in the endoscopic screening group than in the radiographic screening group and the outpatients group. In the endoscopic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer and the patients with interval cancer were nearly equal (P = 0.869). In the radiographic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer was higher than that of the patients with interval cancer (P = 0.009). For gastric cancer-specific death, the hazard ratio of interval cancer in the endoscopic screening group was 0.216 for gastric cancer death (95%CI: 0.054-0.868) compared with the outpatient group. The survival rate and the risk of gastric cancer death among the patients with screen-detected cancer and patients with interval cancer were not significantly different in the annual endoscopic screening. These results suggest the potential of endoscopic screening in reducing

  17. An analysis of the survivability of sensor darts in impacts with trees.

    Energy Technology Data Exchange (ETDEWEB)

    Prentice, John K. (Sci-Tac, Inc., Boulder, CO.); Gardner, David Randall

    2005-07-01

    A methodology was developed for computing the probability that the sensor dart for the 'Near Real-Time Site Characterization for Assured HDBT Defeat' Grand-Challenge LDRD project will survive deployment over a forested region. The probability can be decomposed into three approximately independent probabilities that account for forest coverage, branch density and the physics of an impact between the dart and a tree branch. The probability that a dart survives an impact with a tree branch was determined from the deflection induced by the impact. If a dart that was deflected so that it impacted the ground at an angle of attack exceeding a user-specified, threshold value, the dart was assumed to not survive the impact with the branch; otherwise it was assumed to have survived. A computer code was developed for calculating dart angle of attack at impact with the ground and a Monte Carlo scheme was used to calculate the probability distribution of a sensor dart surviving an impact with a branch as a function of branch radius, length, and height from the ground. Both an early prototype design and the current dart design were used in these studies. As a general rule of thumb, it we observed that for reasonably generic trees and for a threshold angle of attack of 5{sup o} (which is conservative for dart survival), the probability of reaching the ground with an angle of attack less than the threshold is on the order of 30% for the prototype dart design and 60% for the current dart design, though these numbers should be treated with some caution.

  18. Fulvestrant versus anastrozole for the treatment of advanced breast carcinoma: a prospectively planned combined survival analysis of two multicenter trials.

    Science.gov (United States)

    Howell, Anthony; Pippen, John; Elledge, Richard M; Mauriac, Louis; Vergote, Ignace; Jones, Stephen E; Come, Steven E; Osborne, C Kent; Robertson, John F R

    2005-07-15

    Fulvestrant is an estrogen receptor antagonist with no agonist effects. In the second-line treatment of advanced breast carcinoma, fulvestrant was shown previously to be as effective as the third-generation aromatase inhibitor, anastrozole, in terms of time to disease progression and objective response rates. The authors reported the overall survival results from these studies. A prospectively planned, combined, overall survival analysis was performed, including data from two Phase III trials that compared the efficacy and tolerability of fulvestrant (250 mg monthly; n = 428) with anastrozole (1 mg daily; n = 423) in the treatment of postmenopausal women with advanced breast carcinoma who had disease progression after receipt of previous endocrine treatment. At an extended median follow-up of 27.0 months (range, 0-66.9 months), 319 (74.5%) patients in the fulvestrant group and 322 (76.1%) patients in the anastrozole group had died. Prolonged survival was observed with both drugs, with 10-20% of patients still alive > 5 years after randomization. The median overall survival was similar between treatments, being 27.4 months and 27.7 months in fulvestrant and anastrozole-treated patients, respectively (hazards ratio, 0.98; 95% confidence interval, 0.84-1.15; P = 0.809). Fulvestrant continued to be well tolerated, and was associated with a significantly lower incidence of joint disorders compared with anastrozole (P = 0.0234). The current analysis showed that fulvestrant was similar to anastrozole with respect to overall survival in the second-line treatment of postmenopausal women with advanced breast carcinoma.

  19. Efficacy and survival analysis of percutaneous radiofrequency versus microwave ablation for hepatocellular carcinoma: an Egyptian multidisciplinary clinic experience.

    Science.gov (United States)

    Abdelaziz, Ashraf; Elbaz, Tamer; Shousha, Hend Ibrahim; Mahmoud, Sherif; Ibrahim, Mostafa; Abdelmaksoud, Ahmed; Nabeel, Mohamed

    2014-12-01

    Hepatocellular carcinoma (HCC) is a primary tumor of the liver with poor prognosis. For early stage HCC, treatment options include surgical resection, liver transplantation, and percutaneous ablation. Percutaneous ablative techniques (radiofrequency and microwave techniques) emerged as best therapeutic options for nonsurgical patients. We aimed to determine the safety and efficacy of radiofrequency and microwave procedures for ablation of early stage HCC lesions and prospectively follow up our patients for survival analysis. One Hundred and 11 patients with early HCC are managed in our multidisciplinary clinic using either radiofrequency or microwave ablation. Patients are assessed for efficacy and safety. Complete ablation rate, local recurrence, and overall survival analysis are compared between both procedures. Radiofrequency ablation group (n = 45) and microwave ablation group (n = 66) were nearly comparable as regards the tumor and patients characteristics. Complete ablation was achieved in 94.2 and 96.1% of patients managed by radiofrequency and microwave ablation techniques, respectively (p value 0.6) with a low rate of minor complications (11.1 and 3.2, respectively) including subcapsular hematoma, thigh burn, abdominal wall skin burn, and pleural effusion. Ablation rates did not differ between ablated lesions ≤ 3 and 3-5 cm. A lower incidence of local recurrence was observed in microwave group (3.9 vs. 13.5% in radiofrequency group, p value 0.04). No difference between both groups as regards de novo lesions, portal vein thrombosis, and abdominal lymphadenopathy. The overall actuarial probability of survival was 91.6% at 1 year and 86.1% at 2 years with a higher survival rates noticed in microwave group but still without significant difference (p value 0.49). Radiofrequency and microwave ablations led to safe and equivalent ablation and survival rates (with superiority for microwave ablation as regards the incidence of local recurrence).

  20. Treatment Challenges and Survival Analysis of Human Epidermal Growth Factor Receptor 2-positive Breast Cancer in Real World.

    Science.gov (United States)

    Adusumilli, Praveen; Konatam, Meher Lakshmi; Gundeti, Sadashivudu; Bala, Stalin; Maddali, Lakshmi Srinivas

    2017-01-01

    Advent of trastuzumab has brought tremendous changes in the survival of human epidermal growth factor receptor 2 (Her2)-positive breast cancer patients. Despite the availability of the drug, it is still out of reach for many patients. There is very limited real world data regarding treatment challenges and survival analysis of these patients. Primary objective is disease-free survival (DFS) and secondary objective is overall survival (OS) and toxicity profile. Statistical analysis is done using GraphPad Prism 7.02. This is a retrospective study of all patients diagnosed with Her2-positive (Her2+) nonmetastatic invasive breast cancer from January 2007 to December 2013. In the period of this study, 885 patients are diagnosed with carcinoma breast, of which 212 are Her2/neu positive (23.9%). Of the 212 patients, only 76 (35.8%) patients received trastuzumab along with chemotherapy. Patients receiving trastuzumab with chemotherapy have longer 5-year DFS compared to those receiving chemotherapy alone, 92% and 52.6%, respectively (P = 0.0001). Five-year OS is 90.5% and 41.7% in those patients who received chemotherapy with and without trastuzumab, respectively (P = 0.0001). Seven patients (9.45%) developed Grade II reversible diastolic dysfunction. Grade II/III peripheral neuropathy due to paclitaxel is the main adverse effect seen in 21 patients. In spite of improvement in DFS and OS with trastuzumab, the number of patient receiving targeted therapy is very low due to financial constraints which need to be addressed to bridge the gap in survival of Her2+ patients.

  1. Impact of Resection Margin Distance on Survival of Pancreatic Cancer: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Kim, Kyung Su; Kwon, Jeanny; Kim, Kyubo; Chie, Eui Kyu

    2017-07-01

    While curative resection is the only chance of cure in pancreatic cancer, controversies exist about the impact of surgical margin status on survival. Non-standardized pathologic report and different criteria on the R1 status made it difficult to implicate adjuvant therapy after resection based on the margin status. We evaluated the influence of resection margins on survival by meta-analysis. We thoroughly searched electronic databases of PubMed, EMBASE, and Cochrane Library. We included studies reporting survival outcomes with different margin status: involved margin (R0 mm), margin clearance with ≤ 1 mm (R0-1 mm), and margin with > 1 mm (R>1 mm). Hazard ratio (HR) for overall survival was extracted, and a random-effects model was used for pooled analysis. A total of eight retrospective studies involving 1,932 patients were included. Pooled HR for overall survival showed that patients with R>1 mm had reduced risk of death than those with R0-1 mm (HR, 0.74; 95% confidence interval [CI], 0.61 to 0.88; p=0.001). In addition, patients with R0-1 mm had reduced risk of death than those with R0 mm (HR, 0.81; 95% CI, 0.72 to 0.91; p < 0.001). There was no heterogeneity between the included studies (I(2) index, 42% and 0%; p=0.10 and p=0.82, respectively). Our results suggest that stratification of the patients based on margin status is warranted in the clinical trials assessing the role of adjuvant treatment for pancreatic cancer.

  2. Predictors of immunodeficiency-related death in a cohort of low-income people living with HIV: a competing risks survival analysis.

    Science.gov (United States)

    Albuquerque, M F P M; Alves, D N; Bresani Salvi, C C; Batista, J D L; Ximenes, R A A; Miranda-Filho, D B; Melo, H R L; Maruza, M; Montarroyos, U R

    2017-04-01

    We conducted a survival analysis with competing risks to estimate the mortality rate and predictive factors for immunodeficiency-related death in people living with HIV/AIDS (PLWH) in northeast Brazil. A cohort with 2372 PLWH was enrolled between July 2007 and June 2010 and monitored until 31 December 2012 at two healthcare centres. The event of interest was immunodeficiency-related death, which was defined based on the Coding Causes of Death in HIV Protocol (CoDe). The predictor variables were: sociodemographic characteristics, illicit drugs, tobacco, alcohol, nutritional status, antiretroviral therapy, anaemia and CD4 cell count at baseline; and treatment or chemoprophylaxis for tuberculosis (TB) during follow-up. We used Fine & Gray's model for the survival analyses with competing risks, since we had regarded immunodeficiency-unrelated deaths as a competing event, and we estimated the adjusted sub-distribution hazard ratios (SHRs). In 10 012·6 person-years of observation there were 3·1 deaths/100 person-years (2·3 immunodeficiency-related and 0·8 immunodeficiency-unrelated). TB (SHR 4·01), anaemia (SHR 3·58), CD4 death. This study discloses a 13% coverage by highly active antiretroviral therapy (HAART) in our state and adds that anaemia at baseline or the incidence of TB may increase the specific risk of dying from HIV-immunodeficiency, regardless of HAART and CD4.

  3. A survival analysis of South African children under the age of five years

    Directory of Open Access Journals (Sweden)

    Zeleke Worku

    2011-02-01

    predikatorveranderlikes (duurte van borsvoeding, huwelikstatus en toegang tot ‘n spoeltoilet. Die risikoverhouding van die borsvoeding-veranderlike was 3.09 met P = 0.000 en ‘n 95% sekerheidsinterval van (1.899, 5.033. Die risikoverhouding van die toiletveranderlike was 2.35 met P = 0.006 en 95% sekerheidsinterval van (1.172, 4.707. Die risikoverhouding van die huwelikstatus-veranderlike was 1.74 met P = 0.035 en 95% sekerheidsinterval van (1.041, 2.912. Aanpassings is gemaak vir die opvoedingsvlak van die moeder asook die welgesteldheidsindeks.

    How to cite this article: Worku, Z., 2011, ‘A survival analysis of South African children under the age of five years’, Health SA Gesondheid 16(1, Art. #472, 12 pages.doi:10.4102/hsag.v16i1.472

  4. Testing the social cognitive career theory in Thai nurses' interest to become nurse educators: A structural equation modeling analysis.

    Science.gov (United States)

    Thungjaroenkul, Petsunee; G Cummings, Greta; Tate, Kaitlyn

    2016-09-01

    A shortage of nurse educators generates a systemic problem in nursing education. A model to develop interventions directed at enhancing graduate nursing student interest in assuming a future faculty role is needed. This study used a social cognitive career theory perspective to examine the effects of past performance in teaching and supervision, social influence, observing others teaching, perceived task demands for nurse educators, self-efficacy, and outcome expectations on Thai graduate nursing students' (n=236) interest to become a nurse educator. Results of structural equation modeling analyses revealed that social influence and past performance in teaching and supervision had significant effects on interest to become a nurse educator when mediated by self-efficacy and outcome expectations. Observing others teaching and perceived task demands for nurse educators did not significantly predict interest in faculty roles. These findings provide new knowledge about factors and their influence on the development of interest to assume faculty roles. Implications for nursing education include the design of feasible graduate curricula that enhance students' abilities in faculty role and increases valuation of teaching careers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Adjuvant radiotherapy improves overall survival in patients with resected gastric adenocarcinoma: A National Cancer Data Base analysis.

    Science.gov (United States)

    Stumpf, Priscilla K; Amini, Arya; Jones, Bernard L; Koshy, Matthew; Sher, David J; Lieu, Christopher H; Schefter, Tracey E; Goodman, Karyn A; Rusthoven, Chad G

    2017-09-01

    For patients with resectable gastric adenocarcinoma, perioperative chemotherapy and adjuvant chemoradiotherapy (CRT) are considered standard options. In the current study, the authors used the National Cancer Data Base to compare overall survival (OS) between these regimens. Patients who underwent gastrectomy for nonmetastatic gastric adenocarcinoma from 2004 through 2012 were divided into those treated with perioperative chemotherapy without RT versus those treated with adjuvant CRT. Survival was estimated and compared using univariate and multivariate models adjusted for patient and tumor characteristics, surgical margin status, and the number of lymph nodes examined. Subset analyses were performed for factors chosen a priori, and potential interactions between treatment and covariates were assessed. A total of 3656 eligible patients were identified, 52% of whom underwent perioperative chemotherapy and 48% of whom received postoperative CRT. The median follow-up was 47 months, and the median age of the patients was 62 years. Analysis of the entire cohort demonstrated improved OS with adjuvant RT on both univariate (median of 51 months vs 42 months; P = .013) and multivariate (hazard ratio, 0.874; 95% confidence interval, 0.790-0.967 [P = .009]) analyses. Propensity score-matched analysis also demonstrated improved OS with adjuvant RT (median of 49 months vs 39 months; P = .033). On subset analysis, a significant interaction was observed between the survival impact of adjuvant RT and surgical margins, with a greater benefit of RT noted among patients with surgical margin-positive disease (hazard ratio with RT: 0.650 vs 0.952; P for interaction Cancer Data Base analysis, the use of adjuvant RT in addition to chemotherapy was associated with a significant OS advantage for patients with resected gastric cancer. The survival advantage observed with adjuvant CRT was most pronounced among patients with positive surgical margins. Cancer 2017;123:3402-9. © 2017 American

  6. Survival Benefit of Adjuvant Chemoradiotherapy in Patients With Ampulla of Vater Cancer: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Kwon, Jeanny; Kim, Byoung Hyuck; Kim, Kyubo; Chie, Eui Kyu; Ha, Sung W

    2015-07-01

    We conducted a systematic review and meta-analysis focusing on the impact of adjuvant radiotherapy (RT) on overall survival (OS) in ampulla of Vater (AoV) cancer. The adjuvant treatment for AoV cancer is a subject of controversy without convincing evidence from randomized study. A comprehensive search was performed in the databases of EMBASE, PubMed, Web of Science, Cochrane Library, and Ovid from inception to July 2014. We included studies, which compared survival between patients with or without adjuvant RT after curative surgery solely for AoV cancer. Hazard ratio (HR) for OS was extracted, and a random-effects model was used for pooled analysis. Ten retrospective studies including 3361 patients met all inclusion criteria and were included for the final meta-analysis. Adjuvant RT was delivered with concurrent chemotherapy, mostly 5-fluorouracil, in all institutional studies. Generally, adjuvant RT groups included more patients with locally advanced disease or lymph node metastasis than did the surgery alone groups. The pooled results demonstrated that adjuvant RT significantly reduced the risk of death (HR = 0.75; P = 0.01). Exploratory analyses showed that patients with lymph node metastasis (HR = 0.52; P = 0.001) and locally advanced disease (HR = 0.42; P = 0.001) may also have survival benefit from adjuvant RT. No clear evidence of publication bias was found. This is the first meta-analysis evaluating the role of adjuvant RT in AoV cancer. Our results suggest the potential for survival benefit of adjuvant chemoradiotherapy. Further studies, preferably randomized clinical trials, are needed to confirm our results.

  7. Association of Serum Level of Vitamin D at Diagnosis With Breast Cancer Survival: A Case-Cohort Analysis in the Pathways Study.

    Science.gov (United States)

    Yao, Song; Kwan, Marilyn L; Ergas, Isaac J; Roh, Janise M; Cheng, Ting-Yuan David; Hong, Chi-Chen; McCann, Susan E; Tang, Li; Davis, Warren; Liu, Song; Quesenberry, Charles P; Lee, Marion M; Ambrosone, Christine B; Kushi, Lawrence H

    2017-03-01

    There are long-standing interests in the potential benefits of vitamin D for preventing breast cancer recurrence and mortality, yet data from prospective cohort studies are limited. To investigate a serum biomarker of vitamin D status, 25-hydroxyvitamin D (25OHD) measured at the time of breast cancer diagnosis, to determine the association with prognosis. The Pathways Study is a prospective cohort study of breast cancer survivors established in 2006. Enrollment was completed in 2013; follow-up is ongoing. The cohort was established in Kaiser Permanente Northern California, a large integrated health care delivery system in northern California. Women with a diagnosis of incident invasive breast cancer were typically consented and enrolled within 2 months of diagnosis. The overall enrollment rate was 46% (4505 of 9820). Participants are followed for health outcomes and comorbidities at 12, 24, 48, 72, and 96 months after baseline interview. A case-cohort design was used for efficiency assay of 25OHD, selecting 1666 cohort members with serum samples and ensuring representation in the subcohort of races and clinical subtypes. The data analysis was performed from January 5, 2014, to March 15, 2015. Primary outcomes are breast cancer recurrence, second primary cancer, and death. Mean (SD) age was 58.7 (12.4) years. Serum 25OHD concentrations were lower in women with advanced-stage tumors, and the lowest in premenopausal women with triple-negative cancer. Levels were also inversely associated with hazards of disease progression and death. Compared with the lowest tertile, women with the highest tertile of 25OHD levels had superior overall survival (OS). This association remained after adjustment for clinical prognostic factors (hazard ratio [HR], 0.72; 95% CI, 0.54-0.98). Among premenopausal women, the association with OS was stronger, and there were also associations with breast cancer-specific survival and invasive disease-free survival (OS: HR, 0.45; 95% CI, 0

  8. Effects of temperature on development, survival and reproduction of insects: Experimental design, data analysis and modeling

    Science.gov (United States)

    Jacques Regniere; James Powell; Barbara Bentz; Vincent Nealis

    2012-01-01

    The developmental response of insects to temperature is important in understanding the ecology of insect life histories. Temperature-dependent phenology models permit examination of the impacts of temperature on the geographical distributions, population dynamics and management of insects. The measurement of insect developmental, survival and reproductive responses to...

  9. Botnet C&C Traffic and Flow Lifespans Using Survival Analysis

    Directory of Open Access Journals (Sweden)

    Vaclav Oujezsky

    2017-03-01

    Based on our research we have figured out a possibility to distinguish the individual lifespans of C&C communications that are identical to each other by using survival projection curves, although it occurred in a different time course.

  10. SNP-SNP interaction analysis of NF-κB signaling pathway on breast cancer survival

    DEFF Research Database (Denmark)

    Jamshidi, Maral; Fagerholm, Rainer; Khan, Sofia

    2015-01-01

    , in an extensive dataset (n = 30,431) from the Breast Cancer Association Consortium, we investigated the association of 917 SNPs in 75 genes in the NF-κB pathway with breast cancer prognosis. We explored SNP-SNP interactions on survival using the likelihood-ratio test comparing multivariate Cox' regression models...

  11. Viability of Iberian x Meishan F2 newborn pigs. II. Survival analysis up to weaning.

    Science.gov (United States)

    Casellas, J; Noguera, J L; Varona, L; Sánchez, A; Arqué, M; Piedrafita, J

    2004-07-01

    Iberian x Meishan F2 piglet's preweaning survivability was analyzed using categorical data regression procedures within the proportional hazards assumption. A frailty sire model was assumed with the litter effect treated as an additional random source of variation. Moreover, the relative birth weight within litter and the litter effect were considered time-dependent covariates that changed their values in the second day of life due to cross fostering carried out to standardize litters. Six variables had a significant effect on survivability: birth weight (P piglets (Piglets that were small in relation to their siblings (relative birth weight within litter) also suffered an increased death risk, with a hazard ratio of 1.81 (P Piglets with a rectal temperature lower than 35.4 degrees C 60 min after birth showed the highest hazard ratio (7.18; P piglet survival involves several systematic influences related to birth weight, thermoregulatory ability, and injuries suffered during gestation and farrowing. The genetic variance was small compared with those generated by the common environment, for which the genetic improvement of piglet survival seems difficult.

  12. Teaching Community Survival Skills to Mentally Retarded Adults: A Review and Analysis.

    Science.gov (United States)

    Martin, James E.; And Others

    1982-01-01

    The article reviews research on training mentally retarded adults in the following community survival skills: travel training, money management, meal preparation, clothing and personal care, telephone skill, housekeeping, self-medication, leisure skills, social skills, and conversation. Results are said to indicate the value of behavioral…

  13. Disarticulation of the knee : Analysis of an extended database on survival, wound healing, and ambulation

    NARCIS (Netherlands)

    Nijmeijer, Rachelle; Voesten, Henricus G. J. M.; Geertzen, Joannes H. B.; Dijkstra, Pieter U.

    OBJECTIVE: This study analyzed survival of the amputee patients, wound healing, and ambulation after knee disarticulation (KD). METHODS: Between July 1989 and October 2015, 153 KDs in 138 patients were performed at Nij Smellinghe Hospital, Drachten. Data were retrieved from hospital medical records.

  14. Modeling receptor kinetics in the analysis of survival data for organophosphorus pesticides.

    NARCIS (Netherlands)

    Jager, D.T.; Kooijman, S.A.L.M.

    2005-01-01

    Acute ecotoxicological tests usually focus on survival at a standardized exposure time. However, LC50's decrease in time in a manner that depends both on the chemical and on the organism. DEBtox is an existing approach to analyze toxicity data in time, based on hazard modeling (the internal

  15. Survivalism and Public Opinion on Criminality: A Cross-National Analysis of Prostitution

    Science.gov (United States)

    Stack, Steven; Adamczyk, Amy; Cao, Liqun

    2010-01-01

    Explanations of variability in public opinion on crime have drawn disproportionately from the literature on specific symbolic orientations including religious fundamentalism and racial prejudice. In contrast, this article hypothesizes that public opinion is linked to the strength of a general cultural axis of nations: survivalism vs.…

  16. Association of gender and specialty interest with video-gaming, three-dimensional spatial analysis, and entry-level laparoscopic skills in third-year veterinary students.

    Science.gov (United States)

    Bragg, Heather R; Towle Millard, Heather A; Millard, Ralph P; Constable, Peter D; Freeman, Lyn J

    2016-06-15

    OBJECTIVE To determine whether gender or interest in pursuing specialty certification in internal medicine or surgery was associated with video-gaming, 3-D spatial analysis, or entry-level laparoscopic skills in third-year veterinary students. DESIGN Cross-sectional study. SAMPLE A convenience sample of 68 (42 female and 26 male) third-year veterinary students. PROCEDURES Participants completed a survey asking about their interest in pursuing specialty certification in internal medicine or surgery. Subsequently, participants' entry-level laparoscopic skills were assessed with 3 procedures performed in box trainers, their video-gaming skills were tested with 3 video games, and their 3-D spatial analysis skills were evaluated with the Purdue University Visualization of Rotations Spatial Test. Scores were assigned for laparoscopic, video-gaming, and 3-D spatial analysis skills. RESULTS Significantly more female than male students were interested in pursuing specialty certification in internal medicine (23/42 vs 7/26), and significantly more male than female students were interested in pursuing specialty certification in surgery (19/26 vs 19/42). Males had significantly higher video-gaming skills scores than did females, but spatial analysis and laparoscopic skills scores did not differ between males and females. Students interested in pursuing specialty certification in surgery had higher video-gaming and spatial analysis skills scores than did students interested in pursuing specialty certification in internal medicine, but laparoscopic skills scores did not differ between these 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE For this group of students, neither gender nor interest in specialty certification in internal medicine versus surgery was associated with entry-level laparoscopy skills.

  17. Search Strategy to Identify Dental Survival Analysis Articles Indexed in MEDLINE.

    Science.gov (United States)

    Layton, Danielle M; Clarke, Michael

    2016-01-01

    Articles reporting survival outcomes (time-to-event outcomes) in patients over time are challenging to identify in the literature. Research shows the words authors use to describe their dental survival analyses vary, and that allocation of medical subject headings by MEDLINE indexers is inconsistent. Together, this undermines accurate article identification. The present study aims to develop and validate a search strategy to identify dental survival analyses indexed in MEDLINE (Ovid). A gold standard cohort of articles was identified to derive the search terms, and an independent gold standard cohort of articles was identified to test and validate the proposed search strategies. The first cohort included all 6,955 articles published in the 50 dental journals with the highest impact factors in 2008, of which 95 articles were dental survival articles. The second cohort included all 6,514 articles published in the 50 dental journals with the highest impact factors for 2012, of which 148 were dental survival articles. Each cohort was identified by a systematic hand search. Performance parameters of sensitivity, precision, and number needed to read (NNR) for the search strategies were calculated. Sensitive, precise, and optimized search strategies were developed and validated. The performances of the search strategy maximizing sensitivity were 92% sensitivity, 14% precision, and 7.11 NNR; the performances of the strategy maximizing precision were 93% precision, 10% sensitivity, and 1.07 NNR; and the performances of the strategy optimizing the balance between sensitivity and precision were 83% sensitivity, 24% precision, and 4.13 NNR. The methods used to identify search terms were objective, not subjective. The search strategies were validated in an independent group of articles that included different journals and different publication years. Across the three search strategies, dental survival articles can be identified with sensitivity up to 92%, precision up to 93

  18. Integrative analysis of micro-RNA, gene expression, and survival of glioblastoma multiforme.

    Science.gov (United States)

    Huang, Yen-Tsung; Hsu, Thomas; Kelsey, Karl T; Lin, Chien-Ling

    2015-02-01

    Glioblastoma multiforme (GBM), the most common type of malignant brain tumor, is highly fatal. Limited understanding of its rapid progression necessitates additional approaches that integrate what is known about the genomics of this cancer. Using a discovery set (n = 348) and a validation set (n = 174) of GBM patients, we performed genome-wide analyses that integrated mRNA and micro-RNA expression data from GBM as well as associated survival information, assessing coordinated variability in each as this reflects their known mechanistic functions. Cox proportional hazards models were used for the survival analyses, and nonparametric permutation tests were performed for the micro-RNAs to investigate the association between the number of associated genes and its prognostication. We also utilized mediation analyses for micro-RNA-gene pairs to identify their mediation effects. Genome-wide analyses revealed a novel pattern: micro-RNAs related to more gene expressions are more likely to be associated with GBM survival (P = 4.8 × 10(-5)). Genome-wide mediation analyses for the 32,660 micro-RNA-gene pairs with strong association (false discovery rate [FDR] micro-RNAs and mediated their prognostic effects as well. We further constructed a gene signature using the 16 genes, which was highly associated with GBM survival in both the discovery and validation sets (P = 9.8 × 10(-6)). This comprehensive study discovered mediation effects of micro-RNA to gene expression and GBM survival and provided a new analytic framework for integrative genomics. © 2014 WILEY PERIODICALS, INC.

  19. Dedifferentiated chondrosarcoma: A survival analysis of 159 cases from the SEER database (2001-2011).

    Science.gov (United States)

    Strotman, Patrick K; Reif, Taylor J; Kliethermes, Stephanie A; Sandhu, Jasmin K; Nystrom, Lukas M

    2017-08-01

    Dedifferentiated chondrosarcoma is a rare malignancy with reported 5-year overall survival rates ranging from 7% to 24%. The purpose of this investigation is to determine the overall survival of dedifferentiated chondrosarcoma in a modern patient series and how it is impacted by patient demographics, tumor characteristics, and surgical treatment factors. This is a retrospective review of the Surveillance, Epidemiology, and End Results (SEER) database from 2001 to 2011. Kaplan Meier analyses were used for overall and disease-specific survival. Univariable and multivariable cox regression models were used to identify prognostic factors. Five year overall- and disease-specific survival was 18% (95% CI: 12-26%) and 28% (95% CI: 18-37%), respectively. Individuals with extremity tumors had a worse prognosis than individuals with a primary tumor in the chest wall or axial skeleton (HR 0.20, 95% CI: 0.07-0.56; P = 0.002 and HR 0.60, 95% CI: 0.36-0.99; P = 0.04, respectively). Patients with AJCC stage III or IV disease (HR 2.51, 95% CI: 1.50-4.20; P = 0.001), tumors larger than 8 cm (HR 2.17, 95% CI: 1.11-4.27; P = 0.046), metastatic disease at diagnosis (HR 3.25, 95% CI: 1.98-5.33; P chondrosarcoma is poor with a 5-year overall survival of 18%. Patients with a primary tumor located in the chest wall had a better prognosis. Tumors larger than 8 cm, presence of metastases at diagnosis, and treatment without surgical resection were significant predictors of mortality. © 2017 Wiley Periodicals, Inc.

  20. Incidence and survival of childhood leukemia in Recife, Brazil: A population-based analysis.

    Science.gov (United States)

    Lins, Mecneide Mendes; Santos, Marceli de Oliveira; de Albuquerque, Maria de Fátima Pessoa Militão; de Castro, Claudia Cristina Lima; Mello, Maria Julia Gonçalves; de Camargo, Beatriz

    2017-08-01

    Leukemia is the most common pediatric cancer with incidence rates of around 48 per million for children under 15 years of age. The median age-adjusted incidence rate (AAIR) in children aged 0-14 years in Brazil is 53.3 per million. While overall survival rates for children with leukemia have improved significantly, data for incidence, trends, and relative survival among children and adolescents with leukemia in Recife, Brazil, remain incomplete, which hampers our analyses and provision of the best healthcare. The objective of this report is to provide that data. Data from the Population-Based Cancer Registry of Recife were analyzed from 1998 to 2007. Our analyses included frequencies and AAIR, together with age-specific incidence rates for all leukemias, acute lymphoblastic leukemia, and acute myeloid leukemia. To evaluate incidence trends, joinpoint regression, including annual average percent change, were analyzed. Relative survival was calculated using the life-table method. One hundred seventy-five cases were identified, 51% in females. The review reduced the not otherwise specified (NOS) leukemia category by 50% and diagnosis by death certificate only from 5.7% to 1.1%. The AAIR for leukemia was 41.1 per million, with a peak among children aged 1-4 (78.3 per million). Incidence trends during the period were stable. The five-year relative survival rate was 69.8%. These data represent the incidence rate and survival of childhood leukemia in Recife, located in the northeast region of Brazil, using a high-quality database. © 2016 Wiley Periodicals, Inc.

  1. An online survival analysis tool to rapidly assess the effect of 22,277 genes on breast cancer prognosis using microarray data of 1,809 patients

    DEFF Research Database (Denmark)

    Györffy, B; Lanczky, A; Eklund, Aron Charles

    2010-01-01

    Validating prognostic or predictive candidate genes in appropriately powered breast cancer cohorts are of utmost interest. Our aim was to develop an online tool to draw survival plots, which can be used to assess the relevance of the expression levels of various genes on the clinical outcome both...... for the preliminary assessment of biomarkers, especially for research groups with limited bioinformatic resources.......Validating prognostic or predictive candidate genes in appropriately powered breast cancer cohorts are of utmost interest. Our aim was to develop an online tool to draw survival plots, which can be used to assess the relevance of the expression levels of various genes on the clinical outcome both...

  2. Survival analysis of the association between antenatal care attendance and neonatal mortality in 57 low- and middle-income countries.

    Science.gov (United States)

    Doku, David T; Neupane, Subas

    2017-10-01

    Neonatal mortality is unacceptably high in most low- and middle-income countries (LMICs). In these countries, where access to emergency obstetric services is limited, antenatal care (ANC) utilization offers improved maternal health and birth outcomes. However, evidence for this is scanty and mixed. We explored the association between attendance for ANC and survival of neonates in 57 LMICs. Employing standardized protocols to ensure comparison across countries, we used nationally representative cross-sectional data from 57 LMICs (N = 464 728) to investigate the association between ANC visits and neonatal mortality. Cox proportional hazards multivariable regression models and meta-regression analysis were used to analyse pooled data from the countries. Kaplan-Meier survival curves were used to describe the patterns of neonatal survival in each region. After adjusting for potential confounding factors, we found 55% lower risk of neonatal mortality [hazard ratio (HR) 0.45, 95% confidence interval (CI) 0.42-0.48] among women who met both WHO recommendations for ANC (first visit within the first trimester and at least four visits during pregnancy) in pooled analysis. Furthermore, meta-analysis of country-level risk shows 32% lower risk of neonatal mortality (HR 0.68, 95% CI 0.61-0.75) among those who met at least one WHO recommendation. In addition, ANC attendance was associated with lower neonatal mortality in all the regions except in the Middle East and North Africa. ANC attendance is protective against neonatal mortality in the LMICs studied, although differences exist across countries and regions. Increasing ANC visits, along with other known effective interventions, can improve neonatal survival in these countries.

  3. Computer aided analysis of breast MRI enhancement kinetics using mean shift c lustering and multifeature iterative region of interest selection

    NARCIS (Netherlands)

    Stoutjesdijk, M.J.; Zijp, M.; Hitge-Boetes, C.; Karssemeijer, N.; Barentsz, J.O.; Huisman, H.

    2012-01-01

    PURPOSE: To evaluate automatic characterization of a breast MR lesion by its spatially coherent region of interest (ROI). MATERIALS AND METHODS: The method delineated 247 enhancing lesions using Otsu thresholding after manually placing a sphere. Mean Shift Clustering subdivided each volume, based on

  4. Interest Convergence or Divergence? A Critical Race Analysis of Asian Americans, Meritocracy, and Critical Mass in the Affirmative Action Debate

    Science.gov (United States)

    Park, Julie J.; Liu, Amy

    2014-01-01

    We use the Critical Race Theory frameworks of interest convergence and divergence to critique the anti-affirmative action movement's co-option of Asian Americans. Past discussions of affirmative action and Asian Americans mainly concentrate on how Asian Americans are affected by affirmative action, whether positively or negatively. We demonstrate…

  5. A Self-Interest Analysis of Justice and Tax Compliance: How Distributive Justice Moderates the Effect of Outcome Favorability

    NARCIS (Netherlands)

    Verboon, Peter; van Dijke, Marius

    2008-01-01

    Compliance with tax authorities has been studied mainly in the fields of economics and psychology. The focus has respectively been on self-interest motives and justice concerns in tax compliance. We argue that both concerns are less divergent than is often thought. Specifically, we studied the

  6. The Relationship among Achievement Motivation Orientations, Achievement Goals, and Academic Achievement and Interest: A Multiple Mediation Analysis

    Science.gov (United States)

    Abd-El-Fattah, Sabry M.; Patrick, Rosan R.

    2011-01-01

    The aim of the present study is to examine the relationships among achievement motivation orientations and academic achievement and interest and whether achievement goals mediate these relationships. A sample of 503 students aged 14-16 years from 8 secondary schools in two Australia cities responded to a questionnaire package, comprising measures…

  7. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs

    National Research Council Canada - National Science Library

    Lucy Asher; Naomi D. Harvey; Martin Green; Gary C. W. England

    2017-01-01

    .... The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate...

  8. Survival analysis of patients with interval cancer undergoing gastric cancer screening by endoscopy.

    Directory of Open Access Journals (Sweden)

    Chisato Hamashima

    Full Text Available Interval cancer is a key factor that influences the effectiveness of a cancer screening program. To evaluate the impact of interval cancer on the effectiveness of endoscopic screening, the survival rates of patients with interval cancer were analyzed.We performed gastric cancer-specific and all-causes survival analyses of patients with screen-detected cancer and patients with interval cancer in the endoscopic screening group and radiographic screening group using the Kaplan-Meier method. Since the screening interval was 1 year, interval cancer was defined as gastric cancer detected within 1 year after a negative result. A Cox proportional hazards model was used to investigate the risk factors associated with gastric cancer-specific and all-causes death.A total of 1,493 gastric cancer patients (endoscopic screening group: n = 347; radiographic screening group: n = 166; outpatient group: n = 980 were identified from the Tottori Cancer Registry from 2001 to 2008. The gastric cancer-specific survival rates were higher in the endoscopic screening group than in the radiographic screening group and the outpatients group. In the endoscopic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer and the patients with interval cancer were nearly equal (P = 0.869. In the radiographic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer was higher than that of the patients with interval cancer (P = 0.009. For gastric cancer-specific death, the hazard ratio of interval cancer in the endoscopic screening group was 0.216 for gastric cancer death (95%CI: 0.054-0.868 compared with the outpatient group.The survival rate and the risk of gastric cancer death among the patients with screen-detected cancer and patients with interval cancer were not significantly different in the annual endoscopic screening. These results suggest the potential of endoscopic screening in

  9. How are clinical commissioning groups managing conflicts of interest under primary care co-commissioning in England? A qualitative analysis.

    Science.gov (United States)

    Moran, Valerie; Allen, Pauline; McDermott, Imelda; Checkland, Kath; Warwick-Giles, Lynsey; Gore, Oz; Bramwell, Donna; Coleman, Anna

    2017-11-08

    From April 2015, NHS England (NHSE) started to devolve responsibility for commissioning primary care services to clinical commissioning groups (CCGs). The aim of this paper is to explore how CCGs are managing potential conflicts of interest associated with groups of GPs commissioning themselves or their practices to provide services. We carried out two telephone surveys using a sample of CCGs. We also used a qualitative case study approach and collected data using interviews and meeting observations in four sites (CCGs). We conducted 57 telephone interviews and 42 face-to-face interviews with general practitioners (GPs) and CCG staff involved in primary care co-commissioning and observed 74 meetings of CCG committees responsible for primary care co-commissioning. Conflicts of interest were seen as an inevitable consequence of CCGs commissioning primary care. Particular problems arose with obtaining unbiased clinical input for new incentive schemes and providing support to GP provider federations. Participants in meetings concerning primary care co-commissioning declared conflicts of interest at the outset of meetings. Different approaches were pursued regarding GPs involvement in subsequent discussions and decisions with inconsistency in the exclusion of GPs from meetings. CCG senior management felt confident that the new governance structures and policies dealt adequately with conflicts of interest, but we found these arrangements face limitations. While the revised NHSE statutory guidance on managing conflicts of interest (2016) was seen as an improvement on the original (2014), there still remained some confusion over various terms and concepts contained therein. Devolving responsibility for primary care co-commissioning to CCGs created a structural conflict of interest. The NHSE statutory guidance should be refined and clarified so that CCGs can properly manage conflicts of interest. Non-clinician members of committees involved in commissioning primary care

  10. The impact of Bevacizumab (Avastin on survival in metastatic solid tumors--a meta-analysis and systematic review.

    Directory of Open Access Journals (Sweden)

    Limor Amit

    Full Text Available PURPOSE: To evaluate the effect of Bevacizumab in combination with chemotherapy on overall survival of patients with metastatic solid tumors. DESIGN: A systematic literature search to identify randomized trials comparing chemotherapy with and without Bevacizumab in metastatic cancer. The primary end point was overall survival (OS and the secondary end points were progression free survival (PFS and toxicity. A meta-analysis was performed for each tumor type and for the combination of all tumors. RESULTS: 24 randomized trials with 8 different types of malignancies were included in this meta-analysis. Patients treated with Bevacizumab had an OS benefit, hazard ratio (HR 0.89 (95% CI 0.84-0.93, P<0.00001 I(2-4%. The combined analysis showed a PFS benefit with a HR 0.71 (95% CI 0.68-0.74, P<0.00001, I(2-54%. The toxicity analysis showed a statistically significant increase in fatal adverse events (FAEs in the Bevacizumab treatment arm, risk ratio (RR 1.47 (95% CI 1.1-1.98. A separate analysis of the lung cancer trials showed an increased risk of fatal pulmonary hemorrhage with a RR of 5.65 (95% CI 1.26-25.26. The risk of G3-4 adverse events was increased: RR 1.2 (95% CI 1.15-1.24. CONCLUSION: in this combined analysis Bevacizumab improved OS (with little heterogeneity and PFS. These results should be considered in the light of lack of markers predictive of response and the increased severe and fatal toxicity seen with Bevacizumab treatment.

  11. Survival analysis of stochastic competitive models in a polluted environment and stochastic competitive exclusion principle.

    Science.gov (United States)

    Liu, Meng; Wang, Ke; Wu, Qiong

    2011-09-01

    Stochastic competitive models with pollution and without pollution are proposed and studied. For the first system with pollution, sufficient criteria for extinction, nonpersistence in the mean, weak persistence in the mean, strong persistence in the mean, and stochastic permanence are established. The threshold between weak persistence in the mean and extinction for each population is obtained. It is found that stochastic disturbance is favorable for the survival of one species and is unfavorable for the survival of the other species. For the second system with pollution, sufficient conditions for extinction and weak persistence are obtained. For the model without pollution, a partial stochastic competitive exclusion principle is derived. © Society for Mathematical Biology 2010

  12. Best lung function equations for the very elderly selected by survival analysis

    DEFF Research Database (Denmark)

    Miller, Martin R; Thinggaard, Mikael; Christensen, Kaare

    2014-01-01

    proportional hazard regression found lower FEV1SR was a predictor of mortality having controlled for MMSE, grip strength and sex. The US National Health and Nutrition Examination Survey (NHANES) III (1999) equations gave a better spread of median survival by FEV1SR quartile: 3.94, 3.65, 3.51 and 2.61 years...... with a hazard ratio for death of 1, 1.16, 1.32 and 1.60 respectively, compared with equations derived with the inclusion of elderly subjects.We conclude that extrapolating from NHANES III equations to predict lung function in nonagenarians gave better survival predictions from spirometry than when employing...... equations derived using very elderly subjects with possible selection bias. These findings can help inform how future lung function equations for the elderly are derived....

  13. Impact of renal allograft nephrectomy on graft and patient survival following retransplantation: a systematic review and meta-analysis.

    Science.gov (United States)

    Lin, Jinwen; Wang, Rending; Xu, Ying; Chen, Jianghua

    2018-02-12

    It is not clear whether renal allograft removal affects the outcome of renal retransplantation. This study aimed to determine the effect of allograft nephrectomy (AN) and no-AN (No AN) on renal retransplantation. A systematic review and meta-analysis were conducted using MEDLINE, Embase and the Cochrane Library. Observational studies or randomized controlled trials including renal retransplantation recipients with AN or No-AN were included. The primary outcomes were graft survival, patient survival, acute rejection (AR) and delayed graft dysfunction; the secondary outcomes were positive panel reactive antibody rate and serum creatinine level at 1 year after retransplantation, cold ischemia time and time of hemodialysis before recent transplantation. Pooled estimates of odds ratios (ORs) and the weighted mean difference for outcomes were calculated. A total of 13 studies divided into 20 trials including 1923 patients were analyzed. The No-AN group had a significantly higher 3-year graft survival rate {OR 0.48 [95% confidence interval (CI) 0.34-0.69], 10 studies, n = 1030} and 5-year graft survival rate [OR 0.65 (95% CI 0.44-0.97), 16 studies, n = 1878] than the AN group. The rates of 5-year patient survival [OR 1.82 (95% CI 1.14-2.90), 5 studies, n = 749], positive panel reactive antibody [OR 3.08 (95% CI 2.08-4.56), 12 studies, n = 1225], AR [OR 1.59 (95% CI 1.21-2.09), 15 studies, n = 1388] and delayed graft dysfunction [OR 1.66 (95% CI 1.20-2.03), 8 studies, n = 879] were all significantly higher in the AN group. Compared with the No-AN group, cold ischemia time was longer in the AN group [weighted mean difference 1.84 (95% CI 0.90-2.79), 7 studies, n = 919]. The rate of 1-year graft survival and 10-year graft survival, serum creatinine levels at 1 year after retransplantation and the time of hemodialysis before recent transplantation were similar between the AN and No-AN groups. We recommend allowing the failed graft to remain unless

  14. Long-term outcome after discontinuation of benzodiazepines for insomnia: a survival analysis of relapse.

    Science.gov (United States)

    Morin, Charles M; Bélanger, Lynda; Bastien, Célyne; Vallières, Annie

    2005-01-01

    Discontinuation of benzodiazepine (BZD) treatment for insomnia can be a difficult task. Cognitive-behavior therapy (CBT) for insomnia, combined with a supervised medication taper, can facilitate withdrawal but there is limited evidence on long-term outcome after discontinuation. The objective of this study was to examine medication-free survival time and predictors of relapse (i.e., resumed BZD hypnotics) over a 2-year period in 47 older adults (mean age 62.1 years) with persistent insomnia and prolonged BZD use (average duration of 18.9 years), who had successfully discontinued BZD following CBT for insomnia, a supervised medication taper program, or a combined approach. The Kaplan-Meier product-limit method was used to estimate survival time, defined as time between end-of-treatment and relapse or end of follow-up. By the end of the 24-month follow-up, 42.6% of the samples had resumed BZD use. Participants in the Combined (33.3%) and Taper (30.8%) groups relapsed significantly less than their counterparts from the CBT group (69.2%). Survival rates at 3 months were 61.5% (CBT), 100% (Taper), and 80.9% (Combined). At 12 months, they were 38.5%, 83.3%, and 70.8%, respectively; and, at 24 months, they were 28.9%, 64.8% and 64.9%, respectively. Mean survival time was significantly longer for both the Taper (18.6 months, SE = 2.1) and Combined groups (12.6 months, SE = 1.4), relative to the CBT group (8.5 months, SE = 1.8). Significant predictors of relapse included treatment condition, end of treatment insomnia severity, and psychological distress. In conclusion, there is a substantial relapse rate following BZD discontinuation among prolonged users. CBT booster sessions might enhance compliance with CBT and prove useful in preventing relapse.

  15. A survival analysis using physique-adjusted tumor size of non-small cell lung cancer.

    Science.gov (United States)

    Ozeki, Naoki; Fukui, Takayuki; Kawaguchi, Koji; Nakamura, Shota; Hakiri, Shuhei; Kato, Taketo; Hirakawa, Akihiro; Yokoi, Kohei

    2017-11-29

    Differences in individual body sizes have not been well considered when analyzing the survival of patients with non-small cell lung cancer (NSCLC). We hypothesized that physique-adjusted tumor size is superior to actual tumor size in predicting the prognosis. Eight hundred and forty-two patients who underwent R0 resection of NSCLC between 2005 and 2012 were retrospectively reviewed, and overall survival (OS) was evaluated. The physique-adjusted tumor size was defined as: x-adjusted tumor size = tumor size × mean value of x/individual value of x [x = height, weight, body surface area (BSA), or body mass index (BMI)]. Tumor size category was defined as ≤2, 2-3, 3-5, 5-7, and >7 cm. The separation index (SEP), which is the weighted mean of the absolute value of estimated regression coefficients over the subgroups with respect to a reference group, was used to measure the separation of subgroups. The mean values of height, weight, BSA, and BMI were 160.7 cm, 57.6 kg, 1.59 m2, and 22.2 kg/m2, respectively. The 5-year survival rates ranged from 88-59% in the non-adjusted tumor size model (SEP 1.937), from 90-57% in the height-adjusted model (SEP 2.236), from 91-52% in the weight-adjusted model (SEP 2.146), from 90-56% in the BSA-adjusted model (SEP 2.077), and from 91-51% in the BMI-adjusted model (SEP 2.169). The physique-adjusted tumor size can separate the survival better than the actual tumor size.

  16. Retrospective Analysis of the Survival Benefit of Induction Chemotherapy in Stage IVa-b Nasopharyngeal Carcinoma

    OpenAIRE

    Xiao-Wen Lan; Xue-Bin Zou; Yao Xiao; Jie Tang; Pu-Yun OuYang; Zhen Su; Fang-Yun Xie

    2016-01-01

    Purpose The value of adding induction chemotherapy to chemoradiotherapy in locoregionally advanced nasopharyngeal carcinoma (LA-NPC) remains controversial, yet high-risk patients with LA-NPC have poor outcomes after chemoradiotherapy. We aimed to assess the survival benefits of induction chemotherapy in stage IVa-b NPC. Patients and Methods A total of 602 patients with stage IVa-b NPC treated with intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy with or without inducti...

  17. Mediation Analysis with Survival Outcomes: Accelerated Failure Time Versus Proportional Hazards Models

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    Lois A Gelfand

    2016-03-01

    Full Text Available Objective: Survival time is an important type of outcome variable in treatment research. Currently, limited guidance is available regarding performing mediation analyses with survival outcomes, which generally do not have normally distributed errors, and contain unobserved (censored events. We present considerations for choosing an approach, using a comparison of semi-parametric proportional hazards (PH and fully parametric accelerated failure time (AFT approaches for illustration.Method: We compare PH and AFT models and procedures in their integration into mediation models and review their ability to produce coefficients that estimate causal effects. Using simulation studies modeling Weibull-distributed survival times, we compare statistical properties of mediation analyses incorporating PH and AFT approaches (employing SAS procedures PHREG and LIFEREG, respectively under varied data conditions, some including censoring. A simulated data set illustrates the findings.Results: AFT models integrate more easily than PH models into mediation models. Furthermore, mediation analyses incorporating LIFEREG produce coefficients that can estimate causal effects, and demonstrate superior statistical properties. Censoring introduces bias in the coefficient estimate representing the treatment effect on outcome – underestimation in LIFEREG, and overestimation in PHREG. With LIFEREG, this bias can be addressed using an alternative estimate obtained from combining other coefficients, whereas this is not possible with PHREG.Conclusions: When Weibull assumptions are not violated, there are compelling advantages to using LIFEREG over PHREG for mediation analyses involving survival-time outcomes. Irrespective of the procedures used, the interpretation of coefficients, effects of censoring on coefficient estimates, and statistical properties should be taken into account when reporting results.

  18. Chemoembolization for Hepatocellular Carcinoma: Comprehensive Imaging and Survival Analysis in a 172-Patient Cohort 1

    Science.gov (United States)

    Lewandowski, Robert J.; Mulcahy, Mary F.; Kulik, Laura M.; Riaz, Ahsun; Ryu, Robert K.; Baker, Talia B.; Ibrahim, Saad M.; Abecassis, Michael I.; Miller, Frank H.; Sato, Kent T.; Senthilnathan, Seanthan; Resnick, Scott A.; Wang, Edward; Gupta, Ramona; Chen, Richard; Newman, Steven B.; Chrisman, Howard B.; Nemcek, Albert A.; Vogelzang, Robert L.; Omary, Reed A.; Benson, Al B.

    2010-01-01

    Purpose: To determine comprehensive imaging and long-term survival outcome following chemoembolization for hepatocellular carcinoma (HCC). Materials and Methods: One hundred seventy-two patients with HCC treated with chemoembolization were studied retrospectively in an institutional review board approved protocol; this study was HIPAA compliant. Baseline laboratory and imaging characteristics were obtained. Clinical and laboratory toxicities following treatment were assessed. Imaging characteristics following chemoembolization were evaluated to determine response rates (size and necrosis) and time to progression (TTP). Survival from the time of first chemoembolization treatment was calculated. Subanalyses were performed by stratifying the population according to Child-Pugh, United Network for Organ Sharing, and Barcelona Clinic for Liver Cancer (BCLC) staging systems. Results: Cirrhosis was present in 157 patients (91%); portal hypertension was present in 139 patients (81%). Eleven patients (6%) had metastases at baseline. Portal vein thrombosis was present in 11 patients (6%). Fifty-five percent of patients experienced some form of toxicity following treatment; 21% developed grade 3 or 4 bilirubin toxicity. Post-chemoembolization response was seen in 31% and 64% of patients according to size and necrosis criteria, respectively. Median TTP was 7.9 months (95% confidence interval: 7.1, 9.4) but varied widely by stage. Median survival was significantly different between patients with BCLC stages A, B, and C disease (stage A, 40.0 months; B, 17.4 months; C, 6.3 months; P < .0001). Conclusion: The determination of TTP and survival in patients with HCC is confounded by tumor biology and background cirrhosis; chemoembolization was shown to be a safe and effective therapy in patients with HCC. © RSNA, 2010 PMID:20501733

  19. Chemoembolization for hepatocellular carcinoma: comprehensive imaging and survival analysis in a 172-patient cohort.

    Science.gov (United States)

    Lewandowski, Robert J; Mulcahy, Mary F; Kulik, Laura M; Riaz, Ahsun; Ryu, Robert K; Baker, Talia B; Ibrahim, Saad M; Abecassis, Michael I; Miller, Frank H; Sato, Kent T; Senthilnathan, Seanthan; Resnick, Scott A; Wang, Edward; Gupta, Ramona; Chen, Richard; Newman, Steven B; Chrisman, Howard B; Nemcek, Albert A; Vogelzang, Robert L; Omary, Reed A; Benson, Al B; Salem, Riad

    2010-06-01

    To determine comprehensive imaging and long-term survival outcome following chemoembolization for hepatocellular carcinoma (HCC). One hundred seventy-two patients with HCC treated with chemoembolization were studied retrospectively in an institutional review board approved protocol; this study was HIPAA compliant. Baseline laboratory and imaging characteristics were obtained. Clinical and laboratory toxicities following treatment were assessed. Imaging characteristics following chemoembolization were evaluated to determine response rates (size and necrosis) and time to progression (TTP). Survival from the time of first chemoembolization treatment was calculated. Subanalyses were performed by stratifying the population according to Child-Pugh, United Network for Organ Sharing, and Barcelona Clinic for Liver Cancer (BCLC) staging systems. Cirrhosis was present in 157 patients (91%); portal hypertension was present in 139 patients (81%). Eleven patients (6%) had metastases at baseline. Portal vein thrombosis was present in 11 patients (6%). Fifty-five percent of patients experienced some form of toxicity following treatment; 21% developed grade 3 or 4 bilirubin toxicity. Post-chemoembolization response was seen in 31% and 64% of patients according to size and necrosis criteria, respectively. Median TTP was 7.9 months (95% confidence interval: 7.1, 9.4) but varied widely by stage. Median survival was significantly different between patients with BCLC stages A, B, and C disease (stage A, 40.0 months; B, 17.4 months; C, 6.3 months; P < .0001). The determination of TTP and survival in patients with HCC is confounded by tumor biology and background cirrhosis; chemoembolization was shown to be a safe and effective therapy in patients with HCC. Copyright RSNA, 2010

  20. Yttrium-90 radioembolization for intrahepatic cholangiocarcinoma: safety, response, and survival analysis.

    Science.gov (United States)

    Mouli, Samdeep; Memon, Khairuddin; Baker, Talia; Benson, Al B; Mulcahy, Mary F; Gupta, Ramona; Ryu, Robert K; Salem, Riad; Lewandowski, Robert J

    2013-08-01

    To present data on safety, antitumoral response, and survival following yttrium-90 ((90)Y) radioembolization for patients with unresectable intrahepatic cholangiocarcinoma (ICC). The present study expands on the cohort of 24 patients with ICC described in a pilot study, and includes 46 patients treated with (90)Y radioembolization at a single institution during an 8-year period. Via retrospective review of a prospectively collected database, patients were stratified by performance status, tumor distribution (solitary or multifocal), tumor morphology (infiltrative or peripheral), and presence/absence of portal vein thrombosis. Primary endpoints included biochemical and clinical toxicities, and secondary endpoints included imaging response (World Health Organization [WHO] and European Association for the Study of Liver Disease [EASL] criteria) and survival. Uni-/multivariate analyses were performed. Ninety-two treatments were performed, with a mean of two per patient. Fatigue and transient abdominal pain occurred in 25 patients (54%) and 13 patients (28%), respectively. Treatment-related gastroduodenal ulcer developed in one patient (2%). WHO imaging findings included partial response (n = 11; 25%), stable disease (n = 33; 73%), and progressive disease (n = 1; 2%). EASL imaging findings included partial/complete response (n = 33; 73%) and stable disease (n = 12; 27%). Survival varied based on presence of multifocal (5.7 mo vs 14.6 mo), infiltrative (6.1 mo vs 15.6 mo), and bilobar disease (10.9 mo vs 11.7 mo). Disease was converted to resectable status in five patients, who successfully underwent curative (ie, R0) resection. Radioembolization with (90)Y is safe and demonstrates antitumoral response and survival benefit in select patients with ICC. Results are most pronounced in patients with solitary tumors, for whom conversion to curative resection is possible. Copyright © 2013 SIR. Published by Elsevier Inc. All rights reserved.

  1. Survival benefits of antiretroviral therapy in Brazil: a model-based analysis

    Science.gov (United States)

    Luz, Paula M; Girouard, Michael P; Grinsztejn, Beatriz; Freedberg, Kenneth A; Veloso, Valdilea G; Losina, Elena; Struchiner, Claudio J; MacLean, Rachel L; Parker, Robert A; Paltiel, A David; Walensky, Rochelle P

    2016-01-01

    Objective In Brazil, universal provision of antiretroviral therapy (ART) has been guaranteed free of charge to eligible HIV-positive patients since December 1996. We sought to quantify the survival benefits of ART attributable to this programme. Methods We used a previously published microsimulation model of HIV disease and treatment (CEPAC-International) and data from Brazil to estimate life expectancy increase for HIV-positive patients initiating ART in Brazil. We divided the period of 1997 to 2014 into six eras reflecting increased drug regimen efficacy, regimen availability and era-specific mean CD4 count at ART initiation. Patients were simulated first without ART and then with ART. The 2014-censored and lifetime survival benefits attributable to ART in each era were calculated as the product of the number of patients initiating ART in a given era and the increase in life expectancy attributable to ART in that era. Results In total, we estimated that 598,741 individuals initiated ART. Projected life expectancy increased from 2.7, 3.3, 4.1, 4.9, 5.5 and 7.1 years without ART to 11.0, 17.5, 20.7, 23.0, 25.3, and 27.0 years with ART in Eras 1 through 6, respectively. Of the total projected lifetime survival benefit of 9.3 million life-years, 16% (or 1.5 million life-years) has been realized as of December 2014. Conclusions Provision of ART through a national programme has led to dramatic survival benefits in Brazil, the majority of which are still to be realized. Improvements in initial and subsequent ART regimens and higher CD4 counts at ART initiation have contributed to these increasing benefits. PMID:27029828

  2. Time of Arrival Analysis in NC DETECT to Find Clusters of Interest from Unclassified Patient Visit Records

    Science.gov (United States)

    Li, Meichun; Loschen, Wayne; Deyneka, Lana; Burkom, Howard; Ising, Amy; Waller, Anna

    2013-01-01

    Objective To describe a collaboration with the Johns Hopkins Applied Physics Laboratory (JHU APL), the North Carolina Division of Public Health (NC DPH), and the UNC Department of Emergency Medicine Carolina Center for Health Informatics (CCHI) to implement time-of-arrival analysis (TOA) for hospital emergency department (ED) data in NC DETECT to identify clusters of ED visits for which there is no pre-defined syndrome or sub-syndrome. Introduction TOA identifies clusters of patients arriving to a hospital ED within a short temporal interval. Past implementations have been restricted to records of patients with a specific type of complaint. The Florida Department of Health uses TOA at the county level for multiple sub-syndromes (1). In 2011, NC DPH, CCHI and CDC collaborated to enhance and evaluate this capability for NC DETECT, using NC DETECT data in BioSense 1.0 (2). After this successful evaluation based on exposure complaints, discussions were held to determine the best approach to implement this new algorithm into the production environment for NC DETECT. NC DPH was particularly interested in determining if TOA could be used for identifying clusters of ED visits not filtered by any syndrome or sub-syndrome. In other words, can TOA detect a cluster of ED visits relating to a public health event, even if symptoms from that event are not characterized by a predefined syndrome grouping? Syndromes are continuously added to NC DETECT but a syndrome cannot be created for every potential event of public health concern. This TOA approach is the first attempt to address this issue in NC DETECT. The initial goal is to identify clusters of related ED visits whose keywords, signs and/or symptoms are NOT all expressed by a traditional syndrome, e.g. rash, gastrointestinal, and flu-like illnesses. The goal instead is to identify clusters resulting from specific events or exposures regardless of how patients present – event concepts that are too numerous to pre

  3. SurvExpress: an online biomarker validation tool and database for cancer gene expression data using survival analysis.

    Directory of Open Access Journals (Sweden)

    Raul Aguirre-Gamboa

    Full Text Available Validation of multi-gene biomarkers for clinical outcomes is one of the most important issues for cancer prognosis. An important source of information for virtual validation is the high number of available cancer datasets. Nevertheless, assessing the prognostic performance of a gene expression signature along datasets is a difficult task for Biologists and Physicians and also time-consuming for Statisticians and Bioinformaticians. Therefore, to facilitate performance comparisons and validations of survival biomarkers for cancer outcomes, we developed SurvExpress, a cancer-wide gene expression database with clinical outcomes and a web-based tool that provides survival analysis and risk assessment of cancer datasets. The main input of SurvExpress is only the biomarker gene list. We generated a cancer database collecting more than 20,000 samples and 130 datasets with censored clinical information covering tumors over 20 tissues. We implemented a web interface to perform biomarker validation and comparisons in this database, where a multivariate survival analysis can be accomplished in about one minute. We show the utility and simplicity of SurvExpress in two biomarker applications for breast and lung cancer. Compared to other tools, SurvExpress is the largest, most versatile, and quickest free tool available. SurvExpress web can be accessed in http://bioinformatica.mty.itesm.mx/SurvExpress (a tutorial is included. The website was implemented in JSP, JavaScript, MySQL, and R.

  4. Bayesian Analysis of the Survival Function and Failure Rate of Weibull Distribution with Censored Data

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    Chris Bambey Guure

    2012-01-01

    Full Text Available The survival function of the Weibull distribution determines the probability that a unit or an individual will survive beyond a certain specified time while the failure rate is the rate at which a randomly selected individual known to be alive at time will die at time (. The classical approach for estimating the survival function and the failure rate is the maximum likelihood method. In this study, we strive to determine the best method, by comparing the classical maximum likelihood against the Bayesian estimators using an informative prior and a proposed data-dependent prior known as generalised noninformative prior. The Bayesian estimation is considered under three loss functions. Due to the complexity in dealing with the integrals using the Bayesian estimator, Lindley’s approximation procedure is employed to reduce the ratio of the integrals. For the purpose of comparison, the mean squared error (MSE and the absolute bias are obtained. This study is conducted via simulation by utilising different sample sizes. We observed from the study that the generalised prior we assumed performed better than the others under linear exponential loss function with respect to MSE and under general entropy loss function with respect to absolute bias.

  5. [Survival analysis for patients with severe motor and intellectual disabilities following tracheotomy].

    Science.gov (United States)

    Maruyama, Koichi; Kurahashi, Hirokazu; Suzuki, Motomasa; Miura, Kiyokuni; Kumagai, Toshiyuki

    2012-01-01

    To investigate the survival rate and causes of death in patients with severe motor and intellectual disabilities (SMIDs) that necessitated tracheotomy, we retrospectively analyzed 90 patients who underwent tracheotomy between 1990 and 2009. Indications for tracheotomy in these patients were upper airway obstruction (44 patients), recurrent aspiration pneumonia (28 patients), retained secretions (23 patients), prolonged mechanical ventilation (18 patients), chronic respiratory failure (9 patients), central respiratory failure (5 patients), and gastroesophageal reflux (8 patients). Most of the patients underwent tracheotomy at the age of 0-5 years or 10-19 years. As of April 1, 2010, 28 patients had died. The survival rate was 0.91 at 1 year, 0.74 at 5 years, 0.59 at 10 years, 0.54 at 15 years, and 0.40 at 19 years after tracheotomy. Massive tracheal bleeding due to development of tracheo-innominate artery fistulas occurred in 5 patients, and 4 of them died. They were thirteen years of age or older when they underwent tracheotomy, and developed fistulas after 2 weeks or later. In contrast, 7 patients at high risk for fistula formation, including those that had developed severe tracheomalacia associated with granulation or warning hemorrhages, underwent preventive resection of the innominate artery, and all of them had survived. It is important to regularly evaluate patients with SMIDs who have undergone tracheotomy by using bronchofiberscopy to identify risk factors for tracheoinnominate artery fistulas, a preventable cause of death.

  6. Survival analysis of metal crowns versus restorations in primary mandibular molars.

    Science.gov (United States)

    Maupomé, Gerardo; Yepes, Juan F; Galloway, Madison; Tang, Qing; Eckert, George J; Downey, Timothy; Vinson, LaQuia

    2017-10-01

    The effectiveness of stainless steel crowns (SSCs) versus direct restorations when placed in primary mandibular molars (teeth nos. L and S) is uncertain. The authors evaluated effectiveness by gauging longevity of treatment. The authors obtained private dental insurance claims (2004-2016) from a national dental data warehouse. Paid insurance claims records (n = 1,323,489) included type of treating dentist, treatment placed, and patient age. Dentist specialty, type of treatment, and patient age were significant in predicting failure after the first restoration. The authors found high survival rates for all treatments (> 90%) after 5 years; however, as soon as within 3 years after treatment, SCCs had approximately 6% better survival. Teeth nos. L and S first treated with SSCs lasted longer without new treatment compared with teeth first treated with direct restorations; the difference was small. Teeth treated by pediatric dentists had better survival rates. Primary mandibular first molars initially treated with SSCs lasted longer without new treatment compared with direct restorations. Overall dental care costs of the former were considerably higher. Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.

  7. The effect of statins on average survival in randomised trials, an analysis of end point postponement.

    Science.gov (United States)

    Kristensen, Malene Lopez; Christensen, Palle Mark; Hallas, Jesper

    2015-09-24

    To estimate the average postponement of death in statin trials. A systematic literature review of all statin trials that presented all-cause survival curves for treated and untreated. Statin treatment compared to placebo. The average postponement of death as represented by the area between the survival curves. 6 studies for primary prevention and 5 for secondary prevention with a follow-up between 2.0 and 6.1 years were identified. Death was postponed between -5 and 19 days in primary prevention trials and between -10 and 27 days in secondary prevention trials. The median postponement of death for primary and secondary prevention trials were 3.2 and 4.1 days, respectively. Statin treatment results in a surprisingly small average gain in overall survival within the trials' running time. For patients whose life expectancy is limited or who have adverse effects of treatment, withholding statin therapy should be considered. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Comparative transcriptome analysis quantifies immune cell transcript levels, metastatic progression and survival in osteosarcoma.

    Science.gov (United States)

    Scott, Milcah C; Temiz, Nuri A; Sarver, Anne E; LaRue, Rebecca S; Rathe, Susan K; Varshney, Jyotika; Wolf, Natalie K; Moriarity, Branden S; O'Brien, Timothy D; Spector, Logan G; Largaespada, David A; Modiano, Jaime F; Subramanian, Subbaya; Sarver, Aaron L

    2017-10-24

    Overall survival of patients with osteosarcoma (OS) has improved little in the past three decades and better models for study are needed. OS is common in large dog breeds and is genetically inducible in mice, making the disease ideal for comparative genomic analyses across species. Understanding the level of conservation of inter-tumor transcriptional variation across species and how it is associated with progression to metastasis will enable us to more efficiently develop effective strategies to manage OS and improve therapy. In this study, transcriptional profiles of OS tumors and cell lines derived from humans (n=49), mice (n=103) and dogs (n=34) were generated using RNA-sequencing. Conserved inter-tumor transcriptional variation was present in tumor sets from all three species and comprised gene clusters associated with cell cycle and mitosis and with the presence or absence of immune cells. Further, we developed a novel Gene Cluster Expression Summary Score (GCESS) to quantify inter-tumor transcriptional variation and demonstrated that these GCESS values associated with patient outcome. Human OS tumors with GCESS values suggesting decreased immune cell presence were associated with metastasis and poor survival. We validated these results in an independent human OS tumor cohort and in 15 different tumor data sets obtained from The Cancer Genome Atlas (TCGA). Our results suggest that quantification of immune cell absence and tumor cell proliferation may better inform therapeutic decisions and improve overall survival for OS patients. Copyright ©2017, American Association for Cancer Research.

  9. Electrolyte Disturbances Are Associated with Non-Survival in Dogs—A Multivariable Analysis

    Directory of Open Access Journals (Sweden)

    Robert Goggs

    2017-08-01

    Full Text Available Electrolyte disorders have been individually associated with mortality in small populations of dogs and cats with specific conditions, but the associations and interactions between electrolyte disturbances and outcome have not been evaluated in a large, heterogeneous population. It was hypothesized that abnormalities of sodium, chloride, potassium, and calcium concentrations would be independently and proportionately associated with death from natural causes and with all-cause mortality in dogs. An electronic database containing 33,117 electrolyte profiles was constructed to retrospectively assess the association between disorders of sodium, potassium, corrected chloride, and ionized calcium concentrations with non-survival and with death excluding euthanasia by multivariable modeling. A second database containing 11,249 records was used to validate the models constructed from the first database. All four electrolytes assessed had non-linear U-shaped associations with case fatality rates, wherein concentrations clustered around the reference interval had the lowest case fatality rates, while progressively abnormal concentrations were associated with proportionately increased risk of non-survival (AUROC 0.624 or death (AUROC 0.678. Multivariable modeling suggested that these electrolyte disturbances were associated with non-survival and with death from natural causes independent of each other. This study suggests that measurement of electrolyte concentrations is an important component of the assessment of dogs in emergency rooms or intensive care units. Future studies should focus on confirming these associations in a prospective manner accounting for disease severity.

  10. Cabozantinib versus everolimus, nivolumab, axitinib, sorafenib and best supportive care: A network meta-analysis of progression-free survival and overall survival in second line treatment of advanced renal cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Billy Amzal

    Full Text Available Relative effect of therapies indicated for the treatment of advanced renal cell carcinoma (aRCC after failure of first line treatment is currently not known. The objective of the present study is to evaluate progression-free survival (PFS and overall survival (OS of cabozantinib compared to everolimus, nivolumab, axitinib, sorafenib, and best supportive care (BSC in aRCC patients who progressed after previous VEGFR tyrosine-kinase inhibitor (TKI treatment.Systematic literature search identified 5 studies for inclusion in this analysis. The assessment of the proportional hazard (PH assumption between the survival curves for different treatment arms in the identified studies showed that survival curves in two of the studies did not fulfil the PH assumption, making comparisons of constant hazard ratios (HRs inappropriate. Consequently, a parametric survival network meta-analysis model was implemented with five families of functions being jointly fitted in a Bayesian framework to PFS, then OS, data on all treatments. The comparison relied on data digitized from the Kaplan-Meier curves of published studies, except for cabozantinib and its comparator everolimus where patient level data were available. This analysis applied a Bayesian fixed-effects network meta-analysis model to compare PFS and OS of cabozantinib versus its comparators. The log-normal fixed-effects model displayed the best fit of data for both PFS and OS, and showed that patients on cabozantinib had a higher probability of longer PFS and OS than patients exposed to comparators. The survival advantage of cabozantinib increased over time for OS. For PFS the survival advantage reached its maximum at the end of the first year's treatment and then decreased over time to zero.With all five families of distributions, cabozantinib was superior to all its comparators with a higher probability of longer PFS and OS during the analyzed 3 years, except with the Gompertz model, where nivolumab was

  11. Analysis of feedbacks between nucleation rate, survival probability and cloud condensation nuclei formation

    Science.gov (United States)

    Westervelt, D. M.; Pierce, J. R.; Adams, P. J.

    2014-06-01

    Aerosol nucleation is an important source of particle number in the atmosphere. However, in order to become cloud condensation nuclei (CCN), freshly nucleated particles must undergo significant condensational growth while avoiding coagulational scavenging. In an effort to quantify the contribution of nucleation to CCN, this work uses the GEOS-Chem-TOMAS global aerosol model to calculate changes in CCN concentrations against a broad range of nucleation rates and mechanisms. We then quantify the factors that control CCN formation from nucleation, including daily nucleation rates, growth rates, coagulation sinks, condensation sinks, survival probabilities, and CCN formation rates, in order to examine feedbacks that may limit growth of nucleated particles to CCN. Nucleation rate parameterizations tested in GEOS-Chem-TOMAS include ternary nucleation (with multiple tuning factors), activation nucleation (with two pre-factors), binary nucleation, and ion-mediated nucleation. We find that nucleation makes a significant contribution to boundary layer CCN(0.2%), but this contribution is only modestly sensitive to the choice of nucleation scheme, ranging from 49 to 78% increase in concentrations over a control simulation with no nucleation. Moreover, a two order-of-magnitude increase in the globally averaged nucleation rate (via changes to tuning factors) results in small changes (less than 10%) to global CCN(0.2%) concentrations. To explain this, we present a simple theory showing that survival probability has an exponentially decreasing dependence on the square of the condensation sink. This functional form stems from a negative correlation between condensation sink and growth rate and a positive correlation between condensation sink and coagulational scavenging. Conceptually, with a fixed condensable vapor budget (sulfuric acid and organics), any increase in CCN concentrations due to higher nucleation rates necessarily entails an increased aerosol surface area in the

  12. Gene-gene interaction analysis for the survival phenotype based on the Cox model.

    Science.gov (United States)

    Lee, Seungyeoun; Kwon, Min-Seok; Oh, Jung Mi; Park, Taesung

    2012-09-15

    For the past few decades, many statistical methods in genome-wide association studies (GWAS) have been developed to identify SNP-SNP interactions for case-control studies. However, there has been less work for prospective cohort studies, involving the survival time. Recently, Gui et al. (2011) proposed a novel method, called Surv-MDR, for detecting gene-gene interactions associated with survival time. Surv-MDR is an extension of the multifactor dimensionality reduction (MDR) method to the survival phenotype by using the log-rank test for defining a binary attribute. However, the Surv-MDR method has some drawbacks in the sense that it needs more intensive computations and does not allow for a covariate adjustment. In this article, we propose a new approach, called Cox-MDR, which is an extension of the generalized multifactor dimensionality reduction (GMDR) to the survival phenotype by using a martingale residual as a score to classify multi-level genotypes as high- and low-risk groups. The advantages of Cox-MDR over Surv-MDR are to allow for the effects of discrete and quantitative covariates in the frame of Cox regression model and to require less computation than Surv-MDR. Through simulation studies, we compared the power of Cox-MDR with those of Surv-MDR and Cox regression model for various heritability and minor allele frequency combinations without and with adjusting for covariate. We found that Cox-MDR and Cox regression model perform better than Surv-MDR for low minor allele frequency of 0.2, but Surv-MDR has high power for minor allele frequency of 0.4. However, when the effect of covariate is adjusted for, Cox-MDR and Cox regression model perform much better than Surv-MDR. We also compared the performance of Cox-MDR and Surv-MDR for a real data of leukemia patients to detect the gene-gene interactions with the survival time. leesy@sejong.ac.kr; tspark@snu.ac.kr.

  13. Child survival gains in Tanzania: analysis of data from demographic and health surveys.

    Science.gov (United States)

    Masanja, Honorati; de Savigny, Don; Smithson, Paul; Schellenberg, Joanna; John, Theopista; Mbuya, Conrad; Upunda, Gabriel; Boerma, Ties; Victora, Cesar; Smith, Tom; Mshinda, Hassan

    2008-04-12

    A recent national survey in Tanzania reported that mortality in children younger than 5 years dropped by 24% over the 5 years between 2000 and 2004. We aimed to investigate yearly changes to identify what might have contributed to this reduction and to investigate the prospects for meeting the Millennium Development Goal for child survival (MDG 4). We analysed data from the four demographic and health surveys done in Tanzania since 1990 to generate estimates of mortality in children younger than 5 years for every 1-year period before each survey back to 1990. We estimated trends in mortality between 1990 and 2004 by fitting Lowess regression, and forecasted trends in mortality in 2005 to 2015. We aimed to investigate contextual factors, whether part of Tanzania's health system or not, that could have affected child mortality. Disaggregated estimates of mortality showed a sharp acceleration in the reduction in mortality in children younger than 5 years in Tanzania between 2000 and 2004. In 1990, the point estimate of mortality was 141.5 (95% CI 141.5-141.5) deaths per 1000 livebirths. This was reduced by 40%, to reach a point estimate of 83.2 (95% CI 70.1-96.3) deaths per 1000 livebirths in 2004. The change in absolute risk was 58.4 (95% CI 32.7-83.8; p<0.0001). Between 1999 and 2004 we noted important improvements in Tanzania's health system, including doubled public expenditure on health; decentralisation and sector-wide basket funding; and increased coverage of key child-survival interventions, such as integrated management of childhood illness, insecticide-treated nets, vitamin A supplementation, immunisation, and exclusive breastfeeding. Other determinants of child survival that are not related to the health system did not change between 1999 and 2004, except for a slow increase in the HIV/AIDS burden. Tanzania could attain MDG 4 if this trend of improved child survival were to be sustained. Investment in health systems and scaling up interventions can produce

  14. Analysis of the Capacity of Google Trends to Measure Interest in Conservation Topics and the Role of Online News.

    Directory of Open Access Journals (Sweden)

    Le T P Nghiem

    Full Text Available With the continuous growth of internet usage, Google Trends has emerged as a source of information to investigate how social trends evolve over time. Knowing how the level of interest in conservation topics--approximated using Google search volume--varies over time can help support targeted conservation science communication. However, the evolution of search volume over time and the mechanisms that drive peaks in searches are poorly understood. We conducted time series analyses on Google search data from 2004 to 2013 to investigate: (i whether interests in selected conservation topics have declined and (ii the effect of news reporting and academic publishing on search volume. Although trends were sensitive to the term used as benchmark, we did not find that public interest towards conservation topics such as climate change, ecosystem services, deforestation, orangutan, invasive species and habitat loss was declining. We found, however, a robust downward trend for endangered species and an upward trend for ecosystem services. The quantity of news articles was related to patterns in Google search volume, whereas the number of research articles was not a good predictor but lagged behind Google search volume, indicating the role of news in the transfer of conservation science to the public.

  15. Analysis of the Capacity of Google Trends to Measure Interest in Conservation Topics and the Role of Online News.

    Science.gov (United States)

    Nghiem, Le T P; Papworth, Sarah K; Lim, Felix K S; Carrasco, Luis R

    2016-01-01

    With the continuous growth of internet usage, Google Trends has emerged as a source of information to investigate how social trends evolve over time. Knowing how the level of interest in conservation topics--approximated using Google search volume--varies over time can help support targeted conservation science communication. However, the evolution of search volume over time and the mechanisms that drive peaks in searches are poorly understood. We conducted time series analyses on Google search data from 2004 to 2013 to investigate: (i) whether interests in selected conservation topics have declined and (ii) the effect of news reporting and academic publishing on search volume. Although trends were sensitive to the term used as benchmark, we did not find that public interest towards conservation topics such as climate change, ecosystem services, deforestation, orangutan, invasive species and habitat loss was declining. We found, however, a robust downward trend for endangered species and an upward trend for ecosystem services. The quantity of news articles was related to patterns in Google search volume, whereas the number of research articles was not a good predictor but lagged behind Google search volume, indicating the role of news in the transfer of conservation science to the public.

  16. Adjuvant Chemoradiotherapy is Associated with Improved Survival for Patients with Resected Gallbladder Carcinoma: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Kim, Byoung Hyuck; Kwon, Jeanny; Chie, Eui Kyu; Kim, Kyubo; Kim, Young Hoon; Seo, Dong Wan; Narang, Amol K; Herman, Joseph M

    2017-10-27

    The impact of adjuvant radiotherapy (ART) on survival from gallbladder carcinoma (GBC) remains underexplored, with conflicting results reported. A systematic review and meta-analysis was performed to clarify the impact of ART in GBC. A systematic literature search of several databases was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, from inception to August 2016. Studies that reported survival outcomes for patients with or without ART after curative surgery were included. All the inclusion criteria was met by 14 retrospective studies including 9364 analyzable patients, but most of the studies had a moderate risk of bias. Generally, the ART group had more patients with unfavorable characteristics than the group that had surgery alone. Nevertheless, the pooled results showed that ART significantly reduced the risk of death (hazard ratio [HR], 0.54; 95% confidence interval [CI] 0.44-0.67; p < 0.001) and recurrence (HR 0.61; 95% CI 0.38-0.98; p = 0.04) of GBC compared with surgery alone. Exploratory analyses demonstrated a survival benefit from ART for a subgroup of patients with lymph node-positive diseases (HR 0.61; p < 0.001) and R1 resections (HR 0.55; p < 0.001), but not for patients with lymph node-negative disease (HR 1.06; p = 0.78). No evidence of publication bias was found (p = 0.663). This study is the first meta-analysis to evaluate the role of ART and to provide supporting evidence that ART may offer survival benefits, especially for high-risk patients. However, further confirmation with a randomized prospective study is needed to clarify the subgroup of GBC patients who would benefit most from ART.

  17. Survival Analysis of Advanced HCC Treated with Radioembolization: Comparing Impact of Clinical Performance Status Versus Vascular Invasion/Metastases.

    Science.gov (United States)

    Ali, Rehan; Gabr, Ahmed; Abouchaleh, Nadine; Al Asadi, Ali; Mora, Ronald A; Kulik, Laura; Abecassis, Michael; Riaz, Ahsun; Salem, Riad; Lewandowski, Robert J

    2017-09-06

    In this study, we aim to compare the effects of prognostic indicators on survival analysis for Barcelona Clinic Liver Cancer (BCLC) C patients undergoing yttrium-90 radioembolization (Y-90). A prospectively acquired database (2003-2017) for BCLC C hepatocellular carcinoma (HCC) patients that underwent radioembolization with Y-90 was searched. The criteria for BCLC C status (Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 1 or 2, metastases, and/or portal vein thrombosis (PVT)) were recorded. Kaplan-Meier survival analyses were performed from the date of the first radioembolization with Y-90, censored to curative treatment, to determine median overall survival (OS). Cox regression hazards model was used for multivariate analyses. Significance was set at P < 0.05. 547 BCLC C patients treated with radioembolization with Y-90 had a median OS of 10.7 months (range: 9.5-12.9). 43% (233 of 547) patients classified as BCLC C solely by their ECOG PS had a median OS of 19.4 months (14.7-23.7); 57% (314 of 547) patients with PVT/metastases had a median OS of 7.7 months (6.7-8.7). On multivariate analysis, ECOG PS was not found to be a statistically significant prognostic indicator of OS in BCLC C whereas metastases and PVT exhibited hazards ratios (95%CI) of 0.51 (0.38-0.69) and 0.49 (0.38-0.63), respectively (P < 0.0001). Patients classified as BCLC C due to ECOG PS 1 demonstrated longer survival when compared to those presenting with PVT, metastases and/or ECOG PS 2. Hence, ECOG PS 1, as an isolated variable, may not be a true indicator of advanced disease.

  18. Developing Cost Accounting and Decision Support Software for Comprehensive Community-Based Support Systems: An Analysis of Needs, Interest, and Readiness in the Field.

    Science.gov (United States)

    Harrington, Robert; Jenkins, Peter; Marzke, Carolyn; Cohen, Carol

    Prominent among the new models of social service delivery are organizations providing comprehensive, community-based supports and services (CCBSS) to children and their families. A needs analysis explored CCBSS sites' interest in and readiness to use a software tool designed to help them make more effective internal resource allocation decisions…

  19. Innovations’ Survival

    Directory of Open Access Journals (Sweden)

    Jakub Tabas

    2016-01-01

    Full Text Available Innovations currently represent a tool of maintaining the going concern of a business entity and its competitiveness. However, effects of innovations are not infinite and if an innovation should constantly preserve a life of business entity, it has to be a continual chain of innovations, i.e. continual process. Effective live of a single innovation is limited while the limitation is derived especially from industry. The paper provides the results of research on innovations effects in the financial performance of small and medium-sized enterprises in the Czech Republic. Objective of this paper is to determine the length and intensity of the effects of technical innovations in company’s financial performance. The economic effect of innovations has been measured at application of company’s gross production power while the Deviation Analysis has been applied for three years’ time series. Subsequently the Survival Analysis has been applied. The analyses are elaborated for three statistical samples of SMEs constructed in accordance to the industry. The results obtained show significant differences in innovations’ survival within these three samples of enterprises then. The results are quite specific for the industries, and are confronted and discussed with the results of authors’ former research on the issue.

  20. A long-term retrospective analysis of survival rates of implants in the mandible.

    Science.gov (United States)

    Balshi, Thomas J; Wolfinger, Glenn J; Stein, Brett E; Balshi, Stephen F

    2015-01-01

    To retrospectively analyze the survival rate of endosseous dental implants placed in the edentulous or partially edentulous mandible over a long-term follow-up period of 10 years or more. The charts of patients who underwent mandibular implant placement at a private prosthodontics practice and received follow-up care for 10 years or more were included in this study. Implants were examined according to the following study variables: patient sex, patient age, degree of edentulism (fully vs partially edentulous), implant location, time of loading (delayed vs immediate), implant size and type, bone quality, prosthesis type, and the presence of other implants during placement. The study sample was composed of 2,394 implants placed in 470 patients with 10 to 27 years of follow-up. Of these 2,394 implants, 176 failed, resulting in an overall cumulative survival rate (CSR) of 92.6%. A total of 1,482 implants were placed in edentulous mandibles, and 912 implants were placed in partially edentulous mandibles, with CSRs of 92.6% and 92.7%, respectively. Comparisons of the study variables with respect to CSR were largely nonsignificant. However, there were significant differences in CSRs between anterior vs posterior locations and rough- vs smooth-surfaced implants in addition to some prosthesis types, ages, and bone qualities. The overall CSR of 92.6% in the present study is high and comparable to survival rates observed in previous long-term analyses of mandibular implants. The significant differences observed between implant locations, patient age groups, bone qualities, and prostheses were not suggestive of any remarkable trends. Patient sex, age, degree of edentulism, implant location, time of loading, implant size and type, bone quality, prosthesis type, and the presence of multiple implants did not result in any significant effect on long-term implant survival. The CSR observed after 10 to 27 years of follow-up in a single private prosthodontic center was high (92

  1. Survival analysis of gastric cancer patients using Cox model: a five year study

    Directory of Open Access Journals (Sweden)

    Biglarian A

    2009-08-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Gastric cancer is the second most common cancer and known as the second cause of death due to cancers worldwide. Adenocarcinoma is the most fatal cancer in Iran and a patient with this kind of cancer, has a lower lifetime than others. In this research, the survival of patients with gastric carcinoma who were registered at Taleghani Hospital, were studied."n"nMethods: 291 patients with Gastric carcinoma who had received care, chemotherapy or chemoradiotherapy, at Taleghani Hospital in Tehran from 2002 to 2007 were studied as a historical cohort. Their survival rates and its relationship with 12 risk factors were assessed."n"nResults: Of the 291 patients with Gastric carcinoma, 70.1 percent were men and others (29.9% were women. The mean age of men was 62.26 years and of women was 59.32 years at the time of diagnosis. Most of patients (93.91% were advanced stage and metastasis. The Cox proportional hazards model showed that age at diagnosis, tumor stage and histology type with survival time had significant relationships (p=0.039, p=0.042 and p=0.032 respectively."n"n Conclusion: The five-year survival rate and median lifetime of gastric cancer patients who underwent chemotherapy or chemoradiotherapy are very

  2. Tobacco price increases and population interest in smoking cessation in Japan between 2004 and 2016: a Google Trends analysis.

    Science.gov (United States)

    Tabuchi, Takahiro; Fukui, Keisuke; Gallus, Silvano

    2018-01-31

    Tobacco price increases can generate increased public interest in smoking cessation, but it is not clear how long this interest lasts. Our objective was to evaluate the duration of the impact of cigarette price increase in Japan using Google search data. Monthly or daily aggregated Google search volume for smoking cessation in Japan from 2004 to 2016 was collected in terms of relative search volume (RSV) ranging from 0-100. Using monthly RSV data, we evaluated possible relationships between the RSVs and tobacco control measures in Japan. Time periods within which the impact of search volume significantly increased were identified by cluster detection test, using daily RSV data. A spike in RSV preceding the enforcement of a cigarette price increase revealed an anticipation effect. Between 2004 and 2016 the three highest monthly RSV spikes were observed in July 2006 (RSV=66), when cigarette prices increased by 11%, and in September (RSV=90) and October 2010 (RSV=100), when cigarette prices increased by 37%. Regarding daily RSV, the detected cluster size around the price increase in 2010 (52 days) was longer than that in 2006 (17 days). In 2010, a cluster period of 25 days before the date of the price increase was observed, suggesting an anticipation effect. After the onset of the price increase, a cluster of 27 days was detected. When the cigarette price increased due to consumption tax in April 2014, almost no anticipation effect was observed. The population impact of tobacco price increases on smoking cessation may be assessed using Google Trends data. The cluster indicates that a higher cigarette price increase had a higher and longer-lasting effect on population interest in cessation, but the impact may continue for a relatively short time. To examine the duration of the impact of cigarette price increases on population interest in smoking cessation in Japan, Google search data for smoking cessation was analyzed. Between 2004 and 2016 the three highest spikes of

  3. Colorectal cancer liver metastases: long-term survival and progression-free survival after thermal ablation using magnetic resonance-guided laser-induced interstitial thermotherapy in 594 patients: analysis of prognostic factors.

    Science.gov (United States)

    Vogl, Thomas J; Dommermuth, Alena; Heinle, Britta; Nour-Eldin, Nour-Eldin A; Lehnert, Thomas; Eichler, Katrin; Zangos, Stephan; Bechstein, Wolf O; Naguib, Nagy N N

    2014-01-01

    The purpose of this study was the evaluation of prognostic factors for long-term survival and progression-free survival (PFS) after treatment of colorectal cancer (CRC) liver metastases with magnetic resonance-guided laser-induced interstital thermotherapy (LITT). We included 594 patients (mean age, 61.2 years) with CRC liver metastases who were treated with LITT. The statistical analysis of the long-term survival and PFS were based on the Kaplan-Meier method. The Cox regression model tested different parameters that could be of prognostic value. The tested prognostic factors were the following: sex, age, the location of primary tumor, the number of metastases, the maximal diameter and total volume of metastases and necroses, the quotient of total volumes of metastases and necroses, the time of appearance of liver metastases and location in the liver, the TNM classification of CRC, extrahepatic metastases, and neoadjuvant treatments. The median survival was 25 months starting from the date of the first LITT. The 1-, 2-, 3-, 4-, and 5-year survival rates were 78%, 50.1%, 28%, 16.4%, and 7.8%, respectively. The median PFS was 13 months. The 1-, 2-, 3-, 4-, and 5-year PFS rates were 51.3%, 35.4%, 30.7%, 25.4%, and 22.3%, respectively. The number of metastases and their maximal diameter were the most important prognostic factors for both long-term survival and PFS. Long-term survival was also highly influenced by the initial involvement of the lymph nodes. For patients treated with LITT for CRC liver metastases, the number and size of metastases, together with the initial lymph node status, are significant prognostic factors for long-term survival.

  4. Surviving in a Cosexual World: A Cost-Benefit Analysis of Dioecy in Tropical Trees.

    Science.gov (United States)

    Bruijning, Marjolein; Visser, Marco D; Muller-Landau, Helene C; Wright, S Joseph; Comita, Liza S; Hubbell, Stephen P; de Kroon, Hans; Jongejans, Eelke

    2017-03-01

    Dioecy has a demographic disadvantage compared with hermaphroditism: only about half of reproductive adults produce seeds. Dioecious species must therefore have fitness advantages to compensate for this cost through increased survival, growth, and/or reproduction. We used a full life cycle approach to quantify the demographic costs and benefits associated with dioecy while controlling for demographic differences between dioecious and hermaphroditic species related to other functional traits. The advantage of this novel approach is that we can focus on the effect of breeding system across a diverse tree community. We built a composite integral projection model for hermaphroditic and dioecious tree populations from Barro Colorado Island, Panama, using long-term demographic and newly collected reproductive data. Integration of all costs and benefits showed that compensation was realized through increased seed production, resulting in no net costs of dioecy. Compensation was also facilitated by the low contribution of reproduction to population growth. Estimated positive effects of dioecy on tree growth and survival were small and insignificant for population growth rates. Our model revealed that, for long-lived organisms, the cost of having males is smaller than generally expected. Hence, little compensation is required for dioecious species to maintain population growth rates similar to those of hermaphroditic species.

  5. The Survival of Class V Composite Restorations and Analysis of Marginal Discoloration.

    Science.gov (United States)

    Kim, J-H; Cho, J; Lee, Y; Cho, B-H

    The aims of this retrospective clinical study were to analyze the longevity of class V composite restorations and compare the results obtained from clinical and laboratory evaluation of marginal discoloration. A total of 186 restorations were evaluated with modified US Public Health Service criteria. Longevity and associated variables were analyzed with the Kaplan-Meier method and a Cox proportional hazard model. Restorations with marginal discoloration were additionally evaluated using digital photographs and epoxy resin replicas under a stereomicroscope. The mean survival time was 15.0 years, with five- and 10-year survival rates of 95.5% and 83.1%, respectively. Z250 had a higher risk of failure (hazard ratio=7.01, 95% confidence interval=2.07-23.72) than Z100. In addition, the presence of occlusal wear facets and bleeding on probing were associated with an increased risk of failure of the restorations. However, the use of an adhesive system (Scotchbond Multi-Purpose or Clearfil SE Bond) did not affect the longevity of the restorations. The results of laboratory evaluation were significantly different from clinical evaluation (p<0.001, McNemar test). Among 55 restorations rated as Bravo in the clinical evaluation, 24 restorations (43.6%) were determined to have penetrating discoloration on laboratory evaluation. When evaluating aged composite restorations, surface refurbishment and the use of a microscope are recommended, which will be helpful in determining the need for timely repair or replacement.

  6. Influence analysis for skew-normal semiparametric joint models of multivariate longitudinal and multivariate survival data.

    Science.gov (United States)

    Tang, An-Min; Tang, Nian-Sheng; Zhu, Hongtu

    2017-04-30

    The normality assumption of measurement error is a widely used distribution in joint models of longitudinal and survival data, but it may lead to unreasonable or even misleading results when longitudinal data reveal skewness feature. This paper proposes a new joint model for multivariate longitudinal and multivariate survival data by incorporating a nonparametric function into the trajectory function and hazard function and assuming that measurement errors in longitudinal measurement models follow a skew-normal distribution. A Monte Carlo Expectation-Maximization (EM) algorithm together with the penalized-splines technique and the Metropolis-Hastings algorithm within the Gibbs sampler is developed to estimate parameters and nonparametric functions in the considered joint models. Case deletion diagnostic measures are proposed to identify the potential influential observations, and an extended local influence method is presented to assess local influence of minor perturbations. Simulation studies and a real example from a clinical trial are presented to illustrate the proposed methodologies. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  7. Iterative Bayesian Model Averaging: a method for the application of survival analysis to high-dimensional microarray data

    Directory of Open Access Journals (Sweden)

    Raftery Adrian E

    2009-02-01

    Full Text Available Abstract Background Microarray technology is increasingly used to identify potential biomarkers for cancer prognostics and diagnostics. Previously, we have developed the iterative Bayesian Model Averaging (BMA algorithm for use in classification. Here, we extend the iterative BMA algorithm for application to survival analysis on high-dimensional microarray data. The main goal in applying survival analysis to microarray data is to determine a highly predictive model of patients' time to event (such as death, relapse, or metastasis using a small number of selected genes. Our multivariate procedure combines the effectiveness of multiple contending models by calculating the weighted average of their posterior probability distributions. Our results demonstrate that our iterative BMA algorithm for survival analysis achieves high prediction accuracy while consistently selecting a small and cost-effective number of predictor genes. Results We applied the iterative BMA algorithm to two cancer datasets: breast cancer and diffuse large B-cell lymphoma (DLBCL data. On the breast cancer data, the algorithm selected a total of 15 predictor genes across 84 contending models from the training data. The maximum likelihood estimates of the selected genes and the posterior probabilities of the selected models from the training data were used to divide patients in the test (or validation dataset into high- and low-risk categories. Using the genes and models determined from the training data, we assigned patients from the test data into highly distinct risk groups (as indicated by a p-value of 7.26e-05 from the log-rank test. Moreover, we achieved comparable results using only the 5 top selected genes with 100% posterior probabilities. On the DLBCL data, our iterative BMA procedure selected a total of 25 genes across 3 contending models from the training data. Once again, we assigned the patients in the validation set to significantly distinct risk groups (p

  8. Survival analysis of factors affecting incidence risk of Salmonella Dublin in Danish dairy herds during a 7-year surveillance period

    DEFF Research Database (Denmark)

    Nielsen, Liza Rosenbaum; Dohoo, Ian

    2012-01-01

    A national surveillance programme for Salmonella Dublin, based on regular bulk-tank milk antibody screening and movements of cattle, was initiated in Denmark in 2002. From 2002 to end of 2009 the prevalence of test-positive dairy herds was reduced from 26% to 10%. However, new infections and spread......-quarters (YQs), either at the start of the study period or after recovery from infection. Survival analysis was performed on a dataset including 6931 dairy herds with 118969 YQs at risk, in which 1523 failures (new infection events) occurred. Predictors obtained from register data were tested in a multivariable...

  9. Survival and Stationary Distribution Analysis of a Stochastic Competitive Model of Three Species in a Polluted Environment.

    Science.gov (United States)

    Zhao, Yu; Yuan, Sanling; Ma, Junling

    2015-07-01

    In this paper, we develop and study a stochastic model for the competition of three species with a generalized dose-response function in a polluted environment. We first carry out the survival analysis and obtain sufficient conditions for the extinction, non-persistence, weak persistence in the mean, strong persistence in the mean and stochastic permanence. The threshold between weak persistence in the mean and extinction is established for each species. Then, using Hasminskii's methods and a Lyapunov function, we derive sufficient conditions for the existence of stationary distribution for each population. Numerical simulations are carried out to support our theoretical results, and some biological significance is presented.

  10. Reduction of cardiac cell death after helium postconditioning in rats: transcriptional analysis of cell death and survival pathways.

    Science.gov (United States)

    Oei, Gezina T M L; Heger, Michal; van Golen, Rowan F; Alles, Lindy K; Flick, Moritz; van der Wal, Allard C; van Gulik, Thomas M; Hollmann, Markus W; Preckel, Benedikt; Weber, Nina C

    2015-01-20

    Helium, a noble gas, has been used safely in humans. In animal models of regional myocardial ischemia/reperfusion (I/R) it was shown that helium conditioning reduces infarct size. Currently, it is not known how helium exerts its cytoprotective effects and which cell death/survival pathways are affected. The objective of this study, therefore, was to investigate the cell protective effects of helium postconditioning by PCR array analysis of genes involved in necrosis, apoptosis and autophagy. Male rats were subjected to 25 min of ischemia and 5, 15 or 30 min of reperfusion. Semiquantitative histological analysis revealed that 15 min of helium postconditioning reduced the extent of I/R-induced cell damage. This effect was not observed after 5 and 30 min of helium postconditioning. Analysis of the differential expression of genes showed that 15 min of helium postconditioning mainly caused upregulation of genes involved in autophagy and inhibition of apoptosis versus I/R alone. The results suggest that the cytoprotective effects of helium inhalation may be caused by a switch from pro-cell-death signaling to activation of cell survival mechanisms, which appears to affect a wide range of pathways.

  11. Evaluation of forensic DNA traces when propositions of interest relate to activities: analysis and discussion of recurrent concerns

    Directory of Open Access Journals (Sweden)

    Alex Biedermann

    2016-12-01

    Full Text Available When forensic scientists evaluate and report on the probative strength of single DNA traces, they commonly rely on only one number, expressing the rarity of the DNA profile in the population of interest. This is so because the focus is on propositions regarding the source of the recovered trace material, such as ‘the person of interest is the source of the crime stain’. In particular, when the alternative proposition is ‘an unknown person is the source of the crime stain’, one is directed to think about the rarity of the profile. However, in the era of DNA profiling technology capable of producing results from small quantities of trace material (i.e., non-visible staining that is subject to easy and ubiquitous modes of transfer, the issue of source is becoming less central, to the point that it is often not contested. There is now a shift from the question ‘whose DNA is this?’ to the question ‘how did it get there?’. As a consequence, recipients of expert information are now very much in need of assistance with the evaluation of the meaning and probative strength of DNA profiling results when the competing propositions of interest refer to different activities. This need is widely demonstrated in day-to-day forensic practice and is also voiced in specialized literature. Yet many forensic scientists remain reluctant to assess their results given propositions that relate to different activities. Some scientists consider evaluations beyond the issue of source as being overly speculative, because of the lack of relevant data and knowledge regarding phenomena and mechanisms of transfer, persistence and background of DNA. Similarly, encouragements to deal with these activity issues, expressed in a recently released European guideline on evaluative reporting 42, which highlights the need for rethinking current practice, are sometimes viewed skeptically or are not considered feasible. In this discussion paper, we select and discuss

  12. Evaluation of Forensic DNA Traces When Propositions of Interest Relate to Activities: Analysis and Discussion of Recurrent Concerns

    Science.gov (United States)

    Biedermann, Alex; Champod, Christophe; Jackson, Graham; Gill, Peter; Taylor, Duncan; Butler, John; Morling, Niels; Hicks, Tacha; Vuille, Joelle; Taroni, Franco

    2016-01-01

    When forensic scientists evaluate and report on the probative strength of single DNA traces, they commonly rely on only one number, expressing the rarity of the DNA profile in the population of interest. This is so because the focus is on propositions regarding the source of the recovered trace material, such as “the person of interest is the source of the crime stain.” In particular, when the alternative proposition is “an unknown person is the source of the crime stain,” one is directed to think about the rarity of the profile. However, in the era of DNA profiling technology capable of producing results from small quantities of trace material (i.e., non-visible staining) that is subject to easy and ubiquitous modes of transfer, the issue of source is becoming less central, to the point that it is often not contested. There is now a shift from the question “whose DNA is this?” to the question “how did it get there?” As a consequence, recipients of expert information are now very much in need of assistance with the evaluation of the meaning and probative strength of DNA profiling results when the competing propositions of interest refer to different activities. This need is widely demonstrated in day-to-day forensic practice and is also voiced in specialized literature. Yet many forensic scientists remain reluctant to assess their results given propositions that relate to different activities. Some scientists consider evaluations beyond the issue of source as being overly speculative, because of the lack of relevant data and knowledge regarding phenomena and mechanisms of transfer, persistence and background of DNA. Similarly, encouragements to deal with these activity issues, expressed in a recently released European guideline on evaluative reporting (Willis et al., 2015), which highlights the need for rethinking current practice, are sometimes viewed skeptically or are not considered feasible. In this discussion paper, we select and discuss

  13. Conflicts of interest and critiques of the use of systematic reviews in policymaking: an analysis of opinion articles

    Science.gov (United States)

    2014-01-01

    Background Strong opinions for or against the use of systematic reviews to inform policymaking have been published in the medical literature. The purpose of this paper was to examine whether funding sources and author financial conflicts of interest were associated with whether an opinion article was supportive or critical of the use of systematic reviews for policymaking. We examined the nature of the arguments within each article, the types of disclosures present, and whether these articles are being cited in the academic literature. Methods We searched for articles that expressed opinions about the use of systematic reviews for policymaking. We included articles that presented opinions about the use of systematic reviews for policymaking and categorized each article as supportive or critical of such use. We extracted all arguments regarding the use of systematic reviews from each article and inductively coded each as internal or external validity argument, categorized disclosed funding sources, conflicts of interest, and article types, and systematically searched for undisclosed financial ties. We counted the number of times each article has been cited in the “Web of Science.” We report descriptive statistics. Results Articles that were critical of the use of systematic reviews (n = 25) for policymaking had disclosed or undisclosed industry ties 2.3 times more often than articles that were supportive of the use (n = 34). We found that editorials, comments, letters, and perspectives lacked published disclosures nearly twice as often (60% v. 33%) as other types of articles. We also found that editorials, comments, letters, and perspectives were less frequently cited in the academic literature than other article types (median number of citations = 5 v. 19). Conclusions It is important to consider whether an article has industry ties when evaluating the strength of the argument for or against the use of systematic reviews for policymaking. We found that journal

  14. Homophobia Is Related to a Low Interest in Sexuality in General: An Analysis of Pupillometric Evoked Responses.

    Science.gov (United States)

    Cheval, Boris; Grob, Emmanuelle; Chanal, Julien; Ghisletta, Paolo; Bianchi-Demicheli, Francesco; Radel, Remi

    2016-10-01

    A recent study by Cheval et al (J Sex Med 2016;13:825-834) found that individuals high in homophobia look significantly less long at sex-related photographs, regardless of their nature (ie, homosexual or heterosexual). Because viewing time is under some conscious control, this result could indicate that individuals high in homophobia have a low sexual interest in any sexual stimuli or are consciously motivated to avoid sexual material in line with their conscious values. To determine the mechanism underlying shorter viewing time of sex-related photographs in individuals high in homophobia using pupil dilatation, which is considered a spontaneous, unconscious, and uncontrollable index of sexual interest. Heterosexual men (N = 36) completed a questionnaire assessing their level of homo-negativity and then performed a picture-viewing task with simultaneous eye-tracking recording to assess their pupillary responses to the presentation of sexually related or neutral photographs. Non-linear mixed models were carried out to fit the individual non-linear trajectories of pupillary reaction. Different parameters were obtained including the final asymptote of the pupillary response. Results showed that the final pupil size of men high in homophobia increased significantly less to the presentation of sex-related images (ie, heterosexual and homosexual) than the pupil size of men low in homophobia. In contrast, no significant difference in the final pupil size reaction toward homosexual images (vs heterosexual images) emerged between men high and men low in homophobia. Theoretically, these findings reinforce the necessity to consider that homophobia might reflect concerns about sexuality in general and not homosexuality in particular. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  15. California's electricity system of the future scenario analysis in support of public-interest transmission system R&D planning

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph; Stovall, John P.

    2003-04-01

    The California Energy Commission directed the Consortium for Electric Reliability Technology Solutions to analyze possible future scenarios for the California electricity system and assess transmission research and development (R&D) needs, with special emphasis on prioritizing public-interest R&D needs, using criteria developed by the Energy Commission. The scenarios analyzed in this report are not predictions, nor do they express policy preferences of the project participants or the Energy Commission. The public-interest R&D needs that are identified as a result of the analysis are one input that will be considered by the Energy Commission's Public Interest Energy Research staff in preparing a transmission R&D plan.

  16. Estimation of Unemployment Duration in Botoşani County Using Survival Analysis

    Directory of Open Access Journals (Sweden)

    Darabă Gabriel

    2017-01-01

    Full Text Available In this paper we aim at estimating the unemployment duration in Botosani County in order tostudy the impact of individual characteristics (gender, age, place of residence, unemploymentbenefit, etc. on the length of unemployment spells. We use Cox regression model to measure theeffects of gender, age, residential environment, etc. on the hazard rate of leaving unemploymentandKaplan-Meier estimator to compare survival probabilities among different categories ofunemployed persons. The study is carried out on a sample of 200 unemployment spellsregisteredwith the Employment Agency of Botoşani County from January 2012 to December 2015. Theresults reveal that place of residence, unemployment benefit and unemployed category have asignificant impact on unemployment spells.

  17. Survivability and injuries from use of rocket-assisted ejection seats: analysis of 232 cases.

    Science.gov (United States)

    Lewis, Matthew E

    2006-09-01

    Ejection injury has been documented with respect to non-rocket-assisted seats, but there is little information on injuries associated with rocket-assisted seats. This study analyses the survivability of military accidents and the injuries associated with rocket-assisted ejection. A total of 232 Royal Air Force accident reports were accessed and aircrews' injuries were related to the aircraft parameters of ejection, aircrew anthropometry, and the ejection seat and parachute dynamics. Ejection sequences were simulated using a computerized modeling tool to provide information relating to the dynamic response index, acceleration of the ejection seats, and performance of the parachutes. Ejection survival was 89.2% overall, 95.7% for within envelope ejections and 23.8% for out of envelope ejections. There were 29.4% of aircrew who sustained spinal fractures. Another 14.2% of aircrew sustained a head injury and the incidence of head injury in Tornado ejectees was higher than the other aircraft types. Compared with 5.8% of ejectees from aircraft with an arm restraint system, 11.2% of aircrew sustained upper limb flail injuries from ejecting from aircraft without an arm restraint system. Arm flail injuries occurred at a higher aircraft speed at ejection compared with ejections where no arm flail injuries were sustained. There was also 18% of aircrew who sustained lower limb parachute landing injuries. Information from this study has lead to a redesign of the Tornado ejection seat headbox, an improvement in the Tornado ejection catapult dynamics, an upgrade of escape system parachutes, and provided evidence that future aircraft should be fitted with an arm restraint system.

  18. Comparison of methods for estimating the attributable risk in the context of survival analysis

    Directory of Open Access Journals (Sweden)

    Malamine Gassama

    2017-01-01

    Full Text Available Abstract Background The attributable risk (AR measures the proportion of disease cases that can be attributed to an exposure in the population. Several definitions and estimation methods have been proposed for survival data. Methods Using simulations, we compared four methods for estimating AR defined in terms of survival functions: two nonparametric methods based on Kaplan-Meier’s estimator, one semiparametric based on Cox’s model, and one parametric based on the piecewise constant hazards model, as well as one simpler method based on estimated exposure prevalence at baseline and Cox’s model hazard ratio. We considered a fixed binary exposure with varying exposure probabilities and strengths of association, and generated event times from a proportional hazards model with constant or monotonic (decreasing or increasing Weibull baseline hazard, as well as from a nonproportional hazards model. We simulated 1,000 independent samples of size 1,000 or 10,000. The methods were compared in terms of mean bias, mean estimated standard error, empirical standard deviation and 95% confidence interval coverage probability at four equally spaced time points. Results Under proportional hazards, all five methods yielded unbiased results regardless of sample size. Nonparametric methods displayed greater variability than other approaches. All methods showed satisfactory coverage except for nonparametric methods at the end of follow-up for a sample size of 1,000 especially. With nonproportional hazards, nonparametric methods yielded similar results to those under proportional hazards, whereas semiparametric and parametric approaches that both relied on the proportional hazards assumption performed poorly. These methods were applied to estimate the AR of breast cancer due to menopausal hormone therapy in 38,359 women of the E3N cohort. Conclusion In practice, our study suggests to use the semiparametric or parametric approaches to estimate AR as a function of

  19. Comparison of methods for estimating the attributable risk in the context of survival analysis.

    Science.gov (United States)

    Gassama, Malamine; Bénichou, Jacques; Dartois, Laureen; Thiébaut, Anne C M

    2017-01-23

    The attributable risk (AR) measures the proportion of disease cases that can be attributed to an exposure in the population. Several definitions and estimation methods have been proposed for survival data. Using simulations, we compared four methods for estimating AR defined in terms of survival functions: two nonparametric methods based on Kaplan-Meier's estimator, one semiparametric based on Cox's model, and one parametric based on the piecewise constant hazards model, as well as one simpler method based on estimated exposure prevalence at baseline and Cox's model hazard ratio. We considered a fixed binary exposure with varying exposure probabilities and strengths of association, and generated event times from a proportional hazards model with constant or monotonic (decreasing or increasing) Weibull baseline hazard, as well as from a nonproportional hazards model. We simulated 1,000 independent samples of size 1,000 or 10,000. The methods were compared in terms of mean bias, mean estimated standard error, empirical standard deviation and 95% confidence interval coverage probability at four equally spaced time points. Under proportional hazards, all five methods yielded unbiased results regardless of sample size. Nonparametric methods displayed greater variability than other approaches. All methods showed satisfactory coverage except for nonparametric methods at the end of follow-up for a sample size of 1,000 especially. With nonproportional hazards, nonparametric methods yielded similar results to those under proportional hazards, whereas semiparametric and parametric approaches that both relied on the proportional hazards assumption performed poorly. These methods were applied to estimate the AR of breast cancer due to menopausal hormone therapy in 38,359 women of the E3N cohort. In practice, our study suggests to use the semiparametric or parametric approaches to estimate AR as a function of time in cohort studies if the proportional hazards assumption appears

  20. Intraoperative radiation therapy in combination with conformation radiation therapy for localized unresectable pancreatic carcinoma; An analysis of 13 patients survived for more than one year

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Atsutake; Tsuruta, Kohji; Tanaka, Yoshiaki (Tokyo Metropolitan Komagome Hospital (Japan)); Onodera, Tokio

    1992-04-01

    The present report is a retrospective analysis of the effect of intraoperative radiation therapy (IORT) for localized but unresectable pancreatic carcinoma. Thirteen of 30 patients treated by IORT in combination with external beam radiation therapy (EBRT) survived for more than one year. The longest survival period, attained by two patients, was 20 months. The 1, and 1.5-year survival rates were 46.5% and 20.8%, respectively, with a median survival of 11 months, whereas the 1-year survival rate was 0%, with a median survival of 6.2 months for the 16 patients treated by IORT alone (N=16). There was a statistically significant difference in survival rate between the two groups (p<0.01). Therefore, additional EBRT may be indispensable for prolongation of the survival period. Moreover, IORT conferred the palliative benefit of relief of pain in more than half of the patients with severe pain. In postmortem examination of seven patients who survived for more than one year, the tumors were replaced by fibrous and hyalinized tissue, as a result of the effect of IORT, and degeneration and necrosis of tumor cells were seen in the center of the tumor, while viable tumor cells remained in the periphery, spreading to the retroperitoneal tissues or neighboring organs. These histopathological findings are distinctive features of carcinoma of the pancreas treated by IORT. (author).

  1. Acinetobacter spp. are associated with a higher mortality in intensive care patients with bacteremia: a survival analysis.

    Science.gov (United States)

    Leão, Aline C Q; Menezes, Paulo R; Oliveira, Maura S; Levin, Anna S

    2016-08-09

    It has been challenging to determine the true clinical impact of Acinetobacter spp., due to the predilection of this pathogen to colonize and infect critically ill patients, who often have a poor prognosis. The aim of this study was to assess whether Acinetobacter spp. bacteremia is associated with lower survival compared with bacteremia caused by other pathogens in critically ill patients. This study was performed at Hospital das Clínicas, University of São Paulo, Brazil. There are 12 intensive care units (ICUs) in the hospital: five Internal Medicine ICUs (emergency, nephrology, infectious diseases and respiratory critical care), three surgical ICU (for general surgery and liver transplantion), an Emergency Department ICU for trauma patients, an ICU for burned patients, a neurosurgical ICU and a post-operative ICU. A retrospective review of medical records was conducted for all patients admitted to any of the ICUs, who developed bacteremia from January 2010 through December 2011. Patients with Acinetobacter spp. were compared with those with other pathogens (Klebsiella pneumoniae, Staphylococcus aureus, Enterobacter spp., Enterococcus spp., Pseudomonas aeruginosa). We did a 30-day survival analysis. The Kaplan-Meier method and log-rank test were used to determine the overall survival. Potential prognostic factors were identified by bivariate and multivariate Cox regression analysis. One hundred forty-one patients were evaluated. No differences between patients with Acinetobacter spp. and other pathogens were observed with regard to age, sex, APACHE II score, Charlson Comorbidity Score and type of infection. Initial inappropriate antimicrobial treatment was more frequent in Acinetobacter bacteremia (88 % vs 51 %). Bivariate analysis showed that age > 60 years, diabetes mellitus, and Acinetobacter spp. infection were significantly associated with a poor prognosis. Multivariate model showed that Acinetobacter spp. infection (HR = 1.93, 95 % CI: 1

  2. Postmastectomy Radiation Therapy Is Associated With Improved Survival in Node-Positive Male Breast Cancer: A Population Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Abrams, Matthew J., E-mail: mabrams@tuftsmedicalcenter.org [Department of Radiation Oncology, Tufts University School of Medicine, Tufts Medical Center, Boston, Massachusetts (United States); Koffer, Paul P. [Department of Radiation Oncology, Tufts University School of Medicine, Tufts Medical Center, Boston, Massachusetts (United States); Wazer, David E. [Department of Radiation Oncology, Tufts University School of Medicine, Tufts Medical Center, Boston, Massachusetts (United States); Department of Radiation Oncology, The Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island (United States); Hepel, Jaroslaw T. [Department of Radiation Oncology, The Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island (United States)

    2017-06-01

    Purpose: Because of its rarity, there are no randomized trials investigating postmastectomy radiation therapy (PMRT) in male breast cancer. This study retrospectively examines the impact of PMRT in male breast cancer patients in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database. Methods and Materials: The SEER database 8.3.2 was queried for men ages 20+ with a diagnosis of localized or regional nonmetastatic invasive ductal/lobular carcinoma from 1998 to 2013. Included patients were treated by modified radical mastectomy (MRM), with or without adjuvant external beam radiation. Univariate and multivariate analyses evaluated predictors for PMRT use after MRM. Kaplan-Meier overall survival (OS) curves of the entire cohort and a case-matched cohort were calculated and compared by the log-rank test. Cox regression was used for multivariate survival analyses. Results: A total of 1933 patients were included in the unmatched cohort. There was no difference in 5-year OS between those who received PMRT and those who did not (78% vs 77%, respectively, P=.371); however, in the case-matched analysis, PMRT was associated with improved OS at 5 years (83% vs 54%, P<.001). On subset analysis of the unmatched cohort, PMRT was associated with improved OS in men with 1 to 3 positive nodes (5-year OS 79% vs 72% P=.05) and those with 4+ positive nodes (5-year OS 73% vs 53% P<.001). On multivariate analysis of the unmatched cohort, independent predictors for improved OS were use of PMRT: HR=0.551 (0.412-0.737) and estrogen receptor–positive disease: HR=0.577 (0.339-0.983). Predictors for a survival detriment were higher grade 3/4: HR=1.825 (1.105-3.015), larger tumor T2: HR=1.783 (1.357-2.342), T3/T4: HR=2.683 (1.809-3.978), higher N-stage: N1 HR=1.574 (1.184-2.091), N2/N3: HR=2.328 (1.684-3.218), black race: HR=1.689 (1.222-2.336), and older age 81+: HR=4.164 (1.497-11.582). Conclusions: There may be a survival benefit with the

  3. Impact of human immunodeficiency virus on survival after liver transplantation: analysis of United Network for Organ Sharing database.

    Science.gov (United States)

    Mindikoglu, Ayse L; Regev, Arie; Magder, Laurence S

    2008-02-15

    The outcome of liver transplantation (LT) in patients infected with human immunodeficiency virus (HIV) has been a matter of controversy. A retrospective cohort study was performed to assess the impact of HIV on LT survival by using United Network for Organ Sharing registry Standard Transplant Analysis and Research files. A total of 138 HIV(+) and 30,520 HIV(-) patients who were > or =18 years old and underwent LT during the highly active antiretroviral therapy era (starting January 1, 1997) in the United States were included. Among all HIV(+) patients, the estimated 2-year survival probability was lower (70%) than among non-HIV patients (81%). This excess risk appeared entirely among those with coinfections, that is, HIV with hepatitis B virus or hepatitis C virus (HCV), as none of the 24 HIV-infected patients who did not have hepatitis B virus or HCV died during an average of 1.2 years of follow-up per person. Among HCV(+) patients, those with HIV coinfection had significantly lower survival rates than patients without HIV (P=0.006). Controlling for age, coinfection, Model for End-Stage Liver Disease scores, and other potential confounders in a proportional hazards regression analysis, HIV(+) patients had a hazard ratio of 1.41 (P=0.14, 95% confidence interval: 0.90-2.22) for mortality after LT. HIV(+) patients without HCV coinfection seemed to have good prognosis, whereas patients who had HIV/HCV coinfection had poor outcomes, which were significantly worse than that seen in those with HCV alone.

  4. Comparative Analysis of Clinicopathologic Features of, Treatment in, and Survival of Americans with Lung or Bronchial Cancer.

    Directory of Open Access Journals (Sweden)

    Dan Li

    Full Text Available Ethnic disparities in lung and bronchial cancer diagnoses and disease-specific survival (DSS rates in the United States are well known. However, few studies have specifically assessed these differences in Asian subgroups. The primary objectives of the retrospective analysis described herein were to identify any significant differences in clinicopathologic features, treatment, and survival rate between Asian lung cancer patients and lung cancer patients in other broad ethnic groups in the United States and to determine the reasons for these differences among subgroups of Asian patients with lung or bronchial cancer. We searched the Surveillance, Epidemiology, and End Results Program database to identify patients diagnosed with lung or bronchial cancer from 1990 to 2012. Differences in clinicopathologic features, treatment, and DSS rate in four broad ethnic groups and eight Asian subgroups were compared. The study population consisted of 849,088 patients, 5.2% of whom were of Asian descent. Female Asian patients had the lowest lung and bronchial cancer incidence rates, whereas male black patients had the highest rates. Asian patients had the best 5-year DSS rate. In our Asian subgroup analysis, Indian/Pakistani patients had the best 5-year DSS rate, whereas Hawaiian/Pacific Islander patients had the worst 5-year DSS rates. We found the differences in DSS rate among the four broad ethnic groups and eight Asian subgroups when we grouped patients by age and disease stage, as well. Asian patients had better DSS rates than those in the other three broad ethnic groups in almost every age and disease-stage group, especially in older patients and those with advanced-stage disease. In conclusion, we found that clinicopathologic features and treatment of lung and bronchial cancer differ by ethnicity in the United States, and the differences impact survival in each ethnic group.

  5. Conflict of interest reporting by authors involved in promotion of off-label drug use: an analysis of journal disclosures.

    Directory of Open Access Journals (Sweden)

    Aaron S Kesselheim

    Full Text Available Litigation documents reveal that pharmaceutical companies have paid physicians to promote off-label uses of their products through a number of different avenues. It is unknown whether physicians and scientists who have such conflicts of interest adequately disclose such relationships in the scientific publications they author.We collected whistleblower complaints alleging illegal off-label marketing from the US Department of Justice and other publicly available sources (date range: 1996-2010. We identified physicians and scientists described in the complaints as having financial relationships with defendant manufacturers, then searched Medline for articles they authored in the subsequent three years. We assessed disclosures made in articles related to the off-label use in question, determined the frequency of adequate disclosure statements, and analyzed characteristics of the authors (specialty, author position and articles (type, connection to off-label use, journal impact factor, citation count/year. We identified 39 conflicted individuals in whistleblower complaints. They published 404 articles related to the drugs at issue in the whistleblower complaints, only 62 (15% of which contained an adequate disclosure statement. Most articles had no disclosure (43% or did not mention the pharmaceutical company (40%. Adequate disclosure rates varied significantly by article type, with commentaries less likely to have adequate disclosure compared to articles reporting original studies or trials (adjusted odds ratio [OR] = 0.10, 95%CI = 0.02-0.67, p = 0.02. Over half of the authors (22/39, 56% made no adequate disclosures in their articles. However, four of six authors with ≥ 25 articles disclosed in about one-third of articles (range: 10/36-8/25 [28%-32%].One in seven authors identified in whistleblower complaints as involved in off-label marketing activities adequately disclosed their conflict of interest in subsequent journal publications. This is

  6. Efficiency and limits of Stability Charts in the analysis of limit equilibrium state of slopes of geological interest

    Science.gov (United States)

    Ausilia Paparo, Maria; Tinti, Stefano

    2014-05-01

    The stability charts are one of the most common tools used in engineering and applied geology to derive the value of the Safety Factor, say F, of slopes of engineering and geological interest. Its importance is due to the easiness of finding the solution for F without falling into complex numerical calculations. These charts propose a graphical method to derive F=F(Ns), where Ns is the Stability Number, obtained by a combination of geotechnical (cohesion, friction angle, weight) and geometrical parameters (angle of incline and slope height): for each value of Ns it is possible to find one single value of F. Taylor (1948) was the first to introduce the stability charts method and later until recently many others proposed different improved versions of them (Michalowski, 1997; 2002; Baker, 1999; 2003; Baker et al. 2006; Easa and Vatankhah, 2011). The aim of this work is to show that there is no univocal relationship between F and Ns like it is erroneously assumed by the stability charts method. Indeed, the comparison of the stability charts with new charts obtained with the Minimum Lithostatic Deviation (MLD) method (Tinti and Manucci, 2006; 2008) reveals that F depends separately on all the parameters that concur to form the stability number, though the dependence on some of them, especially the soil weight, is more relevant. The work has been conducted not only on soil parameter configurations typical of embankments and dykes, but also on configurations typical of homogeneous slopes of geophysical interest. It is found that the values of F usually fall below the ones predicted by the stability charts though the general trend of the stability curves is confirmed. This discrepancy is particularly crucial when the value of F is close to the critical value of 1, since in this case classical methods could indicate that a slope is stable, even though it is not. One can therefore state that the classical stability single-valued curves F(Ns) can provide an acceptable first

  7. Long-term drug survival and predictor analysis of the whole psoriatic patient population on biological therapy in Hungary.

    Science.gov (United States)

    Pogácsás, Lilla; Borsi, András; Takács, Péter; Remenyik, Éva; Kemény, Lajos; Kárpáti, Sarolta; Holló, Péter; Wikonkál, Norbert; Gyulai, Rolland; Károlyi, Zsuzsanna; Rakonczai, Pál; Balázs, Tamás; Szegedi, Andrea

    2017-11-01

    Persistence is an important component of therapeutic success, which depends on a variety of factors. Persistence measured under optimal conditions during clinical trials does not necessarily coincide with persistence observed in the real-world settings. The aim of the present study was to compare persistence rate of TNF-alpha inhibitors and interleukin 12/23 inhibitor in all psoriasis patients in Hungary, as well as to analyze the predictors of persistence. Data collected from 1263 patients over a period of 46 months were subjected to a retrospective analysis. Drug survival rate has been calculated according to Kaplan-Meier analysis and Cox regression was used to study the predictors. The overall persistence rate for the four biologicals exceeded 60% after 3 years. The persistence rate of ustekinumab at 3 years was 67.83%, which was superior compared to that of the TNF-alpha inhibitors, where the mean persistence rate was shown to be 50.76% (p < .05). Male patients showed significantly higher persistence than females (HR = .76, p < .05 CI: 0.63, 0.92). Age, therapy-naïve status and use of concomitant MTX did not have significant effect on drug survival. Persistence rate of ustekinumab was significantly higher than that of TNF-alpha inhibitors, and among predictors, only male gender influenced persistence significantly.

  8. Meta-Analysis of Microarray Data Identifies GAS6 Expression as an Independent Predictor of Poor Survival in Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Michelle Buehler

    2013-01-01

    Full Text Available Seeking new biomarkers for epithelial ovarian cancer, the fifth most common cause of death from all cancers in women and the leading cause of death from gynaecological malignancies, we performed a meta-analysis of three independent studies and compared the results in regard to clinicopathological parameters. This analysis revealed that GAS6 was highly expressed in ovarian cancer and therefore was selected as our candidate of choice. GAS6 encodes a secreted protein involved in physiological processes including cell proliferation, chemotaxis, and cell survival. We performed immunohistochemistry on various ovarian cancer tissues and found that GAS6 expression was elevated in tumour tissue samples compared to healthy control samples (. In addition, GAS6 expression was also higher in tumours from patients with residual disease compared to those without. Our data propose GAS6 as an independent predictor of poor survival, suggesting GAS6, both on the mRNA and on the protein level, as a potential biomarker for ovarian cancer. In clinical practice, the staining of a tumour biopsy for GAS6 may be useful to assess cancer prognosis and/or to monitor disease progression.

  9. Microarray-based analysis of survival of soil microbial community during ozonation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian; Van Nostrand, Joy D.; He, Zhili; Wu, Liyou; Deng, Ye; Zhang, Xu; Zhou, Jizhong; Li, Guanghe

    2010-05-17

    A 15 h ozonation was performed on bioremediated soil to remove recalcitrant residual oil. To monitor the survival of indigenous microorganisms in the soil during in-situ chemical oxidation(ISCO) culturing and a functional genearray, GeoChip, was used to examine the functional genes and structure of the microbial community during ozonation (0h, 2h, 4h, 6h, 10hand15h). Breakthrough ozonation decreased the population of cultivable heterotrophic bacteria by about 3 orders of magnitude. The total functional gene abundance and diversity decreased during ozonation, as the number of functional genes was reduced by 48percent after 15 h. However, functional genes were evenly distributed during ozonation as judged by the Shannon-Weaver Evenness index. A sharp decrease in gene number was observed in the first 6 h of ozonation followed by a slower decrease in the next 9 h, which was consistent with microbial populations measured by a culture based method. Functional genes involved in carbon, nitrogen, phosphors and sulfur cycling, metal resistance and organic remediation were detected in all samples. Though the pattern of gene categories detected was similar for all time points, hierarchica lcluster of all functional genes and major functional categories all showed a time-serial pattern. Bacteria, archaea and fungi decreased by 96.1percent, 95.1percent and 91.3percent, respectively, after 15 h ozonation. Delta proteobacteria, which were reduced by 94.3percent, showed the highest resistance to ozonation while Actinobacteria, reduced by 96.3percent, showed the lowest resistance. Microorganisms similar to Rhodothermus, Obesumbacterium, Staphylothermus, Gluconobacter, and Enterococcus were dominant at all time points. Functional genes related to petroleum degradation decreased 1~;;2 orders of magnitude. Most of the key functional genes were still detected after ozonation, allowing a rapid recovery of the microbial community after ozonation. While ozone had a large impact on the

  10. A meta-analysis of four genome-wide association studies of survival to age 90 years or older

    DEFF Research Database (Denmark)

    Newman, Anne B; Walter, Stefan; Lunetta, Kathryn L

    2010-01-01

    BACKGROUND: Genome-wide association studies (GWAS) may yield insights into longevity. METHODS: We performed a meta-analysis of GWAS in Caucasians from four prospective cohort studies: the Age, Gene/Environment Susceptibility-Reykjavik Study, the Cardiovascular Health Study, the Framingham Heart...... Study, and the Rotterdam Study participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. Longevity was defined as survival to age 90 years or older (n = 1,836); the comparison group comprised cohort members who died between the ages of 55 and 80 years (n = 1...... significant SNPs, 24 were independent signals, and 16 of these SNPs were successfully genotyped in the second discovery stage, with one association for rs9664222, reaching 6.77 x 10(-7) for the combined meta-analysis of CHARGE and the stage 2 cohorts. The SNP lies in a region near MINPP1 (chromosome 10...

  11. Subtubercle Osteotomy for Medial Compartment Osteoarthritis of the Knee Using Ilizarov Technique: Survival Analysis and Clinical Outcomes.

    Science.gov (United States)

    Warner, Stephen J; O'Connor, Daniel P; Brinker, Mark R

    2018-01-03

    High tibial osteotomy with acute correction and internal fixation can be used to correct malalignment and malorientation and reduce symptoms in patients with medial compartment osteoarthritis of the knee. To address the inadequacies of this technique, we performed a series of subtubercle tibial osteotomy (STO) procedures using circular ring fixation to correct knee varus malalignment and joint malorientation. The purpose of this study was to analyze the ability of this technique to delay subsequent knee arthroplasty and decrease symptoms. Sixty-one patients had a total of 72 STO procedures using the Ilizarov technique to correct a varus deformity of the proximal part of the tibia. Radiographic measurements were performed at the time of presentation and after osseous union and frame removal. Clinical and radiographic variables were compared from presentation to the time of the latest follow-up. We performed a survival analysis, and our primary outcome was the time to conversion to knee arthroplasty. Radiographic measurements, including mechanical axis deviation, medial proximal tibial angle, and joint line congruence angle, significantly improved after deformity correction (p < 0.001 for all). In patients with a preoperative flexion contracture, the proximal posterior tibial angle significantly increased toward normal values (mean, 77.8° pretreatment versus 82.4° posttreatment; p = 0.007). Survival analysis demonstrated a rate of native knee-joint survival without conversion to arthroplasty of 94.2% (95% confidence interval [CI], 83% to 98%) at 5 years, 84.0% (95% CI, 69% to 92%) at 10 years, and 51.3% (95% CI, 28% to 71%) at 15 years. In addition, time-trade-off and Brief Pain Inventory outcomes significantly improved (p < 0.001). The complication rate was 8%. STO procedures using the Ilizarov technique for symptomatic varus knee deformity, performed over the course of 18 years, resulted in high knee survival rates without arthroplasty and significant improvement

  12. [A middle to long-term clinical study on pars flaccida and pars tensa cholesteatoma using survival analysis].

    Science.gov (United States)

    Somekawa, Yukihiro; Nagashima, Tsutomu; Masaki, Tomoyuki; Asano, Katsuji; Yajima, Ryoto; Himi, Tetsuo

    2014-12-01

    The current clinical study was performed on 311 cases of pars flaccida and 89 cases of pars tensa cholesteatoma which were treated with canal wall reconstructed tympanoplasty between 1991 and 2012. The average follow-up time of these patients was 5.3 years. Since follow-up periods were different in each case and some censored patients were involved, we used survival analysis on this study to discuss the cumulative rates of disease-free successful cases and the rates of recurrent cholesteatoma throughout the postoperative course. The disease-free successful cases were defined as those cases in which patients were both out of re-operation with recurrent and residual cholesteatoma and out of revision operation with another problem, furthermore, maintained good hearing outcome. Based on the criteria set by the Japan Otological Society (2010), the cases that satisfied the following were evaluated as good hearing results; (a) a successful case in which preoperative bone conduction was used, and (b) a case in which the postoperative air-bone gap was within 20dB after tympanoplasty for chronic otitis media. The analysis results were shown for each of (a) and (b). 1. In pars flaccida cholesteatoma, the 5-year survival rate of successful case was (a) 76.1% and (b) 83.9%, the 10-year survival rate was (a) 58.9% and (b) 73.0%. In pars tensa cholesteatoma, the 5-year survival rate of successful cases was (a) 57.7% and (b) 63.5%, the 10-year rate was (a) 42.1% and (b) 56.9%. A significant difference was seen between pars flaccida and pars tensa cholesteatoma (p pars flaccida cholesteatoma, the 5-year recurrence rate was 7.6% and the 10-year rate was 15.3%, and the recurrence rate increased gradually throughout the follow-up period. On the other hand, in pars tensa cholesteatoma, the increase in the recurrence rate reached a peak 15.8% at 5.5 years after the surgery. A long-term follow-up is necessary when evaluating the clinical results after tympanoplasty.

  13. Systematic analysis underlying the quality of the scientific evidence and conflicts of interest in interventional medicine subspecialty guidelines.

    Science.gov (United States)

    Feuerstein, Joseph D; Akbari, Mona; Gifford, Anne E; Hurley, Christine M; Leffler, Daniel A; Sheth, Sunil G; Cheifetz, Adam S

    2014-01-01

    To determine the validity of guidelines published by interventional medical societies. We reviewed the interventional medicine subspecialty society websites of the American Association for Bronchology and Interventional Pulmonology (AABIP), American Society of Diagnostic and Interventional Nephrology (ASDIN), American Society for Gastrointestinal Endoscopy (ASGE), and Society for Cardiovascular Angiography and Interventions (SCAI) as of November 15, 2012, for published interventional guidelines. The study was performed between November 15, 2012, and January 1, 2013. The AABIP did not publish guidelines, so American Thoracic Society and American College of Chest Physicians guidelines were reviewed. All the guidelines were reviewed for graded levels of evidence, methods used to grade the evidence, and disclosures of conflicts of interest (COIs). Of 153 interventional guidelines evaluated, 4 were duplicates. Forty-six percent of guidelines (69 of 149) graded the quality of evidence using 7 different methods. The ASGE graded 71% of guidelines (46 of 65) compared with 29% (23 of 78) by the SCAI and 0 by the ASDIN (n=4) and the pulmonary societies (n=2). Of the 3425 recommendations reviewed, 11% (n=364) were supported by level A, 42% (n=1432) by level B, and 48% (n=1629) by level C. The mean age of the guidelines was 5.2 years. Additionally, 62% of the guidelines (92 of 149) failed to comment on COIs; when disclosed, 91% of guidelines (52 of 57) reported COIs. In total, 1827 COIs were reported by 45% of the authors (317 of 697), averaging 5.8 COIs per author. Most of the interventional guidelines failed to grade the evidence. When present, most guidelines used lower-quality evidence. Furthermore, most guidelines failed to disclose COIs. When commented on, numerous COIs were present. Future guidelines should clearly state the quality of evidence, use a standard grading system, be transparent regarding potential biases, and provide frequent updates. Copyright © 2014 Mayo

  14. Quantitative analysis applied to contrast medium extravasation by using the computed-tomography number within the region of interest

    Science.gov (United States)

    Lee, Jae-Seung; Im, In-Chul; Kim, Moon-Jib; Goo, Eun-Hoe; Kim, Sun-Ju; Kim, Kwang; Kwak, Byung-Joon

    2014-02-01

    The present study was carried out to present a method to analyze extravasation quantitatively by measuring the computed tomography (CT) number after determining the region of interest (ROI) in the CT images obtained from patients suspected of extravasation induced by contrast medium auto-injection. To achieve this, we divided the study subjects into a group of patients who incurred extravasation and a group of patients who underwent routine scans without incurring extravasation. The CT numbers at IV sites were obtained as reference values, and CT numbers at extravasation sites and hepatic portal veins, respectively, were obtained as relative values. Thereupon, the predicted time for extravasation ( T EP ) and the predicted ratio for extravasation ( R EP ) of an extravasation site were obtained and analyzed quantitatively. In the case of extravasation induced by a dual auto-injector, the values of the CT numbers were confirmed to be lower and the extravasation site to be enlarged when compared to the extravasation induced by a single autoinjector. This is because the physiological saline introduced after the injection of the contrast agent diluted the concentration of the extravasated contrast agent. Additionally, the T EP caused by the auto-injector was about 40 seconds, and we could perform a precise quantitative assessment of the site suspected of extravasation. In conclusion, the dual auto-injection method, despite its advantage of reducing the volume of contrast agent and improving the quality of images for patients with good vascular integrity, was judged to be likely to increase the risk of extravasation and aggravate outcomes for patients with poor vascular integrity by enlarging extravasation sites.

  15. [Survival analysis of hematopoietic stem cell transplantation in children with primary immunodeficiency in Spain].

    Science.gov (United States)

    Hladun, R; Badell, I; González, M; Martínez, A M; Sánchez de Toledo, J; Olivé, M T; González, M E; Elorza, I; Díaz de Heredia, C

    2015-02-01

    Children with primary immunodeficiency have severe life-threatening infections and a higher prevalence of autoimmune problems, allergy and lymphoproliferative disorders. Allogenic hematopoietic stem cell transplantation has been the only potentially curative option. Patients with primary immunodeficiency underwent allogenic stem cell transplantation in the period 1985-2011, and registered in the Spanish Working Party for Bone Marrow Transplantation in Children. One hundred and fifty nine patients underwent 173 allogenic stem cell transplantations, of whom 97 had severe combined immunodeficiency, 30 with immune dysregulation disorders, 25 Wiskott-Aldrich syndrome, and 21 phagocyte disorders. The median patient age at diagnosis was 6 months (range: 17 days - 168 months) and the median patient age at transplant was 12 months (range: 1 month - 189 months). The donors were 30 (19%) identical siblings, 40 (25%) alternative family donors, and 89 (56%) unrelated donors. The source of stem cells was bone marrow in 68 (43%), cord blood in 52 (33%), and peripheral blood in 39 (24%). Ninety eight (61.6%) are alive, 57 (35.9%) died. Event-free survival at 10 years was 63%, with 90% for children transplanted from identical siblings, 36% for those transplanted from alternative family donors, and 66% for those transplanted from unrelated donors. The best results have been obtained with identical siblings, but other options may be considered. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  16. Health-related quality of life and long-term prognosis in chronic hypercapnic respiratory failure: a prospective survival analysis

    Directory of Open Access Journals (Sweden)

    Schmidbauer Kathrin

    2007-12-01

    Full Text Available Abstract Background Health-related quality of life (HRQL is considered as an important outcome parameter in patients with chronic diseases. This study aimed to assess the role of disease-specific HRQL for long-term survival in patients of different diagnoses with chronic hypercapnic respiratory failure (CHRF. Methods In a cohort of 231 stable patients (chronic obstructive pulmonary disease (COPD, n = 98; non-COPD (obesity-hypoventilation syndrome, restrictive disorders, neuromuscular disorders, n = 133 with CHRF and current home mechanical ventilation (HMV, HRQL was assessed by the disease-specific Severe Respiratory Insufficiency (SRI questionnaire and its prognostic value was prospectively evaluated during a follow-up of 2–4 years, using univariate and multivariate regression analysis. Results HRQL was more impaired in COPD (mean ± SD SRI-summary score (SRI-SS 52.5 ± 15.6 than non-COPD patients (67.6 ± 16.4; p 1 turned out to be independent predictors (p Conclusion In patients with CHRF and HMV, the disease-specific SRI was an overall predictor of long-term survival in addition to established risk factors. However, the SRI predominantly beared information regarding long-term survival in non-COPD patients, while in COPD patients objective measures of the disease state were superior. This on one hand highlights the significance of HRQL in the long-term course of patients with CHRF, on the other hand it suggests that the predictive value of HRQL depends on the underlying disease.

  17. Which is a more accurate predictor in colorectal survival analysis? Nine data mining algorithms vs. the TNM staging system.

    Science.gov (United States)

    Gao, Peng; Zhou, Xin; Wang, Zhen-ning; Song, Yong-xi; Tong, Lin-lin; Xu, Ying-ying; Yue, Zhen-yu; Xu, Hui-mian

    2012-01-01

    Over the past decades, many studies have used data mining technology to predict the 5-year survival rate of colorectal cancer, but there have been few reports that compared multiple data mining algorithms to the TNM classification of malignant tumors (TNM) staging system using a dataset in which the training and testing data were from different sources. Here we compared nine data mining algorithms to the TNM staging system for colorectal survival analysis. Two different datasets were used: 1) the National Cancer Institute's Surveillance, Epidemiology, and End Results dataset; and 2) the dataset from a single Chinese institution. An optimization and prediction system based on nine data mining algorithms as well as two variable selection methods was implemented. The TNM staging system was based on the 7(th) edition of the American Joint Committee on Cancer TNM staging system. When the training and testing data were from the same sources, all algorithms had slight advantages over the TNM staging system in predictive accuracy. When the data were from different sources, only four algorithms (logistic regression, general regression neural network, bayesian networks, and Naïve Bayes) had slight advantages over the TNM staging system. Also, there was no significant differences among all the algorithms (p>0.05). The TNM staging system is simple and practical at present, and data mining methods are not accurate enough to replace the TNM staging system for colorectal cancer survival prediction. Furthermore, there were no significant differences in the predictive accuracy of all the algorithms when the data were from different sources. Building a larger dataset that includes more variables may be important for furthering predictive accuracy.

  18. Which is a more accurate predictor in colorectal survival analysis? Nine data mining algorithms vs. the TNM staging system.

    Directory of Open Access Journals (Sweden)

    Peng Gao

    Full Text Available OBJECTIVE: Over the past decades, many studies have used data mining technology to predict the 5-year survival rate of colorectal cancer, but there have been few reports that compared multiple data mining algorithms to the TNM classification of malignant tumors (TNM staging system using a dataset in which the training and testing data were from different sources. Here we compared nine data mining algorithms to the TNM staging system for colorectal survival analysis. METHODS: Two different datasets were used: 1 the National Cancer Institute's Surveillance, Epidemiology, and End Results dataset; and 2 the dataset from a single Chinese institution. An optimization and prediction system based on nine data mining algorithms as well as two variable selection methods was implemented. The TNM staging system was based on the 7(th edition of the American Joint Committee on Cancer TNM staging system. RESULTS: When the training and testing data were from the same sources, all algorithms had slight advantages over the TNM staging system in predictive accuracy. When the data were from different sources, only four algorithms (logistic regression, general regression neural network, bayesian networks, and Naïve Bayes had slight advantages over the TNM staging system. Also, there was no significant differences among all the algorithms (p>0.05. CONCLUSIONS: The TNM staging system is simple and practical at present, and data mining methods are not accurate enough to replace the TNM staging system for colorectal cancer survival prediction. Furthermore, there were no significant differences in the predictive accuracy of all the algorithms when the data were from different sources. Building a larger dataset that includes more variables may be important for furthering predictive accuracy.

  19. SPSS survival manual a step by step guide to data analysis using SPSS

    CERN Document Server

    Pallant, Julie

    2010-01-01

    In this thoroughly revised edition of her bestselling text, now covering up to version 18 of the SPSS soft