ML and REML estimation in survival analysis with time dependent correlated frailty.

abstract：:Interim analyses are conducted to allow for early termination of the trial, for ethical as well as economical reasons. Here we consider interim analyses in repeated measurements studies where the measurements are binary. Two methods for analysing this kind of data are compared according to their operating characterist...

journal_title：Statistics in medicine

authors： Spiessens B,Lesaffre E,Verbeke G

更新日期：2003-02-28 00:00:00

abstract：:Biostatisticians have frequently uncritically accepted the measurements provided by their medical colleagues engaged in clinical research. Such measures often involve considerable loss of information. Particularly, unfortunate is the widespread use of the so-called 'responder analysis', which may involve not only a lo...

journal_title：Statistics in medicine

authors： Senn S,Julious S

更新日期：2009-11-20 00:00:00

abstract：:Interval-censored data are commonly found in studies of diseases that progress without symptoms, which require clinical evaluation for detection. Several techniques have been suggested with independent assumption. However, the assumption will not be valid if observations come from clusters. Furthermore, when the clust...

journal_title：Statistics in medicine

authors： Kim YJ

更新日期：2010-12-10 00:00:00

abstract：:Patient reported outcome and observer evaluative studies in clinical trials and post-hoc analyses often use instruments that measure responses on ordinal-rating or Likert scales. We propose a flexible distributional approach by modeling the change scores from the baseline to the end of the study using independent beta...

journal_title：Statistics in medicine

authors： Zou KH,Carlsson MO,Quinn SA

更新日期：2010-10-30 00:00:00

abstract：:Bioequivalence assessment is an issue of great interest. Development of statistical methods for assessing bioequivalence is an important area of research for statisticians. Bioequivalence is usually determined based on the normal distribution. We relax this assumption and develop a semi-parametric mixed model for bioe...

journal_title：Statistics in medicine

authors： Ghosh P,Rosner GL

更新日期：2007-03-15 00:00:00

abstract：:Appropriate methods for meta-regression applied to a set of clinical trials, and the limitations and pitfalls in interpretation, are insufficiently recognized. Here we summarize recent research focusing on these issues, and consider three published examples of meta-regression in the light of this work. One principal m...

journal_title：Statistics in medicine

authors： Thompson SG,Higgins JP

更新日期：2002-06-15 00:00:00

abstract：:When the event time of interest depends on the censoring time, conventional two-sample test methods, such as the log-rank and Wilcoxon tests, can produce an invalid test result. We extend our previous work on estimation using auxiliary variables to adjust for dependent censoring via multiple imputation, to the compari...

journal_title：Statistics in medicine

authors： Hsu CH,Taylor JM

更新日期：2009-02-01 00:00:00

abstract：:We construct nonparametric regression estimators of a number of temporal functions in a multistate system based on a continuous univariate baseline covariate. These estimators include state occupation probabilities, state entry, exit, and waiting (sojourn) time distribution functions of a general progressive (e.g., ac...

journal_title：Statistics in medicine

authors： Mostajabi F,Datta S

更新日期：2013-07-30 00:00:00

abstract：:Among subjects who have experienced a biological event, such as menarche, menopause or a delivery, one cannot distinguish the effects of time since the event from age at the event due to the linear dependency among these time variables and age at study ('current age'). This is a well-known problem that also exists in ...

journal_title：Statistics in medicine

authors： Hsieh CC,Lan SJ

更新日期：1996-07-30 00:00:00

abstract：:This paper presents a mixture model which combines features of the usual Cox proportional hazards model with those of a class of models, known as mixtures-of-experts. The resulting model is more flexible than the usual Cox model in the sense that the log hazard ratio is allowed to vary non-linearly as a function of th...

journal_title：Statistics in medicine

authors： Rosen O,Tanner M

更新日期：1999-05-15 00:00:00

abstract：:In the analysis of composite endpoints in a clinical trial, time to first event analysis techniques such as the logrank test and Cox proportional hazard test do not take into account the multiplicity, importance, and the severity of events in the composite endpoint. Several generalized pairwise comparison analysis met...

journal_title：Statistics in medicine

authors： Verbeeck J,Spitzer E,de Vries T,van Es GA,Anderson WN,Van Mieghem NM,Leon MB,Molenberghs G,Tijssen J

更新日期：2019-12-30 00:00:00

abstract：:The "some invalid, some valid instrumental variable estimator" (sisVIVE) is a lasso-based method for instrumental variables (IVs) regression of outcome on an exposure. In principle, sisVIVE is robust to some of the IVs in the analysis being invalid, in the sense of being related to the outcome variable through pathway...

journal_title：Statistics in medicine

authors： Bao Y,Clarke PS,Smart M,Kumari M

更新日期：2019-04-30 00:00:00

abstract：:Incomplete and unbalanced multivariate data often arise in longitudinal studies due to missing or unequally-timed repeated measurements and/or the presence of time-varying covariates. A general approach to analysing such data is through maximum likelihood analysis using a linear model for the expected responses, and s...

journal_title：Statistics in medicine

authors： Schluchter MD

更新日期：1988-01-01 00:00:00

abstract：:Providing personalized treatments designed to maximize benefits and minimizing harms is of tremendous current medical interest. One problem in this area is the evaluation of the interaction between the treatment and other predictor variables. Treatment effects in subgroups having the same direction but different magni...

journal_title：Statistics in medicine

authors： Chen W,Ghosh D,Raghunathan TE,Norkin M,Sargent DJ,Bepler G

更新日期：2012-12-10 00:00:00

abstract：:We studied the problem of testing a hypothesized distribution in survival regression models when the data is right censored and survival times are influenced by covariates. A modified chi-squared type test, known as Nikulin-Rao-Robson statistic, is applied for the comparison of accelerated failure time models. This st...

journal_title：Statistics in medicine

authors： Tahir MR,Tran QX,Nikulin MS

更新日期：2017-05-30 00:00:00

abstract：:This paper, arising out of an event to honour the statistical and scientific contributions of Professor Peter Armitage, is concerned with research strategies and needs for chronic disease prevention. A few highlights from recent intervention trials for the prevention of cancer, cardiovascular disease, fractures and di...

journal_title：Statistics in medicine

authors： Prentice RL

更新日期：2004-11-30 00:00:00

abstract：:Funnel plots are widely used to visualize grouped data, for example, in institutional comparison. This paper extends the concept to a multi-level setting, displaying one level at a time, adjusted for the other levels, as well as for covariates at all levels. These level-adjusted funnel plots are based on a Markov chai...

journal_title：Statistics in medicine

authors： Lindhagen L,Darkahi B,Sandblom G,Berglund L

更新日期：2014-09-20 00:00:00

abstract：BACKGROUND:Multiple imputation is becoming increasingly popular for handling missing data, with Markov chain Monte Carlo assuming multivariate normality (MVN) a commonly used approach. Imputing categorical variables (which are clearly non-normal) using MVN imputation is challenging, and several approaches have been sug...

journal_title：Statistics in medicine

authors： Lee KJ,Galati JC,Simpson JA,Carlin JB

更新日期：2012-12-30 00:00:00

abstract：:We present a model for describing correlated binocular data from reader-based diagnostic studies, where the same group of readers evaluates the presence or absence of certain diseases on binocular organs (e.g., fellow eyes) of patients. Multiple random effects are incorporated to meaningfully delineate various associa...

journal_title：Statistics in medicine

authors： Withanage N,de Leon AR,Rudnisky CJ

更新日期：2015-12-20 00:00:00

abstract：:Residuals in normal regression are used to assess a model's goodness-of-fit (GOF) and discover directions for improving the model. However, there is a lack of residuals with a characterized reference distribution for censored regression. In this article, we propose to diagnose censored regression with normalized rando...

journal_title：Statistics in medicine

authors： Li L,Wu T,Feng C

更新日期：2020-12-13 00:00:00

abstract：:In recent years, quality control charts have been increasingly applied in the healthcare environment, for example, to monitor surgical performance. Risk-adjusted cumulative (CUSUM) charts that utilize risk scores like the Parsonnet score to estimate the probability of death of a patient from an operation turn out to b...

journal_title：Statistics in medicine

authors： Knoth S,Wittenberg P,Gan FF

更新日期：2019-05-30 00:00:00

abstract：:Although prostate cancer and benign prostatic hyperplasia are major health problems in U.S. men, little is known about the early stages of the natural history of prostate disease. A molecular biomarker called prostate specific antigen (PSA), together with a unique longitudinal bank of frozen serum, now allows a histor...

journal_title：Statistics in medicine

authors： Pearson JD,Morrell CH,Landis PK,Carter HB,Brant LJ

更新日期：1994-03-15 00:00:00

abstract：:This paper presents a statistically optimal exact hypothesis testing procedure for detecting changes in sales adjusted adverse drug reaction (ADR) rates between historical and current periods, with a computer program that implements this test appended. We provide discussions and illustrations on how to monitor ADR rat...

journal_title：Statistics in medicine

authors： Norwood PK,Sampson AR

更新日期：1988-10-01 00:00:00

abstract：:Sensible plans for health-care needs and determination of priorities for expenditure require regular assessment of trends in HIV incidences. In particular, trends in the relative HIV incidences of different risk categories are useful when assessing whether current control strategies are working equally well for all ri...

journal_title：Statistics in medicine

authors： Becker NG,Cui JS

更新日期：1996-08-30 00:00:00

abstract：:Relative survival provides a measure of the proportion of patients dying from the disease under study without requiring the knowledge of the cause of death. We propose an overall strategy based on regression models to estimate the relative survival and model the effects of potential prognostic factors. The baseline ha...

journal_title：Statistics in medicine

authors： Remontet L,Bossard N,Belot A,Estève J,French network of cancer registries FRANCIM.

更新日期：2007-05-10 00:00:00

abstract：:Standard methods for analysing survival data or case-control data normally concern factors affecting a subject as a whole. However, in a study of a condition that might develop in one or both of a pair of bodily organs information on response and on covariates may be available for each separately. This information can...

journal_title：Statistics in medicine

authors： Whitehead J,Dorse C

更新日期：1988-05-01 00:00:00

abstract：:Conditional power (CP) is the probability that the final study result will be statistically significant, given the data observed thus far and a specific assumption about the pattern of the data to be observed in the remainder of the study, such as assuming the original design effect, or the effect estimated from the c...

journal_title：Statistics in medicine

authors： Lachin JM

更新日期：2005-09-30 00:00:00

abstract：:Biomarkers that predict the efficacy of treatment can potentially improve clinical outcomes and decrease medical costs by allowing treatment to be provided only to those most likely to benefit. We consider the design of a randomized clinical trial in which one objective is to evaluate a treatment selection marker. The...

journal_title：Statistics in medicine

authors： Janes H,Brown MD,Pepe MS

更新日期：2015-11-30 00:00:00

abstract：:Population dynamic models, commonly used tools in the study of epidemics and other complex population processes, are implicit non-linear mathematical equations. Inference based on such models can be difficult due to the problems associated with high dimensional parameters that may be non-identified and complex likelih...

journal_title：Statistics in medicine

authors： Brookhart MA,Hubbard AE,van der Laan MJ,Colford JM Jr,Eisenberg JN

更新日期：2002-12-15 00:00:00

abstract：:Statistical methods are available for performing a meta-analysis when the response variable of interest is the same in each study. Problems arise when studies exploring a common therapeutic question use different patient response types. This article presents statistical methods for combining studies which involve diff...

journal_title：Statistics in medicine

authors： Whitehead A,Jones NM

更新日期：1994-12-15 00:00:00