Estimating patterns of CD4 lymphocyte decline using data from a prevalent cohort of HIV infected individuals.

abstract：:Before introducing a new measurement tool it is necessary to evaluate its performance. Several statistical methods have been developed, or used, to evaluate the reliability and validity of a new assessment method in such circumstances. In this paper we review some commonly used methods. Data from a study that was cond...

journal_title：Statistics in medicine

authors： White SA,van den Broek NR

更新日期：2004-05-30 00:00:00

abstract：:The focus of this paper is dietary intervention trials. We explore the statistical issues involved when the response variable, intake of a food or nutrient, is based on self-report data that are subject to inherent measurement error. There has been little work on handling error in this context. A particular feature of...

journal_title：Statistics in medicine

authors： Keogh RH,Carroll RJ,Tooze JA,Kirkpatrick SI,Freedman LS

更新日期：2016-11-10 00:00:00

abstract：:The National Children's Study is a national household probability sample designed to identify 100,000 children at birth and follow the sampled children for 21 years. Data from the study will support examining numerous hypotheses concerning genetic and environmental effects on the health and development of children. Th...

journal_title：Statistics in medicine

authors： Montaquila JM,Brick JM,Curtin LR

更新日期：2010-06-15 00:00:00

abstract：:Studies in health research are commonly carried out in clustered settings, where the individual response data are correlated within clusters. Estimation and modelling of the extent of between-cluster variation contributes to understanding of the current study and to design of future studies. It is common to express be...

journal_title：Statistics in medicine

authors： Turner RM,Omar RZ,Thompson SG

更新日期：2006-05-15 00:00:00

abstract：:Systematic reviews often provide recommendations for further research. When meta-analyses are inconclusive, such recommendations typically argue for further studies to be conducted. However, the nature and amount of future research should depend on the nature and amount of the existing research. We propose a method ba...

journal_title：Statistics in medicine

authors： Roloff V,Higgins JP,Sutton AJ

更新日期：2013-01-15 00:00:00

abstract：:There is growing interest in how best to adapt and readapt treatments to individuals to maximize clinical benefit. In response, adaptive treatment strategies (ATS), which operationalize adaptive, sequential clinical decision making, have been developed. From a patient's perspective an ATS is a sequence of treatments, ...

journal_title：Statistics in medicine

authors： Almirall D,Compton SN,Gunlicks-Stoessel M,Duan N,Murphy SA

更新日期：2012-07-30 00:00:00

abstract：:Multilevel mixed effects survival models are used in the analysis of clustered survival data, such as repeated events, multicenter clinical trials, and individual participant data (IPD) meta-analyses, to investigate heterogeneity in baseline risk and covariate effects. In this paper, we extend parametric frailty model...

journal_title：Statistics in medicine

authors： Crowther MJ,Look MP,Riley RD

更新日期：2014-09-28 00:00:00

abstract：:Studies involving longitudinal binary responses are widely applied in the health and biomedical sciences research and frequently analyzed by generalized estimating equations (GEE) method. This article proposes an alternative goodness-of-fit test based on the nonparametric smoothing approach for assessing the adequacy ...

journal_title：Statistics in medicine

authors： Lin KC,Chen YJ,Shyr Y

更新日期：2008-09-30 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：:One Sentence Summary: A Bayesian repeated measures model based on quantitative muscle strength data from a prospective Natural History Study was developed to determine disease progression and design clinical trials for GNE myopathy, a rare and slowly progressive muscle disease. GNE myopathy is a rare muscle disease ch...

journal_title：Statistics in medicine

authors： Quintana M,Shrader J,Slota C,Joe G,McKew JC,Fitzgerald M,Gahl WA,Berry S,Carrillo N

更新日期：2019-04-15 00:00:00

abstract：:Correlated data are obtained in longitudinal epidemiological studies, where repeated measurements are taken on individuals or groups over time. Such longitudinal data are ideally analyzed using multilevel modeling approaches, which appropriately account for the correlations in repeated responses in the same individual...

journal_title：Statistics in medicine

authors： Xanthakis V,Sullivan LM,Vasan RS

更新日期：2013-12-10 00:00:00

abstract：:Clinical trials studying treatments for rare diseases are challenging to design and conduct due to the limited number of patients eligible for the trial. One design used to address this challenge is the small n, sequential, multiple assignment, randomized trial (snSMART). We propose a new snSMART design that investiga...

journal_title：Statistics in medicine

authors： Fang F,Hochstedler KA,Tamura RN,Braun TM,Kidwell KM

更新日期：2021-02-20 00:00:00

abstract：:Arming the immune system against cancer has emerged as a powerful tool in oncology during recent years. Instead of poisoning a tumor or destroying it with radiation, therapeutic cancer vaccine, a type of cancer immunotherapy, unleashes the immune system to combat cancer. This indirect mechanism-of-action of vaccines p...

journal_title：Statistics in medicine

authors： Xu Z,Zhen B,Park Y,Zhu B

更新日期：2017-02-20 00:00:00

abstract：:The primary purpose of a disease surveillance system is to provide data for the detection of changes in the incidence of the disease. Methods for the analysis of data from surveillance systems are reviewed. A new procedure is proposed for use when the system includes geographically dispersed reporting units, such as h...

journal_title：Statistics in medicine

authors： Raubertas RF

更新日期：1989-03-01 00:00:00

abstract：:Identification of the latency period for the effect of a time-varying exposure is key when assessing many environmental, nutritional, and behavioral risk factors. A pre-specified exposure metric involving an unknown latency parameter is often used in the statistical model for the exposure-disease relationship. Likelih...

journal_title：Statistics in medicine

authors： Peskoe SB,Spiegelman D,Wang M

更新日期：2019-03-30 00:00:00

abstract：:The lifetime risk of a clinical condition is the probability of onset of the condition during one's lifespan. Recent advances in Alzheimer's disease (AD) research have identified screening tests for biomarkers that can identify persons who are in the earliest stages of the AD process but who do not yet have any clinic...

journal_title：Statistics in medicine

authors： Brookmeyer R,Abdalla N

更新日期：2019-04-30 00:00:00

abstract：:Most phase I dose-finding methods in oncology aim to find the maximum-tolerated dose from a set of prespecified doses. However, in practice, because of a lack of understanding of the true dose-toxicity relationship, it is likely that none of these prespecified doses are equal or reasonably close to the true maximum-to...

journal_title：Statistics in medicine

authors： Chu Y,Pan H,Yuan Y

更新日期：2016-09-10 00:00:00

abstract：:Mediation analysis is a standard approach to understanding how and why an intervention works in social and medical sciences. However, the presence of missing data, especially missing not at random data, poses a great challenge for the applicability of this approach in practice. Current methods for handling such missin...

journal_title：Statistics in medicine

authors： Li W,Zhou XH

更新日期：2017-11-10 00:00:00

abstract：:Biological drug products are therapeutic moieties manufactured by a living system or organisms. These are important life-saving drug products for patients with unmet medical needs. Because of expensive cost, only a few patients have access to life-saving biological products. Most of the early biological products will ...

journal_title：Statistics in medicine

authors： Lin JR,Chow SC,Chang CH,Lin YC,Liu JP

更新日期：2013-02-10 00:00:00

abstract：:The statistical analysis of panel count data has recently attracted a great deal of attention, and a number of approaches have been developed. However, most of these approaches are for situations where the observation and follow-up processes are independent of the underlying recurrent event process unconditional or co...

journal_title：Statistics in medicine

authors： Li N,Zhao H,Sun J

更新日期：2013-07-30 00:00:00

abstract：:We examine the common clinical belief that there is an interaction between epilepsy type and the two standard anti-epileptic drugs, valproate and carbamazepine, using data from several randomized clinical trials. Epilepsy type is not always easy to define, and three possible reclassifications are investigated to see w...

journal_title：Statistics in medicine

authors： Williamson PR,Clough HE,Hutton JL,Marson AG,Chadwick DW

更新日期：2002-09-30 00:00:00

abstract：:We propose a joint model to analyze the structure and intensity of the association between longitudinal measurements of an ordinal marker and time to a relevant event. The longitudinal process is defined in terms of a proportional-odds cumulative logit model. Time-to-event is modeled through a left-truncated proportio...

journal_title：Statistics in medicine

authors： Armero C,Forné C,Rué M,Forte A,Perpiñán H,Gómez G,Baré M

更新日期：2016-12-10 00:00:00

abstract：:The mixed effect models for repeated measures (MMRM) analysis is sometimes used as a primary analysis in longitudinal randomized clinical trials. The SE for the treatment effect in the MMRM analysis is usually estimated by assuming the orthogonality of the fixed effect and variance-covariance parameters, which is the ...

journal_title：Statistics in medicine

authors： Maruo K,Ishii R,Yamaguchi Y,Doi M,Gosho M

更新日期：2020-04-30 00:00:00

abstract：:A method is proposed to infer the randomized treatment effect on survival after an adjustment for a post-randomization variable. The post-randomization variable is made independent of the treatment assignment and is considered a surrogate for baseline prognostic factors. The relationship between the post-randomization...

journal_title：Statistics in medicine

authors： Heller G

更新日期：2001-11-30 00:00:00

abstract：:Researchers in clinical science and bioinformatics frequently aim to learn which of a set of candidate biomarkers is important in determining a given outcome, and to rank the contributions of the candidates accordingly. This article introduces a new approach to research questions of this type, based on targeted maximu...

journal_title：Statistics in medicine

authors： Bembom O,Petersen ML,Rhee SY,Fessel WJ,Sinisi SE,Shafer RW,van der Laan MJ

更新日期：2009-01-15 00:00:00

abstract：:Subjects in randomized controlled trials do not always comply to the treatment condition they have been assigned to. This may cause the estimated effect of the intervention to be biased and also affect efficiency, coverage of confidence intervals, and statistical power. In cluster randomized trials non-compliance may ...

journal_title：Statistics in medicine

authors： Moerbeek M,Schie SV

更新日期：2019-11-20 00:00:00

abstract：:We develop analysis methods for clinical trials with time-to-event outcomes which correct for treatment changes during follow-up, yet are based on comparisons of randomized groups and not of selected groups. A causal model relating observed event times to event times that would have been observed under other treatment...

journal_title：Statistics in medicine

authors： White IR,Babiker AG,Walker S,Darbyshire JH

更新日期：1999-10-15 00:00:00

abstract：:With the increasing availability of detailed clinical information, there is optimism that treatment choices can be selectively directed to those individuals most likely to benefit. While standard clinical trials can establish whether a treatment appears to be effective on average, subsequent work is needed to determin...

journal_title：Statistics in medicine

authors： Sitlani CM,Heagerty PJ

更新日期：2014-07-30 00:00:00

abstract：:In clinical research, we are often interested in assessing how a biomarker changes with time, and whether it could be used as a surrogate marker when evaluating the efficacy of a new drug. However, when the longitudinal marker is correlated with survival, linear mixed models for longitudinal data may be inappropriate....

journal_title：Statistics in medicine

authors： Deslandes E,Chevret S

更新日期：2007-12-30 00:00:00

abstract：:The semi-Markov assumption emphasizes the importance of time spent in a state. In order to compute this type of multistate model, most transition times are always considered to be exactly identified or right censored. However, in the longitudinal analysis of chronic diseases, investigators are often confronted with in...

journal_title：Statistics in medicine

authors： Foucher Y,Giral M,Soulillou JP,Daures JP

更新日期：2007-12-30 00:00:00