Assessing the incremental predictive performance of novel biomarkers over standard predictors.

abstract：:The back-calculation method has been used to estimate the number of HIV infections from AIDS incidence data in a particular population. We present an extension of back calculation that provides estimates of the numbers of HIV infectives in different stages of infection. We model the staging process with a time-depende...

journal_title：Statistics in medicine

authors： Longini IM Jr,Byers RH,Hessol NA,Tan WY

更新日期：1992-04-01 00:00:00

abstract：:Non-tumor cell-based model systems have recently gained interest in pharmacogenetic research as a hypothesis generating tool. The hypotheses generated from these model systems can be followed up in functional studies, or tested in individuals taking the same investigational agents. The current cellular phenotypes (e.g...

journal_title：Statistics in medicine

authors： Fridley BL,Jenkins G,Schaid DJ,Wang L

更新日期：2009-09-20 00:00:00

abstract：:The validity and practical utility of observational medical research depends critically on good study design, excellent data quality, appropriate statistical methods and accurate interpretation of results. Statistical methodology has seen substantial development in recent times. Unfortunately, many of these methodolog...

journal_title：Statistics in medicine

authors： Sauerbrei W,Abrahamowicz M,Altman DG,le Cessie S,Carpenter J,STRATOS initiative.

更新日期：2014-12-30 00:00:00

abstract：:The problem for assessing biosimilarity and drug interchangeability of follow-on biologics (biosimilar products) is studied. Unlike the generic products, the development of biosimilar products is much more complicated because of fundamental differences in functional structures and manufacturing processes. As a result,...

journal_title：Statistics in medicine

authors： Chow SC,Wang J,Endrenyi L,Lachenbruch PA

更新日期：2013-02-10 00:00:00

abstract：:The incremental life expectancy, defined as the difference in mean survival times between two treatment groups, is a crucial quantity of interest in cost-effectiveness analyses. Usually, this quantity is very difficult to estimate from censored survival data with a limited follow-up period. The paper develops estimati...

journal_title：Statistics in medicine

authors： Titman AC

更新日期：2016-09-10 00:00:00

abstract：:Appropriate quantification of added usefulness offered by new markers included in risk prediction algorithms is a problem of active research and debate. Standard methods, including statistical significance and c statistic are useful but not sufficient. Net reclassification improvement (NRI) offers a simple intuitive w...

journal_title：Statistics in medicine

authors： Pencina MJ,D'Agostino RB Sr,Steyerberg EW

更新日期：2011-01-15 00:00:00

abstract：:The cost and efficiency of training clinical centre staff and of duplicate data entry in clinical trials is reviewed. Training is an essential component of quality assurance programmes and it is usually carried out at regular intervals in long-term clinical trials. Initial training of staff and regular retraining is i...

journal_title：Statistics in medicine

authors： Neaton JD,Duchene AG,Svendsen KH,Wentworth D

更新日期：1990-01-01 00:00:00

abstract：:For genome-wide association studies, we propose a new method for identifying significant biological pathways. In this approach, we aggregate data across single-nucleotide polymorphisms to obtain summary measures at the gene level. We then use a hierarchical Bayesian model, which takes the gene-level summary measures a...

journal_title：Statistics in medicine

authors： Shahbaba B,Shachaf CM,Yu Z

更新日期：2012-05-10 00:00:00

abstract：:We discuss the use of the trichotomous logistic model to discriminate between patients with gastrointestinal (GI) cancer, patients with benign GI disease and 'normal' subjects, using symptoms and the concentrations of some serum proteins that are potentially indicative of malignancy as covariates. A parsimonious model...

journal_title：Statistics in medicine

authors： Marshall RJ,Chisholm EM

更新日期：1985-07-01 00:00:00

abstract：:It has been increasingly common to analyze simultaneously repeated measures and time to failure data. In this paper we propose a joint model when the repeated measures are semi-continuous, characterized by the presence of a large portion of zero values, as well as right skewness of non zero (positive) values. Examples...

journal_title：Statistics in medicine

authors： Liu L

更新日期：2009-03-15 00:00:00

abstract：:Geocoding a study population as completely as possible is an important data assimilation component of many spatial epidemiologic studies. Unfortunately, complete geocoding is rare in practice. The failure of a substantial proportion of study subjects' addresses to geocode has consequences for spatial analyses, some of...

journal_title：Statistics in medicine

authors： Zimmerman DL,Fang X,Mazumdar S

更新日期：2008-09-20 00:00:00

abstract：:Mediation analyses can help us to understand the biological mechanism in which an exposure or treatment affects an outcome. Single mediator analyses have been used in various applications, but may not be appropriate for analyzing intricate mechanisms involving multiple mediators that affect each other. Thus, in this a...

journal_title：Statistics in medicine

authors： Lai EY,Shih S,Huang YT,Wang S

更新日期：2020-05-15 00:00:00

abstract：:The goal of phase I cancer trials is to determine the highest dose of a treatment regimen with an acceptable toxicity rate. Traditional designs for phase I trials, such as the Continual Reassessment Method (CRM) and the 3 + 3 design, require each patient or a cohort of patients to be fully evaluated for the dose-limit...

journal_title：Statistics in medicine

authors： Polley MY

更新日期：2011-07-30 00:00:00

abstract：:The matched case-control designs are commonly used to control for potential confounding factors in genetic epidemiology studies especially epigenetic studies with DNA methylation. Compared with unmatched case-control studies with high-dimensional genomic or epigenetic data, there have been few variable selection metho...

journal_title：Statistics in medicine

authors： Sun H,Wang S

更新日期：2013-05-30 00:00:00

abstract：:The setting of a quarantine time for an emerging infectious disease will depend on current knowledge concerning incubation times. Methods for the analysis of information on incubation times are investigated with a particular focus on inference regarding a possible maximum incubation time, after which an exposed indivi...

journal_title：Statistics in medicine

authors： Farewell VT,Herzberg AM,James KW,Ho LM,Leung GM

更新日期：2005-11-30 00:00:00

abstract：:New combination regimens evaluated in phase II cancer clinical trials often show promising results compared to the standard therapy for a disease system. Selection of patients with a better prognosis can be a prominent factor for this optimism. For most disease systems, prognostic variables that are related to the out...

journal_title：Statistics in medicine

authors： Mazumdar M,Fazzari M,Panageas KS

更新日期：2001-03-30 00:00:00

abstract：:Most statistical methodology for phase III clinical trials focuses on the comparison of a single experimental treatment with a control. An increasing desire to reduce the time before regulatory approval of a new drug is sought has led to development of two-stage or sequential designs for trials that combine the defini...

journal_title：Statistics in medicine

authors： Stallard N,Todd S

更新日期：2003-03-15 00:00:00

abstract：:A study of long term survival of 1487 patients given an allogeneic bone marrow transplant for acute myelogenous leukaemia and 729 patients given a transplant for severe aplastic anaemia was conducted by the International Bone Marrow Transplant Registry. One aim of this study is to determine if the mortality rates of t...

journal_title：Statistics in medicine

authors： Andersen PK,Horowitz MM,Klein JP,Socie G,Stone JV,Zhang MJ

更新日期：1999-06-30 00:00:00

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：:We discuss some of the statistical approaches to the design and analysis of phase I clinical trials in cancer. An attempt is made to identify the issues, particular to this type of trial, that should be addressed by an appropriate methodology. A brief review of schemes currently in use is provided together with our vi...

journal_title：Statistics in medicine

authors： O'Quigley J,Chevret S

更新日期：1991-11-01 00:00:00

abstract：:The most popular model used for survival analysis is the proportional hazards regression model proposed by Cox. This is mainly due to its exceptional simplicity. Nevertheless the fundamental assumption of the Cox model is the proportionality of the hazards. For many applications, however, this assumption is doubtful. ...

journal_title：Statistics in medicine

authors： Berger U,Schäfer J,Ulm K

更新日期：2003-04-15 00:00:00

abstract：:Causal inference for non-censored response variables, such as binary or quantitative outcomes, is often based on either (1) direct standardization ('G-formula') or (2) inverse probability of treatment assignment weights ('propensity score'). To do causal inference in survival analysis, one needs to address right-censo...

journal_title：Statistics in medicine

authors： Andersen PK,Syriopoulou E,Parner ET

更新日期：2017-07-30 00:00:00

abstract：:We consider using observational data to estimate the effect of a treatment on disease recurrence, when the decision to initiate treatment is based on longitudinal factors associated with the risk of recurrence. The effect of salvage androgen deprivation therapy (SADT) on the risk of recurrence of prostate cancer is in...

journal_title：Statistics in medicine

authors： Kennedy EH,Taylor JM,Schaubel DE,Williams S

更新日期：2010-11-10 00:00:00

abstract：:Huntington's disease (HD) is a neurodegenerative disorder with a dominant genetic mode of inheritance caused by an expansion of CAG repeats on chromosome 4. Typically, a longer sequence of CAG repeat length is associated with increased risk of experiencing earlier onset of HD. Previous studies of the association betwe...

journal_title：Statistics in medicine

authors： Ma Y,Wang Y

更新日期：2014-04-15 00:00:00

abstract：:When estimating the probability of natural conception from observational data on couples with an unfulfilled child wish, the start of assisted reproductive therapy (ART) is a competing event that cannot be assumed to be independent of natural conception. In clinical practice, interest lies in the probability of natura...

journal_title：Statistics in medicine

authors： van Geloven N,Geskus RB,Mol BW,Zwinderman AH

更新日期：2014-11-20 00:00:00

abstract：:Quality of life (QOL) assessment is a key component of many clinical studies and frequently requires the use of single global summary measures that capture the overall balance of findings from a potentially wide-ranging assessment of QOL issues. We propose and evaluate an irregular multilevel latent variable model sui...

journal_title：Statistics in medicine

authors： Kifley A,Heller GZ,Beath KJ,Bulger D,Ma J,Gebski V

更新日期：2012-05-20 00:00:00

abstract：:In medical research, risk difference (RD) and number needed to treat (NNT) measures for survival times have been mainly proposed without consideration of covariates. In this paper, we develop adjusted RD and NNT measures for use in observational studies with survival time outcomes within the framework of the Cox propo...

journal_title：Statistics in medicine

authors： Laubender RP,Bender R

更新日期：2010-03-30 00:00:00

abstract：:This paper considers the regression analysis of CD4 cell counts, a commonly used indicator and prognostic factor of AIDS progression. For this purpose, a number of methods have been proposed and most of them are based on random effects models. We present an alternative that is based on a mean function regression model...

journal_title：Statistics in medicine

authors： Sun J

更新日期：2001-11-15 00:00:00

abstract：:Propensity score analysis is widely used in observational studies to adjust for confounding and estimate the causal effect of a treatment on the outcome. When the outcome is survival time, there are special considerations on the definition of the causal estimand, point, and variance estimation that have not been thoro...

journal_title：Statistics in medicine

authors： Mao H,Li L,Yang W,Shen Y

更新日期：2018-11-20 00:00:00

abstract：:Joint models initially dedicated to a single longitudinal marker and a single time-to-event need to be extended to account for the rich longitudinal data of cohort studies. Multiple causes of clinical progression are indeed usually observed, and multiple longitudinal markers are collected when the true latent trait of...

journal_title：Statistics in medicine

authors： Proust-Lima C,Dartigues JF,Jacqmin-Gadda H

更新日期：2016-02-10 00:00:00