Abstract:
:We consider evaluation and comparison of the diagnostic accuracy of biomarkers with continuous test outcomes, possibly correlated due to repeated measurements. We develop nonparametric group sequential testing procedures to evaluate and compare the area of biomarkers under their receiver operating characteristic curves, with either independent or paired test outcomes. These procedures rely on the construction of a two-dimensional statistic of Whitehead (Statist. Med. 1999; 18:2271-2286) so that design methods based on Brownian motion can be applied.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Liu A,Wu C,Schisterman EFdoi
10.1002/sim.3203subject
Has Abstractpub_date
2008-05-10 00:00:00pages
1667-78issue
10eissn
0277-6715issn
1097-0258journal_volume
27pub_type
杂志文章abstract::Kappa coefficients are measures of correlation between categorical variables often used as reliability or validity coefficients. We recapitulate development and definitions of the K (categories) by M (ratings) kappas (K x M), discuss what they are well- or ill-designed to do, and summarize where kappas now stand with ...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/sim.1180
更新日期:2002-07-30 00:00:00
abstract::A trial of Duchenne muscular dystrophy involved tracking boys of all ages through a one-year baseline period, followed by a one-year trial of leucine versus placebo treatment. In this paper we develop a model for a total-muscle-strength score that uses the data of the extended baseline period in the evaluation of the ...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1002/sim.4780050304
更新日期:1986-05-01 00:00:00
abstract::Health questionnaires are often built up from sets of questions that are totaled to obtain a sum score. An important consideration in designing questionnaires is to minimize respondent burden. An increasingly popular method for efficient measurement is computerized adaptive testing; unfortunately, many health question...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5936
更新日期:2014-02-10 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
pub_type: 杂志文章
doi:10.1002/sim.1187
更新日期:2002-06-15 00:00:00
abstract::In recent years, follow-on biological products (biosimilars) have received much attention from both the biotechnology industry and the regulatory agencies, especially after the passage of the 2010 healthcare reform bill. Unlike the traditional small-molecule drug products, the development of biological products is not...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5568
更新日期:2013-02-10 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
pub_type: 杂志文章,meta分析
doi:10.1002/sim.1044
更新日期:2002-09-30 00:00:00
abstract::Among many other uses, positron emission tomography (PET) can be used in studies to estimate the density of a neuroreceptor at each location throughout the brain by measuring the concentration of a radiotracer over time and modeling its kinetics. There are a variety of kinetic models in common usage and these typicall...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3510
更新日期:2009-03-15 00:00:00
abstract::We consider counting process methods for analysing time-to-event data with multiple or recurrent outcomes, using the models developed by Anderson and Gill, Wei, Lin and Weissfeld and Prentice, Williams and Peterson. We compare the methods, and show how to implement them using popular statistical software programs. By ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970930)16:18<2029::aid-s
更新日期:1997-09-30 00:00:00
abstract::We applied a computationally practical form of probit analysis for multiple response variables to data on early childhood development of four psychiatric disorders: disruptive disorders (DD-attention deficit disorders, oppositional defiant disorder, conduct disorder); adjustment disorders (ADJ); emotional disorders (E...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19981115)17:21<2487::aid-s
更新日期:1998-11-15 00:00:00
abstract::A new method is proposed for the surveillance of Down's syndrome among newborn. Despite the strong dependence of overall risk of Down's syndrome on maternal age, it has been suggested that an environmentally induced increase in risk may be additive over all maternal ages. The surveillance method introduced here is spe...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780120104
更新日期:1993-01-15 00:00:00
abstract::In a long-running longitudinal study using complex machinery to obtain measurements, it is sometimes necessary to replace the machine. This can result in lack of continuity in the measurements that can overwhelm any treatment effect or time trend. We propose a Bayesian procedure implemented using Markov chain Monte Ca...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1868
更新日期:2004-09-30 00:00:00
abstract::A preference trial is a special form of cross-over trial where clinical conditions determine when patients change treatment, in a prescribed order. This can be modelled using a geometric distribution. The model can be simply fitted using standard logistic regression methodology. The procedure is applied to a trial stu...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0258(19960229)15:4<443::AID-SIM
更新日期:1996-02-28 00:00:00
abstract::We have used Monte Carlo methods to compare the type I error properties of the conditional and unconditional versions of the generalized t and the generalized rank-sum tests to those of the independent samples t and Wilcoxon rank-sum tests. Results showed inflated type I errors for the conditional generalized tests bu...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780110410
更新日期:1992-02-28 00:00:00
abstract::Mesothelioma is a rare cancer caused by exposure to asbestos. Belgium has a known long history of asbestos production, resulting in one of the highest mesothelioma mortality rates worldwide. While the production of asbestos has stopped completely, the long latency period of mesothelioma, which can fluctuate between 20...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8697
更新日期:2020-11-20 00:00:00
abstract::Obtaining accurate estimates of the performance of a diagnostic test for some population of patients might be difficult when the sample of subjects used for this purpose is not representative for the whole population. Thus, in the motivating example of this paper a test is evaluated by comparing its results with those...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3099
更新日期:2008-06-15 00:00:00
abstract::Many quantitative assay measurements of metabolites of environmental toxicants in clinical investigations are subject to left censoring due to values falling below assay detection limits. Moreover, when observations occur in both unexposed individuals and exposed individuals who reflect a mixture of two distributions ...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1002/sim.2079
更新日期:2005-07-15 00:00:00
abstract::This paper presents a procedure for obtaining short-term projections and lower bounds on the size of the acquired immunodeficiency syndrome (AIDS) epidemic. The method is similar to that proposed by Brookmeyer and Gail but adapted to the situation where individual dates of AIDS diagnosis are available. It gives result...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780081210
更新日期:1989-12-01 00:00:00
abstract::During a course of human immunodeficiency virus (HIV-1) infection, the viral load usually increases sharply to a peak following infection and then drops rapidly to a steady state, where it remains until progression to AIDS. This steady state is often referred to as the viral set point. It is believed that the HIV vira...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3038
更新日期:2008-01-15 00:00:00
abstract::For each of 211 arteriosclerosis obliterans patients, the degree of stenosis of arteries at four sites were examined at Hiroshima University Hospital to analyse the relationship between the degree of stenosis and age, sex and site. The generalized estimating equations using a proportional odds model for the stenosis p...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1363
更新日期:2003-07-15 00:00:00
abstract::In applications such as medical statistics and genetics, we encounter situations where a large number of highly correlated predictors explain a response. For example, the response may be a disease indicator and the predictors may be treatment indicators or single nucleotide polymorphisms (SNPs). Constructing a good pr...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4014
更新日期:2010-10-30 00:00:00
abstract::While genome-wide association studies (GWASs) have been widely used to uncover associations between diseases and genetic variants, standard SNP-level GWASs often lack the power to identify SNPs that individually have a moderate effect size but jointly contribute to the disease. To overcome this problem, pathway-based ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8442
更新日期:2020-03-15 00:00:00
abstract::In the recent years, studies of hepatitis B (HBV) and hepatitis C virus (HCV) dynamics have drawn great attention as they provide insight into the process of virus elimination/production and of infected cells decay during antiviral treatment. Estimates of viral dynamic parameters may be used to determine the lifetime ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3457
更新日期:2008-12-30 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
pub_type: 杂志文章
doi:10.1002/sim.5524
更新日期:2013-01-15 00:00:00
abstract::When a cancer patient develops a new tumor it is necessary to determine if it is a recurrence (metastasis) of the original cancer, or an entirely new occurrence of the disease. This is accomplished by assessing the histo-pathology of the lesions. However, there are many clinical scenarios in which this pathological di...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3866
更新日期:2010-07-10 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
pub_type: 杂志文章
doi:10.1002/sim.7297
更新日期:2017-07-30 00:00:00
abstract::The introduction of potent antiretroviral therapies for treatment of HIV infection typically results in a dramatic reduction in plasma HIV RNA concentration, often to levels undetectable by current measurement practices. However, although a high proportion of patients achieve 'undetectability', many then experience a ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1325
更新日期:2003-02-15 00:00:00
abstract::In multiple-record systems estimation it is usually assumed that all registration relate to the same population. In this paper, we develop a method which can be used when the registrations relate to different populations, in the sense that they cover, for example, different time periods or regions. We show that under ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1818
更新日期:2004-07-30 00:00:00
abstract::In psychiatry, clinicians use criteria sets from the Diagnostic and Statistical Manual of Mental Disorders to diagnose mental disorders. Most criteria sets have several symptom domains, and in order to be diagnosed, an individual must meet the minimum number of symptoms required by each domain. Some efforts are now fo...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8173
更新日期:2019-07-20 00:00:00
abstract::Adaptive designs or flexible designs in a broader sense have increasingly been considered in planning pivotal registration clinical trials. Sample size reassessment design and adaptive selection design are two of such designs that appear in regulatory applications. At the design stage, consideration of sample size rea...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4021
更新日期:2011-06-15 00:00:00
abstract::A technique is presented which provides guidance on the spacing of follow-up waves in a multiwave study. Only information from the baseline wave is needed, as well as rough parameter estimates for the survival distribution. The computations use the expected Fisher information; a new method for its calculation is given...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780101209
更新日期:1991-12-01 00:00:00