Abstract:
:This paper presents tables analogous to T-tables for use in the 2 x 2 multinomial trial, where the continuity corrected Z-statistic is used to make exact unconditional inference. This is the first solution of a discrete exact unconditional inference problem involving a multivariate nuisance parameter for which no ancillary statistic exists.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Shuster JJdoi
10.1002/sim.4780110708subject
Has Abstractpub_date
1992-05-01 00:00:00pages
913-22issue
7eissn
0277-6715issn
1097-0258journal_volume
11pub_type
杂志文章abstract::Longitudinal studies collect information on a sample of individuals which is followed over time to analyze the effects of individual and time-dependent characteristics on the observed response. These studies often suffer from attrition: individuals drop out of the study before its completion time and thus present inco...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3604
更新日期:2009-08-30 00:00:00
abstract::Recent studies have indicated variation in the infectivity beta of HIV among heterosexual couples. We represent this heterogeneity by modelling beta as a random variable. Using data on the number of contacts and seroconversion of couples, we fit the model by maximum-likelihood estimation with a beta distribution and a...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780080110
更新日期:1989-01-01 00:00:00
abstract::Day and Walter derived methods of joint maximum likelihood estimation for the sojourn time distribution and the false negative rate for a screening programme. Their methods are not directly applicable to a programme which uses alternate screening by two modalities whose sojourn times and false negative rates will diff...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780080611
更新日期:1989-06-01 00:00:00
abstract::Multi-state models are useful for modelling disease progression where the state space of the process is used to represent the discrete disease status of subjects. Often, the disease process is only observed at clinical visits, and the schedule of these visits can depend on the disease status of patients. In such situa...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6582
更新日期:2015-12-20 00:00:00
abstract::We have developed a method to longitudinally classify subjects into two or more prognostic groups using longitudinally observed values of markers related to the prognosis. We assume the availability of a training data set where the subjects' allocation into the prognostic group is known. The proposed method proceeds i...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3849
更新日期:2010-12-30 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 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
pub_type: 杂志文章
doi:10.1002/sim.968
更新日期:2001-11-30 00:00:00
abstract::We examine Goodman and Kruskal's lambda using Efron's approach to regression and analysis of variance (ANOVA) for zero-one outcome data. For a binary response cross-classified by a single nominal predictor, we present a computationally simple ANOVA table in which lambda is analogous to Pearson's R-square. We character...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780080511
更新日期:1989-05-01 00:00:00
abstract::We consider methods for selecting the joint specification of the mean and variance functions in statistical models for rates or counts. Based on analyses of diagnosis-specific hospital discharge rates in Michigan, we show that a Poisson model with an extra variance component for the systematic variation is superior to...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780100908
更新日期:1991-09-01 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
pub_type: 杂志文章
doi:10.1002/sim.3480
更新日期:2009-02-01 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::Case-control studies are usually defined to investigate risk factors for a single disease of interest. However, subsequent to data collection, investigators may wish to examine as an 'outcome' a variable that was an exposure in the original study. A naive analysis that disregards the sampling strategy that gave rise t...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2398
更新日期:2005-12-30 00:00:00
abstract::The purpose of this research was to develop appropriate methods for analysing repeated ordinal categorical data that arose in an intervention trial to prevent oesophageal cancer. The measured response was the degree of oesophageal dysplasia at 2.5 and 6 years after randomization. An important feature was that some res...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780130511
更新日期:1994-03-15 00:00:00
abstract::Childhood acute lymphoblastic leukaemia is treated with long-term intensive chemotherapy. During the latter part of the treatment, the maintenance therapy, the patients receive oral doses of two cytostatics. The doses are tailored to blood counts measured on a weekly basis, and the treatment is therefore highly dynami...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4393
更新日期:2012-02-28 00:00:00
abstract::A survey is conducted at w of K selection units or lists, e.g. health care institutions or weeks in a year, to estimate N, the total number of individuals with particular characteristics. Our estimator utilizes two items determined for each survey participant: the number, u, among the w lists in S and the number, j, a...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3614
更新日期:2009-07-30 00:00:00
abstract::Optimal prevention and treatment strategies for a disease of multiple causes, such as pneumonia, must be informed by the population distribution of causes among cases, or cause-specific case fractions (CSCFs). CSCFs may further depend on additional explanatory variables. Existing methodological literature in disease e...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8804
更新日期:2021-02-20 00:00:00
abstract::Graphical methods are often used to check goodness-of-fit of models to data. It is common to plot residuals against a reference distribution so that when the model fits the data, the configuration should be close to a straight line. Since the resemblance to a straight line is often unclear, it has been suggested to ad...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780141607
更新日期:1995-08-30 00:00:00
abstract::Although statistical methodology is well-developed for comparing diagnostic tests in terms of their sensitivity and specificity, comparative inference about predictive values is not. In this paper, we consider the analysis of studies comparing operating characteristics of two diagnostic tests that are measured on all ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6485
更新日期:2015-07-10 00:00:00
abstract::Clustered grouped survival data arise naturally in clinical medicine and biological research. For example, in a randomized clinical trial, the variable of interest is the time to occurrence of a certain event with or without a new treatment and the data are collected from possibly correlated subjects from independent ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1323
更新日期:2003-06-30 00:00:00
abstract::A relationship between baseline risk and treatment effect is increasingly investigated as a possible explanation of between-study heterogeneity in clinical trial meta-analysis. An approach that is still often applied in the medical literature is to plot the estimated treatment effects against the estimated measures of...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20001230)19:24<3497::aid-sim830>
更新日期:2000-12-30 00:00:00
abstract::Hospital length of stay (LOS) is an important measure of healthcare utilization and is generally positively skewed and heterogeneous. We fit a Coxian phase-type distribution to LOS and identify the hidden states of the underlying latent homogeneous Markov model. We demonstrate that selecting an appropriate number of p...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4490
更新日期:2012-06-30 00:00:00
abstract::When estimating the average effect of a binary treatment (or exposure) on an outcome, methods that incorporate propensity scores, the G-formula, or targeted maximum likelihood estimation (TMLE) are preferred over naïve regression approaches, which are biased under misspecification of a parametric outcome model. In con...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7628
更新日期:2018-07-20 00:00:00
abstract::The construction, validation and updating of a prognostic model for kidney graft survival is reported using data from the Eurotransplant database. First, a model is constructed for data from transplantations in the period 1984 to 1987. The model is later updated for the 1988 1990 data. The first data set was randomly ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780141806
更新日期:1995-09-30 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
pub_type: 杂志文章
doi:10.1002/sim.3100
更新日期:2007-12-30 00:00:00
abstract::Missing data arise in crossover trials, as they do in any form of clinical trial. Several papers have addressed the problems that missing data create, although almost all of these assume that the probability that a planned observation is missing does not depend on the value that would have been observed; that is, the ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4497
更新日期:2012-07-20 00:00:00
abstract::It is often of interest to use observational data to estimate the causal effect of a target exposure or treatment on an outcome. When estimating the treatment effect, it is essential to appropriately adjust for selection bias due to observed confounders using, for example, propensity score weighting. Selection bias du...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8549
更新日期:2020-08-15 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
pub_type: 杂志文章
doi:10.1002/sim.4477
更新日期:2012-05-10 00:00:00
abstract::Results from an analysis of traffic accidents from a study of the police records of four police stations in the Bangkok metropolis are presented. The main emphasis in this study was put on the development of a measure for traffic accident density. The traffic flow was estimated at the various study locations by traine...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780142113
更新日期:1995-11-15 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
pub_type: 杂志文章
doi:10.1002/sim.8104
更新日期:2019-05-30 00:00:00
abstract::Recently, there has been much work on early phase cancer designs that incorporate both toxicity and efficacy data, called phase I-II designs because they combine elements of both phases. However, they do not explicitly address the phase II hypothesis test of H0 : p ≤ p0 , where p is the probability of efficacy at the ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6124
更新日期:2014-07-20 00:00:00