Abstract:
:We consider a latent variable hazard model for clustered survival data where clusters are a random sample from an underlying population. We allow interactions between the random cluster effect and covariates. We use a maximum pseudo-likelihood estimator to estimate the mean hazard ratio parameters. We propose a bootstrap sampling scheme to obtain an estimate of the variance of the proposed estimator. Application of this method in large multi-centre clinical trials allows one to assess the mean treatment effect, where we consider participating centres as a random sample from an underlying population. We evaluate properties of the proposed estimators via extensive simulation studies. A real data example from the Studies of Left Ventricular Dysfunction (SOLVD) Prevention Trial illustrates the method.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Cai J,Zhou H,Davis CEdoi
10.1002/(sici)1097-0258(19970915)16:17<2009::aid-ssubject
Has Abstractpub_date
1997-09-15 00:00:00pages
2009-20issue
17eissn
0277-6715issn
1097-0258pii
10.1002/(SICI)1097-0258(19970915)16:17<2009::AID-Sjournal_volume
16pub_type
杂志文章abstract::Hot-deck imputation is an intuitively simple and popular method of accommodating incomplete data. Users of the method will often use the usual multiple imputation variance estimator which is not appropriate in this case. However, no variance expression has yet been derived for this easily implemented method applied to...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970115)16:1<5::aid-sim46
更新日期:1997-01-15 00:00:00
abstract::Measures that quantify the impact of heterogeneity in univariate meta-analysis, including the very popular I(2) statistic, are now well established. Multivariate meta-analysis, where studies provide multiple outcomes that are pooled in a single analysis, is also becoming more commonly used. The question of how to quan...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5453
更新日期:2012-12-20 00:00:00
abstract::This paper presents a simple method for estimation of population vaccination effectiveness, which is the fraction of disease cases prevented by a vaccination programme. The method is based on the susceptible-infectious-recovered (SIR) model for the spread of an epidemic in a heterogeneous population under non-homogene...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970330)16:6<601::aid-sim
更新日期:1997-03-30 00:00:00
abstract::In this paper, we consider pooling schemes in which samples are to be tested in two-stages. We show that when batch size is limited as well as pool size, selection schemes tend to be more efficient and flexible. Formulae for the efficiencies of square arrays in all dimensions and for all selection schemes are given in...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3965
更新日期:2010-09-20 00:00:00
abstract::This paper describes the Stoke Index which has been designed to give a global measure of disease activity in rheumatoid arthritis. The index is based on two objective laboratory measurements, one subjective and two semi-objective clinical measurements, chosen from 13 measurements using clinical judgement. Variable sel...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780121206
更新日期:1993-06-30 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::Rationalization of antibiotic therapy in the management of infectious diseases is helped by a knowledge of the patterns of sensitivity and resistance of bacteria to antibiotics and their possible changes both in time and from one hospital unit to another. In this paper we present the results regarding the sensitivitie...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2447
更新日期:2006-10-30 00:00:00
abstract::Randomized clinical trial designs commonly include one or more planned interim analyses. At these times an external monitoring committee reviews the accumulated data and determines whether it is scientifically and ethically appropriate for the study to continue. With failure-time endpoints, it is common to schedule an...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.843
更新日期:2001-07-30 00:00:00
abstract::The power prior has been widely used in many applications covering a large number of disciplines. The power prior is intended to be an informative prior constructed from historical data. It has been used in clinical trials, genetics, health care, psychology, environmental health, engineering, economics, and business. ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6728
更新日期:2015-12-10 00:00:00
abstract::We provide a Bayesian analysis of data categorized into two levels of age (younger than 50 years, at least 50 years) and three levels of bone mineral density (normal, osteopenia, osteoporosis) for white females at least 20 years old in the third National Health and Nutrition Examination Survey. For the sample, the age...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1985
更新日期:2005-04-15 00:00:00
abstract::One may encounter the application of the two independent samples t-test to ordinal scaled data (for example, data that assume only the values 0, 1, 2, 3) from small samples. This situation clearly violates the underlying normality assumption for the t-test and one cannot appeal to large sample theory for validity. In ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780060110
更新日期:1987-01-01 00:00:00
abstract::We analyze data obtained from a study designed to evaluate training effects on the performance of certain motor activities of Parkinson's disease patients. Maximum likelihood methods were used to fit beta-binomial/Poisson regression models tailored to evaluate the effects of training on the numbers of attempted and su...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3303
更新日期:2008-07-30 00:00:00
abstract::For bivariate meta-analysis of diagnostic studies, likelihood approaches are very popular. However, they often run into numerical problems with possible non-convergence. In addition, the construction of confidence intervals is controversial. Bayesian methods based on Markov chain Monte Carlo (MCMC) sampling could be u...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3858
更新日期:2010-05-30 00:00:00
abstract::In this paper, we proposed a mechanistic breast cancer survival model based on the axillary lymph node chain structure, considering lymph nodes as a potential dissemination arrangement. We assume a naive breast cancer treatment protocol consisting of exposing patients first to a chemotherapy treatment on r intervals a...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5576
更新日期:2013-04-30 00:00:00
abstract::Within the rich literature on generalized linear models, substantial efforts have been devoted to models for categorical responses that are either completely ordered or completely unordered. Few studies have focused on the analysis of partially ordered outcomes, which arise in practically every area of study, includin...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4318
更新日期:2012-01-13 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
pub_type: 杂志文章
doi:10.1002/sim.5429
更新日期:2012-12-10 00:00:00
abstract::This field study sought to measure the effects of dental delivery and school-based, dental health education on use of dental health care by children in grades K-6. We attempted to control for two potential confounding factors by an approximate randomization of children into treatment groups with stratification on grad...
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.4780020107
更新日期:1983-01-01 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::Clinical studies that involve the recording of two or more distinct and well-defined events on each subject give rise to multiple event data. Treatment comparisons are usually reported in univariate analyses of time to first event or number of events observed. However, this approach may not uncover the 'full story' of...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,多中心研究,随机对照试验
doi:10.1002/(sici)1097-0258(19970430)16:8<941::aid-sim
更新日期:1997-04-30 00:00:00
abstract::In the pharmaceutical industry, an assay method is considered validated if the accuracy and precision for an assay meet some acceptable limits. This paper discusses the assessment of assay precision in terms of the estimation of total variability of an assay from a one-way random effects model which is often considere...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780101006
更新日期:1991-10-01 00:00:00
abstract::The use of classification and regression tree (CART) methodology is explored for the diagnosis of patients complaining of anterior chest pain. The results are compared with those previously obtained using correspondence analysis and independent Bayes classification. The technique is shown to be of potential value for ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970415)16:7<717::aid-sim
更新日期:1997-04-15 00:00:00
abstract::Non-linear mixed-effects models (NLMEMs) are used to improve information gathering from longitudinal studies and are applied to treatment evaluation in disease-evolution studies, such as human immunodeficiency virus (HIV) infection. The estimation of parameters and the statistical tests are critical issues in NLMEMs s...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2950
更新日期:2007-11-30 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::In cancer clinical trials, patients often experience a recurrence of disease prior to the outcome of interest, overall survival. Additionally, for many cancers, there is a cured fraction of the population who will never experience a recurrence. There is often interest in how different covariates affect the probability...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6056
更新日期:2014-05-10 00:00:00
abstract::We compared eight nominal 95 per cent confidence intervals for the ratio of two Poisson parameters, both assumed small, on their true coverage (the probability that the interval includes the ratio of Poisson parameters) and median width. The commonly used log-linear interval, justified by asymptotic considerations, pr...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3234
更新日期:2008-09-10 00:00:00
abstract::Girardeau, Ravaud and Donner in 2008 presented a formula for sample size calculations for cluster randomised crossover trials, when the intracluster correlation coefficient, interperiod correlation coefficient and mean cluster size are specified in advance. However, in many randomised trials, the number of clusters is...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8191
更新日期:2019-08-15 00:00:00
abstract::In a medical study we are often interested in graphically displaying the relationship between continuous variables and clinical events indicating disease progression. Often, it is reasonable to make the minimal assumption that the risk of progression is an arbitrary monotone function of the continuous variable. Someti...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1561
更新日期:2003-10-30 00:00:00
abstract::Sam Greenhouse joined the Census Bureau as a clerk at an interesting time period for the agency. The first use of sampling in the decennial census occurred in 1940. There was a major expansion of the amount of data collected. The organization of the Census Bureau underwent radical changes, including the growth of the ...
journal_title:Statistics in medicine
pub_type: 传,历史文章,杂志文章
doi:10.1002/sim.1627
更新日期:2003-11-15 00:00:00
abstract::To compare the survival functions based on right-truncated data, Lagakos et al. proposed a weighted logrank test based on a reverse time scale. This is in contrast to Bilker and Wang, who suggested a semi-parametric version of the Mann-Whitney test by assuming that the distribution of truncation times is known or can ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2556
更新日期:2007-02-20 00:00:00
abstract::Many complex diseases are known to be affected by the interactions between genetic variants and environmental exposures beyond the main genetic and environmental effects. Study of gene-environment (G×E) interactions is important for elucidating the disease etiology. Existing Bayesian methods for G×E interaction studie...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8434
更新日期:2020-02-28 00:00:00