Abstract:
:Crossover studies have been successfully conducted in the case of continuous responses. Existing procedures of analysis for ordinal responses, on the other hand, are rarely satisfactory unless strict, usually unrealistic, assumptions are made. In this paper we investigate a random effects model and show that the model is simple and general. Interpretation of parameters is easy, though with a complicated fitting procedure.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Ezzet F,Whitehead Jdoi
10.1002/sim.4780100611subject
Has Abstractpub_date
1991-06-01 00:00:00pages
901-6; discussion 906-7issue
6eissn
0277-6715issn
1097-0258journal_volume
10pub_type
杂志文章abstract::Korn and Whittemore have presented methods for analyzing longitudinal data where the number of observations per individual is large relative to the number of variables considered for each subject. However, this is often not the case in epidemiologic studies, since one usually collects data at relatively few time point...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780040407
更新日期:1985-10-01 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::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::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::Correct specification of the inverse probability weighting (IPW) model is necessary for consistent inference from a marginal structural Cox model (MSCM). In practical applications, researchers are typically unaware of the true specification of the weight model. Nonetheless, IPWs are commonly estimated using parametric...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7266
更新日期:2017-06-15 00:00:00
abstract::In survival analyses, inverse-probability-of-treatment (IPT) and inverse-probability-of-censoring (IPC) weighted estimators of parameters in marginal structural Cox models are often used to estimate treatment effects in the presence of time-dependent confounding and censoring. In most applications, a robust variance e...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7823
更新日期:2018-10-30 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
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::Hypothesis testing, in which the null hypothesis specifies no difference between treatment groups, is an important tool in the assessment of new medical interventions. For randomized clinical trials, permutation tests that reflect the actual randomization are design-based analyses for such hypotheses. This means that ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(20000530)19:10<1319::aid-s
更新日期:2000-05-30 00:00:00
abstract::The intraclass correlation coefficient rho plays a key role in the design of cluster randomized trials. Estimates of rho obtained from previous cluster trials and used to inform sample size calculation in planned trials may be imprecise due to the typically small numbers of clusters in such studies. It may be useful t...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1643
更新日期:2003-12-30 00:00:00
abstract::Diseases can be interconnected. In the recent years, there has been a surge of multidisease studies. Among them, HDN (human disease network) analysis takes a system perspective, examines the interconnections among diseases along with their individual properties, and has demonstrated great potential. Most of the existi...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8472
更新日期:2020-04-30 00:00:00
abstract::A considerable number of the clinical reports which are presented to the Dutch Board for the Evaluation of Drugs, have deficiencies and/or shortcomings. A number of these, including loose description of the target population and sampling method, methodological flaws, incorrect treatment of withdrawals, confounding of ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780020209
更新日期:1983-04-01 00:00:00
abstract::Lower urinary tract symptoms can indicate the presence of urinary tract infection (UTI), a condition that if it becomes chronic requires expensive and time consuming care as well as leading to reduced quality of life. Detecting the presence and gravity of an infection from the earliest symptoms is then highly valuable...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6786
更新日期:2016-04-15 00:00:00
abstract::Various aspects of portfolio management and project prioritization within the pharmaceutical industry are examined. It is shown that the cost and probability architecture of a project is a crucial aspect of its value. An appropriate simple tool for ranking projects is the Pearson index. Various difficulties are consid...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0258(19961230)15:24<2689::AID-S
更新日期:1996-12-30 00:00:00
abstract::This paper presents combinatorial (exact) methods that are useful in the analysis of disease cluster data obtained from small environments, such as buildings and neighbourhoods. Maxwell-Boltzmann and Fermi-Dirac occupancy models are compared in terms of appropriateness of representation of disease incidence patterns (...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780121906
更新日期:1993-10-01 00:00:00
abstract::Longitudinal studies are often concerned with estimating the recurrence rate of a non-fatal event. In many cases, only the total number of events occurring during successive time intervals is known. We compared a mixed Poisson-gamma regression method proposed by Thall and a quasi-likelihood method proposed by Zeger an...
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.4780121406
更新日期:1993-07-30 00:00:00
abstract::Case-control studies are prone to low power for testing gene-environment interactions (GXE) given the need for a sufficient number of individuals on each strata of disease, gene, and environment. We propose a new study design to increase power by strategically pooling biospecimens. Pooling biospecimens allows us to in...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5357
更新日期:2012-11-20 00:00:00
abstract::For many HIV-infected patients, use of antiretroviral therapy (ART) results in a sustained suppression of plasma viral load to undetectable levels. However, due to lack of antigenic stimulation, this may also result in a gradual loss of cell-mediated immune (CMI) responses that help control HIV infection. In concept, ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2555
更新日期:2007-02-10 00:00:00
abstract::Outcomes research often requires estimating the impact of a binary treatment on a binary outcome in a non-randomized setting, such as the effect of taking a drug on mortality. The data often come from self-selected samples, leading to a spurious correlation between the treatment and outcome when standard binary depend...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2226
更新日期:2006-02-15 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
pub_type: 杂志文章
doi:10.1002/sim.5565
更新日期:2013-02-10 00:00:00
abstract::Wittes and Brittain recommended using an 'internal pilot study' to adjust sample size. The approach involves five steps in testing a general linear hypothesis for a general linear univariate model, with Gaussian errors. First, specify the design, hypothesis, desired test size, power, a smallest 'clinically meaningful'...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19990530)18:10<1199::aid-s
更新日期:1999-05-30 00:00:00
abstract::The FDA Guidance, while highly appropriate for industry sponsored trials, need not be imposed on publicly (e.g. NIH) financed clinical trials. While the potential for conflicts of interest exist in the latter, they are in general manageable and pose an acceptable low risk of threatening the integrity of a study. Howev...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1787
更新日期:2004-05-30 00:00:00
abstract::Several relative risk models for survival time data in drug combination therapy are derived and their properties are discussed. The main intention of this paper is to clarify the differences among the models in order to help to choose the appropriate one in a given situation. The models are motivated by discussing the...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780091216
更新日期:1990-12-01 00:00:00
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 anci...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780110708
更新日期:1992-05-01 00:00:00
abstract::This paper models monthly AIDS diagnosis counts in terms of smooth secular trend, calendar month effects, and the number of workdays per month. A parameterization of month effects allows separation of true seasonal effects from a linear trend over the calendar year and an arbitrary June effect. There is strong evidenc...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780131905
更新日期:1994-10-15 00:00:00
abstract::A problem occurring in chronic disease modeling is the estimation of transition probabilities of moving from one state of a categorical risk factor to another. Transitions could be obtained from a cohort study, but often such data may not be available. However, under the assumption that transitions remain stable over ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4423
更新日期:2012-03-15 00:00:00
abstract::In this paper, we discuss statistical inference for a 2 × 2 table under inverse sampling, where the total number of cases is fixed by design. We demonstrate that the exact unconditional distributions of some relevant statistics differ from the distributions under conventional sampling, where the sample size is fixed b...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6511
更新日期:2015-08-30 00:00:00
abstract::In a phase I clinical trial in cancer patients, the drug involved had one known main adverse effect, which also occurs spontaneously in cancer patients with a fairly high frequency. Experiments in rats have shown marked effects of the drug on tumour growth in high doses, but also dose-dependent toxicity. Consequently,...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780140909
更新日期:1995-05-15 00:00:00
abstract::Determination of the equation that relates an ordered dependent variable to ordered independent variables is sought. One solution, non-parametric discriminant analysis (NPD), involves obtaining the best monotonic step function by means of a computer search procedure. Although one can use alternative selection criteria...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780110804
更新日期:1992-06-15 00:00:00
abstract::In observational studies, many continuous or categorical covariates may be related to an outcome. Various spline-based procedures or the multivariable fractional polynomial (MFP) procedure can be used to identify important variables and functional forms for continuous covariates. This is the main aim of an explanatory...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5639
更新日期:2013-06-15 00:00:00
abstract::Omitted variable bias is discussed in the context of linear models. It is shown that the effect of omitted variables can be controlled in linear models for metric dependent variables by using data from follow-up studies. Two different models for analysing such data are proposed. In the first model the omitted variable...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780110906
更新日期:1992-06-30 00:00:00