Abstract:
:Matched-pair designs have been commonly employed in diagnostic, epidemiologic and laboratory studies. For estimation of a ratio of two marginal probabilities in matched-pair data, a Wald-type logarithmic method is computationally simple, but an actual coverage rate is known to be smaller than a nominal one and a length of the confidence interval is shorter than it should be. The Fieller-type method based on constrained maximum likelihood (CML) estimators possesses asymptotically optimum statistical properties and a coverage rate is close to a nominal one. However, hitherto the limits have been obtained by numerical iterations. In this paper, we derive the efficient confidence limits based on CML as analytical solutions of a quartic equation and present the confidence limits in a closed form.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Nam JMdoi
10.1002/sim.3685subject
Has Abstractpub_date
2009-10-15 00:00:00pages
2929-35issue
23eissn
0277-6715issn
1097-0258journal_volume
28pub_type
杂志文章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::When asking 'what is known' about a drug or therapy or program at any time, both researchers and practitioners often confront more than a single study. Facing a variety of findings, where conflicts may outweigh agreement, how can a reviewer constructively approach the task? In this discussion, I will outline some ques...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780060304
更新日期:1987-04-01 00:00:00
abstract::There are inconsistencies between the formulas for the variance of standardized mean difference (SMD) in the Cochrane Handbook for Systematic Reviews and the variance reported in other sources. Instead of the variance appropriate for the SMD of a crossover experiment, the Cochrane Handbook uses the variance appropriat...
journal_title:Statistics in medicine
pub_type: 信件
doi:10.1002/sim.8669
更新日期:2020-11-30 00:00:00
abstract::Many gene expression data are based on two experiments where the gene expressions of the targeted genes under both experiments are correlated. We consider problems in which objectives are to find genes that are simultaneously upregulated/downregulated under both experiments. A Bayesian methodology is proposed based on...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6555
更新日期:2015-11-10 00:00:00
abstract::The randomized clinical trial, LU19, conducted by the Medical Research Council Lung Cancer Working Party, was designed to compare ACE (doxorubicin, cyclophosphamide and etoposide) chemotherapy plus G-CSF (granulocyte colony-stimulating factor) at 2-week intervals versus ACE chemotherapy alone at standard 3-week interv...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章
doi:10.1002/1097-0258(20001015)19:19<2657::aid-sim557>
更新日期:2000-10-15 00:00:00
abstract::Meta-analysis has generally been accepted as a fundamental tool for combining effect estimates from several studies. For binary studies with rare events, the Peto odds ratio (POR) method has become the relative effect estimator of choice. However, the POR leads to biased estimates for the OR when treatment effects are...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6301
更新日期:2014-12-10 00:00:00
abstract::We describe rank-based approaches to assess principal stratification treatment effects in studies where the outcome of interest is only well-defined in a subgroup selected after randomization. Our methods are sensitivity analyses, in that estimands are identified by fixing a parameter and then we investigate the sensi...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5849
更新日期:2013-11-20 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6584
更新日期:2015-12-20 00:00:00
abstract::Clinical trials studying treatments for rare diseases are challenging to design and conduct due to the limited number of patients eligible for the trial. One design used to address this challenge is the small n, sequential, multiple assignment, randomized trial (snSMART). We propose a new snSMART design that investiga...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8813
更新日期:2021-02-20 00:00:00
abstract::A good measure of field vaccine efficacy should evaluate the direct protective effect of vaccination on the person who receives the vaccine. The conventional estimator for vaccine efficacy depends on population level factors that are either unrelated or indirectly related to the direct biological action of the vaccine...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780120309
更新日期:1993-02-01 00:00:00
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...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780100611
更新日期:1991-06-01 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::A method has been developed for simultaneously comparing the usefulness of many treatments of established value for symptomatic medical conditions. Medical assessment of outcome is not employed. Instead patients are required to assess treatments prescribed during the course of ordinary general practice rather than und...
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.4780040104
更新日期:1985-01-01 00:00:00
abstract::Small but important therapeutic effects of new treatments can be most efficiently detected through the study of large randomized prospective series of patients. Such large scale clinical trials are nowadays commonplace. The alternative is years of polemic and debate surrounding several trials each too small to detect ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780010105
更新日期:1982-01-01 00:00:00
abstract::Members of a cohort of workers in chemical industry (the so-called Boehringer cohort) exposed to 2, 3, 7, 8-tetrachlorodibenzo-para-dioxin (TCDD) from 1950 to 1984 were subject in the years 1985-1986 and 1992-1994 to an extensive biomonitoring programme on the TCDD levels of the individual workers. For establishing a ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3074
更新日期:2008-05-30 00:00:00
abstract::This article introduces a global hypothesis test intended for studies with multiple endpoints. Our test makes use of a priori predictions about the direction of the result of each endpoint and we weight these predictions using the sample correlation matrix. The global alternative hypothesis concerns a parameter, ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8724
更新日期:2020-12-10 00:00:00
abstract::Patient compliance (adherence) with prescribed medication is often erratic, while clinical outcomes are causally linked to actual, rather than nominal medication dosage. We propose here a hierarchical Markov model for patient compliance. At the first stage, conditional upon individual random effects and a set of indiv...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19981030)17:20<2313::aid-s
更新日期:1998-10-30 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::A common problem encountered in many medical applications is the comparison of survival curves. Often, rather than comparison of the entire survival curves, interest is focused on the comparison at a fixed point in time. In most cases, the naive test based on a difference in the estimates of survival is used for this ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2864
更新日期:2007-10-30 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::Medical costs data with administratively censored observations often arise in cost-effectiveness studies of treatments for life-threatening diseases. Mean of medical costs incurred from the start of a treatment until death or a certain time point after the implementation of treatment is frequently of interest. In many...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1556
更新日期:2004-11-15 00:00:00
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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::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
pub_type: 杂志文章
doi:10.1002/sim.2206
更新日期:2005-11-30 00:00:00
abstract::To construct a confidence interval for the mean of a log-normal distribution in small samples, we propose likelihood-based approaches - the signed log-likelihood ratio and modified signed log-likelihood ratio methods. Extensive Monte Carlo simulation results show the advantages of the modified signed log-likelihood ra...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1381
更新日期:2003-06-15 00:00:00
abstract::Disease incidence or disease mortality rates for small areas are often displayed on maps. Maps of raw rates, disease counts divided by the total population at risk, have been criticized as unreliable due to non-constant variance associated with heterogeneity in base population size. This has led to the use of model-ba...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20000915/30)19:17/18<2377::aid-s
更新日期:2000-09-15 00:00:00
abstract::In biomedical studies and clinical trials, repeated measures are often subject to some upper and/or lower limits of detection. Hence, the responses are either left or right censored. A complication arises when more than one series of responses is repeatedly collected on each subject at irregular intervals over a perio...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8017
更新日期:2019-03-15 00:00:00
abstract::Two features commonly exhibited by randomized trials of health promotion interventions are cluster randomization and stratification. Ignoring correlations between individuals within clusters can lead to an inflated type I error rate and hence a P-value which overstates the significance of the result. This paper compar...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1256
更新日期:2002-12-30 00:00:00
abstract::We propose a probability distribution for an equivalence class of classification trees (that is, those that ignore the value of the cutpoints but retain tree structure). This distribution is parameterized by a central tree structure representing the true model, and a precision or concentration coefficient representing...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19990330)18:6<727::aid-sim
更新日期:1999-03-30 00:00:00
abstract::Relative survival provides a measure of the proportion of patients dying from the disease under study without requiring the knowledge of the cause of death. We propose an overall strategy based on regression models to estimate the relative survival and model the effects of potential prognostic factors. The baseline ha...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2656
更新日期:2007-05-10 00:00:00
abstract::We suggest measures to quantify the degrees of necessity and of sufficiency of prognostic factors for dichotomous and for survival outcomes. A cause, represented by certain values of prognostic factors, is considered necessary for an event if, without the cause, the event cannot develop. It is considered sufficient fo...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8331
更新日期:2019-10-15 00:00:00