Abstract:
:This paper describes statistical procedures for use in an experiment that compares two handwashing protocols. The evaluation of a handwashing protocol entails collection of the wash effluent. Colony counts for the effluent reflect the number of flora removed by the wash protocol. The analysis aims to formulate and estimate an odds ratio that represents the relative efficacy of a test as compared with a standard protocol.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Le CTdoi
10.1002/sim.4780050412subject
Has Abstractpub_date
1986-07-01 00:00:00pages
393-6issue
4eissn
0277-6715issn
1097-0258journal_volume
5pub_type
临床试验,杂志文章,随机对照试验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::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::We extend the shared frailty model of recurrent events and a dependent terminal event to allow for a nonparametric covariate function. We include a Gaussian random effect (frailty) in the intensity functions of both the recurrent and terminal events to capture correlation between the two processes. We employ the penal...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4297
更新日期:2011-09-30 00:00:00
abstract::In noninferiority studies, a limit of indifference is used to express a tolerance in results such that the clinician would regard such results as being acceptable or 'not worse'. We applied this concept to a measure of accuracy, the Receiver Operating Characteristic (ROC) curve, for a sequence of tests. We expressed a...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5741
更新日期:2013-07-20 00:00:00
abstract::Phase II and phase III trials play a crucial role in drug development programs. They are costly and time consuming and, because of high failure rates in late development stages, at the same time risky investments. Commonly, sample size calculation of phase III is based on the treatment effect observed in phase II. The...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6624
更新日期:2016-01-30 00:00:00
abstract::The design of clinical trials often requires knowledge of quantities such as between- and within subject variances about which only imprecise information exists. To provide assurance that the study has the desired power to detect a minimum clinically meaningful difference between treatment groups. Gould, Gould and Shi...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780142007
更新日期:1995-10-30 00:00:00
abstract::Although all clinical trials are designed and monitored using more than one endpoint, methods are needed to assure that decision criteria are chosen to reflect the clinically relevant tradeoffs that assure the trial's scientific integrity. This article presents a framework for the design and monitoring clinical trials...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8696
更新日期:2020-11-20 00:00:00
abstract::Equivalence trials aim to show that two treatments have equivalent therapeutic effects. The approach is to define, in advance, a range of equivalence -d to +d for the treatment difference such that any value in the range is clinically unimportant. If the confidence interval for the difference, calculated after the tri...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19980815/30)17:15/16<1691:
更新日期:1998-08-15 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
abstract:BACKGROUND:Multiple imputation is becoming increasingly popular for handling missing data, with Markov chain Monte Carlo assuming multivariate normality (MVN) a commonly used approach. Imputing categorical variables (which are clearly non-normal) using MVN imputation is challenging, and several approaches have been sug...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5445
更新日期:2012-12-30 00:00:00
abstract::In this paper, we consider a full likelihood method to analyze continuous longitudinal responses with non-ignorable non-monotone missing data. We consider a transition probability model for the missingness mechanism. A first-order Markov dependence structure is assumed for both the missingness mechanism and observed d...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5359
更新日期:2012-12-10 00:00:00
abstract::We propose a goodness-of-fit test statistic for linear regression with heterogeneous variance, which is asymptotically chi-square if the given model is correct. The test statistic is computed as a quadratic form of observed minus predicted responses. We apply the method to a linear regression for an ordinal categorica...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780130205
更新日期:1994-01-30 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::This paper introduces a dynamic clustering methodology based on multi-valued descriptors of dermoscopic images. The main idea is to support medical diagnosis to decide if pigmented skin lesions belonging to an uncertain set are nearer to malignant melanoma or to benign nevi. Melanoma is the most deadly skin cancer, an...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4285
更新日期:2011-09-10 00:00:00
abstract::Ewell and Ibrahim derived the large sample distribution of the logrank statistic under general local alternatives. Their asymptotic results enable us to extend several group sequential designs which allow for early stopping in favour of the null hypothesis to the setting in which the cure rate model is appropriate. In...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20001130)19:22<3023::aid-sim638>
更新日期:2000-11-30 00:00:00
abstract::Huntington's disease (HD) is a neurodegenerative disorder with a dominant genetic mode of inheritance caused by an expansion of CAG repeats on chromosome 4. Typically, a longer sequence of CAG repeat length is associated with increased risk of experiencing earlier onset of HD. Previous studies of the association betwe...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5971
更新日期:2014-04-15 00:00:00
abstract::Equal allocation of patients to treatment in a randomized clinical trial may have disadvantages ethically if the new treatment is believed to be at least as beneficial as the standard treatment. Others have considered, in a non-sequential setting, unbalanced randomized designs which allocate fewer patients to the pote...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780010309
更新日期:1982-07-01 00:00:00
abstract::Random forest is a supervised learning method that combines many classification or regression trees for prediction. Here we describe an extension of the random forest method for building event risk prediction models in survival analysis with competing risks. In case of right-censored data, the event status at the pred...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5775
更新日期:2013-08-15 00:00:00
abstract::Interim analyses are conducted to allow for early termination of the trial, for ethical as well as economical reasons. Here we consider interim analyses in repeated measurements studies where the measurements are binary. Two methods for analysing this kind of data are compared according to their operating characterist...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1361
更新日期:2003-02-28 00:00:00
abstract::Linear mixed effects (LME) models are increasingly used for analyses of biological and biomedical data. When the multivariate normal assumption is not adequate for an LME model, then a robust estimation approach is preferable to the maximum likelihood one. M-estimators were considered before for robust estimation of t...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4169
更新日期:2011-06-30 00:00:00
abstract::In many studies, interest lies in determining whether members of the study population will undergo a particular event of interest. Such scenarios are often termed 'mover-stayer' scenarios, and interest lies in modelling two sub-populations of 'movers' (those who have a propensity to undergo the event of interest) and ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5529
更新日期:2013-02-20 00:00:00
abstract::The case-control study is a simple and an useful method to characterize the effect of a gene, the effect of an exposure, as well as the interaction between the two. The control-free case-only study is yet an even simpler design, if interest is centered on gene-environment interaction only. It requires the sometimes pl...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4028
更新日期:2010-10-30 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::Two correction methods are considered for multiple logistic regression models with some covariates measured with error. Both methods are based on approximating the complicated regression model between the response and the observed covariates with simpler models. The first model is the logistic approximation proposed b...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780131105
更新日期:1994-06-15 00:00:00
abstract::This paper is a compendium of exact and asymptotic formulae and tables for estimating the sample size in a clinical trial with two treatment groups and a dichotomous outcome. The paper provides separate formulae for equal and unequal treatment group sizes, formulae for the calculation of power given the sample size, a...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/(SICI)1097-0258(19960115)15:1<1::AID-SIM13
更新日期:1996-01-15 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::The Response Evaluation Criteria in Solid Tumors are used as standard guidelines for the clinical evaluation of cancer treatments. The assessment is based on the anatomical tumor burden: change in size of target lesions and evolution of nontarget lesions (NTL). Despite unquestionable advantages of this standard tool, ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7640
更新日期:2018-06-15 00:00:00
abstract::Tumour registry linkage, chart review and patient self-report are all commonly used ascertainment methods in cancer epidemiology. These methods are used for estimating the incidence or prevalence of different cancer types in a population, and for investigating the effects of possible risk factors for cancer. Tumour re...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2116
更新日期:2005-08-15 00:00:00
abstract::We consider statistical procedures for hypothesis testing of real valued functionals of matched pairs with missing values. In order to improve the accuracy of existing methods, we propose a novel multiplication combination procedure. Dividing the observed data into dependent (completely observed) pairs and independent...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8178
更新日期:2019-07-30 00:00:00
abstract::There is growing interest in how best to adapt and readapt treatments to individuals to maximize clinical benefit. In response, adaptive treatment strategies (ATS), which operationalize adaptive, sequential clinical decision making, have been developed. From a patient's perspective an ATS is a sequence of treatments, ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4512
更新日期:2012-07-30 00:00:00