Abstract:
:Previous work on the consequences of regression to the mean for the interpretation of responses to treatment is extended to the situation where the response measured is the proportional change in some variable. Methods for correcting for the bias are discussed.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Curnow RNdoi
10.1002/sim.4780060203subject
Has Abstractpub_date
1987-03-01 00:00:00pages
113-7issue
2eissn
0277-6715issn
1097-0258journal_volume
6pub_type
杂志文章abstract::We investigate a binary partitioning algorithm in the case of a continuous repeated measures outcome. The procedure is based on the use of the likelihood ratio statistic to evaluate the performance of individual splits. The procedure partitions a set of longitudinal data into two mutually exclusive groups based on an ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1266
更新日期:2002-11-30 00:00:00
abstract::Prevalence data provided by cancer registries are generally biased, since the patients that were diagnosed before the starting of the registry's activity cannot be included in the statistics. The relevance of this incompleteness bias is estimated in this paper. Incidence and relative survival are modelled as parametri...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970228)16:4<425::aid-sim
更新日期:1997-02-28 00:00:00
abstract::Relative potency is a measure that has been used for many years to summarize the comparison of dose-response curves in parallel line bioassays. When response curves for two preparations are not parallel the traditional definition of relative potency no longer applies. We review the concept of relative potency and show...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970530)16:10<1151::aid-s
更新日期:1997-05-30 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::We estimate a Cox proportional hazards model where one of the covariates measures the level of a subject's cognitive functioning by grading the total score obtained by the subject on the items of a questionnaire. A case study is presented where the sample includes partial respondents, who did not answer some questionn...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3773
更新日期:2010-01-30 00:00:00
abstract::Prognostic models are used in medicine for investigating patient outcome in relation to patient and disease characteristics. Such models do not always work well in practice, so it is widely recommended that they need to be validated. The idea of validating a prognostic model is generally taken to mean establishing tha...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(20000229)19:4<453::aid-sim
更新日期:2000-02-29 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::Statistical methods for testing and interval estimation of the ratio of marginal probabilities in the matched-pair setting are considered in this paper. We are especially interested in the situation where the null value is not one, as in one-sided equivalence trials. We propose a Fieller-type statistic based on constr...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1017
更新日期:2002-03-15 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::Many critical questions in medicine require the analysis of complex multivariate data, often from large data sets describing numerous variables for numerous subjects. In this paper, we describe CoPlot, a tool for visualizing multivariate data in medicine. CoPlot is an adaptation of multidimensional scaling (MDS) that ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3078
更新日期:2008-05-30 00:00:00
abstract::We propose to use a very simple model to test whether a cancer cluster is due to chance alone. We focus on the acute childhood leukaemia cluster in Columbus, Ohio. In 1975, 12 leukaemia cases were observed in Columbus while the expected number is 6 cases per year. According to our simple model, the probability of such...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20000830)19:16<2195::aid-sim522>
更新日期:2000-08-30 00:00:00
abstract::Estimation and group comparison of survival curves are two very common issues in survival analysis. In practice, the Kaplan-Meier estimates of survival functions may be biased due to unbalanced distribution of confounders. Here we develop an adjusted Kaplan-Meier estimator (AKME) to reduce confounding effects using in...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2174
更新日期:2005-10-30 00:00:00
abstract::Nutritional exposures are often measured with considerable error in commonly used surrogate instruments such as the food frequency questionnaire (FFQ) (denoted by Q(i) for the ith subject). The error can be both systematic and random. The diet record (DR) denoted by R(i) for the ith subject is considered an alloyed go...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3238
更新日期:2008-08-15 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::Maps of estimated disease rates over multiple time periods are useful tools for gaining etiologic insights regarding potential exposures associated with specific locations and times. In this paper, we describe an extension of the Gangnon-Clayton model for spatial clustering to spatio-temporal data. As in the purely sp...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3984
更新日期:2010-09-30 00:00:00
abstract::Conditional power (CP) is the probability that the final study result will be statistically significant, given the data observed thus far and a specific assumption about the pattern of the data to be observed in the remainder of the study, such as assuming the original design effect, or the effect estimated from the c...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/sim.2151
更新日期:2005-09-30 00:00:00
abstract::In designed longitudinal studies, information from the same set of subjects are collected repeatedly over time. The longitudinal measurements are often subject to missing data which impose an analytic challenge. We propose a functional multiple imputation approach modeling longitudinal response profiles as smooth curv...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4201
更新日期:2011-05-10 00:00:00
abstract::We propose a joint model to analyze the structure and intensity of the association between longitudinal measurements of an ordinal marker and time to a relevant event. The longitudinal process is defined in terms of a proportional-odds cumulative logit model. Time-to-event is modeled through a left-truncated proportio...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7065
更新日期:2016-12-10 00:00:00
abstract::We present a new method of detection and inference for spatial clusters of a disease. To avoid ad hoc procedures to test for clustering, we have a clearly defined alternative hypothesis and our test statistic is based on the likelihood ratio. The proposed test can detect clusters of any size, located anywhere in the s...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780140809
更新日期:1995-04-30 00:00:00
abstract::Genetic markers can be used as instrumental variables, in an analogous way to randomization in a clinical trial, to estimate the causal relationship between a phenotype and an outcome variable. Our purpose is to extend the existing methods for such Mendelian randomization studies to the context of multiple genetic mar...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3843
更新日期:2010-05-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,随机对照试验
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abstract::The generalized estimating equations (GEE) approach is commonly used to model incomplete longitudinal binary data. When drop-outs are missing at random through dependence on observed responses (MAR), GEE may give biased parameter estimates in the model for the marginal means. A weighted estimating equations approach g...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1241
更新日期:2002-10-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
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更新日期:2018-04-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1107
更新日期:2002-05-15 00:00:00
abstract::Correlated data are obtained in longitudinal epidemiological studies, where repeated measurements are taken on individuals or groups over time. Such longitudinal data are ideally analyzed using multilevel modeling approaches, which appropriately account for the correlations in repeated responses in the same individual...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5880
更新日期:2013-12-10 00:00:00
abstract::In many epidemiological studies it is common to resort to regression models relating incidence of a disease and its risk factors. The main goal of this paper is to consider inference on such models with error-prone observations and variances of the measurement errors changing across observations. We suppose that the o...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3343
更新日期:2008-11-10 00:00:00
abstract::There has been substantial statistical literature in the last several decades on assessing agreement, and coverage probability approach was selected as a preferred index for assessing and improving measurement agreement in a core laboratory setting. With this approach, a satisfactory agreement is based on pre-specifie...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6903
更新日期:2016-08-15 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6415
更新日期:2015-04-30 00:00:00
abstract::Data on alcohol availability and problems in all cities in Los Angeles County were collected from several different sources and linked together to form a Local Alcohol Availability Database (LAAD). The two major purposes of the project are to provide a city-level alcohol availability and alcohol-related problems datab...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780140517
更新日期:1995-03-15 00:00:00
abstract::This article deals with determination of a sample size that guarantees the success of a trial. We follow a Bayesian approach and we say an experiment is successful if it yields a large posterior probability that an unknown parameter of interest (an unknown treatment effect or an effects-difference) is greater than a c...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3175
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