Abstract:
:The proposed guidelines for the assessment of the effect of new pharmaceutical agents on the QT interval (beginning of QRS complex to end of T wave on the electrocardiogram) are based on the maximum of a series over time of simple one-sided 95 per cent upper confidence bounds. This procedure is typically very conservative as a procedure for obtaining a 95 per cent bound for the maximum of the population parameters. This paper proposes new bounds for the maximum, both analytical and bootstrap-based, that are lower but still achieve correct coverage in the context of crossover and parallel designs for the most realistic portions of the parameter space.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Boos DD,Hoffman D,Kringle R,Zhang Jdoi
10.1002/sim.2826subject
Has Abstractpub_date
2007-09-10 00:00:00pages
3801-17issue
20eissn
0277-6715issn
1097-0258journal_volume
26pub_type
杂志文章abstract::Growth trends in children are often based on cross-sectional studies, in which a sample of the population is investigated at one given point in time. Estimating age-related percentiles in such studies involves fitting data distributions, each of which is specific for one age group, and a subsequent smoothing of the pe...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(20000315)19:5<697::aid-sim
更新日期:2000-03-15 00:00:00
abstract::When the event time of interest depends on the censoring time, conventional two-sample test methods, such as the log-rank and Wilcoxon tests, can produce an invalid test result. We extend our previous work on estimation using auxiliary variables to adjust for dependent censoring via multiple imputation, to the compari...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3480
更新日期:2009-02-01 00:00:00
abstract::Composite endpoints are frequently used in clinical trials, but simple approaches, such as the time to first event, do not reflect any ordering among the endpoints. However, some endpoints, such as mortality, are worse than others. A variety of procedures have been proposed to reflect the severity of the individual en...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8431
更新日期:2020-02-28 00:00:00
abstract::Meta-analysis to investigate the joint effect of multiple factors in the aetiology of a disease is of increasing importance in epidemiology. This task is often challenging in practice, because studies typically concentrate on studying the effect of only one exposure, sometimes may report the interaction between two ex...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2689
更新日期:2006-12-30 00:00:00
abstract::Standard randomization-based tests of sharp null hypotheses in randomized clinical trials, that is, intent-to-treat analyses, are valid without extraneous assumptions, but generally can be appropriately powerful only with alternative hypotheses that involve treatment assignment having an effect on outcome. In the cont...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19980215)17:3<371::aid-sim
更新日期:1998-02-15 00:00:00
abstract::This work is motivated by a longitudinal study of women and their ectopic pregnancy outcomes in Lund, Sweden. In this article, we review and apply the Liang-Zeger methodology to the Lund ectopic pregnancy data set. We further analyse the ectopic pregnancy data using conditional modelling approaches suggested by Rosner...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19971115)16:21<2403::aid-s
更新日期:1997-11-15 00:00:00
abstract::In many medical and health studies, high-dimensional data are often encountered. Principal component analysis (PCA) is a commonly used technique to reduce such data to a few components that includes most of the information provided by the original data. However, PCA is known to be very sensitive to some abnormal obser...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2747
更新日期:2007-06-15 00:00:00
abstract::Non-tumor cell-based model systems have recently gained interest in pharmacogenetic research as a hypothesis generating tool. The hypotheses generated from these model systems can be followed up in functional studies, or tested in individuals taking the same investigational agents. The current cellular phenotypes (e.g...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3649
更新日期:2009-09-20 00:00:00
abstract::Pattern-mixture models (PMM) and selection models (SM) are alternative approaches for statistical analysis when faced with incomplete data and a nonignorable missing-data mechanism. Both models make empirically unverifiable assumptions and need additional constraints to identify the parameters. Here, we first introduc...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6302
更新日期:2014-11-30 00:00:00
abstract::Novel therapies are challenging the standards of drug development. Agents with specific biologic targets, unknown dose-efficacy curves, and limited toxicity mandate novel designs to identify biologically optimal doses. We review two model-based designs that utilize either a proportional odds model or a continuation ra...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3706
更新日期:2010-05-10 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
abstract::We consider Cox proportional hazards regression when the covariate vector includes error-prone discrete covariates along with error-free covariates, which may be discrete or continuous. The misclassification in the discrete error-prone covariates is allowed to be of any specified form. Building on the work of Nakamura...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3159
更新日期:2008-05-20 00:00:00
abstract::Health surveillance involves collecting public health data on chronic and infectious diseases to detect changes in disease incidence rates in order to improve public health. Timely detection of disease clusters is essential in prospective public health surveillance. Most existing health surveillance research is based ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3877
更新日期:2011-02-28 00:00:00
abstract::Some clinical trials aim to demonstrate therapeutic equivalence on multiple primary endpoints. For example, therapeutic equivalence studies of agents for the treatment of osteoarthritis use several primary endpoints including investigator's global assessment of disease activity, patient's global assessment of response...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.985
更新日期:2001-11-15 00:00:00
abstract::We consider recurrent events of the same type that occur during alternating restraint and non-restraint time periods. This research is motivated by a study on juvenile recidivism, where the probationers were followed for re-offenses during alternating placement periods and free-time periods. During the placement perio...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7150
更新日期:2017-02-20 00:00:00
abstract::To summarize safety data such as clinical adverse experiences in clinical trials with a moderate to long-term follow-up, we may use a measurement which accounts for the potential differences in the follow-up duration between treatment groups. The incidence rate, which uses the total person-time follow-up in a treatmen...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2335
更新日期:2006-04-30 00:00:00
abstract::Assessment of equivalence or non-inferiority in accuracy between two diagnostic procedures often involves comparisons of paired areas under the receiver operating characteristic (ROC) curves. With some pre-specified clinically meaningful limits, the current approach to evaluating equivalence is to perform the two one-...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2358
更新日期:2006-04-15 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::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::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::In Part I we presented a covariance structure model for analysing measurement error in the assessment of nitrogen intake. In this paper we include data on urine nitrogen excretion which allows a critical assessment of the model proposed. Inclusion of urine nitrogen data produces more pessimistic estimates of the quali...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780121005
更新日期:1993-05-30 00:00:00
abstract::The induced smoothing technique overcomes the difficulties caused by the non-smoothness in rank-based estimating functions for accelerated failure time models, but it is only natural when the estimating function has Gehan's weight. For a general weight, the induced smoothing method does not provide smooth estimating f...
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::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::Among subjects who have experienced a biological event, such as menarche, menopause or a delivery, one cannot distinguish the effects of time since the event from age at the event due to the linear dependency among these time variables and age at study ('current age'). This is a well-known problem that also exists in ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0258(19960730)15:14<1545::AID-S
更新日期:1996-07-30 00:00:00
abstract::In the analysis of composite endpoints in a clinical trial, time to first event analysis techniques such as the logrank test and Cox proportional hazard test do not take into account the multiplicity, importance, and the severity of events in the composite endpoint. Several generalized pairwise comparison analysis met...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8388
更新日期:2019-12-30 00:00:00
abstract::The two-period cross-over design with two sequences of drug administration is a standard experimental design when bioequivalence of one test formulation is to be assessed in comparison with a reference formulation. Previously, an approach based on Fieller's confidence interval has been presented for the assessment of ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19971015)16:19<2229::aid-s
更新日期:1997-10-15 00:00:00
abstract::Systematic reviews often provide recommendations for further research. When meta-analyses are inconclusive, such recommendations typically argue for further studies to be conducted. However, the nature and amount of future research should depend on the nature and amount of the existing research. We propose a method ba...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5524
更新日期:2013-01-15 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::The Spearman (rho(s)) and Kendall (tau) rank correlation coefficient are routinely used as measures of association between non-normally distributed random variables. However, confidence limits for rho(s) are only available under the assumption of bivariate normality and for tau under the assumption of asymptotic norma...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2547
更新日期:2007-02-10 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