Comparison of population pharmacokinetic modeling methods using simulated data: results from the Population Modeling Workgroup.

abstract：:Patients who switch treatment groups in randomized clinical trials can cause problems in the interpretation of the results. Although the intention-to-treat method is recognized as being the most reliable analysis, it may result in an underestimate of the treatment effect if there have been patients who switch treatmen...

journal_title：Statistics in medicine

authors： Law MG,Kaldor JM

更新日期：1996-10-15 00:00:00

abstract：:Assessing and comparing the performance of correlated predictive scores are of current interest in precision medicine. Given the limitations of available theoretical approaches for assessing and comparing the predictive accuracy, numerical methods are highly desired which, however, have not been systematically develop...

journal_title：Statistics in medicine

authors： Zhang Y,Shao Y

更新日期：2020-09-10 00:00:00

abstract：:Motivated by a previously published study of HIV treatment, we simulated data subject to time-varying confounding affected by prior treatment to examine some finite-sample properties of marginal structural Cox proportional hazards models. We compared (a) unadjusted, (b) regression-adjusted, (c) unstabilized, and (d) s...

journal_title：Statistics in medicine

authors： Westreich D,Cole SR,Schisterman EF,Platt RW

更新日期：2012-08-30 00:00:00

abstract：:Comparative calibration is the broad statistical methodology used to assess the calibration of a set of p instruments, each designed to measure the same characteristic, on a common group of individuals. Different from the usual calibration problem, the true underlying quantity measured is unobservable. Many authors ha...

journal_title：Statistics in medicine

authors： Lu Y,Ye K,Mathur AK,Hui S,Fuerst TP,Genant HK

更新日期：1997-08-30 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

authors： Coffey CS,Muller KE

更新日期：1999-05-30 00:00:00

abstract：:In case-control studies, the Cochran-Armitage (CA) trend test is powerful for detection of an association between a risk allele and a marker. To apply this test, a score should be assigned to the genotypes based on the genetic model. When the underlying genetic model is unknown, the trend test statistic is a function ...

journal_title：Statistics in medicine

authors： Zheng G

更新日期：2003-08-30 00:00:00

abstract：:Vaccination in populations can have several kinds of effects. Establishing that vaccination produces population-level effects beyond the direct effects in the vaccinated individuals can have important consequences for public health policy. Formal methods have been developed for study designs and analysis that can esti...

journal_title：Statistics in medicine

authors： Halloran ME,Hudgens MG

更新日期：2018-01-30 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

authors： Remontet L,Bossard N,Belot A,Estève J,French network of cancer registries FRANCIM.

更新日期：2007-05-10 00:00:00

abstract：:In some randomized controlled trials, subjects with a better prognosis may be diverted into the treatment group. This subverting of randomization results in an unobserved non-compliance with the originally intended treatment assignment. Consequently, the estimate of treatment effect from these trials may be biased. Th...

journal_title：Statistics in medicine

authors： Marcus SM

更新日期：2001-02-28 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

authors： Patricia Bernardo MV,Ibrahim JG

更新日期：2000-11-30 00:00:00

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

authors： Preisser JS,Lohman KK,Rathouz PJ

更新日期：2002-10-30 00:00:00

abstract：:Funnel plots are widely used to visualize grouped data, for example, in institutional comparison. This paper extends the concept to a multi-level setting, displaying one level at a time, adjusted for the other levels, as well as for covariates at all levels. These level-adjusted funnel plots are based on a Markov chai...

journal_title：Statistics in medicine

authors： Lindhagen L,Darkahi B,Sandblom G,Berglund L

更新日期：2014-09-20 00:00:00

abstract：:We review two recent trends: the emergence of evidence-based medicine and the growing use of Bayesian statistics in medical applications. Evidence-based medicine requires an integrated assessment of the available evidence, and associated uncertainty, but there is also an emphasis on decision-making, for individual pat...

journal_title：Statistics in medicine

authors： Ashby D,Smith AF

更新日期：2000-12-15 00:00:00

abstract：:Outcome-dependent sampling (ODS) scheme is a cost-effective sampling scheme where one observes the exposure with a probability that depends on the outcome. The well-known such design is the case-control design for binary response, the case-cohort design for the failure time data, and the general ODS design for a conti...

journal_title：Statistics in medicine

authors： Lu TS,Longnecker MP,Zhou H

更新日期：2017-03-15 00:00:00

abstract：:A popular method to control multiplicity in confirmatory clinical trials is to use a so-called hierarchical, or fixed sequence, test procedure. This requires that the null hypotheses are ordered a priori, for example, in order of clinical importance. The procedure tests the hypotheses in this order using alpha-level t...

journal_title：Statistics in medicine

authors： Edwards D,Madsen J

更新日期：2007-12-10 00:00:00

abstract：:In this paper, we construct a partial additive regression (PAR) model to predict the survival times of cancer patients based on microarray gene expression data with right censoring. The area under time-dependent receiver operating characteristic curve is used as a model evaluation criterion. We conduct a simulation st...

journal_title：Statistics in medicine

authors： Zhao Y,Zhou Y,Zhao M

更新日期：2009-01-30 00:00:00

abstract：:Appropriate methods for meta-regression applied to a set of clinical trials, and the limitations and pitfalls in interpretation, are insufficiently recognized. Here we summarize recent research focusing on these issues, and consider three published examples of meta-regression in the light of this work. One principal m...

journal_title：Statistics in medicine

authors： Thompson SG,Higgins JP

更新日期：2002-06-15 00:00:00

abstract：:Longitudinal designs are important in medical research and in many other disciplines. Complete longitudinal studies, in which each subject is evaluated at each measurement occasion, are often very expensive and motivate a search for more efficient designs. Recently developed statistical methods foster the use of inten...

journal_title：Statistics in medicine

authors： Helms RW

更新日期：1992-10-01 00:00:00

abstract：:Patient reported outcome and observer evaluative studies in clinical trials and post-hoc analyses often use instruments that measure responses on ordinal-rating or Likert scales. We propose a flexible distributional approach by modeling the change scores from the baseline to the end of the study using independent beta...

journal_title：Statistics in medicine

authors： Zou KH,Carlsson MO,Quinn SA

更新日期：2010-10-30 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

authors： Rubin DB

更新日期：1998-02-15 00:00:00

abstract：:In the presence of confounding, the consistency assumption required for identification of causal effects may be violated due to misclassification of the outcome variable. We introduce an inverse probability weighted approach to rebalance covariates across treatment groups while mitigating the influence of differential...

journal_title：Statistics in medicine

authors： Gravel CA,Platt RW

更新日期：2018-02-10 00:00:00

abstract：:Observational cohort studies often feature longitudinal data subject to irregular observation. Moreover, the timings of observations may be associated with the underlying disease process and must thus be accounted for when analysing the data. This paper suggests that multiple outputation, which consists of repeatedly ...

journal_title：Statistics in medicine

authors： Pullenayegum EM

更新日期：2016-05-20 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

authors： Stukel TA

更新日期：1993-07-30 00:00:00

abstract：:Most phase I dose-finding methods in oncology aim to find the maximum-tolerated dose from a set of prespecified doses. However, in practice, because of a lack of understanding of the true dose-toxicity relationship, it is likely that none of these prespecified doses are equal or reasonably close to the true maximum-to...

journal_title：Statistics in medicine

authors： Chu Y,Pan H,Yuan Y

更新日期：2016-09-10 00:00:00

abstract：:Meta-analyses of clinical trials are increasingly seeking to go beyond estimating the effect of a treatment and may also aim to investigate the effect of other covariates and how they alter treatment effectiveness. This requires the estimation of treatment-covariate interactions. Meta-regression can be used to estimat...

journal_title：Statistics in medicine

authors： Simmonds MC,Higgins JP

更新日期：2007-07-10 00:00:00

abstract：:We present an approach for inference on contrasts of clinically meaningful functionals of a survivor distribution (e.g., restricted mean, quantiles) that can avoid strong parametric or semiparametric assumptions on the underlying structure of the data. In this multistage approach, we first use an adaptive predictive m...

journal_title：Statistics in medicine

authors： Rudser KD,LeBlanc ML,Emerson SS

更新日期：2012-07-20 00:00:00

abstract：:Randomized clinical trial designs commonly include one or more planned interim analyses. At these times an external monitoring committee reviews the accumulated data and determines whether it is scientifically and ethically appropriate for the study to continue. With failure-time endpoints, it is common to schedule an...

journal_title：Statistics in medicine

authors： Bagiella E,Heitjan DF

更新日期：2001-07-30 00:00:00

abstract：:For the meta-analysis of controlled clinical trials or epidemiological studies, in which the responses are at least approximately normally distributed, a refined test for the hypothesis of no overall treatment effect is proposed. The test statistic is based on a direct estimation function for the variance of the overa...

journal_title：Statistics in medicine

authors： Hartung J,Knapp G

更新日期：2001-06-30 00:00:00

abstract：:This paper considers the analysis of longitudinal data complicated by the fact that during follow-up patients can be in different disease states, such as remission, relapse or death. If both the response of interest (for example, quality of life (QOL)) and the amount of missing data depend on this disease state, ignor...

journal_title：Statistics in medicine

authors： le Cessie S,de Vries EG,Buijs C,Post WJ

更新日期：2009-12-30 00:00:00

abstract：:For time-to-event outcomes, a rich literature exists on the bias introduced by covariate measurement error in regression models, such as the Cox model, and methods of analysis to address this bias. By comparison, less attention has been given to understanding the impact or addressing errors in the failure time outcome...

journal_title：Statistics in medicine

authors： Oh EJ,Shepherd BE,Lumley T,Shaw PA

更新日期：2018-04-15 00:00:00