Modification of the sample size and the schedule of interim analyses in survival trials based on data inspections.

abstract：:We consider the problem of identifying subgroups of participants in a clinical trial that have enhanced treatment effect. Recursive partitioning methods that recursively partition the covariate space based on some measure of between groups treatment effect difference are popular for such subgroup identification. The m...

journal_title：Statistics in medicine

authors： Steingrimsson JA,Yang J

更新日期：2019-09-20 00:00:00

abstract：:In a typical bioequivalence trial, summary measures of the plasma concentration versus time profile are used to compare two formulations of a drug product. Commonly used measures include area under the curve (AUC), maximum plasma concentration (C(max)) and time to maximum concentration (T(max)). Equivalence of these s...

journal_title：Statistics in medicine

authors： Mauger DT,Chinchilli VM

更新日期：2000-10-30 00:00:00

abstract：:Frequently, multiple doses of an active treatment and multiple endpoints are simultaneously considered in the designs of clinical trials. For these trials, traditional multiplicity adjustment procedures such as Bonferroni, Hochberg and Hommel procedures can be applied when treating the comparisons of different doses t...

journal_title：Statistics in medicine

authors： Quan H,Luo X,Capizzi T

更新日期：2005-07-30 00:00:00

abstract：:We consider using observational data to estimate the effect of a treatment on disease recurrence, when the decision to initiate treatment is based on longitudinal factors associated with the risk of recurrence. The effect of salvage androgen deprivation therapy (SADT) on the risk of recurrence of prostate cancer is in...

journal_title：Statistics in medicine

authors： Kennedy EH,Taylor JM,Schaubel DE,Williams S

更新日期：2010-11-10 00:00:00

abstract：:With increasingly abundant spatial data in the form of case counts or rates combined over areal regions (eg, ZIP codes, census tracts, or counties), interest turns to formal identification of difference "boundaries," or barriers on the map, in addition to the estimated statistical map itself. "Boundary" refers to a bo...

journal_title：Statistics in medicine

authors： Guhaniyogi R

更新日期：2017-11-10 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

authors： Rosner B,Glynn RJ

更新日期：2007-02-10 00:00:00

abstract：:Spatial scan statistics are widely used for count data to detect geographical disease clusters of high or low incidence, mortality or prevalence and to evaluate their statistical significance. Some data are ordinal or continuous in nature, however, so that it is necessary to dichotomize the data to use a traditional s...

journal_title：Statistics in medicine

authors： Jung I,Kulldorff M,Klassen AC

更新日期：2007-03-30 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：:There are many settings in which the distribution of error in a mismeasured covariate varies with the value of another covariate. Take, for example, the case of HIV phylogenetic cluster size, large values of which are an indication of rapid HIV transmission. Researchers wish to find behavioral correlates of HIV phylog...

journal_title：Statistics in medicine

authors： Parveen N,Moodie E,Brenner B

更新日期：2017-07-30 00:00:00

abstract：:Geocoding a study population as completely as possible is an important data assimilation component of many spatial epidemiologic studies. Unfortunately, complete geocoding is rare in practice. The failure of a substantial proportion of study subjects' addresses to geocode has consequences for spatial analyses, some of...

journal_title：Statistics in medicine

authors： Zimmerman DL,Fang X,Mazumdar S

更新日期：2008-09-20 00:00:00

abstract：:Sam Greenhouse joined the Census Bureau as a clerk at an interesting time period for the agency. The first use of sampling in the decennial census occurred in 1940. There was a major expansion of the amount of data collected. The organization of the Census Bureau underwent radical changes, including the growth of the ...

journal_title：Statistics in medicine

authors： Keller J,Clark CZ

更新日期：2003-11-15 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

authors： Altman DG,Royston P

更新日期：2000-02-29 00:00:00

abstract：:I discuss alternatives to the one compartment model, delta Yt = alpha + beta exp(- gamma t). Instead of comparing the one and two compartment models, I derive statistics for testing mixtures of the parameters (beta, gamma) in the one compartment model. I apply the proposed methods to the problem of hydrogen clearance ...

journal_title：Statistics in medicine

authors： Zelterman D

更新日期：1989-08-01 00:00:00

abstract：:Machine learning techniques such as classification and regression trees (CART) have been suggested as promising alternatives to logistic regression for the estimation of propensity scores. The authors examined the performance of various CART-based propensity score models using simulated data. Hypothetical studies of v...

journal_title：Statistics in medicine

authors： Lee BK,Lessler J,Stuart EA

更新日期：2010-02-10 00:00:00

abstract：:This paper investigates the Bayesian procedures for comparing proportions. These procedures are especially suitable for accepting (or rejecting) the equivalence of two population proportions. Furthermore the Bayesian predictive probabilities provide a natural and flexible tool in monitoring trials, especially for choo...

journal_title：Statistics in medicine

authors： Lecoutre B,Derzko G,Grouin JM

更新日期：1995-05-15 00:00:00

abstract：:We describe the usual statistical concepts and consequent appropriate simulations of a prospective study for the simple case of a single risk variable and an assumed logistic model. We examine the simulations of Lilienfeld and Pyne, and show that they are seriously flawed. Contrary to those authors' claims, the estima...

journal_title：Statistics in medicine

authors： Halperin M,Abbott RD,Blackwelder WC,Jacobowitz R,Lan KK,Verter JI,Wedel H

更新日期：1985-04-01 00:00:00

abstract：:Methodology for the meta-analysis of individual patient data with survival end-points is proposed. Motivated by questions about the reliance on hazard ratios as summary measures of treatment effects, a parametric approach is considered and percentile ratios are introduced as an alternative to hazard ratios. The genera...

journal_title：Statistics in medicine

authors： Siannis F,Barrett JK,Farewell VT,Tierney JF

更新日期：2010-12-20 00:00:00

abstract：:Although estimation and confidence intervals have become popular alternatives to hypothesis testing and p-values, statisticians usually determine sample sizes for randomized clinical trials by controlling the power of a statistical test at an appropriate alternative, even those statisticians who recommend the use of c...

journal_title：Statistics in medicine

authors： Bristol DR

更新日期：1989-07-01 00:00:00

abstract：:In order for national statistical offices to maintain the trust of the public to collect data and publish statistics of importance to society and decision-making, it is imperative that respondents (persons or establishments) be guaranteed privacy and confidentiality in return for providing requested confidential data....

journal_title：Statistics in medicine

authors： Gonzalez JF Jr,Cox LH

更新日期：2005-02-28 00:00:00

abstract：:The power prior has been widely used in many applications covering a large number of disciplines. The power prior is intended to be an informative prior constructed from historical data. It has been used in clinical trials, genetics, health care, psychology, environmental health, engineering, economics, and business. ...

journal_title：Statistics in medicine

authors： Ibrahim JG,Chen MH,Gwon Y,Chen F

更新日期：2015-12-10 00:00:00

abstract：:We discuss some of the statistical approaches to the design and analysis of phase I clinical trials in cancer. An attempt is made to identify the issues, particular to this type of trial, that should be addressed by an appropriate methodology. A brief review of schemes currently in use is provided together with our vi...

journal_title：Statistics in medicine

authors： O'Quigley J,Chevret S

更新日期：1991-11-01 00:00:00

abstract：:We present methods for binomial regression when the outcome is determined using the results of a single diagnostic test with imperfect sensitivity and specificity. We present our model, illustrate it with the analysis of real data, and provide an example of WinBUGS program code for performing such an analysis. Conditi...

journal_title：Statistics in medicine

authors： McInturff P,Johnson WO,Cowling D,Gardner IA

更新日期：2004-04-15 00:00:00

abstract：:Both traditional phase I designs and the increasingly popular continual reassessment method (CRM) designs select an estimate of maximum tolerable dose (MTD) from among a set of prespecified dose levels. Although CRM designs use an implied dose-response model to select the next dose level, in general it is neither assu...

journal_title：Statistics in medicine

authors： Storer BE

更新日期：2001-08-30 00:00:00

abstract：:In medical and health studies, heterogeneities in clustered count data have been traditionally modeled by positive random effects in Poisson mixed models; however, excessive zeros often occur in clustered medical and health count data. In this paper, we consider a three-level random effects zero-inflated Poisson model...

journal_title：Statistics in medicine

authors： Ma R,Hasan MT,Sneddon G

更新日期：2009-08-15 00:00:00

abstract：:In many chronic diseases, therapy aims to prevent or reduce the frequency of episodes of a disease manifestation, for example cardiac ischaemic episodes or epileptic seizures. Entry criteria for clinical trials typically include a minimum number of episodes within a baseline period, and regression to the mean should b...

journal_title：Statistics in medicine

authors： McMahon RP,Proschan M,Geller NL,Stone PH,Sopko G

更新日期：1994-04-30 00:00:00

abstract：:The general linear mixed model provides a useful approach for analysing a wide variety of data structures which practising statisticians often encounter. Two such data structures which can be problematic to analyse are unbalanced repeated measures data and longitudinal data. Owing to recent advances in methods and sof...

journal_title：Statistics in medicine

authors： Cnaan A,Laird NM,Slasor P

更新日期：1997-10-30 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

authors： Bansal NK,Jiang H,Pradeep P

更新日期：2015-11-10 00:00:00

abstract：:When estimating the average effect of a binary treatment (or exposure) on an outcome, methods that incorporate propensity scores, the G-formula, or targeted maximum likelihood estimation (TMLE) are preferred over naïve regression approaches, which are biased under misspecification of a parametric outcome model. In con...

journal_title：Statistics in medicine

authors： Luque-Fernandez MA,Schomaker M,Rachet B,Schnitzer ME

更新日期：2018-07-20 00:00:00

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_title：Statistics in medicine

authors： Curnow RN

更新日期：1987-03-01 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

authors： Zucker DM,Spiegelman D

更新日期：2008-05-20 00:00:00