Sample sizes for phase II and phase III clinical trials: an integrated approach.

abstract：:A number of variance formulae for the attributable fraction have been presented, but none is consistent in sparse data, such as found in individually matched case-control studies. This paper employs Mantel-Haenszel estimation to derive variance estimators for attributable fractions that are dually consistent, that is,...

journal_title：Statistics in medicine

authors： Greenland S

更新日期：1987-09-01 00:00:00

abstract：:When interpreting screening mammograms radiologists decide whether suspicious abnormalities exist that warrant the recall of the patient for further testing. Previous work has found significant differences in interpretation among radiologists; their false-positive and false-negative rates have been shown to vary widel...

journal_title：Statistics in medicine

authors： Woodard DB,Gelfand AE,Barlow WE,Elmore JG

更新日期：2007-03-30 00:00:00

abstract：:Bioequivalence assessment is an issue of great interest. Development of statistical methods for assessing bioequivalence is an important area of research for statisticians. Bioequivalence is usually determined based on the normal distribution. We relax this assumption and develop a semi-parametric mixed model for bioe...

journal_title：Statistics in medicine

authors： Ghosh P,Rosner GL

更新日期：2007-03-15 00:00:00

abstract：:Phase II trials often test the null hypothesis H(0): p or=p(1), where p is the true unknown proportion responding to the new treatment, p(0) is the greatest response proportion which is deemed clinically ineffective, and p(1) is the smallest response proportion which is deemed clinically effe...

journal_title：Statistics in medicine

authors： Ayanlowo AO,Redden DT

更新日期：2007-03-30 00:00:00

abstract：:Multivariate outcomes measured longitudinally over time are common in medicine, public health, psychology and sociology. The typical (saturated) longitudinal multivariate regression model has a separate set of regression coefficients for each outcome. However, multivariate outcomes are often quite similar and many out...

journal_title：Statistics in medicine

authors： Jia J,Weiss RE

更新日期：2009-06-15 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

authors： Chiou S,Kang S,Yan J

更新日期：2015-04-30 00:00:00

abstract：:The present study investigates the performance of several statistical tests to detect publication bias in diagnostic meta-analysis by means of simulation. While bivariate models should be used to pool data from primary studies in diagnostic meta-analysis, univariate measures of diagnostic accuracy are preferable for t...

journal_title：Statistics in medicine

authors： Bürkner PC,Doebler P

更新日期：2014-08-15 00:00:00

abstract：:In an individually matched case-control study, effects of potential risk factors are ascertained through conditional logistic regression (CLR). Extension of CLR to situations with multiple disease or reference categories has been made through polychotomous CLR and is shown to be more efficient than carrying out separa...

journal_title：Statistics in medicine

authors： Mukherjee B,Liu I,Sinha S

更新日期：2007-07-30 00:00:00

abstract：:In the pharmaceutical industry, an assay method is considered validated if the accuracy and precision for an assay meet some acceptable limits. This paper discusses the assessment of assay precision in terms of the estimation of total variability of an assay from a one-way random effects model which is often considere...

journal_title：Statistics in medicine

authors： Chow SC,Tse SK

更新日期：1991-10-01 00:00:00

abstract：:The EQ-5D, a widely used multiattribute utility instrument, is commonly used in health economic evaluations where the goal is to decide on which treatments to reimburse. Like other instruments, value sets of the EQ-5D are constructed using valuation studies typically valuing a subset of the health states and using pre...

journal_title：Statistics in medicine

authors： Shams S,Pullenayegum E

更新日期：2020-10-15 00:00:00

abstract：:Intraclass correlation coefficient (ICC) estimates must be provided when reporting the results of a cluster randomized trial. This study demonstrates that estimating this parameter with one-way ANOVA and an underlying mixed-effects statistical model leads to biased estimates. The bias depends on the effect size of the...

journal_title：Statistics in medicine

authors： Giraudeau B

更新日期：2006-03-30 00:00:00

abstract：:Longitudinal biomarker data are often collected in studies, providing important information regarding the probability of an outcome of interest occurring at a future time. With many new and evolving technologies for biomarker discovery, the number of biomarker measurements available for analysis of disease progression...

journal_title：Statistics in medicine

authors： Zhao L,Murray S,Mariani LH,Ju W

更新日期：2020-11-20 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：:Quality of life (QOL) assessment is a key component of many clinical studies and frequently requires the use of single global summary measures that capture the overall balance of findings from a potentially wide-ranging assessment of QOL issues. We propose and evaluate an irregular multilevel latent variable model sui...

journal_title：Statistics in medicine

authors： Kifley A,Heller GZ,Beath KJ,Bulger D,Ma J,Gebski V

更新日期：2012-05-20 00:00:00

abstract：:Several large-sample confidence intervals for the ratio of independent binomial proportions are compared in terms of exact coverage probability and width. A non-iterative approximate Bayesian interval is derived and its frequency properties are superior to all of the non-iterative confidence intervals considered. The ...

journal_title：Statistics in medicine

authors： Price RM,Bonett DG

更新日期：2008-11-20 00:00:00

abstract：:Slow recruitment in clinical trials leads to increased costs and resource utilization, which includes both the clinic staff and patient volunteers. Careful planning and monitoring of the accrual process can prevent the unnecessary loss of these resources. We propose two hierarchical extensions to the existing Bayesian...

journal_title：Statistics in medicine

authors： Jiang Y,Simon S,Mayo MS,Gajewski BJ

更新日期：2015-02-20 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：:Clinical trials often assess efficacy by comparing treatments on the basis of two or more event-time outcomes. In the case of cancer clinical trials, progression-free survival (PFS), which is the minimum of the time from randomization to progression or to death, summarizes the comparison of treatments on the hazards f...

journal_title：Statistics in medicine

authors： Finkelstein DM,Schoenfeld DA

更新日期：2014-05-30 00:00:00

abstract：:The recent revision of the Declaration of Helsinki and the existence of many new therapies that affect survival or serious morbidity, and that therefore cannot be denied patients, have generated increased interest in active-control trials, particularly those intended to show equivalence or non-inferiority to the activ...

journal_title：Statistics in medicine

authors： Rothmann M,Li N,Chen G,Chi GY,Temple R,Tsou HH

更新日期：2003-01-30 00:00:00

abstract：:New combination regimens evaluated in phase II cancer clinical trials often show promising results compared to the standard therapy for a disease system. Selection of patients with a better prognosis can be a prominent factor for this optimism. For most disease systems, prognostic variables that are related to the out...

journal_title：Statistics in medicine

authors： Mazumdar M,Fazzari M,Panageas KS

更新日期：2001-03-30 00:00:00

abstract：:In genetic and genomic studies, gene-environment (G×E) interactions have important implications. Some of the existing G×E interaction methods are limited by analyzing a small number of G factors at a time, by assuming linear effects of E factors, by assuming no data contamination, and by adopting ineffective selection...

journal_title：Statistics in medicine

authors： Wu C,Shi X,Cui Y,Ma S

更新日期：2015-12-30 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：:The analysis of multivariate time-to-event (TTE) data can become complicated due to the presence of clustering, leading to dependence between multiple event times. For a long time, (conditional) frailty models and (marginal) copula models have been used to analyze clustered TTE data. In this article, we propose a gene...

journal_title：Statistics in medicine

authors： Tran TMP,Abrams S,Braekers R

更新日期：2020-05-30 00:00:00

abstract：:Meta-analyses of data from epidemiological studies are often based on odds ratios (ORs) or relative risks (RRs) and their 95 per cent confidence intervals (CIs) as reported by the authors. Where possible ORs, RRs and CIs should be checked against the source data. Some simple methods are presented for checking the vali...

journal_title：Statistics in medicine

authors： Lee PN

更新日期：1999-08-15 00:00:00

abstract：:A review is given of different ways of estimating the error rate of a prediction rule based on a statistical model. A distinction is drawn between apparent, optimum and actual error rates. Moreover it is shown how cross-validation can be used to obtain an adjusted predictor with smaller error rate. A detailed discussi...

journal_title：Statistics in medicine

authors： Van Houwelingen JC,Le Cessie S

更新日期：1990-11-01 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：:Misclassification introduces errors in categorical variables. This paper presents a review of methods for misclassified categorical data in epidemiology. Different sampling schemes for a 2 x 2 x 2 table and methods of analyses will be discussed first. A misclassification matrix is defined, and the usual misclassificat...

journal_title：Statistics in medicine

authors： Chen TT

更新日期：1989-09-01 00:00:00

abstract：:Although prostate cancer and benign prostatic hyperplasia are major health problems in U.S. men, little is known about the early stages of the natural history of prostate disease. A molecular biomarker called prostate specific antigen (PSA), together with a unique longitudinal bank of frozen serum, now allows a histor...

journal_title：Statistics in medicine

authors： Pearson JD,Morrell CH,Landis PK,Carter HB,Brant LJ

更新日期：1994-03-15 00:00:00

abstract：:In medical research, a two-phase study is often used for the estimation of the area under the receiver operating characteristic curve (AUC) of a diagnostic test. However, such a design introduces verification bias. One of the methods to correct verification bias is inverse probability weighting (IPW). Since the probab...

journal_title：Statistics in medicine

authors： Wu Y

更新日期：2020-11-30 00:00:00

abstract：:Many models for clinical prediction (prognosis or diagnosis) are published in the medical literature every year but few such models find their way into clinical practice. The reason may be that since in most cases models have not been validated in independent data, they lack generality and/or credibility. In this pape...

journal_title：Statistics in medicine

authors： Royston P,Parmar MK,Sylvester R

更新日期：2004-03-30 00:00:00