A statistical assessment of clinical equivalence.

abstract：:Prediction performance of a risk scoring system needs to be carefully assessed before its adoption in clinical practice. Clinical preventive care often uses risk scores to screen asymptomatic population. The primary clinical interest is to predict the risk of having an event by a prespecified future time t0 . Accuracy...

journal_title：Statistics in medicine

authors： Yuan Y,Zhou QM,Li B,Cai H,Chow EJ,Armstrong GT

更新日期：2018-05-10 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：:Ordinal data appear in a wide variety of scientific fields. These data are often analyzed using ordinal logistic regression models that assume proportional odds. When this assumption is not met, it may be possible to capture the lack of proportionality using a constrained structural relationship between the odds and t...

journal_title：Statistics in medicine

authors： Capuano AW,Dawson JD

更新日期：2013-06-15 00:00:00

abstract：:The "some invalid, some valid instrumental variable estimator" (sisVIVE) is a lasso-based method for instrumental variables (IVs) regression of outcome on an exposure. In principle, sisVIVE is robust to some of the IVs in the analysis being invalid, in the sense of being related to the outcome variable through pathway...

journal_title：Statistics in medicine

authors： Bao Y,Clarke PS,Smart M,Kumari M

更新日期：2019-04-30 00:00:00

abstract：:Crossover studies have been successfully conducted in the case of continuous responses. Existing procedures of analysis for ordinal responses, on the other hand, are rarely satisfactory unless strict, usually unrealistic, assumptions are made. In this paper we investigate a random effects model and show that the model...

journal_title：Statistics in medicine

authors： Ezzet F,Whitehead J

更新日期：1991-06-01 00:00:00

abstract：:Interim analyses are conducted to allow for early termination of the trial, for ethical as well as economical reasons. Here we consider interim analyses in repeated measurements studies where the measurements are binary. Two methods for analysing this kind of data are compared according to their operating characterist...

journal_title：Statistics in medicine

authors： Spiessens B,Lesaffre E,Verbeke G

更新日期：2003-02-28 00:00:00

abstract：:An important problem in oncology is comparing chemotherapy (chemo) agents in terms of their effects on survival or progression-free survival time. When the goal is to evaluate individual agents, a difficulty commonly encountered with observational data is that many patients receive a chemo combination including two or...

journal_title：Statistics in medicine

authors： Thall PF,Liu DD,Berrak SG,Wolff JE

更新日期：2011-07-10 00:00:00

abstract：:Mesothelioma is a rare cancer caused by exposure to asbestos. Belgium has a known long history of asbestos production, resulting in one of the highest mesothelioma mortality rates worldwide. While the production of asbestos has stopped completely, the long latency period of mesothelioma, which can fluctuate between 20...

journal_title：Statistics in medicine

authors： Petrof O,Neyens T,Nuyts V,Nackaerts K,Nemery B,Faes C

更新日期：2020-11-20 00:00:00

abstract：:A relationship between baseline risk and treatment effect is increasingly investigated as a possible explanation of between-study heterogeneity in clinical trial meta-analysis. An approach that is still often applied in the medical literature is to plot the estimated treatment effects against the estimated measures of...

journal_title：Statistics in medicine

authors： Arends LR,Hoes AW,Lubsen J,Grobbee DE,Stijnen T

更新日期：2000-12-30 00:00:00

abstract：:Biological drug products are therapeutic moieties manufactured by a living system or organisms. These are important life-saving drug products for patients with unmet medical needs. Because of expensive cost, only a few patients have access to life-saving biological products. Most of the early biological products will ...

journal_title：Statistics in medicine

authors： Lin JR,Chow SC,Chang CH,Lin YC,Liu JP

更新日期：2013-02-10 00:00:00

abstract：:The National Children's Study is a national household probability sample designed to identify 100,000 children at birth and follow the sampled children for 21 years. Data from the study will support examining numerous hypotheses concerning genetic and environmental effects on the health and development of children. Th...

journal_title：Statistics in medicine

authors： Montaquila JM,Brick JM,Curtin LR

更新日期：2010-06-15 00:00:00

abstract：:In noninferiority studies, a limit of indifference is used to express a tolerance in results such that the clinician would regard such results as being acceptable or 'not worse'. We applied this concept to a measure of accuracy, the Receiver Operating Characteristic (ROC) curve, for a sequence of tests. We expressed a...

journal_title：Statistics in medicine

authors： Ahmed AE,Schubert CM,McClish DK

更新日期：2013-07-20 00:00:00

abstract：:Regression to the mean arises often in statistical applications where the units chosen for study relate to some observed characteristic in the extreme of its distribution. Gardner and Heady attribute the effect of regression to the mean to measurement errors. They assume the model Yi = U + ei, where U is a fixed withi...

journal_title：Statistics in medicine

authors： Johnson WD,George VT

更新日期：1991-08-01 00:00:00

abstract：:Important differences between explanatory and pragmatic studies were originally argued by Schwartz and Lellouch. Three important differences between the two types of study involve study control, study violators and inclusion criteria. It was originally argued that explanatory studies are highly controlled, and pragmat...

journal_title：Statistics in medicine

authors： McMahon AD

更新日期：2002-05-30 00:00:00

abstract：:Providing personalized treatments designed to maximize benefits and minimizing harms is of tremendous current medical interest. One problem in this area is the evaluation of the interaction between the treatment and other predictor variables. Treatment effects in subgroups having the same direction but different magni...

journal_title：Statistics in medicine

authors： Chen W,Ghosh D,Raghunathan TE,Norkin M,Sargent DJ,Bepler G

更新日期：2012-12-10 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：:In a cluster randomized cross-over trial, all participating clusters receive both intervention and control treatments consecutively, in separate time periods. Patients recruited by each cluster within the same time period receive the same intervention, and randomization determines order of treatment within a cluster. ...

journal_title：Statistics in medicine

authors： Turner RM,White IR,Croudace T,PIP Study Group.

更新日期：2007-01-30 00:00:00

abstract：:This paper reviews several emerging and recurrent issues relating to the drug development process. These emerging issues include changes to the FDA regulatory environment, internationalization of drug development, advances in computer technology and visualization tools, and efforts to incorporate meta-analysis methodo...

journal_title：Statistics in medicine

authors： Anello C

更新日期：1999-09-15 00:00:00

abstract：:This paper discusses the benefits and limitations of adaptive sample size re-estimation for phase 3 confirmatory clinical trials. Comparisons are made with more traditional fixed sample and group sequential designs. It is seen that the real benefit of the adaptive approach arises through the ability to invest sample s...

journal_title：Statistics in medicine

authors： Mehta CR,Pocock SJ

更新日期：2011-12-10 00:00:00

abstract：:In randomised trials, continuous endpoints are often measured with some degree of error. This study explores the impact of ignoring measurement error and proposes methods to improve statistical inference in the presence of measurement error. Three main types of measurement error in continuous endpoints are considered:...

journal_title：Statistics in medicine

authors： Nab L,Groenwold RHH,Welsing PMJ,van Smeden M

更新日期：2019-11-30 00:00:00

abstract：:Confidence intervals for a standardized effect are derived after stabilizing the variance of the Welch t-statistic. Simulation studies demonstrate the viability of the resulting intervals for a wide range of parameter values and sample sizes as small as five. The methodology is extended to the combination of results f...

journal_title：Statistics in medicine

authors： Kulinskaya E,Staudte RG

更新日期：2007-06-30 00:00:00

abstract：:We develop a simulation-based procedure for determining the required sample size in binomial regression risk assessment studies when response data are subject to misclassification. A Bayesian average power criterion is used to determine a sample size that provides high probability, averaged over the distribution of po...

journal_title：Statistics in medicine

authors： Cheng D,Stamey JD,Branscum AJ

更新日期：2009-02-28 00:00:00

abstract：:In this article, we investigate procedures for comparing two independent Poisson variates that are observed over unequal sampling frames (i.e. time intervals, populations, areas or any combination thereof). We consider two statistics (with and without the logarithmic transformation) for testing the equality of two Poi...

journal_title：Statistics in medicine

authors： Ng HK,Tang ML

更新日期：2005-03-30 00:00:00

abstract：:The World Health Organization and collaborating institutions in four developing countries have conducted a multi-centre randomized controlled trial, in which clinics were allocated at random to two antenatal care (ANC) models. These were the standard 'Western' ANC model and a 'new' ANC model consisting of tests, clini...

journal_title：Statistics in medicine

authors： Piaggio G,Carroli G,Villar J,Pinol A,Bakketeig L,Lumbiganon P,Bergsjø P,Al-Mazrou Y,Ba'aqeel H,Belizán JM,Farnot U,Berendes H,WHO Antenatal Care Trial Research Group.

更新日期：2001-02-15 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：:A study of long term survival of 1487 patients given an allogeneic bone marrow transplant for acute myelogenous leukaemia and 729 patients given a transplant for severe aplastic anaemia was conducted by the International Bone Marrow Transplant Registry. One aim of this study is to determine if the mortality rates of t...

journal_title：Statistics in medicine

authors： Andersen PK,Horowitz MM,Klein JP,Socie G,Stone JV,Zhang MJ

更新日期：1999-06-30 00:00:00

abstract：:A method has been developed for simultaneously comparing the usefulness of many treatments of established value for symptomatic medical conditions. Medical assessment of outcome is not employed. Instead patients are required to assess treatments prescribed during the course of ordinary general practice rather than und...

journal_title：Statistics in medicine

authors： Charlton JR,D'Souza MF,Tooley M,Silver R

更新日期：1985-01-01 00:00:00

abstract：:Clinical trials studying treatments for rare diseases are challenging to design and conduct due to the limited number of patients eligible for the trial. One design used to address this challenge is the small n, sequential, multiple assignment, randomized trial (snSMART). We propose a new snSMART design that investiga...

journal_title：Statistics in medicine

authors： Fang F,Hochstedler KA,Tamura RN,Braun TM,Kidwell KM

更新日期：2021-02-20 00:00:00

abstract：:A stochastic approximation EM algorithm (SAEM) is described for exploratory factor analysis of dichotomous or ordinal variables. The factor structure is obtained from sufficient statistics that are updated during iterations with the Robbins-Monro procedure. Two large-scale simulations are reported that compare accurac...

journal_title：Statistics in medicine

authors： Camilli G,Geis E

更新日期：2019-09-20 00:00:00

abstract：:In this paper the following problem of clinical research is explored. Several potential new treatments are available for use against a certain disease. These are evaluated in a series of pilot studies which will constitute phase II clinical trials. The most promising will then be compared with a standard treatment in ...

journal_title：Statistics in medicine

authors： Whitehead J

更新日期：1986-09-01 00:00:00