Combining classification trees using MLE.

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：:Clinical trials of treatments for rare or fatal diseases must often use historical rather than randomized concurrent controls. Randomized trials may not be possible if (1) the number of patients available is quite small, (2) ethical considerations discourage the assignment of patients to control treatments known to be...

journal_title：Statistics in medicine

authors： Hoehler FK,Mantel N,Gehan E,Kahana E,Alter M

更新日期：1984-07-01 00:00:00

abstract：:Dependence between observations on a dichotomous variable renders invalid the usual chi-square tests of independence and inflates the variances of parameter estimates. Such a situation occurs, for example, when subjects consist of members of the same family or with repeated observations on the same person. In this pap...

journal_title：Statistics in medicine

authors： Donald A,Donner A

更新日期：1987-06-01 00:00:00

abstract：:It is well established that neural activity is stochastically modulated over time. Therefore, direct comparisons across experimental conditions and determination of change points or maximum firing rates are not straightforward. This study sought to compare temporal firing probability curves that may vary across groups...

journal_title：Statistics in medicine

authors： Roca-Pardiñas J,Cadarso-Suárez C,Pardo-Vazquez JL,Leboran V,Molenberghs G,Faes C,Acuña C

更新日期：2011-06-30 00:00:00

abstract：:The intraclass correlation coefficient rho plays a key role in the design of cluster randomized trials. Estimates of rho obtained from previous cluster trials and used to inform sample size calculation in planned trials may be imprecise due to the typically small numbers of clusters in such studies. It may be useful t...

journal_title：Statistics in medicine

authors： Ukoumunne OC,Davison AC,Gulliford MC,Chinn S

更新日期：2003-12-30 00:00:00

abstract：:The 'landmark' and 'Simon and Makuch' non-parametric estimators of the survival function are commonly used to contrast the survival experience of time-dependent treatment groups in applications such as stem cell transplant versus chemotherapy in leukemia. However, the theoretical survival functions corresponding to th...

journal_title：Statistics in medicine

authors： Bernasconi DP,Rebora P,Iacobelli S,Valsecchi MG,Antolini L

更新日期：2016-03-30 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：:The additional time to complete a three-period two-treatment (3P2T) cross-over trial may cause a greater number of patient dropouts than with a two-period trial. This paper develops maximum likelihood (ML), single imputation and multiple imputation missing data analysis methods for the 3P2T cross-over designs. We use ...

journal_title：Statistics in medicine

authors： Richardson BA,Flack VF

更新日期：1996-01-30 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：:Clinical trials utilizing predictive biomarkers have become a research focus in personalized medicine. We investigate the effects of biomarker misclassification on the design and analysis of stratified biomarker clinical trials. For a variety of inference problems including marker-treatment interaction in particular, ...

journal_title：Statistics in medicine

authors： Liu C,Liu A,Hu J,Yuan V,Halabi S

更新日期：2014-08-15 00:00:00

abstract：:A survey is conducted at w of K selection units or lists, e.g. health care institutions or weeks in a year, to estimate N, the total number of individuals with particular characteristics. Our estimator utilizes two items determined for each survey participant: the number, u, among the w lists in S and the number, j, a...

journal_title：Statistics in medicine

authors： Laska EM,Meisner M,Wanderling J

更新日期：2009-07-30 00:00:00

abstract：:In many chronic disease processes subjects are at risk of two or more types of events. We describe a bivariate mixed Poisson model in which a copula function is used to model the association between two gamma distributed random effects. The resulting model is a bivariate negative binomial process in which each type of...

journal_title：Statistics in medicine

authors： Cook RJ,Lawless JF,Lee KA

更新日期：2010-03-15 00:00:00

abstract：:Clustered grouped survival data arise naturally in clinical medicine and biological research. For example, in a randomized clinical trial, the variable of interest is the time to occurrence of a certain event with or without a new treatment and the data are collected from possibly correlated subjects from independent ...

journal_title：Statistics in medicine

authors： Lam KF,Ip D

更新日期：2003-06-30 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：:When data are dichotomous, this paper notes the utility of inverse sampling in establishing equivalence with respect to the risk ratio. This paper develops an exact equivalence test that accounts for the risk ratio under inverse sampling and further discusses the relationship between the exact equivalence test and the...

journal_title：Statistics in medicine

authors： Lui KJ

更新日期：1997-08-15 00:00:00

abstract：:Data monitoring committees (DMCs) have become an increasingly common component of randomized clinical trials in recent years. As experience has accumulated, and more individuals and organizations have become involved in such activities, a variety of approaches to the operation of such committees has inevitably arisen....

journal_title：Statistics in medicine

authors： Ellenberg SS

更新日期：2001-09-15 00:00:00

abstract：:We have formulated the problem of determining whether there has been an upturn in HIV-1 seroconversion incidence over the first five years of follow-up in the Multicenter AIDS Cohort Study (MACS) as that of locating the minimum of a quadratic regression or examination of two-knot piecewise spline models. Under a quadr...

journal_title：Statistics in medicine

authors： Zhou SY,Kingsley LA,Taylor JM,Chmiel JS,He DY,Hoover DR

更新日期：1993-01-30 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：:Two features commonly exhibited by randomized trials of health promotion interventions are cluster randomization and stratification. Ignoring correlations between individuals within clusters can lead to an inflated type I error rate and hence a P-value which overstates the significance of the result. This paper compar...

journal_title：Statistics in medicine

authors： Dobbins TA,Simpson JM

更新日期：2002-12-30 00:00:00

abstract：:Testing the equality of 2 proportions for a control group versus a treatment group is a well-researched statistical problem. In some settings, there may be strong historical data that allow one to reliably expect that the control proportion is one, or nearly so. While one-sample tests or comparisons to historical cont...

journal_title：Statistics in medicine

authors： Gabriel EE,Nason M,Fay MP,Follmann DA

更新日期：2018-03-30 00:00:00

abstract：:The relationship between association and surrogacy has been the focus of much debate in the surrogate marker literature. Recently, the individual causal association (ICA) has been introduced as a metric of surrogacy in the causal inference framework, when both the surrogate and the true endpoint are normally distribut...

journal_title：Statistics in medicine

authors： Meyvisch P,Alonso A,Van der Elst W,Molenberghs G

更新日期：2020-11-20 00:00:00

abstract：:We present an estimate of the kappa-coefficient of agreement between two methods of rating based on matched pairs of binary responses and show that the estimate depends on the common intraclass correlation coefficient between the pairs. Via Monte Carlo simulation, we investigate power of the test of significance on ka...

journal_title：Statistics in medicine

authors： Shoukri MM,Martin SW,Mian IU

更新日期：1995-01-15 00:00:00

abstract：:We propose a new design for dose finding for cytotoxic agents in two ordered groups of patients. By ordered groups, we mean that prior to the study there is clinical information that would indicate that for a given dose one group would be more susceptible to toxicities than patients in the other group. The designs are...

journal_title：Statistics in medicine

authors： Conaway MR,Wages NA

更新日期：2017-01-30 00:00:00

abstract：:Meta-analysis is the methodology for combining findings from similar research studies asking the same question. When the question of interest involves multiple outcomes, multivariate meta-analysis is used to synthesize the outcomes simultaneously taking into account the correlation between the outcomes. Likelihood-bas...

journal_title：Statistics in medicine

authors： Ma Y,Mazumdar M

更新日期：2011-10-30 00:00:00

abstract：:This paper presents combinatorial (exact) methods that are useful in the analysis of disease cluster data obtained from small environments, such as buildings and neighbourhoods. Maxwell-Boltzmann and Fermi-Dirac occupancy models are compared in terms of appropriateness of representation of disease incidence patterns (...

journal_title：Statistics in medicine

authors： Grimson RC

更新日期：1993-10-01 00:00:00

abstract：:The explanation of heterogeneity plays an important role in meta-analysis. The random effects meta-regression model allows the inclusion of trial-specific covariates which may explain a part of the heterogeneity. We examine the commonly used tests on the parameters in the random effects meta-regression with one covari...

journal_title：Statistics in medicine

authors： Knapp G,Hartung J

更新日期：2003-09-15 00:00:00

abstract：:Sequential analysis is frequently employed to address ethical and financial issues in clinical trials. Sequential analysis may be performed using standard group sequential designs, or, more recently, with adaptive designs that use estimates of treatment effect to modify the maximal statistical information to be collec...

journal_title：Statistics in medicine

authors： Emerson SC,Rudser KD,Emerson SS

更新日期：2011-05-20 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

authors： Hadgu A,Koch G,Westrom L

更新日期：1997-11-15 00:00:00

abstract：:Unmeasured confounding is a common concern when researchers attempt to estimate a treatment effect using observational data or randomized studies with nonperfect compliance. To address this concern, instrumental variable methods, such as 2-stage predictor substitution (2SPS) and 2-stage residual inclusion (2SRI), have...

journal_title：Statistics in medicine

authors： Wan F,Small D,Mitra N

更新日期：2018-05-30 00:00:00

abstract：:We consider methods for selecting the joint specification of the mean and variance functions in statistical models for rates or counts. Based on analyses of diagnosis-specific hospital discharge rates in Michigan, we show that a Poisson model with an extra variance component for the systematic variation is superior to...

journal_title：Statistics in medicine

authors： Wolfe RA,Petroni GR,McLaughlin CG,McMahon LF Jr

更新日期：1991-09-01 00:00:00