abstract：:This paper reviews methods for mapping geographical variation in disease incidence and mortality. Recent results in Bayesian hierarchical modelling of relative risk are discussed. Two approaches to relative risk estimation, along with the related computational procedures, are described and compared. The first is an em...

journal_title：Statistics in medicine

authors： Bernardinelli L,Montomoli C

更新日期：1992-06-15 00:00:00

abstract：:This paper presents tables analogous to T-tables for use in the 2 x 2 multinomial trial, where the continuity corrected Z-statistic is used to make exact unconditional inference. This is the first solution of a discrete exact unconditional inference problem involving a multivariate nuisance parameter for which no anci...

journal_title：Statistics in medicine

authors： Shuster JJ

更新日期：1992-05-01 00:00:00

abstract：:The back-calculation method has been used to estimate the number of HIV infections from AIDS incidence data in a particular population. We present an extension of back calculation that provides estimates of the numbers of HIV infectives in different stages of infection. We model the staging process with a time-depende...

journal_title：Statistics in medicine

authors： Longini IM Jr,Byers RH,Hessol NA,Tan WY

更新日期：1992-04-01 00:00:00

abstract：:Estimates of transmission probabilities for sexually transmitted diseases historically come from studies of uninfected individuals exposed to those with a high disease prevalence (for example, prostitutes). However, changes in sexual behaviour, much of which relates to concerns about AIDS, has made identification of p...

journal_title：Statistics in medicine

authors： Katz BP

更新日期：1992-03-01 00:00:00

abstract：:This article concerns construction of a confidence surface for tangential slopes of the dose-response surface of a combination therapy to identify where response increases as a function of drug dosage. This approach extends to the assessment of the effectiveness of the combination therapy. ...

journal_title：Statistics in medicine

authors： Hung HM

更新日期：1992-03-01 00:00:00

abstract：:We have used Monte Carlo methods to compare the type I error properties of the conditional and unconditional versions of the generalized t and the generalized rank-sum tests to those of the independent samples t and Wilcoxon rank-sum tests. Results showed inflated type I errors for the conditional generalized tests bu...

journal_title：Statistics in medicine

authors： Blair RC,Morel JG

更新日期：1992-02-28 00:00:00

abstract：:Thomas et al. presented the application of empirical-Bayes methods to the problem of multiple inference in epidemiologic studies. One limitation of their approach, which they noted, was the need to assume exchangeable log relative-risk parameters, and independent relative-risk estimates. Numerical integration was also...

journal_title：Statistics in medicine

authors： Greenland S

更新日期：1992-01-30 00:00:00

abstract：:A technique is presented which provides guidance on the spacing of follow-up waves in a multiwave study. Only information from the baseline wave is needed, as well as rough parameter estimates for the survival distribution. The computations use the expected Fisher information; a new method for its calculation is given...

journal_title：Statistics in medicine

authors： Chappell R

更新日期：1991-12-01 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：: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：: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

abstract：:We simulated multinomial AIDS incidence counts from 27 'representative' AIDS epidemics that spanned a period corresponding to previous applications of backcalculation (1 January 1977 to 1 July 1987) and assessed mean square error for several back-calculated estimators of HIV prevalence and short-term AIDS projections....

journal_title：Statistics in medicine

authors： Rosenberg PS,Gail MH,Pee D

更新日期：1991-08-01 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：:Clinical trials with multiple endpoints incur increased familywise type I errors. The Bonferroni correction is a common method used to modify the p-values to account for multiple significance testing. For independent endpoints the Bonferroni method is slightly conservative whereas with high correlation the conservatis...

journal_title：Statistics in medicine

authors： James S

更新日期：1991-07-01 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：:The identification of new adverse drug reactions is often tricky. For a given case, the relationship between drug exposure and symptom occurrence is usually questionable. It could be investigated statistically from a series of drug-event association cases with an independence test between the two variables. Analysing ...

journal_title：Statistics in medicine

authors： Tubert P,Begaud B

更新日期：1991-06-01 00:00:00

abstract：:Reference ranges which take time (such as age) into account are often required in medicine, but simple, systematic and efficient statistical methods for constructing them are lacking. A method is described which is based on low order polynomial curves (linear, quadratic or occasionally cubic), together with guidelines...

journal_title：Statistics in medicine

authors： Royston P

更新日期：1991-05-01 00:00:00

abstract：:This paper gives a standard error for Cohen's Kappa, conditional on the margins of the observed r x r table. An explicit formula is given for the 2 x 2 table, and a procedure for the more general situation. A parsimonious log-linear model is suggested for the general case and an approximate confidence interval for kap...

journal_title：Statistics in medicine

authors： Garner JB

更新日期：1991-05-01 00:00:00

abstract：:This paper considers the effect of non-differential outcome misclassification on the population attributable fraction and the population prevented fraction. I examine the bias in the attributable and the prevented fraction derived from a risk ratio estimate as a function of the sensitivity and specificity of the outco...

journal_title：Statistics in medicine

authors： Hsieh CC

更新日期：1991-03-01 00:00:00

abstract：:In this paper we examine the efficiency of a generalization of the traditional normal linear (LDA) or quadratic (QDA) discriminant analysis. This procedure (the generalized discriminant analysis, GDA) replaces each normal density used in the traditional classification rule by a Fourier series density estimator which '...

journal_title：Statistics in medicine

authors： Odom-Maryon T,Langholz B,Niland J,Azen S

更新日期：1991-03-01 00:00:00

abstract：:Although the literature on contraceptive failure is vast and is expanding rapidly, our understanding of the relative efficacy of methods is quite limited because of defects in the research design and in the analytical tools used by investigators. Errors in the literature range from simple arithmetical mistakes to outr...

journal_title：Statistics in medicine

authors： Trussell J

更新日期：1991-02-01 00:00:00

abstract：:Experimental designs with repeated measures allow response patterns over time (or dose) to be modelled and compared between different homogeneous groups. Issues in data analysis often focus on the pattern of variation of the repeated measures, the appropriateness of a univariate or multivariate analysis, and the shape...

journal_title：Statistics in medicine

authors： Stanek EJ 3rd,Kline G

更新日期：1991-01-01 00:00:00

abstract：:Several relative risk models for survival time data in drug combination therapy are derived and their properties are discussed. The main intention of this paper is to clarify the differences among the models in order to help to choose the appropriate one in a given situation. The models are motivated by discussing the...

journal_title：Statistics in medicine

authors： Kübler J,Schumacher M

更新日期：1990-12-01 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：:Variation in heart disease (HD) mortality rates across census tracts is greater than expected given binomial error and available explanatory variables. We extended an extra-binomial variation model for rates standardized by the direct method. The overdispersion parameter accounted for 36 per cent of the observed varia...

journal_title：Statistics in medicine

authors： Jarjoura D,Logue E

更新日期：1990-10-01 00:00:00

abstract：:The Cardiac Arrythmia Suppression Trial was stopped much earlier than planned. Statistical considerations played a very important role in the decision. Flexible group sequential testing was developed for the trial by implementing a Lan and DeMets procedure with use of the permutation test. We compute P-values from the...

journal_title：Statistics in medicine

authors： Pawitan Y,Hallstrom A

更新日期：1990-09-01 00:00:00

abstract：:The first randomized clinical trial at the National Cancer Institute (NCI), planned in 1954, commenced in 1955 for the treatment of patients with acute leukaemia. The programme in clinical trials at NCI had strong influence from the clinician and administrator, C. Gordon Zubrod, who introduced the randomized clinical ...

journal_title：Statistics in medicine

authors： Gehan EA,Schneiderman MA

更新日期：1990-08-01 00:00:00

abstract：:We obtained maximum likelihood estimates (MLEs) of the proportion cured pi c and mean log survival time mu t for a sample of 4355 patients with intraocular melanoma whose survival times subsequent to treatment were assumed to follow a log-normal distribution. Following stratification by tumour size, MLEs of pi c and m...

journal_title：Statistics in medicine

authors： Gamel JW,McLean IW,Rosenberg SH

更新日期：1990-08-01 00:00:00

abstract：:In clinical trials, treatment comparisons are often performed by models that incorporate important prognostic factors. Since these models require complete covariate information on all patients, statisticians frequently resort to complete case analysis or to omission of an important covariate. A probability imputation ...

journal_title：Statistics in medicine

authors： Schemper M,Smith TL

更新日期：1990-07-01 00:00:00

abstract：:With considerable current interest in longitudinal epidemiologic studies, little is available regarding sample size requirements. This paper considers a method for analysis of longitudinal data, where one compares the mean rates of change for two or more groups, and proposes a statistic for use in determining sample s...

journal_title：Statistics in medicine

authors： Lefante JJ

更新日期：1990-04-01 00:00:00

abstract：:The one-step (Peto) method for obtaining pooled effect estimates can yield extremely biased results when applied to unbalanced data. Even for balanced studies, the one-step estimate may incorporate an unacceptable degree of bias. In place of the one-step estimate, we recommend use of ordinary Mantel-Haenszel, weighted...

journal_title：Statistics in medicine

authors： Greenland S,Salvan A

更新日期：1990-03-01 00:00:00

abstract：:The cost and efficiency of training clinical centre staff and of duplicate data entry in clinical trials is reviewed. Training is an essential component of quality assurance programmes and it is usually carried out at regular intervals in long-term clinical trials. Initial training of staff and regular retraining is i...

journal_title：Statistics in medicine

authors： Neaton JD,Duchene AG,Svendsen KH,Wentworth D

更新日期：1990-01-01 00:00:00

abstract：:This paper discusses the various philosophies that influence the selection of patients for entry into randomized controlled trials. Although a number of different and often competing issues have to be considered depending upon the trial, keeping entry criteria simple, wide and at times even flexible is usually prefera...

journal_title：Statistics in medicine

authors： Yusuf S,Held P,Teo KK,Toretsky ER

更新日期：1990-01-01 00:00:00

abstract：:This paper presents a procedure for obtaining short-term projections and lower bounds on the size of the acquired immunodeficiency syndrome (AIDS) epidemic. The method is similar to that proposed by Brookmeyer and Gail but adapted to the situation where individual dates of AIDS diagnosis are available. It gives result...

journal_title：Statistics in medicine

authors： Tango T

更新日期：1989-12-01 00:00:00

abstract：:Two important qualities of controlled clinical trials are that they reduce dependence on historical standards for evaluating therapy and separate the effect of treatment from the confounding influence of time. Whatever the theory of the clinical trial, however, time has not easily been banished from the analysis of me...

journal_title：Statistics in medicine

authors： Senn SJ

更新日期：1989-11-01 00:00:00

abstract：:A measure of similarity for response curves is presented and its potential use is discussed. The distribution of a suitable test statistic for testing the independence of the course of two curves is derived. The method proposed is compared with other proposals in the literature for the analysis of paired response curv...

journal_title：Statistics in medicine

authors： Schulgen G

更新日期：1989-11-01 00:00:00

abstract：:We survey models for analysing repeated observations on an ordered categorical response variable. The models presented are univariate models that permit correlation among repeated measurements. The models describe simultaneously the dependence of marginal response distributions on values of explanatory variables and o...

journal_title：Statistics in medicine

authors： Agresti A

更新日期：1989-10-01 00:00:00

abstract：:Both the variation of positive responses (negative responses) among individuals and the internal correlation among responses for the same individual affect the precision of the estimate of sensitivity (specificity). To estimate the sensitivity (specificity) of a medical diagnostic test, this paper proposes a Bayesian ...

journal_title：Statistics in medicine

authors： Lui KJ

更新日期：1989-10-01 00:00:00

abstract：:Weak measurement of epidemiologic exposures is an impediment to appreciation of the effects of those exposures. This paper discusses two strategies to assess the true effects of weakly measured exposure. The first is to use external information about the extent of mismeasurement to adjust estimates of the effects of e...

journal_title：Statistics in medicine

authors： Marshall JR

更新日期：1989-09-01 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