摘要:

The expansion, in standard form, consists of some 66 terms involving polyno - mials in a normal deviate, and cumulants and cumulant products to order ten. An assumed order of magnitude reduces these terms to eight groups. Sign patterns in the terms are not obvious. We take a number of Pearson densities and assess from the expansions a set of standard percentiles (1%, 5%, 95%, 99%). Validity of the as-sessments is pivoted on two alternative models:(i) the Bowman-Shenton algorithm for percentage points of Pearson densities, (ii) the 4-moment Johnson translation model. This approach has wide application since the models have proved to be remarkably reliable when compared, and also when compared with simulation as-sessments. A brief account is given of acceleration of convergence for the series, but there seems to be no analogue of the Padè or Levin algorithms.

ISSN:0361-0918    

DOI:10.1080/03610919708813384

出版商:Marcel Dekker, Inc.    

年代:1997

数据来源: Taylor

摘要:

Binary data from human reproductive studies occur naturally in clusters and often exhibit strong intracluster correlation which results in overdispersion. Although several methods for analyzing clustered data, particularly those with covariates specific to each binary outcome, have been proposed recently, the properties of many of these models have not been rigorously evaluated in simulation studies, nor have they been compared amongst each other. In this paper, three such models which are applicable to the analysis of spontaneous abortions in humans are evaluated. In all three cases, the maximum likelihood estimates of effect are biased. In addition, naive logistic regression to the whole data set of simulated pregnancy outcomes, ignoring intracluster correlation, is shown to be biased toward the null in the presence of an effect.

ISSN:0361-0918    

DOI:10.1080/03610919708813385

出版商:Marcel Dekker, Inc.    

年代:1997

数据来源: Taylor

ISSN:0361-0918    

DOI:10.1080/03610919708813386

出版商:Marcel Dekker, Inc.    

年代:1997

数据来源: Taylor

ISSN:0361-0918    

DOI:10.1080/03610919708813363

出版商:Marcel Dekker, Inc.    

年代:1997

数据来源: Taylor