摘要:

AbstractA scoring system for possibly censored monotonic processes is presented which allows to analyze such processes by means of standard parametric or nonparametric tests. In either case the analyses are invariant to monotonic transformations of time. Such analyses are of relevance whenever changes in degree of function are observed rather than the single and 100% loss of function of survival analysis. An example of gradually increasing function after particular reconstructive surgery is supplied.

ISSN:0323-3847    

DOI:10.1002/bimj.4710330402

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractCrossover experiments usually are modelled with fixed treatment, carryover, and period effects while the effects of subjects are assumed to be random. In actual realisations of crossover experiments however periods are quite arbitrary intervals of time, depending on administrative affairs for instance and possibly they are even varying from subject to subject. Modelling these arbitrary periods as random effects either globally for all subjects or individually for each one seems to be more adequate than the assumption of fixed period effects. This paper is concerned with the two treatments, two periods crossover design. It is described that—in spite of the somewhat involved covariance structure—the estimators and tests developed for models with fixed period effects remain valid for models with random effects for periods provided that no treatment X period interaction exi

ISSN:0323-3847    

DOI:10.1002/bimj.4710330403

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0323-3847    

DOI:10.1002/bimj.4710330404

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractIn this paper we consider balanced three‐treatment three‐period crossover designs. Using a strategy similar to that applied in the analysis of split‐plot experiments we describe both the within and the between sample units models, as well as the corresponding Analysis of Variance. We illustrate these procedures with a numerical example and discuss their implementation through computer programs designed for the analysis of the general linear

ISSN:0323-3847    

DOI:10.1002/bimj.4710330405

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractIn biology and medicine many substances and drugs enter the system not at regular time intervals but rather according to a random process. In the present article a situation is investigated where input enters a 2‐compartment system according to a Poisson process. The arising two random concentration curvesy(t), one for the central and one for the peripheral compartment are discussed (shot noise).The equations forE[y(t)] and Var [y(t)] are derived. The dependence ofE[y(t)] and Var [y(t)] and of the index of dispersionID[y(t)] on the rate parameters is analysed and discussed in both compartments. The arising calculations were considerably simplified by means of “Mathematica”, a computer program which allows to perform symbolic calcula

ISSN:0323-3847    

DOI:10.1002/bimj.4710330406

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0323-3847    

DOI:10.1002/bimj.4710330407

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractA competing risk model, accommodating both Type I censoring and random withdrawals, is expanded to incorporate concomitant information by allowing the parameters of the underlying distributions to be a linear function of two covariates. The model is developed for two competing risks, one following a Weibull distribution and the other a Rayleigh distribution, and random withdrawals following a Weibull distribution. A method is developed for testing the equality of the coefficients for a given covariate for each of the competing risks using MLE'.

ISSN:0323-3847    

DOI:10.1002/bimj.4710330408

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0323-3847    

DOI:10.1002/bimj.4710330409

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractA procedure for comparing survival times between several groups of patients through rank analysis of covariance was introduced by WOOLSONand LACHENBRUCH(1983). It is a modification of Quade' rank analysis of covariance procedure (1967) and can be used for the analysis of right‐censored data. In this paper, two additional modifications of Quade' original test statistic are proposed and compared to the original modification introduced by Woolson and Lachenbruch. These statistics are compared to one another and to the score test from Cox' proportional hazards model by way of a limited Monte Carlo study. One of the statistics, QR2, is recommended for general use for the rank analysis of covariance of right‐censored survivorship d

ISSN:0323-3847    

DOI:10.1002/bimj.4710330410

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0323-3847    

DOI:10.1002/bimj.4710330411

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY