Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
A BAYESIAN-ANALYSIS OF MIXED SURVIVAL MODELS
Autore:
DUCROCQ V; CASELLA G;
Indirizzi:
INRA,GENET QUANTITAT & APPL STN F-78352 JOUY EN JOSAS FRANCE CORNELL UNIV,DEPT ANIM SCI ITHACA NY 14852 CORNELL UNIV,BIOMETR UNIT ITHACA NY 14852
Titolo Testata:
Genetics selection evolution
fascicolo: 6, volume: 28, anno: 1996,
pagine: 505 - 529
SICI:
0999-193X(1996)28:6<505:ABOMSM>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
MAXIMUM-LIKELIHOOD; PRODUCTIVE LIFE; EM ALGORITHM; DAIRY-COWS; INFERENCE; APPROXIMATIONS; DISTRIBUTIONS; FRAILTY; LENGTH; TRAITS;
Keywords:
SURVIVAL ANALYSIS; MIXED MODEL; VARIANCE COMPONENT ESTIMATION; BAYESIAN ANALYSIS; PROPORTIONAL HAZARDS MODEL;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
55
Recensione:
Indirizzi per estratti:
Citazione:
V. Ducrocq e G. Casella, "A BAYESIAN-ANALYSIS OF MIXED SURVIVAL MODELS", Genetics selection evolution, 28(6), 1996, pp. 505-529

Abstract

In proportional hazards models, the hazard of an animal lambda(t), ie, its probability of dying or being culled at time t given it is aliveprior to t, is described as lambda(t) = lambda(0)(t)e(w'theta) where lambda(0)(t) is a 'baseline' hazard function and e(w'theta) representsthe effect of covariates w on culling rate. A distribution can be attached to elements s(q) in theta, identifying, for example, genetic effects and leading to mixed survival models, also called 'frailty' models. To estimate the parameters tau of the distribution of frailty terms, a Bayesian analysis is proposed. Inferences are drawn from the marginal posterior density pi(tau) which can be derived from the joint posterior density via Laplacian integration, a powerful technique related to saddlepoint approximations. The validity of this technique is shownhere on simulated examples by comparing the resulting approximate pi(tau) to the one obtained by algebraic integration. This exact calculation is feasible in very specific cases only, whereas the saddlepoint approximation can be applied to situations where Xo(t) is arbitrary (Cox models) or parametric (eg, Weibull), where the frailty terms are correlated through a known relationship matrix, or in more general modelswith stratification and/or time-dependent covariates. The influence of the censoring rate and the data structure is also illustrated.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 13:12:07