Flexible modeling of the effects of continuous prognostic factors in relative survival.
Stat Med
; 30(12): 1351-65, 2011 May 30.
Article
em En
| MEDLINE
| ID: mdl-21432891
ABSTRACT
Relative survival methods permit separating the effects of prognostic factors on disease-related 'excess mortality' from their effects on other-causes 'natural mortality', even when individual causes of death are unknown. As in conventional 'crude' survival, accurate assessment of prognostic factors requires testing and possibly modeling of non-proportional effects and, for continuous covariates, of non-linear relationships with the hazard. We propose a flexible extension of the additive-hazards relative survival model, in which the observed all-causes mortality hazard is represented by a sum of disease-related 'excess' and natural mortality hazards. In our flexible model, the three functions representing (i) the baseline hazard for 'excess' mortality, (ii) the time-dependent effects, and (iii) for continuous covariates, non-linear effects, on the logarithm of this hazard, are all modeled by low-dimension cubic regression splines. Non-parametric likelihood ratio tests are proposed to test the time-dependent and non-linear effects. The accuracy of the estimated functions is evaluated in multivariable simulations. To illustrate the new insights offered by the proposed model, we apply it to re-assess the effects of patient age and of secular trends on disease-related mortality in colon cancer.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Modelos de Riscos Proporcionais
/
Análise de Sobrevida
/
Interpretação Estatística de Dados
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Stat Med
Ano de publicação:
2011
Tipo de documento:
Article