Within-subject exposure dependency in case-crossover studies.
Stat Med
; 20(20): 3039-49, 2001 Oct 30.
Article
en En
| MEDLINE
| ID: mdl-11590631
ABSTRACT
In the case-crossover design, only cases are sampled and the hazard ratio is estimated from within-subject comparisons of exposures at the event time and in M control periods prior to the event. We consider the effect of within-subject dependence of exposures in successive time periods. We show that estimates obtained from the conditional logistic model are biased. This bias disappears if the distribution of exposures in the M+1 successive time intervals is exchangeable. In contrast, the Mantel-Haenszel estimator for the odds ratio is approximately unbiased provided that exposures are stationary. Suitable methods of analysis of case-crossover designs using maximum likelihood may be derived from cohort rather than case-control models.
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Base de datos:
MEDLINE
Asunto principal:
Estudios de Casos y Controles
/
Modelos Logísticos
/
Estudios Cruzados
Tipo de estudio:
Clinical_trials
/
Observational_studies
/
Risk_factors_studies
Idioma:
En
Revista:
Stat Med
Año:
2001
Tipo del documento:
Article