[Survival analysis example based on an event history model from a clinical trial in cardiology].
BACKGROUND
The main purpose of this paper is to present a survival analysis example based on an event history model in a competitive risks framework. Our example is derived from a clinical trial designed for comparing survival of a beta-blocker therapy group and a placebo group.


METHODS
Competitive risks under study were non lethal cardiovascular events, permanent treatment withdrawals and deaths. The event history model was assumed to be semi-Markovian. The Cox proportional hazards model was used for modeling effects of treatments and regression variables on the transition rates.


RESULTS
After taking into account all covariables influencing survival, mortality in patients who had one non lethal cardiovascular event after randomization but remained treated was shown to be reduced in the beta-blocker therapy group (RR=0.41; CI 95%=[0.17-0.98], p=0.04).


CONCLUSIONS
Our analysis indicates that beta-blocker therapy should not necessarily be stopped in patients who experience a non lethal cardiovascular event under treatment. This finding requires confirmation in a separate setting.
Lancar
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INSERM SC4, Faculté St Antoine, 75571 Paris Cedex 12.
Funck-Brentano
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D006331:Heart Diseases / Q000401:mortality* / Q000628:therapy; D006801:Humans; D015233:Models, Statistical; D016016:Proportional Hazards Models; D016019:Survival Analysis