Annals of epidemiology
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Annals of epidemiology · Jan 2006
Comparative StudyDisparities in mortality among high risk pregnant women in Illinois: a population based study.
Researchers are increasingly studying maternal mortality in the context of maternal morbidity in order to identify risk and protective factors operating at each point along the morbidity-mortality continuum. This study examined factors associated with mortality in pregnant women with severe morbidity. In particular, the Black-White disparity was examined. ⋯ Medical risk status alone cannot explain disparities in maternal mortality. The Black-White disparity for risk of death persisted in both overall and condition-specific analyses.
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Annals of epidemiology · Jan 2006
Randomized controlled trials with time-to-event outcomes: how much does prespecified covariate adjustment increase power?
We evaluated the effects of various strategies of covariate adjustment on type I error, power, and potential reduction in sample size in randomized controlled trials (RCTs) with time-to-event outcomes. ⋯ Adjustment for one predictive baseline characteristic yields greater power to detect a true treatment effect than unadjusted analysis, without inflation of type I error and with potentially moderate reductions in sample size. Analysis of RCTs with time-to-event outcomes should adjust for predictive covariates.