Weir, J.

study trial outcome patient model analysis covariate effect brain injury injury treatment sample size prognostic sample approach difference center brain impact treatment effect covariate adjustment adjustment between-center differences power split result scale dichotomy odds model prognosis randomized reduction number selection ordinal simulation between-center baseline 3 cov 7 cov ratio erasmus univ rotterdam characteristic impact database 0.0 table database survey design neurotrauma odds ratio patient characteristics phase iii trials recruitment phase population study duration distribution estimate group trial design criteria steyerberg ew odds ratios score mortality head injury steyerberg glasgow heterogeneity ef ficiency prognostic models prognostic bands dichotomy approach point dichotomous analysis covariate risk model variation efficiency duration