Perel, P.

trial effect outcome model treatment treatment effect injury study patient analysis crash brain injury covariate adjustment covariate prognostic impact score adjustment brain centre difference sample size mortality regression power head injury sample characteristic crash trial between-centre differences scale ordinal treatment effects ratio odds ratio result corticosteroid reactivity steyerberg ew prognostic models between-centre murray gd steyerberg pupil randomized design prognosis analyses measure predictor reference country table butcher i prediction glasgow coma scale population reference analysis individual approach ordinal analysis 14- day mortality glasgow pupil reactivity information pupillary reactivity 1.0 odds ratios strategy prognostic scores baseline group ordinal outcome analysis motor ficient example range disability murray validation