Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: The added value of ordinal analysis in clinical trials: an example in traumatic brain injury. | Roozenbeek et al. Critical Care 2011 15 R127 http content 15 3 R127 KS CRITICAL CARE RESEARCH Open Access The added value of ordinal analysis in clinical trials an example in traumatic brain injury Prihi P ìri7Citìhoolz1 2Wocfor R I inncmn2 PsiKIm Dorol3 Dhil RH A 2rHc3 l n Dr ihorfc3 Pi L li irr x 4 DUU Roozenbeek Hester F Lingsma Pdblo Perel rllll Edwards Idn Roberts Gordon D Mundy Andrew IR Mdds1 and Ewout W Steyerberg2 for the IMPACT International Mission on Prognosis and Clinical Trial Design in Traumatic Drain Injury Study Group and the CRASH Corticosteroid Randomisation After Significant Head Injury Trial Collaborators Abstract Introduction In clinical trials ordinal outcome measures are often dichotomized into two categories. In traumatic brain injury TBI the 5-point Glasgow outcome scale GOS is collapsed into unfavourable versus favourable outcome. Simulation studies have shown that exploiting the ordinal nature of the GOS increases chances of detecting treatment effects. The objective of this study is to quantify the benefits of ordinal analysis in the real-life situation of a large TDI trial. Methods We used data from the CRASH trial that investigated the efficacy of corticosteroids in TDI patients n 9 554 . We applied two techniques for ordinal analysis proportional odds analysis and the sliding dichotomy approach where the GOS is dichotomized at different cut-offs according to baseline prognostic risk. These approaches were compared to dichotomous analysis. The information density in each analysis was indicated by a Wald statistic. All analyses were adjusted for baseline characteristics. Results Dichotomous analysis of the six-month GOS showed a non-significant treatment effect OR 95 CI to P . Ordinal analysis with proportional odds regression or sliding dichotomy showed highly statistically significant treatment effects OR 95 CI to P and 95 CI to P with and .
