Modelling probability based injury severity scores in logistic regression models: the logit transformation should be used.

Raw probability scores should not be used to predict the logit of mortality. We have shown that a simple logit transformation of the ICISS and the TRAIS provides an important improvement in the accuracy of mortality prediction. Better model calibration has an important impact on the accuracy of predicted mortality probabilities, which in turn will improve the validity of the results of quality control evaluation and trauma research. (Author/publisher)