Emergency department prediction of post-concussive syndrome following mild traumatic brain injury-an international cross-validation study

Background: Between 20-50% of those suffering a mild traumatic brain injury (MTBI) will suffer symptoms beyond 3 months or post-concussive disorder (PCD). Researchers in Sydney conducted a prospective controlled study which identified that bedside recordings of memory impairment together with recordings of moderate or severe pain could predict those who would suffer PCS with 80% sensitivity and specificity of 76%. Primary objective: This study is a cross-validation study of the Sydney predictive model conducted at Montreal General Hospital, Montreal, Canada. Methods: One hundred and seven patients were assessed in the Emergency Department following a MTBI and followed up by phone at 3 months. The Rivermead Post-Concussive Questionnaire was the main outcome measure. Results: Regression analysis showed that immediate verbal recall and quantitative recording of headache was able to predict PCD with a sensitivity of 71.4% and a specificity of 63.3%. In the combined MTBI groups from Sydney and Montreal the sensitivity was 70.2% and the specificity was 64.2%. Conclusion: This is the first study to compare populations from different countries with diverse language groups using a predictive model for identifying PCD following MTBI. The model may be able to identify an 'at risk' population to whom pre-emptive treatment can be offered.