Admission examination factors predicting cognitive improvement during acute brain injury rehabilitation

In this study 46 brain-injured patients admitted to a brain injury inpatient rehabilitation programme after acute care were evaluated at the bedside with a comprehensive mental status examination and physical evaluation. Using multiple regression analysis, elements of the cognitive and physical examinations were studied to determine if any of these items, individually or collectively, had predictive value for discharge functional status. A principal-components analysis identified meaningful clusters of items. Factor I, Simple Cognitive Operations, consisted of word repetition, naming and comprehension of simple commands. Factor IV, Higher Cognitive Operations, consisted of interpretation of similarities and reverse digit span. Other items, including elements of the physical examination such as eye movements, hearing and ambulatory function, were also clustered into factors. Stepwise multiple regression analysis led to a conclusion that only factor IV was a significant predictor of Discharge Rancho Level, with the predictive power of factor I and Admission Rancho Level subsumed by factor IV. This model, using a few items from a bedside mental status examination, accounted for 27% of the variance in Discharge Rancho Level in patients admitted to a brain injury rehabilitation unit after injury. We conclude that a brief mental status examination in a rehabilitation inpatient setting can be useful in predicting outcome in patients with brain injuries. More research is needed to identify additional test items that will add prognostic power to the initial evaluation of patients with brain injuries admitted to a rehabilitation unit.