Time of rehabilitation admission and severity of trauma: effect on brain injury outcome. Outcome after traumatic brain injury, defined by the Glasgow Outcome Scale (GOS) and length of stay in acute rehabilitation, was measured in 59 patients admitted to an intensive rehabilitation program to examine the effects of severity of the initial brain injury, severity of multiple trauma, and length of stay in the acute care hospital. Severity of initial brain injury, best measured by length of coma, was the most significant predictor of GOS outcome. Length of acute hospitalization was a small, but significant, predictor of GOS. Severity of initial brain injury, length of acute hospitalization, and gender emerged as predictors of length of rehabilitation hospital stay. Although length of acute hospitalization is apparently affected by severity of brain injury, it adds significantly--more than severity of brain injury--to the prediction of length of rehabilitation. 