Trends in hospitalization associated with traumatic brain injury in a publicly insured population, 1992-2002.

BACKGROUND Traumatic brain injury (TBI) is a leading cause of death and disability in developed countries. We document trends in TBI-related hospitalizations in Ontario, Canada, between April 1992 and March 2002, focusing on relationships between inpatient hospitalization rates, age, sex, cause of injury, severity level, and in-hospital mortality. METHODS Information on all acute hospital separations in Ontario with a diagnosis of TBI was analyzed using logistic regression. RESULTS Hospitalization rates fell steeply among children and young adults but remained stable among adults aged 66 and older. The proportion of TBI hospitalizations with mild injuries decreased from 75% to 54%, whereas the proportion with moderate injuries increased from 19% to 37%. Adjusting for other risk factors, in-hospital deaths were higher for injuries because of motor vehicle crashes than those because of falls. In-hospital death rates were stable for patients with moderate or severe injuries, but increased over time among those whose injuries were classified as mild, suggesting a trend toward more serious injury within the "mild" classification. CONCLUSIONS Hospitalizations for TBI involve fewer mild injuries over time and are highest in the oldest segment of the population.