Disability in young people and adults one year after head injury: prospective cohort study.

OBJECTIVE To determine the frequency of disability in young people and adults admitted to hospital with a head injury and to estimate the annual incidence in the community. DESIGN Prospective, hospital based cohort study, with one year follow up of sample stratified by coma score. SETTING Five acute hospitals in Glasgow. SUBJECTS 2962 patients (aged 14 years or more) with head injury; 549 (71%) of the 769 patients selected for follow up participated. MAIN OUTCOME MEASURES Glasgow outcome scale and problem orientated questionnaire. RESULTS Survival with moderate or severe disability was common after mild head injury (47%, 95% confidence interval 42% to 52%) and similar to that after moderate (45%, 35% to 56%) or severe injury (48%, 36% to 60%). By extrapolation from the population identified (90% of whom had mild injuries), it was estimated that annually in Glasgow (population 909 498) 1400 young people and adults are still disabled one year after head injury. CONCLUSION The incidence of disability in young people and adults admitted with a head injury is higher than expected. This reflects the high rate of sequelae previously unrecognised in the large number of patients admitted to hospital with an apparently mild head injury.