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.