Health care utilization of workers' compensation claimants associated with mild traumatic brain injury: a historical population-based cohort study of workers injured in 1997-1998

OBJECTIVE: To compare the health care use of workers with an injury before and after making a workers' compensation claim for mild traumatic brain injury (MTBI). DESIGN: Cohort study of workers with an MTBI who received workers' compensation benefits. SETTING: Workers' compensation system in Ontario, Canada. PARTICIPANTS: Workers (N=728) who made an incident claim involving MTBI to the Ontario Workplace Safety and Insurance Board between 1997 and 1998. We linked workers' compensation and Ontario Health Insurance Plan files and collected all health care services accrued during the year before and 2 years after the claim was initiated. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We report our results as a 7-day simple moving average of health care services per 1000 claimants per day. We stratified our analysis by age, sex, the preclaim level of health care utilization, diagnostic category, and health care specialty. RESULTS: Over the 2 years, 728 claims related to MTBI were filed by workers with an injury. The majority of the claims (65.8%) were filed by men, and 28.3% were filed by those aged between 25 and 34 years. The cumulative rate of health care utilization was stable (mean=67.6 visits/1000 claimants per day; 95% confidence interval [CI], 65.0-70.2) throughout the year before claim initiation. Health care utilization peaked during the first 4 weeks following the initiation of the claim (mean=274.3 visits/1000 claimants per day; 95% CI, 172.2-376.4) and remained on average 182% higher than that at baseline throughout the 5th to 12th week postclaim. Two years after the initiation of the claim, utilization remained 9.5% higher than the preclaim level. The increase was more pronounced (125% higher) for workers with less than the median preclaim utilization level. CONCLUSIONS: Making a workers' compensation claim involving MTBI is associated with a long-term increase in health care use