Time-to-Subsequent Head Injury From Sports and Recreation Activities

Objective: To provide population-based risk estimates for sustaining subsequent head injuries (HIs), which occur in sports and recreation (SR). Design: Population-based, retrospective, cross-sectional study. Setting: Retrospective review of data from 2 tertiary care and 3 community care emergency departments (EDs) in Edmonton, Alberta, Canada. Patients: Individuals younger than 36 years presenting to an ED with an SR-related injury between April 1, 1997, and March 31, 2008. There were 9246 subsequent ED records identified for 8958 patients in the main analysis. Main Outcome Measures: Clinically diagnosed HI occurring in SR activities after an index presentation, and the number of days between ED presentations for diagnosed SR-HIs. Results: Individuals with 1 and 2 previous SR-related HIs were 2.62 [95% confidence interval (CI), 2.23-3.07] and 5.94 times, respectively, more likely (95% CI, 3.43-10.29) to sustain a subsequent HI than those without a previous HI. The median time-to first HI was 758 days from an initial injury and decreased to 613 days and 303 days for those at risk of second and third SR-related HIs (P < 0.0001). Individuals aged 7 to 13 years were 4.29 times more likely (95% CI, 2.65-6.92) to sustain an HI when presenting with a subsequent SR injury, compared with those aged 30 to 35 years. Conclusions: The odds of sustaining a subsequent HI substantially increase with each successive HI. Time between SR-related HIs shortens as the number of HIs increases. Initial HI may be a key marker to institute high-risk injury prevention measures directed at young persons who present to EDs.