Risk of Subsequent Concussion Among Children and Adolescents Participating in Sports

In 2012, an amendment to the California Education Code (CA-AB 25) was enacted requiring school-based athletic programs to remove youth from the sport played when the concussion occurred.  Youth were required to obtain written clearance from their health care provider before returning to play.

A retrospective cohort study was conducted of Kaiser Permanente Northern California members ages 10-17 with sports-related concussions from 2009-2010 and 2012-2013.  Our aim was to compare risk factors for subsequent/reconcussion before and after enactment of CA-AB 25. Data obtained determined type of sport, presenting symptoms, and evidence of prior and subsequent concussion. Chi-square tests and logistic regression were performed to assess the association of demographic and clinical characteristics with subsequent/reconcussion.

Preliminary results (n=1002) showed 7.4% had reconcussion within 18 months; the mean age (at index concussion) was 14.6 years. There were more subsequent/reconcussions among those with prior concussions compared with those without (11.6% vs. 6.3%, p=0.01). Those playing contact/collision sports were more likely to have subsequent/reconcussions compared with limited/non-contact sports (9.3% vs. 4.8%, p=0.007). Of reconcussed subjects, those who played contact/collision sports were more likely to be reconcussed due to sports participation compared with those who played limited/non-contact sports (80.8% vs. 55%, p=0.02). In multivariable analyses ages 14-17 compared to ages 10-13 (OR:2.56, 95% CI 1.38-5.13); blurred vision/light sensitivity (OR: 2.22, 95% CI 1.21-3.95) and dizziness/lightheadedness (OR:1.85, 95% CI 1.08-3.17) vs. absence of these symptoms were significantly associated with reconcussion.

Preliminary findings show risk of reconcussion in athletic youth is a serious public health problem.