To study the effects of a school-based injury prevention program on physical activity injury incidence and severity.
Cluster randomized controlled trial performed from January 1, 2006, through July 31, 2007.
Forty Dutch primary schools.
A total of 2210 children (aged 10-12 years).
Schools were randomized to receive either the regular curriculum or an intervention program that targeted physical activity injuries.
Incidence and severity of physical activity injuries per 1000 hours of physical activity participation.
A total of 100 injuries in the intervention group and 104 injuries in the control group were registered. Nonresponse at baseline or follow-up was minimal (8.7%). The Cox regression analyses adjusted for clustering showed a small nonsignificant intervention effect on total (HR, 0.81; 95% confidence interval [CI], 0.41-1.59), sports club (0.69; 0.28-1.68), and leisure time injuries (0.75; 0.36-1.55). However, physical activity appeared to be an effect modifier. In those who were less physically active, the intervention had a larger effect. The intervention reduced the total and leisure time injury incidence (HR, 0.47; 95% CI, 0.21-1.06; and 0.43; 0.16-1.14; respectively). Sports club injury incidence was significantly reduced (HR, 0.23; 95% CI, 0.07-0.75).
We found a substantial and relevant reduction in physical activity injuries, especially in children in the low active group, because of the intervention. This school-based injury prevention program is promising, but future large-scale research is needed.