Compliance with a comprehensive warm-up programme to prevent injuries in youth football.

Background: Participants' compliance, attitudes and beliefs have the potential to influence the efficacy of an intervention greatly.
Objective: To characterise team and player compliance with a comprehensive injury prevention warm-up programme for football (The 11+), and to assess attitudes towards injury prevention among coaches and their association with compliance and injury risk.
Study Design: A prospective cohort study and retrospective survey based on a cluster-randomised controlled trial with teams as the unit of randomisation.
Methods: Compliance, exposure and injuries were registered prospectively in 65 of 125 football teams (1055 of 1892 female Norwegian players aged 13-17 years and 65 of 125 coaches) throughout one football season (March-October 2007). Standardised telephone interviews were conducted to assess coaches' attitudes towards injury prevention.
Results: Teams completed the injury prevention programme in 77% (mean 1.3 sessions per week) of all training and match sessions, and players in 79% (mean 0.8 sessions per week) of the sessions they attended. Compared with players with intermediate compliance, players with high compliance with the programme had a 35% lower risk of all injuries (RR 0.65, 95% CI 0.46 to 0.91, p=0.011). Coaches who had previously utilised injury prevention training coached teams with a 46% lower risk of injury (OR 0.54, 95% CI 0.33 to 0.87, p=0.011).
Conclusions: Compliance with the injury prevention programme was high, and players with high compliance had significantly lower injury risk than players with intermediate compliance. Positive attitudes towards injury prevention correlated with high compliance and lower injury risk.