Causal effects are commonly defined as comparisons of the potential outcomes under treatment and control, but this definition is threatened by the possibility that either the treatment or the control condition is not well defined, existing instead in more than one version. This is often a real possibility in nonexperimental or observational…

Concussions are a brain injury that affects the athlete on and off the playing field. The aim of our investigation was to give PE teachers another strategy to use in addition to the recommended approaches set forth by national organizations to convey the message to adolescents regarding the negative effects of concussion. Using the website…

Context: Concussion management is potentially complicated by the lack of reporting due to poor educational intervention in youth athletics. Objective: Determine if a concussion-education video developed for high school athletes will increase the reporting of concussive injuries and symptom recognition in this group. Design: Cross-sectional,…