THEMATIC ISSUE Risk Factors and Risk Statistics for Sports Injuries

Background: Risk factors for sports injuries include characteristics and behaviors of athletes and characteristics of sports and the envi-ronment that are associated with some measure of risk of injury. Objective: To introduce risk statistics to clinicians evaluating studies of sports injuries. Methods: Plain-language review of risk statistics and their prac-tical application to sports injuries. Results: The various measures of injury incidence are injury risk (proportion of athletes injured in a given period of training, playing, or other exposure time), injury rate (number of injuries per unit of exposure time), odds of injury (probability injury will happen divided by probability injury will not happen), injury hazard (instantaneous proportion injured per unit of time or mean injury count per unit of time), and mean time or mean number of playing exposures to injury. Effects of risk factors are estimated as values of effect statistic