Injury surveillance in young athletes: a clinician's guide to sports injury literature.

As participation in junior, high-school and college sports has increased dramatically over the last three decades, sports injuries have increased commensurately. In the US alone, sports-related injuries account for 2.6 million visits to the emergency room made by children and young adults (aged 5-24 years). Injuries sustained by high-school athletes have resulted in 500000 doctor visits, 30000 hospitalisations and a total cost to the healthcare system of nearly 2 billion dollars per year. Sports injury surveillance studies have long formed the backbone of injury prevention research, serving to highlight the types and patterns of injury that merit further investigation. Injury surveillance studies have been integral in guiding rule changes, equipment improvement and training regimens that prevent injury. Despite findings that the methodology of injury surveillance studies may significantly influence the design and efficacy of preventative interventions, relatively few sources address epidemiological considerations involved in such studies. The purpose of this review is 3-fold. First, to perform a review of the current injury surveillance literature in order to identify key epidemiological and methodological issues that arise when reading or conducting an injury surveillance study. Second, to identify and describe how injury surveillance studies have addressed these issues. Third, to provide recommendations about the identified issues in order to guide clinicians in the interpretation of data presented in such studies. Searches of Ovid MEDLINE (1966-present) and PubMed were performed. Thirty-three descriptive and review articles addressing epidemiological and methodological considerations in injury surveillance were selected, as well as 54 cohort studies and studies with an experimental design. Data with respect to each study's treatment of the three epidemiological issues of interest were extracted and synthesised into a table. This review identifies the following three key epidemiological issues to consider when reading injury surveillance literature or when designing an injury surveillance study: (i) the definition of a sports injury; (ii) the denominator with which injuries are reported; and (iii) the method of data collection. A meaningful definition of injury should incorporate time lost from participation in order to reduce the bias associated with estimates of incidence. The use of multiple denominators (e.g. both athlete-hours of exposure and total athletes) provides the most precise information about injury rate and injury risk. The method of data collection that captures the widest range of injuries, while also allowing for the collection of exposure data, will vary depending on geographical location and the organisation of youth sports in that area.