Incidence and burden of hospital-treated sports injury in people aged 15+ years in Victoria, Australia, 2004-2010: Future epidemic of osteoarthritis?

Abstract

Purpose: Previous sports injury is a known risk factor for subsequent osteoarthritis, but population-based rates of sports injury are unknown. Osteoarthritis places a large burden on health care systems. Any increase in the incidence of joint-related sports injuries is likely to further increase this burden. Therefore a greater understanding of the rate and burden of sports injury, is urgently required if a potential future epidemic of OA is to be avoided. The aims of this study were to: i) describe the trends in the population incidence and burden of all hospital-treated sports injury in Victoria, Australia in adults aged 15+ years; ii) determine the incidence of sports-relates lower limb and knee injuries as a subset of these injuries; and iii) quantify their population health burden in terms of direct hospital treatment cost and length of stay. Methods: Health sector data relating to people aged 15+ years, for the calendar years 2004-2010 inclusive, was extracted from the Victorian Admitted Episodes Dataset and Victorian Emergency Minimum Dataset. Data relating to sports injuries were identified using International Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modifications (ICD-10-AM) diagnosis codes S70-S99, which included injuries to the hip, thigh, knee, lower leg, ankle, foot and toes. Knee and lower leg injuries, as a subset of all lower limb injuries were identified using the codes S80-S89; while dislocation, sprain or strain of the joints and ligaments of the knee were identified using the code S83. Rates of sports participation were collected from annual Exercise, Recreation and Sport Surveys. Trends in injury frequency and rates were determined. Economic burden was calculated as the average Victorian cost per Australian Refined Diagnosis Related Group (AR-DRG) for the relevant year for each admission. Results: Between the dates January 2004 and December 2010 there were 165,496 hospital treated sports injuries in people aged 15+ years in Victoria, Australia. Of these, 59,399 (35.9% of all sports injury cases) were lower limb injuries, 29,430 (17.8%) were injuries to the knee and lower leg and 11,749 (7.1%) were knee dislocations, strains and sprains. The overall annual rate of hospital treated sports injuries increased by 24% (p=0.001) over the 7-years. The annual rate of lower limb sports injuries increased by 26% (p=0.001) over the 7-years. The associated accumulated economic burden was $265 million for all sports injuries and $110 million for lower limb injuries over the 7-years. Conclusions: Previous sports injury is an important known risk factor for the development of osteoarthritis. Assuming a direct correlation between sports injury rates and the subsequent development of OA, it could be expected that this could lead to an increase in the population-level incidence of sports-related OA cases in coming decades. Importantly, a large number of sports injuries do not present at hospitals, and are instead managed by general practitioners, sports physicians and sports physiotherapists through primary referral. This suggests that our findings are a very conservative estimate, and the overall burden of sports injury is likely to be much greater than reported within the current study. The findings of this study have direct implications of the planning of health services to deal with more OA patients in the future. Population-wide preventive strategies that reduce the risk of sports injury are urgently required in order to reduce the future health care system burden of osteoarthritis and other conditions secondary to sports injury.