Abstract
Several important methodological issues need to be considered when designing sports injury case-control studies. Major design goals for case-control studies include the accounting for prior injury risk exposure, and optimal definitions of both cases and suitable controls are needed to ensure this. This article reviews methodological aspects of published sports injury case-control studies, particularly with regard to the selection of controls. It argues for a new approach towards selecting controls for case-control studies that draws on an interface between epidemiological and biomechanical concepts. A review was conducted to identify sport injury case-control studies published in the peer-review literature during 1985–2008. Overall, 32 articles were identified, of which the majority related to upper or lower extremity injuries. Matching considerations were used for control selection in 16 studies. Specific mention of application of biomechanical principles in the selection of appropriate controls was absent from all studies, including those purporting to evaluate the benefits of personal protective equipment to protect against impact injury. This is a problem because it could lead to biased conclusions, as cases and controls are not fully comparable in terms of similar biomechanical impact profiles relating to the injury incident, such as site of the impact on the body. The strength of the conclusions drawn from case-control studies, and the extent to which results can be generalized, is directly influenced by the definition and recruitment of cases and appropriate controls. Future studies should consider the interface between epidemiological and biomechanical concepts when choosing appropriate controls to ensure that proper adjustment of prior exposure to injury risk is made. To provide necessary guidance for the optimal selection of controls in case-control studies of interventions to prevent sports-related impact injury, this review outlines a new case-control selection strategy that reflects the importance of biomechanical considerations, which ensures that controls are selected based on the presence of the same global injury mechanism as the cases. To summarize, the general biomechanical principles that should apply to the selection of controls in future case-control studies are as follows: (i) each control must have been exposed to the same global injury mechanism as the case, (e.g. head impact, fall onto outstretched arm); and (ii) intrinsic (individual) factors (e.g. age, sex, skill level) that might modify the person’s response to the relevant biomechanical loads are adjusted when either selecting the controls or are in the analysis phase. The same considerations for control selection apply to other study designs such as matched cohort studies or case-crossover studies.
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References
Brooks J, Fuller C. The influence of methodological issues on the results and conclusions from epidemiological studiesof sports injuries: illustrative examples. Sports Med 2006; 36 (6): 459–72
Chalmers DJ. Injury prevention in sport: not yet part of the game? Inj Prev 2002; 8 (4): iv22–5
Finch C. A new framework for research leading to sports injury prevention. J Sci Med Sport 2006; 9 (1-2): 3–9
van Mechelen W. To count or not to count sports injuries: what is the question? Br J Sports Med 1998; 32: 297–8
Bahr R, Holme I. Risk factors for sports injuries: a methodological approach. Br J Sports Med 2003; 37 (5): 384–92
Altman D, Schulz K, Moher D, et al. The revised CONSORT statement for reporting randomized trials: explanation andelaboration. Ann Intern Med 2001; 134: 663–94
Von Elm E, Altman D, Egger M, et al. The strengthening the reporting of observational studies in epidemiology (strobe)statement: guidelines for reporting observational studies. Lancet 2007; 370: 1453–7
Connor J. Risk factor identification: the role of epidemiology. In: McClure R, Stevenson M, McEvoy S, editors. The scientific basis of injury prevention and control. Melbourne (VIC): IP Communications, 2004: 125–43
Kraus J. Cohort studies in injury research. In: Rivara F, Cummings P, Koepsell T, et al., editors. Injury control:a guide to research and program evaluation. New York: Cambridge University Press, 2001: 129–38
Robertson L. Injury epidemiology: research and control strategies. 3rd ed. New York: Oxford University Press, 2001: 139–56
Cummings P, Koepsell T, Roberts I. Case-control studies in injury research. In: Rivara F, Cummings P, Koepsell T, et al., editors. Injury control: a guide to research and programevaluation. Cambridge: Cambridge University Press, 2001: 139–56
Lilienfeld AM, Lilienfeld DE. A century of case-control studies: progress? J Chronic Dis 1979; 32 (1-2): 5–13
Roberts I. Methodologic issues in injury case-control studies. Inj Prev 1995; 1: 45–8
Rothman KJ, Greenland S, Lash TL. Modern epidemiology. Philadelphia (PA): Lippincott Williams & Wilkins, 2008
Schootman M, Powell JW, Torner JC. Study designs and potential biases in sports injury research: the case-controlstudy. Sports Med 1994; 18 (1): 22–37
Woodward M. Epidemiology: study design and data analysis. Boca Raton (FL): Chapman & Hall/CRC, 2005
Vandenbroucke J, von Elm E, Altman D, et al. Strengthening the reporting of observational studies in epidemiology(strobe): explanation and elaboration. PLoS Med 2007; 4 (10): 1628–54
Schulz KF, Grimes DA. Case-control studies: research in reverse. Lancet 2002; 359 (9304): 431–4
Kelsey JL, Whittemore AS, Evans AS, et al. Methods in observational epidemiology. New York: Oxford UniversityPress, 1996
Bahr R, Krosshaug T. Understanding injury mechanisms: a key component of preventing injuries in sport. Br J Sports Med 2005; 39: 324–9
McIntosh A. Risk compensation, motivation, injuries, and biomechanics in competitive sport. Br J Sports Med 2005; 39: 2–3
Winston FK, Schwarz DF, Baker SP. Biomechanical epidemiology: a new approach to injury control research. J Trauma 1996; 40 (5): 820–4
Sherker S, Ozanne-Smith J, Rechnitzer G, et al. Development of a multidisciplinary method to determine risk factorsfor arm fracture in falls from playground equipment. Inj Prev 2003 Sep; 9 (3): 279–83
Elliott B. Biomechanics: an integral part of sport science and sport medicine research. J Sci Med Sport 1999; 2 (4): 283–94
Taunton J, McKenzie D, Clement D. The role of biomechanics in the epidemiology of injuries. Sports Med 1988; 6: 107–20
Taunton JE, Ryan MB, Clement DB, et al. A retrospective case-control analysis of 2002 running injuries. Br J Sports Med 2002; 36 (2): 95–101
Slaney GM, Finn JC, Cook A, et al. Wrist guards and wrist and elbow injury in snowboarders [letter]. Med J Aust 2008; 189 (7): 412
Bissell BT, Johnson RJ, Shafritz AB, et al. Epidemiology and risk factors of humerus fractures among skiers andsnowboarders. Am J Sports Med 2008; 36: 1880–8
Myer GD, Ford KR, Paterno MV, et al. The effects of generalized joint laxity on risk of anterior cruciate ligamentinjury in young female athletes. Am J Sports Med 2008; 36: 1073–80
Langran M, Manimekalai TK. Risk factors for snow sports injuries among children in Scotland [abstract]. Br J Sports Med 2008; 42 (6): 530–1
Mueller BA, Cummings P, Rivara FP, et al. Injuries of the head, face and neck in relation to ski helmet use. Epidemiology 2008; 19 (2): 270–6
Fakhruddin KS, Lawrence HP, Kenny DJ, et al. Use of mouthguards among 12- to 14-year-old Ontario schoolchildren. J Can Dent Assoc 2007; 73 (6): 505–10
Tanriverdi F, Unluhizarci K, Coksevim B, et al. Kickboxing sport as a new cause of traumatic brain injury-mediatedhypopituitarism. Clin Endocrinol 2007; 66 (3): 360–6
Kramer LC, Denegar CR, Buckley WE, et al. Factors associated with anterior cruciate ligament injury: history infemale athletes. J Sports Med Phys Fitness 2007 Dec; 47 (4): 446–54
Stefanyshyn D, Stergiou P, Lun V, et al. Knee angular impulse as a predictor of patellofemoral pain in runners. Am J Sports Med 2006; 34: 1844–51
Olsen L, Samuel J, Fleisig GS, et al. Risk factors for shoulder and elbow injuries in adolescent baseball pitchers. Am J Sports Med 2006; 34: 905–12
Maquirrain J, Megey PJ. Tennis specific limitations in players with an ACL deficient knee. Br J Sports Med 2006; 40: 451–3
Sulheim S, Holme I, Ekeland A, et al. Helmet use and risk of head injuries in alpine skiers and snowboarders. JAMA 2006 Feb; 295 (8): 919–24
Alsop JC, Morrison L, Williams SM, et al. Playing conditions, player preparation and rugby injury: a case-controlstudy. J Sci Med Sport 2005; 8 (2): 171–80
Hagel B, Pless IB, Goulet C. The effect of wrist guard use on upper-extremity injuries in snowboarders. Am J Epidemiol 2005; 162 (2): 149–56
Hagel BE, Pless IB, Goulet C, et al. Effectiveness of helmets in skiers and snowboarders: case-control and case crossoverstudy. BMJ 2005; 330 (7486): 281–85
Hagel B, Pless IB, Goulet C, et al. The effect of helmet use on injury severity and crash circumstances in skiers andsnowboarders. Accid Anal Prev 2005; 37: 103–8
Flynn RK, Pedersen CL, Birmingham TB, et al. The familial predisposition toward tearing the anterior cruciate ligament:a case control study. Am J Sports Med 2005 Jan; 33 (1): 23–8
Jones SJ, Lyons RA, Evans R, et al. Effectiveness of rugby headgear in preventing soft tissue injuries to the head:a case-control and video cohort study. Br J Sports Med 2004; 28 (2): 159–62
Langran M, Selvaraj S. Increased injury risk among firstday skiers, snowboarders, and skiboarders. Am J Sports Med 2004 Jan-Feb; 32 (1): 96–103
Langran M, Selvaraj S. Snow sports injuries in Scotland: a case-control study. Br J Sports Med 2002 Apr; 36 (2): 135–40
Korpelainen R, Orava S, Karpakka J, et al. Risk factors for recurrent stress fractures in athletes. Am J Sports Med 2001; 29 (3): 304–10
Joensen AM, Hahn T, Gelineck J, et al. Articular cartilage lesions and anterior knee pain. Scand J Med Sci Sports 2001; 115–9
Gabbe B, Finch C. A pilot case-control study to identify injury risk factors in community-level Australian Footballplayers. J Sci Med Sport 2000; 3 (2Suppl.): 23–30
Goulet C, Régnier G, Grimard G, et al. Risk factors associated with alpine skiing injuries in children: a case-controlstudy. Am J Sports Med 1999; 27 (5): 644–50
Garraway WM, Lee AJ, Macleod DAD, et al. Factors influencing tackle injuries in rugby union football. Br JSports Med 1999; 33: 37–41
Schieber RA, Branche-Dorsey CM, Ryan GW, et al. Risk factors for injuries from in-line skating and the effectivenessof safety gear. N Engl J Med 1996; 335 (22): 1630–5
Loudon JK, Jenkins W, Loudon KL. The relationship between static posture and ACL injury in female athletes. J Orthop Sports Phys Ther 1996; 24 (2): 91–7
Persson LG, Kiliaridis S. Dental injuries, temporomandibular disorders, and caries in wrestlers. Scand J Dental Res 1994; 102 (6): 367–71
Mundt DJ, Kelsey JL, Golden AL, et al. An epidemiologic study of sports and weight lifting as possible risk factors forherniated lumbar and cervical discs. Am J Sports Med 1993 Nov-Dec; 21 (6): 854–60
Dirx M, Bouter LM, de Geus GH. Aetiology of handball injuries: a case-control study. Br J Sports Med 1992; 26 (3): 121–4
Myburgh KH, Hutchins J, Fataar AB, et al. Low bone density is an etiologic factor for stress fractures in athletes. Ann Intern Med 1990; 113 (10): 754–9
Bouter LM, Knipschild PG, Volovics A. Binding function in relation to injury risk in downhill skiing. Am J Sports Med 1989 Mar-Apr; 17 (2): 226–33
Fung Y. The application of biomechanics to the understanding of injury and healing. In: Nahum A, Melvin J, editors. Accidental injury: biomechanics and prevention. New York: Springer-Verlag, 1993: 1–11
Janda DH. The prevention of baseball and softball injuries. Clin Orthop Rel Res 2003; (409): 20–8
McIntosh A, McCrory P, Finch C. Performance enhanced headgear: a scientific approach to the development ofprotective headgear. Br J Sports Med 2004; 34 (1): 46–9
Dempsey AR, Lloyd D, Elliott B, et al. The effect of technique change on knee loads during sidestep cutting. Med Sci Sports Exerc 2007; 39 (10): 1765–73
Hewett T, Ford K, Myer G. Anterior cruciate ligament injuries in female athletes: part 2. A meta-analysis of neuromuscularinterventions aimed at injury prevention. Am JSports Med 2006; 34 (3): 490–8
McIntosh A, McCrory P. Impact energy attenuation performance of football headgear. Br J Sports Med 2000; 34 (10): 337–41
Hoshizaki TB, Brien SE. The science and design of head protection in sport. Neurosurgery 2004; 55 (4): 956–67
McIntosh A, McCrory P. Preventing head and neck injury. Br J Sports Med 2005; 39: 314–8
Wacholder S, McLaughlin JK, Silverman DT, et al. Selection of controls in case-control studies: I. Principles. Am JEpidemiol 1992; 135 (9): 1019–28
Wacholder S, Silverman DT, McLaughlin JK, et al. Selection of controls in case-control studies: II. Types of controls. Am J Epidemiol 1992; 135 (9): 1029–41
Wacholder S, Silverman DT, McLaughlin JK, et al. Selection of controls in case-control studies: III. Design options. Am J Epidemiol 1992; 135 (9): 1042–50
McIntosh A, McCrory P, Comerford J. The dynamics of concussive head impacts in rugby and Australian rulesfootball. Med Sci Sports Exerc 2000; 32 (12): 1980–4
Fréche`de B, McIntosh A. Numerical reconstruction of reallife concussive football impacts. Med Sci Sports Exerc 2009; 41: 390–6
Shrier I. Understanding casual inference: the future direction in sports injury prevention. Clin J Sport Med 2007; 17 (3): 220–4
Cummings P, McKnight B, Greenland S. Matched cohort methods for injury research. Epidemiol Rev 2003; 25 (1): 43–50
Acknowledgements
Professor Caroline Finch was supported by a National Health and Medical Research Council (NHMRC), Principal Research Fellowship. Dr Shahid Ullah was supported by an Injury Trauma and Rehabilitation Research Fellowship funded through a (NHMRC) Capacity Building Grant in Population Health. Peter Richardson assisted with the original literature searches and retrieval of published articles for the review. The authors have no conflicts of interest that are directly relevant to the content of this review.
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Finch, C.F., Ullah, S. & McIntosh, A.S. Combining Epidemiology and Biomechanics in Sports Injury Prevention Research. Sports Med 41, 59–72 (2011). https://doi.org/10.2165/11537260-000000000-00000
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DOI: https://doi.org/10.2165/11537260-000000000-00000