Looking for the evidence: a systematic review of prevention strategies addressing sport and recreational injury among children and youth

Looking for the evidence: a systematic review of prevention strategies addressing sport and recreational

injury among children and youth

M MacKay 1, A Scanlan 2, L Olsen 2, D Reid 1, M Clark 2, K McKim 2 & P Raina 2,3,4

1plan-it-Safe, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada. 2British Columbnia Injury Research and Prevention Unit, Vancouver, Canada. 3Department of Clinical

Epidemiology and Biostatistics, Faculty of Health Sceinces, McMaster University, Hamilton, Ontario, Canada. 4Department of Health Care and Epidemiology, University of British Columbia, Vancouver,

Canada.

Objectives: To examine evidence on the effectiveness of current injury prevention strategies in selected sport and recreational activities, determine the applicability of the evidence to children and youth and discuss the implications related to policy, programming and future research. Methods: Research questions and relevance criteria were developed a priori. Potentially relevant studies were located through electronic and hand searches. Two independent assessors assessed articles for first relevance and then quality. Relevant articles were abstracted and synthesised for activities that had three or more relevant articles. Results: A total of 21,499 articles identified through database and manual searching yielded 117 that met inclusion criteria. The majority of the studies (93 or 89%) involved eight activities: baseball, basketball, cycling, football, ice hockey, rugby, alpine skiing and soccer. Children and youth were identified as the specific target group in 45% of the studies and another 12% included children in their sample. Studies addressed a range of intervention strategies and varied on quality of evidence. Conclusions: Surprisingly few well-designed and controlled studies investigating strategies to prevent injuries were found and an even smaller number evaluated strategies to reduce injury in children and youth. As governments in developed countries continue to focus on increasing physical activity among children and youth, thought must be given to the issue of risk of injury and the relative lack of evidence of effective preventive measures.

(J Sci Med Sport 2004; 7:1:58-73)

Introduction Children and youth spend a considerable amount of time participating in sport a n d r e c r e a t i o n a l ac t iv i t ies . On average , C a n a d i a n c h i l d r e n b e t w e e n the ages of five a n d 12 y e a r s s p e n d 18 h o u r s e n g a g e d in p h y s i c a l ac t iv i ty every w e e k whi le t h o s e b e t w e e n 13 a n d 17 y e a r s s p e n d 15 h o u r s 1. In t he Un i t ed S t a t e s i t is e s t i m a t e d t h a t over 30 mi l l ion c h i l d r e n a n d y o u t h p a r t i c i p a t e in o r g a n i s e d s p o r t s a n n u a l l y 2-4. As a r e su l t , s p o r t a n d r e c r e a t i o n a l ac t iv i t ies a c c o u n t for a la rge n u m b e r a n d s u b s t a n t i a l p r o p o r t i o n of al l i n ju r i e s to c h i l d r e n a n d y o u t h 5- 6. Wi th c h i l d r e n a n d y o u t h b e i n g e n c o u r a g e d to p a r t i c i p a t e in s p o r t s a n d r e c r e a t i o n a l ac t iv i t ies in r e c o r d n u m b e r s , u n d e r s t a n d i n g a n d p r e v e n t i n g t h e s e i n j u r i e s is b e c o m i n g i n c r e a s i n g l y i m p o r t a n t 7-9.

The p r e v e n t i o n of s p o r t a n d r e c r e a t i o n a l i n j u r i e s a m o n g c h i l d r e n a n d y o u t h h a s m e r i t on seve ra l f ronts . F i r s t , i n c r e a s i n g p h y s i c a l ac t iv i ty t h r o u g h p a r t -

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Looking for the evidence: a systematic review...

icipation in sport and recreational activities has numerous benefits including reducing the risk of obesity and its associated health related conditions 1°-13, increasing motor skills 14.15 and self- esteem 16. According to the National Center for Injury Prevention and Control, injuries are a leading reason people stop participating in potentially beneficial physical activity 17. Limiting the risk of injury during sport and recreational activities through the application of effective preventive strategies increases the likelihood of continued benefit. Second, al though the majority of sport and recreational injuries among children and youth are not severe enough to require hospitalisation, and current injury classification systems make it difficult to capture accurately the economic impact of these injuries alone, they occur frequently enough collectively to have a significant impact both in terms of direct costs of medical care and indirect costs ls-21. When injuries are catastrophic, the costs to society can be even higher if they resul t in litigious activities 22.

To be effective, the practice of injury prevention needs to be evidenced-based. This requires an assessment of interventions for their efficacy and effectiveness. Systematic reviews are an accepted way of assessing and synthesising current levels of evidence. Key aspects of a systematic review include a well- formulated review question; explicit inclusion criteria; identification and inclusion of all relevant evidence, description of the methodology used to conduct the review, and an effort explicitly to link resulting recommendat ions to the evidence 2a.

This paper describes the methodology used in a systematic review of injury prevention strategies among children and youth and comments on the findings, specifically the amount and quality of evaluations addressing this important cause of morbidity among children and youth. Activity specific results are available elsewhere 24-25. The specific objectives of the project were to: 1) examine existing evidence on the effectiveness of current prevention strategies in selected sport and recreational activities; 2) determine the applicability of this evidence to children and youth; and 3} make recommendat ions related to best practice (policy and programming) and future research needs in this area.

Methods and Procedures Methodology of this systematic review is detailed in Table 1. The research team consisted of professionals from the British Columbia Injury Research and Prevention Unit and Plan-it Safe, the Injury Prevention Centre at the Children's Hospital of Eas tern Ontario, with a minimum Masters level of preparation and expertise in injury epidemiology a n d / o r prevention and previous experience conducting systematic reviews. The electronic search strategies were developed in collaboration with a research librarian with extensive experience in conducting searches for systematic reviews.

A broad search filter (a series of subject-related keywords to extract potentially relevant articles from a computerised database) was developed for baseball (randomly selected as test case) and refined by running the search and ensuring it picked up known potentially relevant articles. Eight electronic databases were then searched using the broad filter with the addition specific search terms for each sport or activity, including cross-cultural synonyms (eg, softball and baseball, soccer and football) for each of the targeted activities plus general preventive strategies (Table 2). In order to reduce the number of

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1. Development of research question and a priori relevance criteria.

2. Establishment of panel Of experts from the University of British Columbia, Simon Fraser University, University Of Victoria and the Sports Medicine Council of British Columbia representing injury prevention, epidemiology and sports medicine and recreation.

3. Selection of target sport and recreational activities using an analysis Of the incidence and severity of pediatric sport and recreational injuries captured in the Canadian Hospital Injury Reporting and Prevention Program (CHiRPP) databases at the pediatric emergency departments in Ottawa and Vancouver, Canada. Cycling, which is not coded as a recreational activity in CHIRPP but is responsible for a large proportion of CHIRPP cases, and a general sport strategy addressing more than one sport were subsequently added.

4. Identification of potentially relevant journal articles, chapters and abstracts using strategies listed below, deletion Of duplicates between searches and retrieval Of remaining studies. a. A search of eight electronic bibliographic databases: MEDLINE, Psychinfo, CINAHL, Current Contents,

HealthSTAR, Sportdiscus, the Cochrane Systematic Review database and Controlled Trials Registry and EMBASE was conducted from the earliest records, for all languages and age groups.

b. Reference lists of all review, sport injury textbooks published after 1990, the table of contents from the American Journal of Sports Medicine and a series of sport injury systematic reviews published by the MONASH Injury Prevention Centre in Australia and studies rated as relevant (see process in steP 5 below) were hand searched 26"27.

c. Key informants working in the sports injury field around the world were contacted and questioned to ensure completeness of the literature for the study.

5. Research team members assessed relevance on a pilot set of studies to ensure consistency of application of the criteria listed below. All potentially relevant studies retrieved were reviewed for relevance by pairs of independent reviewers, with disagreements resolved by consensus or a third reviewer. Inter-reviewer agreement was assessed by calculating the intra-class correlation coefficient 28. a. Study addressed unintentional injury prevention (IP) in one or more of the targeted sport or recreation

activities; b. Study evaluated the effectiveness Of one or more of the following strategies: an educational/

behavioral change IP program, environmental/equipment modification, a community effort or a regulatory/legislative change(including rule changes);

c. Study used as Outcome measure(s): injury incidence, injury severity, risk reducing behaviors or compliance with IP measures;

d. Study contained a control group or other comparative measures in its methodological design.

6. Study design specific tools were developed to abstract pertinent information from each article including publication data, population studied, interventions, results and conclusions. All reviewers independently reviewed a pilot set Of studies and pilot assessments were compared and where there wasn't agreement, discussed until an agreement was reached as to the best assessment. Two reviewers independently completed data extraction independently for each article. Articles were not blinded due to the time involved to blind papers and the questionable utility 29. The information was specifically abstracted for the primary OUtcome, details of the intervention (including whether a theoretical framework was used to guide development) and relevant results, if primary outcome was unclear, the most serious outcome was selected (e.g., injury mortality was selected over hospitalisation).

7. The Jadad Scale, a validated quality assessment tool was used to rate quality for randomized controlled trials(30). For all study designs other than randomized controlled trials the research team conducted a literature review but found no assessment tools addressing quality for all Of the study designs needed. Utilizing questions found in the literature 3132 and consulting with the expert panel and several methodology experts, a set of quality assessment tools was developed, tailored to each of the following study designs: Non-Equivalent Control Group Design, Cohort, One-Group Pre-test Post-test, Case Control, and Time Series. The number Of questions varied by design from 15 to 20 and covered quality of reporting, internal and external validity. All reviewers independently reviewed a pilot set of studies and pilot assessments were compared and where there wasn't agreement, discussed until an agreement was reached as to the best assessment. Two reviewers then independently rated each study using the appropriate design specific tool. A total score for each study was calculated and converted to a percentage value to facilitate comparison across study designs. Quality was rated using the following three-point scale: 0%- 49% = Poor; 50% - 89% = Moderate; 90% and greater = Good,

8. Following the identification of relevant studies, a decision was made to limit the final review to those sport or recreational activities with three or more relevant studies.

Table 1: Systematic review process.

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Baseball Basketball Cycling (post 1996) Field hockey Football Golf Gymnastics Horseback riding Ice hockey Ice skating Inline skating Martial arts Ringette Roller hockey Rugby Skateboarding Skiing (alpine) (post 1970) Sledding Snowboarding Soccer Street hockey Swimming Track and field Trampolining Volleyball Wrestling General prevention strategies

1 accident prevention 22 or/13-21 2 wounds and injuries 23 practice guidelines 3 safety 24 guideline 4 prevents or riskS) 25 recommends 5 injurS or accidents or 26 parameter

traumas 27 guidelinS 6 exp accidents 28 rules 7 athletic injuries 29 regulations 8 sprains and strains 30 policS,tw. 9 sprains or strains 31 conditioning or trains 10 or/5-9 32 or/23-31 11 4andlO 33 12or22or32 12 1or 2 or 3 or11 34 baseball 13 head protective devices 35 baseballs or softballs 14 mouth protectors 36 little league 15 ear protective devices 37 base balls or soft balls 16 eye protective devices 38 fastpitch or slowpitch 17 exp protective clothing 39 fast pitch or slow pitch 18 equipment 40 t-ball.tw. 19 sports equipment 41 hard ball or hardball 20 protects 42 or/34-41 21 helmets or mask or 43 33 and 42

glove or pads

Table 3: Example of a search strategy.

Table 2: Targeted sports and recreational activities.

duplicates identified due to either the similarity between identified sport areas (eg, softball and baseball) or terms common to more than one sport (ice-skating and in-line skating), several of the sports were pooled during searching. A total of 20 different searches were run: trampoline, soccer (football, rugby), snowboarding, skating (ice and in-line), baseball, basketball, hockey (ice, street and ringette), horseback riding, sledding and skateboarding, downhill skiing, wrestling, mart ial arts, golfing, gymnastics, volleyball, t rack and field, swimming, cycling and general sport. Table 3 provides as an example the search strategy for baseball.

Studies including biomechanical interventions evaluated in laboratory settings were excluded from the review following the initial examination of search strategy results as they were not specifically included in the search filter and the research t eam/exper t panel questioned the team's ability to evaluate these studies adequately. The relevance protocol was altered for foreign language articles (excluding French). If the title and abstract were available in English, two reviewers assessed relevance. If not available, relevance was completed by a single individual fluent in the language in question.

ReSults Detailed searches of eight electronic databases identified 21,499 articles. A

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review of abs t rac t s and titles identified 740 potentially relevant articles. Hand searching identified 124 additional potentially relevant articles. One hundred and seventeen,(13.5%) met the inclusion criteria. The analysis of inter-reviewer agreement was conducted on 768 paired a s s e s s m e n t s and showed subs tan t ia l agreement regarding eligibility (intra-class correlation coefficient = 0.70). Non- relevant articles were primari ly excluded because they did not address unintent ional injury prevent ion in one or more of the targeted areas (15%); did not evaluate the effectiveness of an injury prevent ion s t ra tegy (60%); did examine b iomechanics of injury in a laboratory sett ing (10%); or did not include a control group or other comparat ive measu re s (5%).

All relevant s tudies were publ ished in English. Studies came from m a n y different countries, with the majori ty from the United States (72%). Relevant articles were found for only 16 of the original 26 activities. Only eight activities had three or more relevant articles and were included in the final review - alpine skiing, baseball , basketbal l , cycling, football, ice hockey , rugby and soccer. The 93 articles tha t related to those eight activities represen t 89% of relevant articles found. The largest n u m b e r of articles were found for American football (n=47). A complete listing of relevant articles in the final review follows the references at the end of this article (Appendix A).

Baseball

Basketball

Cycling

Football

Hockey

Rugby

Skiing

Soccer

~ 4

~ 3

[] Education/behavior change

[] Regulatory

[] Environmental/equipment

~ 7 . . . . . . . . . . 38

~ 4 6

~ 3

• a given citation might include more than one intervention type

10 20

Number of citations*

30 40

Figure t: Type of intervention being evaluated.

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Baseball

Basketball

Cycling

Football

Hockey

Rugby

Skiing

Soccer

~ 4

~3

[] Total number

m Specific to children/youth

[] Children/youth included

~ 12 12

~ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ ~ , , ~ 47 23

23• 8

~ 4

0 10 20 30 40 50

Figure 2: Evaluations targeting child and youth participants (n=93).

Study designs varied from randomised controlled trials to simple one group pre tes t -pos t tes t designs (Table 4). The mos t frequently used design was the prospective cohort (30%), followed by simple one group pre tes t -pos t tes t designs (20%) and randomised controlled trials (16%). The mos t common interventions evalua ted were those examining the effectiveness of env i ronmenta l or equipment modifications (72%) (Figure 1). Intervention types varied by activity, with educat ional /behaviora l change interventions mos t common for cycling, skiing and soccer. Regulatory interventions (eg, policy requiring certain equipment , game rules) were mos t common for cycling, football and hockey. None of the 93 studies included made reference to a theoretical f ramework as the bas is for its intervention design and there was very little consistency in how "injury" was measu red across studies. Overall the quality of the relevant s tudies was found to be low with approximately 48% rated as poor, 51% as modera te and only 1% as good (Table 4). Children and youth were identified as the specific target group in 42 s tudies (45%), while 11 additional studies (12%) included children in their sample (Figure 2).

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Looking f o r t he ev idence: a sys temat ic rev iew. . .

Study Design Quali ty Rating

Non- Pro Retro One group Randomized equivalent spective spective Case. Time pretest. control trial control group cohort cohort Control Seriee posttest Poor Moderate GoOd

Baseball - - - - 4 - - - - (n=4)

Basketball 3 . . . . (n=3)

Cycling 3 4 1 - - 1 (n=12)

Football 6 2 21 4 - - (n=47)

Hockey - - 2 1 - - - - (n=8)

Rugby - - 2 1 t - - (n=5)

Alpine skiing 2 1 - - - - 7 (n=lO)

Soccer 1 1 - - - - - - (n=4)

Total 15 12 28 5 8 [n=93]

m

m

4

2

6

- - 1

- - 2

3 5

10 23

5 4

1 1

- - 8

- - 1

19 45

3 0

1 0

7 0

23 1

4 0

4 0

2 0

3 0

47 1

Table 4: Study design and quality rating by sport~recreational activity.

DisCussion In conduct ing this sys temat ic review we set out to examine evidence-based practice. What we have done is highlight the lack of evidence in relation to effectiveness of interventions. Very few evaluative studies were found for the spor t and recreat ional activities examined. In fact, relevant evaluat ions were found for fewer t han two-thirds of the targeted spor t and recreat ional activities. For m a n y of the mos t popular activities, no s tudies were found at all. This begs the question: on what is cur ren t bes t practice based with respect to injury prevention for these targeted activities? It is clear tha t m a n y strategies perceived to be preventat ive and in common practice on playing fields across the globe have not been evaluated, part icularly among children and youth. This is not to say they are not effective, j u s t tha t there is no evidence. Obvious starting, points for future research would be "common practices".

Several approaches for organising spor ts injury prevent ion have been proposed. In their discussion of these models, Weaver et al propose a s chema tha t integrates nicely with Haddon ' s mat r ix to examine host, agent and envi ronment a3. Using the three Es of injury prevent ion - engineering, educa t ion /behav ior change and enforcement - the s chema suggests tha t spor t and recreational injuries should be preventable by: 1. Ensu r ing t ha t design, deve lopment and m a i n t e n a n c e of spor t and

recreational equipment and facilities mee t safety s tandards ; 2. Influencing at t i tudes toward, and promoting up take of, protective behav-

iours or equipment (eg, wearing protective equipment , physical conditioning};

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3. Adapting playing rules to the par t ic ipants with respect to age, etc, and ensur ing their enforcement.

Most of the s tudies tha t met inclusion criteria for this review were engineer ing-based intervent ions involving the modification of ei ther the envi ronment or a piece of protective equipment; few specifically addressed injury prevention in children and youth. In fact, m u c h of practice in the way of s tandards , equipment and rules for this age group are based on studies among adults. Is it safe to a s s u m e tha t wha t works for an elite 26-year-old is r e a sonab l e for a 16-year-o ld or for a n ine -yea r -o ld? In the field of t ranspor ta t ion safety, effective strategies have t aken into account the fact tha t physiologic and psychological differences between children, youth and adults require child and you th specific preventive strategies (eg, child passenger restraints; g raduated licensing)14,34. It is not clear why similar at tention to age related differences tha t have been noted in the area of sports and recreation safety have not been acted upon 22,35-37. It is clear tha t the development of evidence-based bes t pract ices for children and youth will only be accomplished through significant research and evaluation tha t addresses these differences.

Further, effective engineering-based interventions do not ensure reduction of injury in and of themselves. Often educat ional /promot ional activities to encourage up take a n d / o r policy or regulation requiring use are required to ensure good practice. Without such efforts people can still behave unsafely despite good evidence to suppor t the practice in question. For example, the use of bicycle he lmets i l lus t ra tes how a known effective engineer ing-based intervention is pract ised mos t often when a combinat ion of both educat ion and legislation are in place 38. Preventing sport and recreat ional injuries requires an unders tand ing of the factors tha t contr ibute to both the occurrence of injury and the up take of, or compliance with, potential preventive strategies 39. Challenges for cur rent prevention efforts include, bu t are not limited to, poor knowledge regarding both intrinsic and extrinsic contr ibuting factors, their interaction to increase susceptibility, and a gap between what is known and what is used in developing and implement ing prevention strategies 4°. Thus there is a need for s tudies examining wha t impacts implementa t ion of effective strategies and the integration of those findings into practice.

Even where studies were found and evidence exists, the utility for setting best practice is questionable. For the activities where evaluative studies were found, few employed a randomised control group design 41-55. Only one s tudy was judged to have good quality of reporting, a non-equivalent control group design 56. Future s tudies should employ more rigorous s tudy protocols, where possible applying a randomised control group design 57-5s. In c i rcumstances where randomisa t ion is not possible, s tudies should a t tempt to control for factors including, age, gender, size, playing position, experience, etc., either th rough design or analysis 4°,38. Further, while a consis tent definition of injury is essential to allow a compar ison of resul ts across studies, s t ronger measures of exposure will bet ter elucidate the t rue magni tude of the issue 57-59. Many of the s tudies included in this review failed to apply these basic research s tandards . This s i tuat ion does not seem to have changed m u c h in the last decade 57-5s. The consequence of methodological and reporting weaknesses is tha t the validity of resul ts is called into question and cannot be generalised to other populat ions 57,6°.

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The lack of good evidence to suppor t preventive strategies is both surprising and concerning given the magni tude of sport and recreational injuries among children and youth. Undoubtedly, fur ther research is required to: 1) ascertain the scope of sport and recreational injuries in children and youth and intrinsic and extrinsic factors related to this population; 2) evaluate existing prevention strategies among this age group; and 3) develop interventions specific to the population where none exist. Despite a lack of studies, the synthesis of existing research provides some direction for current practice, a l though the majority of our recommendat ions are for fur ther research. In the absence of strong evidence to the contrary, the cessation of existing practices not previously tested among children and youth cannot be recommended. Rather rigorous evaluation of existing practices is strongly recommended, thereby allowing the development of evidence-based practice recommendat ions.

While this s tudy highlights the lack of evidence for preventive strategies in the sport and recreational activities examined, there are several limitations that should be noted. First, the scope of this review was extremely large. While the project was initially conceptualised as one systematic review of sport and recreational injury prevention strategies in children and youth, by selecting 26 activities to focus upon we chose to conduct 26 systematic reviews. This stretched resources and, as a result, some non-English articles may have been missed. Second, hand searching identified a fairly large number of relevant articles tha t were not captured by our search strategy. Although the reasons for this discrepancy are not clear, indexing of some sport and recreational publications may be a factor. For example, many of the relevant skiing articles came from proceedings of scientific meetings that were not indexed in any of the databases searched. Finally, the na ture of the studies available presented several challenges. In particular, the lack of s tandardised quality assessment tools for non-randomised controlled designs required the development of a new set of tools. In developing the tools, the research team conducted an extensive literature review and consulted experts internationally to develop and pilot test lists of design specific questions that would best differentiate quality of reporting and quality of original s tudy design. Although extensive work was done and where possible existing questions that had been validated were used a2, it is acknowledged that the tools developed were not s tandardised and require fur ther testing. Given the relative lack of randomised controlled trials in the injury prevention literature, this issue will continue to be a challenge until in te rna t iona l s t anda rds of repor t ing such as in the CONSORT statement 61-62 and internationally recognised s tandardised tools to assess quality exist for all research designs.

Conclusions A systematic review of the sport and recreat ional l i terature retrieved surprisingly few well-designed and controlled studies investigating strategies to prevent injuries. An even smaller number of papers evaluated strategies to reduce injury in children and youth. Of the approximately 21,500 articles identified, 864 were judged to be potentially relevant and only 117 met inclusion criteria. The majority had quality ratings of poor to moderate with only one achieving a good rating. Perhaps even more concerning is the lack of

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s tud ies examining prevent ive s t ra tegies for the majori ty of spor t and recreat ional activities examined. As governments in developed countries cont inue to focus on increasing physical activity among children and youth, thought m u s t be given to the issue of r isk of injury and the relative lack of evidence regarding effective preventive measures .

Presented at the Canadian Conference on Injury Prevention and Control, Kananaskis , Alberta, October 2000; the British Columbia Injury Prevention Conference Sydney, B.C., J u n e 2001 and the 6th World Conference on Injury Prevention and Control, Montreal Canada, May 2002.

Funding: Rick Hansen Foundation; CHEO Research Insti tute.

Acknowledgements This project would not have been possible without the financial contribution from the Rick Hansen Insti tute, the British Columbia Office for Injury Prevention and the Children's Hospital of Eas te rn Ontario Research Institute. Dr. Raina holds CIHR/NHRDP National Heal th Scholar Award. We are grateful to Dr. Sam Sheps, Dr. William Mackie, Dr. Frederick Bell, Dr. Doug Nichols, Dr. Don MacKenzie, Ms. Lynda Cannell and Mr. David Moher for their valuable contr ibution and advice on s tudy methodology and document editing, the hard work of Gila Metz in early s tages of the project and Kevin Walsh on the final report.

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43. Garrick JG, Requa RK. Role of external suppor t in the prevention of ankle sprains. Med Sci Sports 1973;5(3):200-203. 44. Hauser W. Experimental prospective skiing injury study. In Skiing Trauma and Safety: Seventh International SymposiunL ASTM STP 1022. Robert J. Johnson , CD Mote Jr., & Marc- Herve Binet, Eds. Philadelphia. American Society for Testing and Materials. 1989. 45. Hendrickson SG, Becker H. Impact of a theory based intervention to increase helmet use in low income children. Inj Prev 1998;4:126-131. 46. Jorgensen U, Fredensborg T, Haraszuk JP et al. Reduction of injuries in downhill skiing by use of a n instruct ional ski-video: a prospective randomized intervention study. Knee Surg Sports Traumatol Arthrosc 1998;6(3): 194-200. 47. Kaufman RS, Kaufman A. An experimental s tudy on the effects of the MORA on football players. Basal Facts 1984;6(4): 119-26. 48. Kim AN, Rivara FP, Koepsell TD. Does shar ing the cost of a bicycle helmet help promote helmet use? Inj Prev 1997;3, 38-42. 49. Kraus JF, Anderson BD, Mueller CE. The effectiveness of a new touch football helmet to reduce head injuries. J Sch Health 1970;40(9):496-500. 50. Kraus JF, Anderson BD, Mueller CE. The quality of officiating as an injury prevention factor in in t ramura l touch football. Med Sci Sports 1970;3(3): 143-7. 51. Macar thur C, Parkin PC, Sidky M e t al. Evaluation of bicycle skills t raining program for young children: a randomized controlled trial. Inj Prev 1998;4:116-121. 52. Quillian WW, Simms RT, Cooper JS. Knee-bracing in preventing injuries in high school football. Int Pediatr 1987;2:255-6. 53. Sitler M, Ryan J, Hopkinson W et al. The efficacy of a prophylactic knee brace to reduce knee injuries in football, a prospective, randomized s tudy at West Point. Am J Sports Med 1990;18(3):310-5. 54. Sitler M, Ryan J, Wheeler B et al. The efficacy of a semi-rigid ankle stabilizer to reduce acute ankle injuries in basketball: a randomized clinical s tudy at West Point. Am J Sports Med 1994;22(4):454-461. 55. Stevenson MJ, Anderson BD. The effects of playing surfaces on injuries in college in t ramura l touch football. J Nat Intramural Recreat Sports Assoc 1981;May:59-64. 56. Grace TG, Skipper BJ, Newberry JC et al. Prophylactic knee braces and injury to the lower extremity. J Bone Joint Surg Am 1988;70{3):422-7. 57. Walter SD, Hart LE. Application of epidemiological methodology to sports and exercise science research. Exerc Sport Sci Rev 1990;18:417-448. 58. Caine CG, Caine DJ, Lindner KJ. The Epidemiologic Approach to Sports Injuries in Epidemiology of Sports Injuries. Caine CG., Caine DJ and Lindner KJ, Eds. Champaign Illinois. Human Kinetics Publishers Inc. 1996. 59. van Mechelen W, Hlobli H, Kemper HC. Incidence, severity, aetiology and prevention of sports injuries: a review of concepts. Sports Med 1992;14(2): 82-89. 60. Hart LE, Meeuwisse WH. Evaluating methodology in the sport medicine literature. Cltn J Sport Med 1994;4:64. 61. Begg C, Cho M, Eastwood S e t al. Improving the quality of reporting of randomized controlled trials: the CONSORT statement . JAMA 1996;276(8):637-639. 62. Moher D. CONSORT: an evolving tool to help improve the quality of reports of randomized controlled trials. Consolidated s t andards of reporting trials. JAMA 1998;279(18): 1489-91.

Appendix A - Articles included in the systematic review

Abularrage J J , DeLuca AJ, Abularrage C.J. Effect of educat ion and legislation on bicycle helmet use in a multiracial population. Arch Pediatr AdoIesc Med 1997; 151:41-44. Adkison JW, Requa RK, Garrick JG. Injury rates in high school football. Comparison of synthetid surfaces and grass fields. Clin Orthop 1974;99:131-6. Albright JP, Powell JW, Smith W e t al. Medial collateral l igament knee sprains in college football. Effectiveness of preventive braces. Am J Sports Med 1994;22(1): 12-8. Andrish JT, Bergfeld JA, Romo LR. A method for the management of cervical injuries in football. A preliminary report. Am Ortho Soc Sports Med 1977;5(2):89-92. Barret t JR, Tanji JL, Drake C et al. High-versus low-top shoes for the prevention of ankle sprains in basketbal l players: a prospective randomized study. Am J Sports Med 1993;21(4):

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582-585. Blyth CS, Mueller FO. Football injury survey 2. Identifying the causes. Physician Sports Med 1974;2(10):71-8. Blyth CS, Mueller FO. Football injury survey 3. Injury rates vary with coaching. Physician Sports Med 1974;2(11):45-50. Bouter LM, Knipschild PG, Volovics A. Binding function in relation to injury risk in downhill skiing. Am J Sports Med 1989;17(2):226-233. Bouter LM, Knipschild PG, Volovics A. In Skiing Trauma and Safety: Seventh International Symposium, ASTM STP 1022. Robert J. Johnson , CD Mote J r and Marc-Herve Binet, Eds. Philadelphia. American Society for Testing and Materials. 1989. Bramwell ST, Requa RK, Garrick JG. High school football injuries: a pilot comparison of playing surfaces. Med Sci Sports 1972;4(3): 166-9. Britt J , Silver I, Rivara FP. Bicycle helmet promotion among low income preschool children. Inj Prev 1988;4:280-283. Brixler B, Jones RL. High-school football injuries: effects of a post-halftime warm-up and stretching routine. Fam Prac Res J 1992;12(2): 131-9. Brodersen MP, Symanowski JT. Use of a double upright knee orthosis prophylactically to decrease severity of knee injuries in football players. Clin J Sport Med 1993;3:31-35. Cahill BR, Griffith EH, Sunder l in J e t al. Effect of preseason conditioning. High school football knee injuries. IMJ 1984;166(5):356-358. Cahill BR, Griffith EH. Effect of preseason conditioning on the incidence and severity of high school football knee injuries. Am J Sports Med 1978;6(4): 180-4. Cameron BM, Davis O. Swivel football shoe: a controlled study. J Sports Med 1973;i(2): 16-27. Caraffa A, Cerulli G, Projetti M e t al. Prevention of anter ior cruciate l igament injuries in soccer: a prospective controlled s tudy of proprioceptive training. Knee Surg Sports Traumatol Arthrosc 1996;4:19-21. Carlin JB, Taylor P, Nolan T. School based bicycle safety educat ion and bicycle injuries in children: a case-control study. Inj Prev 1998;4:22-27. Damoiseaux VMG, de J o n g h AML, Bouter LM et al. Designing effective heal th educat ion for downhill skiers: resul ts of a randomized intervention study. In Skiing Trauma and Safety: Eighth International Symposium, ASTM STP 1104. C.D. Mote, Jr., Robert J . J o h n s o n Eds. Philadelphia. American Society for Testing and Materials. 1991. Davis JO. Sports injuries and s t ress management : an opportunity for research. Sport Psychol 1994;5(2) : Jun- 182 De Wet F, Badenhors t M, Rossouw LM. Mouthguards for rugby players at primary school level. J Dental Assoc S Afr 1981 ;36(4):249-53. Deppen RJ, Landfried MJ. Efficacy of prophylactic knee bracing in high school football players. J Ortho Sports Phys Ther 1994;20(5):243-6. Downs Jr. Incidence of facial t r a u m a in intercollegiate and jun ior hockey. Phys Sports Med 1979;7(2): 88-92. Ekeland A, Holtmoen A, Lystad H. In Skiing Trauma and Safety: Seventh International Symposium, ASTM STP 1022. Robert J. Johnson , CD Mote J r and Marc-Herve Binet, Eds. Philadelphia. American Society for Testing and Materials. 1989. Ekman R, Schelp L, Welander G et al. Can a combinat ion of local, regional and nat ional information substant ia l ly increase bicycle-helmet wearing and reduce injuries? Experiences from Sweden. Accid Anal Prev 1997;29(3):321-328. Ekstrand J, Gillqnist J. Soccer injuries and their mechanisms: a prospective study. Med Sci Sports Exerc 1983;15(3):267-270. Elias SR, Roberts WO, Thorson DC. Team sports in hot weather: guidelines for modifying youth soccer. Physician Sports Med 1991; 19(5):67-78. Fine KM, Vegso J J , Sennet t B e t al. Prevention of cervical spine injuries in football. A model for other sports. Physician Sports Med 1991 ;19(10):54-64. Garrick JG, Requa RK. Role of external suppor t in the prevention of ankle sprains. Med Sci Sports 1973;5(3):200-203. Gissane C, J enn ings D, White J et al. Injury in s u m m e r rugby league football: the experiences of one club. Br J Sports Med 1998;32(2): 149-52. Gorse K, Mickey CA, Bierhals A. Conditioning injuries associated with artificial t u r f in two preseason football t ra ining programs. J Athletic Train 1997;32(4):304-8. Grace TG, Skipper BJ, Newberry JC et al. Prophylactic knee braces and injury to the lower

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extremity. J Bone Joint Surg Am 1988;70(3):422-7. Hansen BL, Ward JC, Diehl RC. The preventive use of the Anderson knee stabler in football. Physician Sports ivied 1985;13(9):75-6,81. Hauser W. Experimental prospective skiing injury study. In Skiing Trauma and Safety: Seventh International Symposium, ASTM STP 1022. Robert J. Johnson, CD Mote J r and Marc-Herve Binet, Eds. Philadelphia. American Society for Testing and Materials. 1989. Hauser W, Asang E, Muller B. Injury risk in alpine skiing. In Skiing Trauma and Safety: Fifth International Symposium, ASTM STP 860. Robert J. Johnson, & CD Mote Jr, Eds. Philadelphia. American Society for Testing and Materials. 1985. Heiser T M, Weber J, Sullivan G et al. Prophylaxis and management of hamstring muscle injuries in intercollegiate football players. Am J Sports Med 1984;12(5): 368-370. Hendrickson SG, Becker H. Impact of a theory based intervention to increase helmet use in low income children. Inj Prev 1998;4:126-131. Hewson GFJ, Mendini RA, Wang JB. Prophylactic knee bracing in college football. Am J Sports Med 1986;14(4):262-6. Jackson RW, Reed SC, Dunbar F. An evaluation of knee injuries in a professional football team - risk factors, type of injuries, and the value of prophylactic knee bracing. Clin J Sport Med 1991;1(1):1-7. Janda DH, Maguire R, Mackesy D et al. Sliding injuries in college and professional baseball - a prospective study comparing standard and break-away bases. Clin J Sport Med 1993;3:78- 81. J anda DH, Wojtys EM, Hankin FM et al. A three-phase analysis of the prevention of recreational softball injuries. Am J Sports Med 1990;18(6):632-635. Jennings DC. Injuries sustained by users and non-users of gum shields in local rugby union. Br J Sports Med 1990;24(3): 159-65. Jorgensen U, Fredensborg T, Haraszuk JP et al. Reduction of injuries in downhill skiing by use of an instructional ski-video: a prospective randomized intervention study. Knee Surg Sports Traumatol Arthrosc 1998;6(3): 194-200. Kaufman RS, Kaufman A. An experimental study on the effects of the MORA on football players. Basal Facts 1984;6(4):119-26. Keene JS, Narechania RG, Sachtjen KM et al. Tartan Turf on trial. Orthop Soc Sports Med 1980;8(1}:43-47. Kim AN, Rivara FP, Koepsell TD. Does sharing the cost of a bicycle helmet help promote helmet use? Inj Prev 1997;3:38-42. Kraus JF, Anderson BD, Mueller CE. The effectiveness of a new touch football helmet to reduce head injuries. J Sch Health 1970;40(9):496-500. Kraus JF, Anderson BD, Mueller CE. The quality of officiating as an injury prevention factor in intramural touch football. Med Sci Sports 1971 ;3{3): 143-7. Kraus JF, Anderson BD, Mueller CE. The effectiveness of a special ice hockey helmet to reduce head injuries in college intramural hockey. Med Sci Sports 1970;2(3):162-4. Lambson RB, Barnhill BS, Higgins RW. Football cleat design and its effect on anterior cruciate ligament injuries: a three-year prospective study. Am J Sports Med 1996;24(2): 155-9. Larson RL, Osternig LR. Traumatic bursitis and artificial turf. J Sports Med 1974;2(4):183- 188. Lehnhard RA, Lehnhard HR, Young R et al. Monitoring injuries on a college soccer team: the effect of strength training. J Strength Cond Res 1996;10(2): 115-119. Logan P, Leadbetter S, Gibson RE et al. Evaluation of a bicycle helmet giveaway program - Texas, 1995. Pediatrics 1998;101(4):578-582. Lystad H. A five-year survey of skiing injuries in Hemsedal, Norway. In Skiing Trauma and Safety: Seventh International Symposium, ASTM STP 1022. Robert J. Johnson, CD. Mote J r and Marc-Herve Binet, Eds. Philadelphia. American Society for Testing and Materials. 1989. Macarthur C, Parkin PC, Sidky M e t al. Evaluation of bicycle skills training program for young children: a randomized controlled trial. Inj Prev 1998;4:116-121. Morton JG, Burton JF. An evaluation of the effectiveness of mouthguards in high-school rugby players. NZ Dent J 1979;75(341): 151-3. Mueller FO, Blyth CS. An update on football deaths and catastrophic injuries. Physician Sports Med 1986;14{10): 139-42. Mueller FO, Blyth CS. Fatalities from head and cervical spine injuries occurring in tackle football: 40 years' experience. Clin Sports Med 1987;6(1):185-96.

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Mueller FO, Blyth CS. North Carolina high school football injury study: equipment and prevention. Sports Med 1974;2( 1): 1 - 10. Ni H, Sacks JJ , Curtis L e t al. Evaluation of a statewide bicycle helmet law via multiple measures of helmet use. Arch Pediatr Adolesc Med 1997;151:59-65. Pashby TJ. Eye injuries in Canadian amateur hockey. Can J Ophthalmol 1985;20(1): 2-4. Pashby TJ. Eye injuries in Canadian hockey. Phase II. CMAJ 1977;117(6): 671-2. Pashby TJ. Eye injuries in Canadian hockey. Phase Ill: older players now most at risk. CMAJ 1979;121(5): 643-4. Pasternack JS, Veenema KR, Cal lahan CM. Baseball injuries: a little league survey. Pediatrics 1996;98(3):445-448. Powell JW, Schootman M. A multivariate risk analysis of selected playing surfaces in the National Football League: 1980 to 1989. An epidemiologic s tudy of knee injuries. A m J S p o r t s Med 1992;20(6):686-94. Powell JW. Incidence of injury associated with playing surfaces in the National Football League 1980-1985. Athletic Train 1987;Fall:202-206. Quillian WW, Simms RT, Cooper JS. Knee-bracing in preventing injuries in high school football. Int Pediatr 1987;2:255-6. Ressler WH, Toledo E, Kasdah B'Rosh Tov: A description and evaluation of the Israeli bicycle helmet campaign. Health Educ Behav 1998;25(3):354-370. Roberts WO, Brus t JD, Leonard B e t al. Fair-play rules and injury reduction in ice hockey. Arch Pediatr Adolesc Med 1996;150(2): 140-5. Robey JM. Contr ibut ion of design and construct ion of football helmets to the occurrence of injuries. Med Sci Sports 1972;4:170-174. Rovere GD, Clarke TJ, Yates CS et al. Retrospective comparison of taping and ankle stabilizers in preventing ankle injuries. A m J Sports Med 1988;16(3):228-33. Rovere GD, Haupt HA, Yates CS. Prophylactic knee bracing in college football. A m J Sports Med 1987;15(2): 111-116. Rowe LM. Varsity footbaU: knee and ankle injury. NY State J Med 1969;Dec:3000-3003. Schriner JL. A two-year s tudy of the effectiveness of knee braces in high school football players. J Sports Med 1987:21-25. Sendre RA, Keating TM, Hornak J E et al. Use of the Hollywood Impact Base and s tandard stationary base to reduce sliding and base - runn ing injuries in basebal l and softball. A m J Sports Med 1994;22(4):450-453. Shaft S, Gilbert J, Loghmanee F et al. Impact of bicycle helmet safety legislation on children admitted to a regional pediatric t r a u m a center. J Pediatr Surg 1998;33(2):317-321. Shaw RA, Brubaker D. The McDavid Knee Guard (MKG) in preventing knee injuries. Texas Coach 1987;31(9):28-29. Shealy JE. Snowboard vs. downhill skiing injuries. In Skiing Trauma and Safety: Ninth International Symposium, ASTM STP 1182. Robert J. Johnson , CD Mote J r and J o h n Zelcer, Eds. Philadelphia. American Society for Testing and Materials. 1993. Sifter M, Ryan J, Hopkinson W e t al. The efficacy of a prophylactic knee brace to reduce knee injuries in football: a prospective, randomized s tudy at West Point. A m J Sports Med 1990;18(3):310-5. Sifter M, Ryan J, Wheeler B e t al. The efficacy of a semi-rigid ankle stabilizer to reduce acute ankle injuries in basketball : a randomized clinical s tudy at West Point. A m J Sports Med 1994;22(4):454-461. Stevenson MJ, Anderson BD. The effects of playing surfaces on injuries in college in t ramura l touch football. J Nat Intramural Recreat Sports Assoc 1981 ;May:59-64. Teitz CC, Hermanson BK, Kronmal RA et al. Evaluation of the use of braces to prevent injury to the knee in collegiate football players. J Bone Joint Surg A m 1987;69(1):2-9. Torg JS, Quedenfeld T. Knee and ankle injuries traced to shoes and cleats. Physician Sports Med 1973;1(2):39-43. Torg JS, Quendenfeld T. Effect of shoe type and cleat length on incidence and severity of knee injuries among high school football players. Res Q 1971;42(2):203-11. Torg JS, Truex RJ, Quedenfeld TC et al. The nat ional football head and neck injury registry: report and conclusions 1978. JAMA 1979;241(14):1477-9. Torg JS, Vegso J J , Sennet t B. The nat ional football head and neck injury registry: 14-year report on cervical quadriplegia ( 1971 - 1984). Clin Sports Med 1987;6( 1 ): 61 -72. Ungerholm S, Gustavsson J. Skiing safety in children: a prospective s tudy of downhill skiing

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injuries and their relation to the skier and his equipment. Int J Sports Med 1985;6(6):353-358. Upson N. Mouthguards, an evaluation of two types for rugby players. Br J Sports Med 1985;19(2) :89-92. Watson RC, Nystrom MA, Buckolz E. Safety in Canadian junior ice hockey: the association between ice surface size and injuries and aggressive penalties in the Ontario hockey league. Clin J Sport Med 1997;7(3): 192-195. Watson RC, Singer CD, Sproule JR. Checking from behind in ice hockey: a s tudy of injury and penalty data in the Ontario University Athletic Association hockey league. Clin J Sport Med 1996;6(2): 108-111. Watts D, O'Shea N, lie A e t al. Effect of bicycle safety program and free bicycle helmet distr ibution on the use of bicycle helmets in elementary school children. J Emerg Nurs 1997;23(5):417-419. Zemper ED. A two-year prospective s tudy of prophylactic knee braces in a national sample of college football players. Sports Train Med Rehabil 1990;1(4):287-96. Zemper ED. Analysis of cerebral concussion frequency with the most commonly used models of football helmets. J Athletic Train 1994;29(1):44-50.

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Documents

Looking for the evidence: a systematic review of prevention strategies addressing sport and recreational injury among children and youth