The large and growing number of high school athletes1
coupled with their high injury incidence3
highlights the urgency of developing an effective national injury surveillance system. By monitoring injury rates and patterns over time, such a surveillance system provides the foundation for developing and evaluating preventive interventions. In this study, the first to assess the feasibility of relying on coaches as data reporters for a national sports injury surveillance system using a geographically dispersed sample (ie, representing 15 states across all 4 US Census geographic regions and including both small [enrollment of 1000 or less] and large [enrollment of more than 1000] schools), we found that coaches had very low participation rates. Therefore, whenever possible, ATs should be the primary data reporters in national surveillance.
Despite 100% participation among ATs in the 18 study schools, fewer than half of the enrolled coaches participated. Some coaches may have signed their school's participation agreement form without intending to participate, perhaps because they felt pressured to do so by their AT, other coaches, or school officials. On average, coaches who did participate submitted only one-third of all expected exposure reports. Some coaches may have misinterpreted study instructions and believed they were only required to submit exposure reports for the weeks in which they had an injury to report.
When coaches did submit exposure reports, they occasionally reported exposures incorrectly by recording the number of practices or competitions rather than athlete-practices or athlete-competitions. For example, a coach with a team of 50 athletes who all practiced 5 times in a week was more likely to incorrectly report 5 athlete-practices than to correctly report 250 athlete-practices. In contrast, all ATs reported AEs correctly throughout the study. Coaches also underreported injury incidence, submitting fewer than one-fifth of the number of injury reports submitted by ATs. Coaches may not have had the time or desire to submit an injury report for every injury coming to their attention, or they may not have been aware of all injuries occurring on their team, particularly if the injured athlete presented directly to the AT and missed little playing time.
Obtaining accurate AE and injury incidence data is a crucial prerequisite for calculating true injury rates, as indicated by the injury rate equation:
If a study's reporters underreported injury incidence, injury rates would be artificially low. If AEs were underreported, injury rates would be artificially high. Either way, inaccurate injury rates may lead researchers to underestimate or overestimate injury incidence, leading to potentially incorrect conclusions or inappropriate or ineffective preventive recommendations.
Sports injury incidence is sometimes used to estimate the number of sports injuries occurring regionally or nationally. Underreporting of injury incidence by data reporters would lead to inaccurate regional or national injury estimates. For example, using AT-reported data, the National High School Sports-Related Injury Surveillance Study estimated that approximately 1.4 million injuries were sustained in 9 US high school sports during the 2005–2006 school year.3
If coaches had been called on as data reporters in place of ATs and if a similar sampling scheme had been employed, then the 84% underreporting that we found would presumably result in a nationally estimated incidence of fewer than 300
000 injuries, a deficit of more than 1 million injuries. Additionally, undersubmission of valid injury reports decreases study generalizability and increases the likelihood of obtaining skewed injury patterns. For example, if coaches are less likely to submit an injury report for athletes who miss more than 21 days of play, then injury patterns based on coach-reported data would incorrectly suggest that athletic injuries are less severe than they actually are.
Surprisingly, 36 coach-submitted injury reports could not be linked to an AT-submitted injury report. One possibility is that the reported dates of injury occurrence were too different, which could happen if a coach submitted the report several weeks after the injury occurred. Because few coaches keep an injury log book, they may have had difficulty remembering the date. Discrepancies may also have occurred in choosing the most serious injury during events in which more than 1 injury occurred. For example, if an athlete sustained both a concussion and a mild ankle sprain at the same time, the coach may have reported the ankle sprain, whereas the AT may have reported the concussion. Also, it is possible that coaches submitted injury reports for events not meeting the injury definition, such as an athlete who initially appeared to be injured but returned the next day.
Numerous discrepancies were identified between linked AT and coach injury reports. Although we cannot ascertain for certain which reports were correct, we assume that ATs are more likely to report correct injury-related information, such as injured body site, need for surgery, and diagnosis, because they are medically trained. Previously, athletic therapists and medical doctors participating in a Canadian sports injury surveillance study were found to record similar diagnoses in more than 80% of reports.21
Conversely, coaches may have been more likely to report correct event-specific information, such as activity at time of injury, as they are more likely to be present when the injury occurs. Future researchers should examine whether ATs have difficulties reporting event-related information accurately, so that any problems can be addressed.
We made extensive efforts to obtain athletes' participation in this study. The athletic director, AT, and coach for each sport of interest signed a participation agreement form indicating that they were aware that athletes were supposed to participate. We also sent ATs and coaches weekly e-mails reminding them to ask their athletes to report and asking them to contact us if they had any questions. Despite these efforts, only 1 athlete logged onto RIO to report. Athlete nonparticipation was likely a combination of athletes not being made aware of the study, athletes being aware of the study but choosing not to participate, and athletes wanting to participate but being unable to do so. Study materials were supposed to flow from study staff to ATs, from ATs to coaches, and from coaches to athletes. Although it is likely that nearly all ATs passed study materials to coaches because all ATs participated, it is possible that some coaches did not pass study materials to athletes. However, almost half of all coaches participated and 1 athlete participated, so at least some coaches passed study materials onto their athletes. Thus, at least several athletes were aware of the study but either chose not to participate or were unable to report. Regardless of the reason, this lack of athlete participation demonstrates that athletes are not suitable reporters for large, national surveillance studies. Researchers cannot feasibly contact, elicit participation, disburse and collect informed consent or assent, and conduct regular, season-long follow-up among thousands of athletes dispersed across the country. Our data show that attempting to do so through mediators such as coaches is ineffective. Although athletes may be able to report reliably and consistently in small, localized studies, when researchers can initiate regular, individualized contact,16
such personalized attention has limited feasibility in a large, national study.
Although ATs play an important role in the high school setting,22
budget constraints have resulted in a decreased number of ATs employed by US high schools.23
Unfortunately, athletes who lack access to the preventive and rehabilitative care provided by ATs may be more likely to sustain injuries or may experience longer recovery times than athletes at schools with ATs.24
If injury rates and patterns differ between schools with and without ATs, then national high school sports injury surveillance cannot be completely representative until either all high schools have access to ATs or researchers develop methods to successfully collect high-quality data from schools without ATs. Although we strongly believe that ATs should be relied on as reporters whenever possible in high school sports injury surveillance, findings from this study suggest that relatively labor-intensive methodologic modifications, such as soliciting and compensating coaches directly, will likely be required in studies calling on coaches as reporters.
Like all studies, this study had limitations. Although we considered ATs to be the “gold standard” for injury surveillance reporting, we do not know whether ATs always reported correctly. However, previous internal validity analyses of the National High School Sports-Related Injury Surveillance Study indicated sensitivity and specificity of injury reporting by ATs was greater than 95% (R.D.C., E.E.Y., C.L.C., unpublished data, 2008). In this study, we only included schools with a National Athletic Trainers' Association–affiliated AT. Although this restriction may limit generalizability if coaches and athletes take a greater interest in injury prevention when their school lacks medical personnel, it was a necessary limitation to directly compare AT, coach, and athlete reporting. Additionally, we did not know the availability of computers among coaches and athletes. However, ATs at these schools were able to access computers regularly, suggesting that coaches and athletes likely could have had computer access if needed.
In conclusion, this study demonstrates the importance of depending on reliable data reporters in high school sports injury surveillance. Whenever possible, ATs should be the primary data reporters in large, national studies. In high schools without access to ATs, researchers must be willing to devote large amounts of time and resources to achieving high levels of participation and study compliance among other data reporters.