Descriptive Epidemiology Of Missing Data In Time Loss Injuries In NCAA Sports: 2014/15 To 2018/19

PURPOSE: Time loss (TL) is commonly used in sports medicine as an observable measure of injury severity. However, missingness in TL data can lead to biased results and incorrect inferences. Prior to addressing this issue, a proper insight of missingness in TL data and associated factors is needed. Therefore, we utilized a large, longitudinal surveillance program to study missingness in TL data in National Collegiate Athletic Association Sports. METHODS: Injuries reported to the NCAA Injury Surveillance Program from 2014/15 - 2018/19 academic years were examined. Prevalence of injuries with missing TL data (MTLD) were expressed as percents. Distributions of MTLD injuries were described by sex, event type, division level, season, diagnosis, and body part. We assessed differential distributions of MTLD injuries across explanatory variables of interest with Injury Proportional Ratios (IPRs). Effect estimates with 95% Confidence Intervals (CIs) excluding 1.00 were deemed statistically significant. RESULTS: During the study period, 21.27% of reported injuries had MTLD (10,976/51,612). Most injuries with MTLD were attributed to men’s sports (63.3%) and regular season events (68.5%). MTLD was most often observed with knee injuries (20.5%) and sprains (26%). The proportion of MTLD was higher in practice than competition (IPR: 1.33, 95% CI: 1.29, 1.36), and higher in DI compared to both DII (IPR: 1.29, 95% CI: 1.24, 1.34) and DIII (IPR: 1.18, 95% CI: 1.15, 1.23). CONCLUSION: Injuries with MTLD were prevalent in men’s sports and regular season events overall. Sprains were also commonly reported with MTLD and injuries attributed to the knee accounted for one-fifth of all MTLD injuries. Based on these findings, attention should be paid to the prevalence of MTLD injuries in men’s sports during the regular season and in knee injuries when assessing TL in sports injuries. Investigating mechanisms behind missing data in sport-related injuries could improve how we address missingness in analyses and maximize the value of surveillance data. Supported by: The NCAA Injury Surveillance Program is funded by the NCAA. The Datalys Center is an independent nonprofit organization that manages the operations of the NCAA ISP. The content of this report is solely the responsibility of the authors and does not necessarily represent the official views of the funding organization. We thank the many ATs who volunteer their time and efforts to submit data to the NCAA ISP. Their efforts are greatly appreciated and have a tremendously positive effect on the safety of collegiate studentathletes.