617 MEP059 – The variation of sports injury epidemiological outcomes according to athletes’ response rates to a weekly online questionnaire

AbstractBackground Prospective data collection is recommended for epidemiological studies and weekly (or every two weeks, or monthly) self-reported online questionnaires for athletes are frequently used. Several strategies can be used to calculate epidemiological outcomes based on weekly athletes' self-reported questionnaires data collection (i.e., only taking into account weekly questionnaires with a response whatever the individual athlete's response rate, including athletes with a minimum individual athlete's response rate, or only athletes with 100% response rate), but their impact on epidemiological outcomes has not been analysed yet.Objective To explore how sports injury epidemiological outcomes vary depending on the response rates to a weekly online self-reported questionnaire for athletes.Design Cohort study with 39-week follow-up.Setting Secondary analysis of data from PREVATHLE randomized controlled trial.Participants 391 female and male competitive athletics athletes.Methods Athletics exposure and injury were collected weekly using an online self-reported questionnaire. The data were used to calculate sports injury epidemiological outcomes (i.e., prevalence, average prevalence, incidence, burden, and time to first injury) for sub-groups with different minimum athletes' individual response rates (i.e., from at least 100%, at least 97%, at least 95%,… to 0% response rate). A descriptive analysis was performed.Results Out of 15249 expected weekly questionnaires 7209 were completed and returned, representing an overall response rate of 47.3%. The prevalence, average weekly prevalence, and time to first injury only varied substantially for the subgroups below a 5%, 10% and 18% minimum response rate, respectively. The incidence and injury burden showed changes for all subgroups with a response rate below 100%.Conclusions Epidemiological outcomes varied depending on the minimum athletes' individual response rate, with injury prevalence, average weekly prevalence, and time to first injury varying less than injury incidence and injury burden. This highlights the need to use individual response rate for calculating epidemiological parameters.