1 Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Canada. Electronic address: ian.shrier@mcgill.ca.
2 Amsterdam Collaboration on Health and Safety in Sports, IOC Research Centre for Prevention of Injury and Protection of Athlete Health, Department of Public and Occupational Health, EMGO+ Institute for Health and Care Research, VU University Medical Center, The Netherlands.
3 Department of Family Medicine and Community Health, University of Minnesota, Minneapolis.