About the Authors
Epidemiology Unit, Medical Research Council, Cambridge, United Kingdom
Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
National Institute for Health Development, Estonian Centre of Behavioural and Health Sciences, Tartuu, Estonia
Department of Sports Medicine, Norwegian University of Sport Sciences, Oslo, Norway
Faculty of Human Movement, Technical University of Lisbon, Lisbon, Portugal
London Sport Institute, Middlesex University, London, United Kingdom
The authors have declared that no competing interests exist.
UE, KF, MH, SAA, LBS, CR, and LBA designed the study. UE and SB analysed the data. KF and LBA enrolled patients. UE, SB, KF, MH, SAA, LBS, CR, and LBA contributed to writing the paper. MH and LBS collected data or did experiments for the study. KF was responsible for collection of data in Denmark. CR organized and participated in international quality-control procedures. LBA administered the database and prepared and cleaned data pooled from the different countries. Maarike Harro, listed as a contributing author to this paper, died before its publication. The corresponding author, Ulf Ekelund, has therefore supplied the information regarding her contribution to the manuscript and her competing interests, and it is correct to the best of his knowledge.