1. Department of Occupational Health and Safety, Faculty of Public Health, Mahidol University, Bangkok 73170, Thailand
2. School of Public Health, Physiotherapy and Sports Science, University College Dublin, D04 V1W8 Dublin, Ireland
3. Research Unit of Population Health, University of Oulu, 90570 Oulu, Finland
4. Department of Community Medicine, University of Tromsø, 9019 Tromsø, Norway