1 Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland and Observatoire Valaisan de la Santé, Sion, Switzerland arnaud.chiolero@chuv.ch.
2 Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada.
3 Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland.