1. Biostatistics and Medical Informatics Research Group, Department of Public Health, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel (VUB) , Brussels, Belgium
2. Department of Dermatology, University Hospitals KU Leuven , Leuven, Belgium
3. Research and Development, Northumbria Healthcare NHS Foundation Trust , North Shields, UK
4. Pain and Rehabilitation Centre, Department of Medical and Health Sciences, Linköping University , Linköping, Sweden