1. Department of Anesthesiology and Pain Medicine, University Hospital Campus Jerez de la Frontera, University of Cadíz, Cadíz, Spain
2. Department of Anesthesiology and Pain Medicine, University Hospital Gasthuisberg, University of Leuven, Leuven, Belgium
3. Interuniversity Institute for Biostatistics and Statistical Bioinformatics (I-BIOSTAT), Universities of Leuven and Hasselt, Leuven and Diepenbeek, Belgium
4. Department of Orthopedics and Traumatology, University Hospital Campus Jerez de la Frontera, University of Cadíz, Cadíz, Spain
5. Multidisciplinary Pain Centre at the Ziekenhuis Oost-Limburg, Genk, Belgium
6. Department of Anesthesiology and Pain Management, Maastricht University Medical Centre, Maastricht, The Netherlands
7. Multidisciplinary Pain Centre at the Ziekenhuis Oost-Limburg , Genk, Belgium
8. Department of Preventive Medicine and Public Health, University of Cadíz, Cádiz, Spain