1. Pain Unit, Hospital Universitari Vall d’Hebrón, Passeig de la Vall d’Hebron 119, Barcelona 08035, Spain
2. Pain Unit, Hospital Universitari de Bellvitge, Carrer de la Feixa Llarga, L’Hospitalet de Llobregat 08907, Spain
3. Pain Unit, Consorci Sanitari Integral, Hospital de Sant Joan Despí Moisès Broggi, Carrer Oriol Martorell 12, Sant Joan Despí 08907, Spain
4. Pain Unit, Institut de Medicina i Cirurgia de Barcelona, Carrer Bisbe Sivilla 46, Barcelona 08022, Spain
5. Pain Unit, Hospital Universitari Sant Joan de Reus, Avinguda Del Doctor Josep Laporte 2, Reus 43204, Spain
6. Pain Unit, Hospital Universitari de La Santa Creu i Sant Pau, Carrer de Sant Quintí 89, Barcelona 08041, Spain
7. Pain Unit, Hospital Universitari Germans Trias i Pujol, Badalona 08916, Spain
8. Pain Unit, Hospital Universitari Joan 23, Carrer Dr. Mallafrè Guasch 4, Tarragona 43005, Spain
9. Department of Design and Biometrics, Medicxact, Plaza Ermita 4, Alpedrete, Spain
10. Pain Unit, Hospital Del Mar, Passeig Marítim 25-29, Barcelona 08003, Spain
11. Department of Clinical Pharmacology, Hospital Universitari de Bellvitge, Carrer de La Feixa Llarga, L’Hospitalet de Llobregat 08907, Spain
12. Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, IDIBELL, University of Barcelona, Carrer de La Feixa Llarga, L’Hospitalet de Llobregat 08907, Spain