1. Galician Health Service EOXI Lugo Cervo e Monforte de Lemos Lugo Spain
2. Department of Surgery and Medical‐Surgical Specialities School of Medicine and Dentistry University of Santiago de Compostela Santiago de Compostela Spain
3. Epidemiology, Statistics, and Research Methodology Unit IDIS Foundation Santiago de Compostela and Lugo Spain
4. Department of Surgery and Medical‐Surgical Specialities School of Medicine and Health Sciences University of Oviedo Oviedo Spain