1. Department of Nursing, Faculty of Health Sciences, University of Las Palmas de Gran Canaria, 35016 Las Palmas de Gran Canaria, Canary Islands, Spain
2. Hospital Insular de Gran Canaria, 35016 Las Palmas de Gran Canaria, Canary Islands, Spain
3. Department of Mathematics, Faculty of Mathematics, University of Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria, Canary Islands, Spain
4. Continuous Training Department, Primary Care Management, Gran Canaria Health Area, 35006 Las Palmas de Gran Canaria, Canary Islands, Spain