1. Madrilenian Health Service (SERMAS), 28046 Madrid, Spain
2. Department of Nursing, Faculty of Health Sciences, Alfonso X el Sabio University, 28691 Madrid, Spain
3. Nursing Department, Faculty of Nursing, University of Valladolid, 47005 Valladolid, Spain
4. Nursing Care Research (GICE), University of Valladolid, 47005 Valladolid, Spain