1. Department of Rheumatology, Hospital de la Princesa, IIS-Princesa, Spain
2. Cátedra UAM-ROCHE, EPID-Future, Department of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
3. Department of Rheumatology, Hospital Universitario Marqués de Valdecilla, IDIVAL, Spain
4. Department of Medicine, University of Cantabria, Santander (Cantabria), Spain