Galindo-Izquierdo, M, Rodriguez-Almaraz, E, Pego-Reigosa, J, Lopez-Longo, F, Calvo-Alen, J, Olive, A, Fernandez-Nebro, A, Martinez-Taboada, V, Vela C, Freire, M, Narvaez, F, Rosas, J, Ibanez-Barcelo, M, Uriarte, E, Tomero, E, Zea, A, Horcada, L, Torrente, V, Castellvi, I, Calvet, J, Menor-Almagro, R, Aguirre Zamorano, M, Raya, E, Diez-Alvarez, E, Vazquez-Rodriguez, T, Garcia de la Pena, P, Movasat, A, Andreu, J, Richi, P, Marras, C, Montilla-Morales, C, Hernandez-Cruz, B, Marenco de la Fuente, J, Gantes, M, Ucar, E, Alegre-Sancho, J, Manero, J, Ibanez-Ruan, J, Rodriguez-Gomez, M, Quevedo, V, Hernandez-Beriain, J, Silva-Fernandez, L, Alonso, F, Perez, S, Rua-Figueroa, I, RELESSER Grp, Spanish Soc Rheumatology Systemic, Universitat de Barcelona, Universidad de Cantabria, The RELESSER Group, from the Spanish Society of Rheumatology Systemic Autoimmune Diseases Study Group (EASSER), [Galindo-Izquierdo,M, Rodriguez-Almaraz,E] Rheumatology Department, Hospital 12 Octubre, Madrid. [Pego-Reigosa,JM] Rheumatology, University Hospital Complex, Instituto de Investigación Biomédica, Vigo, Spain. [López-Longo,FJ] Rheumatology Department, Gregorio Marañón University Hospital, Madrid. [Calvo-Alén,J] Rheumatology Department, Sierrallana Hospital, Torrelavega. [Olivé,A] Rheumatology Department, Germans Trías i Pujol University Hospital, Badalona. [Fernández-Nebro,A] Rheumatology Department, Hospital Regional Universitario de Málaga, Málaga. [Martinez-Taboada,V] Rheumatology Department, Marques de Valdecilla Hospital, Santander. [Vela-Casasempere,P] Rheumatology Department, Hospital General de Alicante, Alicante. [Freire,M] Rheumatology Department, Hospital Universitario Juan Canalejo, Coruña. [Narvaez,FJ] Rheumatology Department, Hospital Universitario de Bellvitge, Barcelona. [Rosas,J] Rheumatology Department, Hospital Marina Baixa, Villajoyosa. [Ibáñez-Barceló,M] Rheumatology Department, Hospital Son Llatzer, Palma de Mallorca. [Uriarte,E] Rheumatology Department, Hospital de Donosti, San Sebastián. [Tomero,E] Rheumatology Department, Hospital Universitario de La Princesa. [Zea,A] Rheumatology Department, Hospital Universitario Ramón y Cajal, Madrid. [Horcada,L] Rheumatology Department, Complejo Hospitalario de Navarra, Pamplona. [Torrente,V] Rheumatology Department, Hospital Moisés Broggi. [Castellvi,I] Rheumatology Department, Hospital de la Santa Creu i Sant Pau, Barcelona. [Calvet,J] Rheumatology Department, Hospital Parc Taulí. Sabadell. [Menor-Almagro,R] Rheumatology Department, Hospital de Jerez, Jerez de la Frontera. [Aguirre Zamorano,MA] Rheumatology Department, IMIBIC-Reina Sofia Hospital, Cordoba. [Raya,E] Rheumatology Department, University Hospital San Cecilio, Granada. [Díez-Álvarez,E] Rheumatology Department, Leon Hospital, Leon. [Vázquez-Rodríguez,T] Rheumatology Department, Hospital Lucus Augusti, Lugo. [García de la Peña,P] Rheumatology Department, Hospital Norte Sanchinarro, Madrid. [Movasat,A] Rheumatology Department, Hospital Universitario Príncipe de Asturias, Alcalá de Henares. [Andreu,JL] Rheumatology Department, Hospital Puerta de Hierro, Majadahonda, Madrid, [Richi,P] Rheumatology Department , Hospital Infanta Sofía, San Sebastián de los Reyes, Madrid. [Marras,C] Rheumatology Department , Hospital Virgen de la Arrixaca, Murcia, Spain. [Montilla-Morales,C] Rheumatology Department , Hospital Clínico Universitario de Salamanca, Salamanca. [Hernández-Cruz,B] Rheumatology Department , University Hospital Virgen Macarena. [Marengo de la Fuente,JL] Rheumatology Department , Hospital de Valme, Sevilla. [Gantes,M] Rheumatology Department, Hospital Universitario de Canarias, Tenerife. [Úcar,E] Rheumatology Department, Hospital de Basurto, Bilbao. [Alegre-Sancho,JJ] Rheumatology Department , Hospital Universitario Dr Peset, Valencia. [Manero,J] Rheumatology Department, Hospital Miguel Servet Zaragoza. [Ibáñez-Ruán,J] Rheumatology Department , Clínica POVISA, Vigo. [Rodríguez-Gómez,M] Rheumatology Department , Complejo Hospitalario Universitario de Ourense, Ourense. [Quevedo,V] Rheumatology Department, Hospital de Monforte, Lugo. [Hernández-Beriaín,J] Rheumatology Department, Hospital Insular de Gran Canaria, Las Palmas de Gran Canaria. [Silva-Fernández,L] Rheumatology Department, Hospital Universitario de Guadalajara, Guadalajara. [Alonso,F, Pérez,S] Statistical Department, Research Unit, Spanish Society of Rheumatology (SER), Madrid. [Rúa-Figueroa,I] Rheumatology Department, Doctor Negrín University Hospital, Gran Canaria, Spain., and This work was supported by the Spanish Society of Rheumatology, FIS/ISCIII (grant number PI11/02857), GSK, Roche, Novartis, and UCB.