Validation of the "World Health Organization Disability Assessment Schedule, WHODAS-2" in patients with chronic diseases oleh Burger Helena, Svetskova Olga, Cieza Alarcos, Alonso Jordi, Vilagut Gemma, Chatterji Somnath, Nieto Marta, Almansa Josué, Ayuso-Mateos Jose, Garin Olatz, Racca Vittorio, Francescutti Carlo, Vieta Eduard, Kostanjsek Nenad, Raggi Alberto, Leonardi Matilde, Ferrer Montse