1. Department of Clinical Epidemiology; Predictive Medicine and Public Health; University of Porto Medical School; Porto Portugal
2. Public Health Institute; University of Porto; Porto Portugal
3. Nova Medical School/Faculdade de Ciências Médicas; Universidade Nova de Lisboa; CEDOC; Lisboa Portugal
4. Rheumatology Department; CEDOC; CHLO; EPE - Hospital Egas Moniz; Lisboa Portugal
5. Hospital Beatriz Ângelo; Loures Portugal
6. Rheumatology Department; EPE-Hospital S. João; Porto Portugal