[1] Red Invest Serv Sanitarios Enfermedades Cron REDI, San Sebastian, Guipuzcoa, Spain
[2] Unidad Invest Atenc Primaria OSIS Guipuzcoa, San Sebastian, Guipuzcoa, Spain
[3] Inst Invest Sanitaria Biodonostia, San Sebastian, Guipuzcoa, Spain
[4] Gobierno Vasco, Direcc Salud Publ & Adicc, Vitoria, Alava, Spain
[5] CIBER Epidemiol & Salud Publ, Madrid, Spain
[6] Gobierno Vasco, Subdirecc Salud Publ Guipuzcoa, San Sebastian, Guipuzcoa, Spain