[1] CIBERESP IIB St Pau, Iberoamer Cochrane Ctr, Barcelona, Spain
[2] Serv Catalan Salud, Div Planificac & Evaluac Operat, Barcelona, Spain
[3] Inst Univ Invest Atencio Primaria Jordi Gol IDIAP, Barcelona, Spain
[4] Univ Autonoma Barcelona, Catedra UAB Novartis Docencia & Invest Med Famili, E-08193 Barcelona, Spain
[5] Univ Zaragoza, Catedra UNIZAR Novartis Docencia & Invest Med Fam, Zaragoza, Spain
[6] Univ Autonoma Madrid, Catedra UAM Novartis Docencia & Invest Med Famili, Madrid, Spain