[1] Univ Porto, Inst Saude Publ, EPIUnit, Porto, Portugal
[2] ARS Norte, ACeS Espinho Gaia, USF Monte Murado, Vila Nova De Gaia, Portugal
[3] Univ Porto, Fac Med, Dept Ciencias Saude Publ & Forenses & Educ Med, Porto, Portugal
[4] Univ Lisbon, Inst Ciencias Sociais, Lisbon, Portugal
[5] Ctr Hosp Sao Joao, Ctr Epidemiol Hosp, Porto, Portugal