[1] NOVA Univ Lisbon, CHRC, Comprehens Hlth Res Ctr, NOVA Natl Sch Publ Hlth,Publ Hlth Res Ctr, Ave Padre Cruz, P-1600560 Lisbon, Portugal
[2] Univ Porto, Fac Med, Dept Publ Hlth & Forens Sci & Med Educ, Alameda Prof Hernani Monteiro, P-4200319 Porto, Portugal
[3] Univ Porto, Inst Publ Hlth, EPI Unit, Rua Taipas 135, P-4050091 Porto, Portugal
[4] Univ Amsterdam, Amsterdam UMC, Amsterdam Publ Hlth Res Inst, Dept Publ & Occupat Hlth, Meibergdreef 9, NL-1105 AZ Amsterdam, Netherlands