[1] Hosp Santa Creu I Sant Pau, Epidemiol & Publ Hlth Dept, Barcelona, Spain
[2] Sant Pau Biomed Res Inst IIB Sant Pau, Iberoamer Cochrane Ctr IbCC, Barcelona, Spain
[3] CIBER Epidemiol & Publ Hlth CIBERESP, Barcelona, Spain
[4] Escola Virolai, Barcelona, Spain
[5] Andalusian Hlth Serv, Malaga, Spain
[6] IDIBELL, Catalan Inst Oncol, Canc Prevent & Control Programme, Barcelona, Spain
[7] Paediat Hosp Sinaloa, Culiacan, Mexico
[8] Norwegian Inst Publ Hlth, Ctr Epidem Intervent Res, Oslo, Norway
[9] Vall dHebron Univ Hosp, Barcelona, Spain
[10] Biodonostia Hlth Res Inst, Clin Epidemiol, San Sebastian, Spain
[11] Donostia Univ Hosp, Osakidetza Basque Hlth Serv, Clin Epidemiol Unit, Donostialdea Integrated Hlth Org, San Sebastian, Spain