Affiliation: | (1) Department, Institut Municipal d'Assistncia Sanitria (IMAS), Health Services Evaluation and Clinical Epidemiology, Barcelona, Spain;(2) Health Services Research Unit, IMIM-IMAS, Barcelona, Spain;(3) Paediatric Service, Institut Municipal d'Assistncia Sanitria (IMAS), Barcelona, Spain;(4) Childhood and Environment Research Unit, Institut Municipal d'Investigaci Mdica (IMIM-IMAS), Barcelona, Spain;(5) Departament de Pediatria, Obstetrcia i Ginecologia i Medicina Preventiva, Universitat Autnoma de Barcelona, Barcelona, Spain |