Authors: Eva Morales; Miquel Porta; Jesús Vioque; Tomás López; Michelle A Mendez; José Pumarega; Núria Malats; Marta Crous-Bou; Joy Ngo; Juli Rifà; Alfredo Carrato; Luisa Guarner; Josep M Corominas; Francisco X Real Journal: J Epidemiol Community Health Date: 2007-07 Impact factor: 3.710