title: How important are paper copies of questionnaires? Testing invitations modes when studying social inequalities in smoking among young adults.
authors.affiliation: Institut de recherche en santé publique de l'Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada, thierry.gagne@umontreal.ca.
authors.forename: Thierry
authors.initials: T
authors.lastname: Gagné
authors.forename: Rowena
authors.initials: R
authors.lastname: Agouri
authors.forename: Michael
authors.initials: M
authors.lastname: Cantinotti
authors.forename: Anis
authors.initials: A
authors.lastname: Boubaker
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Frohlich
mesh_terms: D000293:Adolescent; D000328:Adult; D015982:Bias; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D010209:Paper; D011792:Quebec / Q000453:epidemiology; D012107:Research Design; D012907:Smoking / Q000453:epidemiology*; D012923:Social Class; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D055815:Young Adult