title: Invited commentary: le mystère de Montréal.
authors.affiliation: Institute for Social Research, University of Michigan, Ann Arbor 48106, USA.
authors.forename: P
authors.initials: P
authors.lastname: Lurie
mesh_terms: D015331:Cohort Studies; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D006801:Humans; D015233:Models, Statistical; D018671:Needle-Exchange Programs / Q000706:statistics & numerical data*; D011792:Quebec / Q000453:epidemiology; D012309:Risk-Taking; D015983:Selection Bias; D015819:Substance Abuse, Intravenous