title: Trends in HIV risk behaviour and methadone dosage among HIV-negative drug users: an ecological study.
authors.affiliation: Division of Public Health and Environment, Municipal Health Service, Amsterdam, The Netherlands.
authors.forename: M W
authors.initials: MW
authors.lastname: Langendam
authors.forename: G H
authors.initials: GH
authors.lastname: van Brussel
authors.forename: R A
authors.initials: RA
authors.lastname: Coutinho
authors.forename: E J
authors.initials: EJ
authors.lastname: van Ameijden
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D017280:Condoms / Q000639:trends; D005260:Female; D018023:HIV Seronegativity; D006556:Heroin Dependence / Q000150:complications / Q000523:psychology / Q000534:rehabilitation; D006801:Humans; D008297:Male; D008691:Methadone / Q000008:administration & dosage* / Q000627:therapeutic use; D008875:Middle Aged; D009294:Narcotics / Q000008:administration & dosage* / Q000627:therapeutic use; D016485:Needle Sharing / Q000639:trends; D009426:Netherlands; D012309:Risk-Taking; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000523:psychology / Q000534:rehabilitation*
chemical_list: D009294:Narcotics; D008691:Methadone