title: Self-reports of consumption of amphetamines, cocaine and heroin in a survey among marginalized drug users.
abstract: OBJECTIVE
  Scientific literature offers few measurements of the quantities consumed by individual drug users. Such measurements are used for calculating the total drug consumption by the quantity-frequency method, and are extremely important for the comparison with waste water derived consumption estimates. The aim of this study was to measure quantities of amphetamines, cocaine and heroin consumed by marginalized drug users, using a multi-city questionnaire survey design. Variation by gender, age, frequency of use, main drug used and city was explored.
  
  
  RESULTS
  The self-reported quantity used on the last day of use was for amphetamines on average 800 mg, for cocaine 1,014 mg and for heroin 682 mg. The self-reported usual dose was on average 297 mg, 487 mg and 297 mg respectively, while the median value was 250 mg for all three drugs. Overall, gender and age group were less important than frequency of use and the main drug used for establishing differences regarding the outcome variables. There were some differences regarding cities. No measure of purity was carried out at the interview sites, so the calculation of pure quantities was based on aggregate results from analyses of seizures by police and customs.
  
  
  CONCLUSIONS
  The self-reported quantities of drugs consumed in three cities in Norway was equal to or somewhat higher among marginalized users than earlier assumed, where assumptions were based on limited literature and anecdotal information.
authors.affiliation: Norwegian Institute for Alcohol and Drug Research, P.O. Box 565 Sentrum, NO-0105 Oslo, Norway. Electronic address: eja@sirus.no.
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: Amundsen
authors.affiliation: Norwegian Institute for Water Research, Gaustadalleen 21, NO-0349 Oslo, Norway. Electronic address: Malcolm.Reid@niva.no.
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Reid
mesh_terms: D000328:Adult; D000662:Amphetamines; D002947:Cities / Q000453:epidemiology; D003042:Cocaine; D003625:Data Collection; D055030:Drug Users / Q000706:statistics & numerical data; D005260:Female; D003932:Heroin; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D057566:Self Report; D019966:Substance-Related Disorders / Q000453:epidemiology*
chemical_list: D000662:Amphetamines; D003932:Heroin; D003042:Cocaine
keywords: Amphetamines; Cocaine; Dose; Heroin; Quantity; Self-reported