title: Increased drug use and the timing of social assistance receipt among people who use illicit drugs.
abstract: The monthly disbursement of social assistance (SA) payments to people who use illicit drugs (PWUD) has been temporally associated with increases in drug-related harm. Yet, whether SA receipt changes drug use intensity compared to levels of use at other times in the month has not been established. We therefore examined this relationship among PWUD in Vancouver, Canada (2005-2013).
  
  
  
  Data were derived from prospective cohorts of HIV-positive and HIV-negative PWUD. Every six months, participants were asked about their illicit drug use during the last 180 days and the past week. We determined whether SA receipt occurred within the assessment's one-week recall period. We employed generalized estimating equations controlling for confounders to examine the relationship between SA receipt and the change in drug use intensity, defined as a 100% increase in the average times per day a given drug was used in the last week compared to the previous 6 months. We tested the robustness of this relationship by stratifying analyses by whether individuals primarily used stimulants, illicit opioids or engaged in polydrug use and examining the timing of SA receipt relative to date of assessment.
  
  
  
  Our study included 2661 individuals (median age 36, 32% female) with 1415 (53.2%) reporting SA receipt occurring within the one-week recall period of the assessment at least once. SA receipt was independently associated with intensified drug use (Adjusted Odds Ratio [AOR]: 1.79; 95% Confidence Interval [CI]: 1.53, 2.09), and remained significant when stratified by primary use of stimulants (AOR: 1.87; 95% CI: 1.54, 2.26), opioids (AOR: 1.96; 95% CI: 1.23, 3.13) and polydrug use (AOR: 1.53; 95% CI: 1.11, 2.10).
  
  
  
  We found a temporal association between SA receipt and drug use intensification. While the health and social benefits of SA are significant, these findings suggest that alternative disbursement strategies, such as staggered or smaller and more frequent SA payments may be able to mitigate drug-related harm. Alternatives should be tested rigorously.
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Krebs
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Linwei
authors.initials: L
authors.lastname: Wang
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Olding
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; School of Public Policy, Simon Fraser University, Suite 3271, 515 West Hastings Street, Vancouver, BC, V6B 5K3, Canada.
authors.forename: Kora
authors.initials: K
authors.lastname: DeBeck
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Medicine, Division of AIDS, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Kanna
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Medicine, Division of AIDS, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: M-J
authors.initials: MJ
authors.lastname: Milloy
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Medicine, Division of AIDS, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Evan
authors.initials: E
authors.lastname: Wood
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada. Electronic address: bnosyk@cfenet.ubc.ca.
authors.forename: Bohdan
authors.initials: B
authors.lastname: Nosyk
authors.affiliation: BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Sociology, University of British Columbia, 6303 NW Marine Drive, Vancouver, BC, V6T 1Z1, Canada.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Richardson
mesh_terms: D000328:Adult; D001955:British Columbia; D055030:Drug Users / Q000523:psychology* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects / Q000191:economics*; D008297:Male; D008875:Middle Aged; D012946:Social Welfare / Q000191:economics / Q000523:psychology / Q000706:statistics & numerical data*; D013997:Time Factors
chemical_list: D013287:Illicit Drugs
keywords: Canada; Drug use intensity; Government transfers; Opioids; Polydrug use; Social assistance; Stimulants; Vancouver