title: Multilevel predictors of concurrent opioid use during methadone maintenance treatment among drug users with HIV/AIDS.
abstract: BACKGROUND
  Ongoing drug use during methadone maintenance treatment (MMT) negatively affects outcomes of HIV/AIDS care and treatment for drug users. This study assessed changes in opioid use, and longitudinal predictors of continued opioid use during MMT among HIV-positive drug users in Vietnam, with the aim of identifying changes that might enhance program efficacy.
  
  
  METHODS
  We analyze data of 370 HIV-positive drug users (mean age 29.5; 95.7% male) taking MMT at multi-sites. Opioid use was assessed at baseline, 3, 6, and 9 months using interviews and heroin confirmatory urine tests. A social ecological model was applied to explore multilevel predictors of continued opioid use, including individual, interpersonal, community and service influences. Generalized estimating equations (GEE) statistical models were constructed to adjust for intra-individual correlations.
  
  
  RESULTS
  Over 9 month follow-up, self-reported opioid use and positive heroin urine test substantially decreased to 14.6% and 14.4%. MMT helped improve referrals and access to health care and social services. However, utilization of social integration services was small. GEE models determined that participants who were older (Adjusted Odd Ratio - AOR = 0.97 for 1 year increase), had economic dependents (AOR = 0.33), or were referred to TB treatment (AOR = 0.53) were less likely to continue opioid use. Significant positive predictors of ongoing opioid use included frequency of opioid use prior to MMT, peer pressure, living with sexual partners, taking antiretroviral treatment, other health concerns and TB treatment.
  
  
  CONCLUSIONS
  These findings show that MMT in the Vietnamese context can dramatically reduce opioid use, which is known to be associated with reduced antiretroviral (ART) adherence. Disease stage and drug interactions between antiretrovirals or TB drugs and MMT could explain some of the observed predictors of ongoing drug use; these findings could inform changes in MMT program design and implementation.
authors.affiliation: School of Public Health, University of Alberta, Edmonton, Alberta, Canada. bach@hmu.edu.vn
authors.forename: Bach Xuan
authors.initials: BX
authors.lastname: Tran
authors.forename: Arto
authors.initials: A
authors.lastname: Ohinmaa
authors.forename: Steve
authors.initials: S
authors.lastname: Mills
authors.forename: Anh Thuy
authors.initials: AT
authors.lastname: Duong
authors.forename: Long Thanh
authors.initials: LT
authors.lastname: Nguyen
authors.forename: Philip
authors.initials: P
authors.lastname: Jacobs
authors.forename: Stan
authors.initials: S
authors.lastname: Houston
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy* / Q000821:virology; D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D015331:Cohort Studies; D003710:Demography; D055030:Drug Users; D005260:Female; D006678:HIV / Q000502:physiology*; D006296:Health Services / Q000706:statistics & numerical data; D006297:Health Services Accessibility; D006801:Humans; D060046:Maintenance Chemotherapy; D008297:Male; D008691:Methadone / Q000627:therapeutic use*; D008954:Models, Biological; D055361:Multilevel Analysis; D015999:Multivariate Analysis; D012947:Social Work
chemical_list: D000701:Analgesics, Opioid; D008691:Methadone