Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico

• DOI: 10.1111/dar.12524
• Publication Date: 2017-03-24T12:10:08Z
• Authors: Meredith C. Meacham; Scott C. Roesch; Steffanie A. Stra...; Suzanne Lindsay; Patricia Gonzalez...; Tommi L. Gaines
• Keywords: Adult; Male; Physical Injury - Accidents and Adverse Effects; Biological Psychology; 610; polyroute; HIV Infections; Medical and Health Sciences; Methamphetamine; Drug Users; Substance Misuse; 03 medical and health sciences; Risk-Taking; 0302 clinical medicine; Risk Factors; Behavioral and Social Science; latent class analysis; Psychology; Humans; polydrug; Needle Sharing; PWID; Substance Abuse, Intravenous; Mexico; Prevention; Psychology and Cognitive Sciences; Substance Abuse; Health sciences; Human society; Middle Aged; 3. Good health; Brain Disorders; Infectious Diseases; Good Health and Well Being; Studies in Human Society; HIV/AIDS; Sexually Transmitted Infections; Mental health; Female; HIV risk behaviour; Drug Overdose; Drug Abuse (NIDA only); Intravenous

AbstractIntroduction and AimsPatterns of polydrug use among people who inject drugs (PWID) may be differentially associated with overdose and unique human immunodeficiency virus (HIV) risk factors. Subgroups of PWID in Tijuana, Mexico, were identified based on substances used, route of administration, frequency of use and co‐injection indicators.Design and MethodsParticipants were PWID residing in Tijuana age ≥18 years sampled from 2011 to 2012 who reported injecting an illicit substance in the past month (n = 735). Latent class analysis identified discrete classes of polydrug use characterised by 11 indicators of past 6 months substance use. Multinomial logistic regression examined class membership association with HIV risk behaviours, overdose and other covariates using an automated three‐step procedure in mplus to account for classification error.ResultsParticipants were classified into five subgroups. Two polydrug and polyroute classes were defined by use of multiple substances through several routes of administration and were primarily distinguished from each other by cocaine use (class 1: 5%) or no cocaine use (class 2: 29%). The other classes consisted primarily of injectors: cocaine, methamphetamine and heroin injection (class 3: 4%); methamphetamine and heroin injection (class 4: 10%); and heroin injection (class 5: 52%). Compared with the heroin‐only injection class, memberships in the two polydrug and polyroute use classes were independently associated with both HIV injection and sexual risk behaviours.Discussion and ConclusionsSubstance use patterns among PWID in Tijuana are highly heterogeneous, and polydrug and polyroute users are a high‐risk subgroup who may require more tailored prevention and treatment interventions. [Meacham MC, Roesch SC, Strathdee SA, Lindsay S, Gonzalez‐Zuniga P, Gaines TL. Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico. Drug Alcohol Rev 2018;37:128–136]