Polydrug Use and HIV Risk Among People Who Inject Heroin in Tijuana, Mexico: A Latent Class Analysis

Area of Science:

• Public Health
• Addiction Medicine
• Sociology

Background:

• Most people who inject drugs (PWID) in Tijuana primarily inject heroin, but methamphetamine and cocaine use is also prevalent.
• Understanding polydrug use patterns among PWID is crucial for addressing associated health and social consequences.

Purpose of the Study:

• To examine polydrug use patterns among heroin injectors in Tijuana.
• To identify distinct subtypes of PWID based on their use of methamphetamine and cocaine.
• To inform the development of targeted prevention and treatment strategies.

Main Methods:

• Latent class analysis was used to identify distinct subgroups of PWID.
• Data included self-reported past six-month use of heroin, cocaine, and methamphetamine via injection, smoking, or snorting.
• Participant characteristics were analyzed using multinomial logistic regression.

Main Results:

• A 3-class solution best fit the data, identifying three distinct patterns of drug use.
• Class 1: Predominantly heroin use (50.2%).
• Class 2: Methamphetamine and heroin use (43.7%).
• Class 3: Methamphetamine, cocaine, and heroin use (6.0%).
• Subgroups differed in sexual practices, frequency of heroin injection, age, and gender.

Conclusions:

• Distinct subtypes of heroin PWID were identified based on co-use of methamphetamine and cocaine.
• These findings highlight the need for tailored interventions to mitigate health and social harms associated with specific polydrug use patterns among PWID.