Injection initiation at 30 years of age or older among a sample of syringe services program participants in Seattle, WA

BackgroundInjection drug use is associated with risk for HIV, hepatitis C, and overdose. Despite older age and recent initiation being associated with increased risk, most research of injection initiation has focused on youth.MethodsSurvey data collected in 2019 at a syringe services program (SSP) in Seattle, WA, were used to estimate the proportion and identify correlates of injection initiation >= 30 years old ("later initiates"). We collected data on sociodemographics, past-week drugs used and routes, and concern about depression and anxiety. The analytical sample included participants who were >= 30 years old and reported lifetime injection. We performed multivariable logistic regression with variables selected a priori (age, gender, race) and those significant in bivariate analyses.ResultsOf 390 participants, 156 (40%) were later initiates. A higher proportion of later initiates reported past-week heroin use (73% vs 59%, p = .003) and concern about depression (75% vs 65%, p = .03). In multivariable analyses, heroin use (AOR: 2.62, 95% CI: 1.57-4.36) and concern about depression (AOR: 1.63, 95% CI: 1.00-2.64) were associated with increased odds of later initiation.ConclusionsOver one-third of participants were later initiates. Providing alternative methods for heroin use (e.g., pipes) and integrating mental health care at SSPs may reduce injection initiation among older people who use drugs.