Injecting Alone: Practices and Preferences among People Who Inject Drugs in New York City.

Injecting alone is a suspected risk factor for opioid overdose death among people who inject drugs (PWID). Better understanding of PWID's injecting practices and preferences could guide pragmatic harm reduction and overdose prevention interventions. We investigated injection practices and preferences among PWID attending syringe services programs (SSPs). We surveyed 108 PWID with opioid use disorder from 3 New York City SSPs between November 2020 and August 2021 to ascertain harm reduction service preferences. This secondary analysis examined injection behavior preferences, reasons for these preferences, and self-reported non-fatal lifetime overdoses. Slightly more participants preferred injecting alone (56%) than with someone present (44%), but most in both groups inject alone most of the time (97% vs 52%, p < 0.01). Commonly reported reasons for preferring to inject alone were privacy (82%) and not wanting to be judged (78%), whereas many preferred to inject with others to have someone present in case of overdose (92%), for camaraderie (69%), and to share drugs (65%). Those preferring to inject alone (vs. with someone present) self-reported higher mean number of lifetime overdoses (3.1 vs 2.6), but differences were not statistically significant. In conclusion, most participants injected alone regardless of preference. While not associated with prior non-fatal overdose, injection preference likely carries risk for future overdose. Participants preferred injecting alone to avoid shame or injecting with others in case of overdose, which can inform public health interventions that support both preferences. Reducing stigma while facilitating rapid overdose response can mitigate the risk of fatal overdose.