Improved syringe disposal practices associated with unsanctioned safe consumption site use: A cohort study of people who inject drugs in the United States.

BACKGROUND

Community opposition to safe consumption sites often centers around improper syringe disposal. People are concerned these sites might attract people who inject drugs to the neighborhood, which might in turn lead to more used syringes left in public settings.

METHODS

We evaluated an unsanctioned safe consumption site in an undisclosed United States city in 2018-2020 to assess whether use of the site was associated with improper syringe disposal practices. We recruited people who inject drugs (N=494) using targeted sampling methods, and interviewed participants at baseline, 6 months, and 12 months. We employed a quasi-experimental design involving inverse probability of treatment weighting using propensity scores. We used generalized estimating equations and Poisson models to calculate relative risk and incidence rate ratios of improper syringe disposal.

RESULTS

The risk of any improper syringe disposal was comparable among people who used and did not use the unsanctioned safe consumption site in prior 30 days (relative risk 1.03; 95% confidence interval=0.53, 1.17). The rate of improperly disposed syringes per number of injections in prior 30 days was significantly lower among people who had used the unsanctioned safe consumption site during the same period (incident rate ratio 0.42; 95% confidence interval=0.18, 0.88).

CONCLUSION

When people used this unsanctioned safe consumption site, they disposed of significantly fewer syringes in public places, including streets, sidewalks, parks, or parking lots, than people not using the site. This study helps allay concerns that implementing safe consumption sites in the US would lead to increases in improperly disposed syringes.