Samuel Tobias is a doctoral candidate and fellowship recipient at the University of British Columbia School of Population and Public Health and a graduate researcher with the British Columbia Centre on Substance Use.

Background: Community-based drug checking services have scaled up in response to the illicit drug toxicity crisis across North America. We sought to assess the relationship between the presence of unexpected active drugs in a drug checking sample (where compounds other than or in addition to what was expected were found) and subsequent engagement in risk reduction practices (e.g., used supervised, consumed less, or disposed of drugs).

Methods: We used data from a cross-sectional study of people who used community-based drug checking services in British Columbia (March 2020–July 2024). We restricted participants to those who had reported using their drugs after the drug check. We then constructed bivariable and multivariable logistic regression models to examine the relationship between the presence of unexpected active drugs (i.e., compounds that have psychoactive properties) in a drug checking sample brought in for analysis (using Fourier-transform infrared spectroscopy and immunoassay strips) and reported engagement in subsequent risk reduction practices.

Results: In total, 447 individuals were included in the analysis: 174 (38.9%) reported the presence of unexpected active drugs in their drug checking sample, of which 34 (19.5%) had an unexpected active drug in the absence of their expected drug. Among those with unexpected drugs present, 42 (24.1%) reported engaging in a risk reduction practice. Through multivariable logistic regression, we found a positive association between presence of unexpected active drugs and the engagement in a risk reduction practice (adjusted odds ratio = 2.24; 95% confidence interval: 1.30–3.87) compared to those without unexpected active drugs.

Conclusion: Our study indicated that individuals who found unexpected active drugs in their sample had higher odds of engaging in a risk reduction practice. These findings highlight the importance of drug checking services as a harm reduction tool within a suite of services offered to combat the unpredictable, unregulated drug supply.