Review of: Shira Goldenberg et al., “Police-related barriers to harm reduction linked to non-fatal overdose among sex workers who use drugs: Results of a community-based cohort in Metro Vancouver, Canada,” International Journal of Drug Policy 76 (February 2020).

by Stacey McKenna

Overdoses in Canada represent a serious, and in some places rising, threat to public health. Nationwide, more than 10,300 people died of opioid-related overdoses between 2016 and 2018. In the province of British Columbia, “unintentional illicit drug overdose deaths” increased almost 7-fold from 2010 to 2017, largely driven by growing (and sometimes intentional) exposure to fentanyl and its analogues.

In response, the province has implemented one of the most robust harm reduction systems in the region, with provincial-level policies, syringe exchange, take-home naloxone programs, supervised consumption facilities and more. Such interventions are intended to reduce not only the transmission of blood-borne diseases, but overdose as well.

Sex workers, who are far more likely to use drugs than the general public and are plagued by a number of structural and cultural iniquities that endanger their well-being, are at an increased risk for overdose. However, in many contexts, including the Canadian one, research suggests that “criminalized law enforcement interactions” can serve as a barrier to accessing harm reduction resources. As such, in a recent paper published in the International Journal of Drug Policy, Shira Goldenberg and colleagues describe the prevalence of non-fatal overdose and explore the effects of police-related barriers among women sex workers in Metro Vancouver.

From 2010 to 2017, the study—“An Evaluation of Sex Workers Health Access”purposively sampled individuals who identified as women, were at least 14 years old at enrollment, had exchanged sex for money within the last 30 days and provided written informed consent. The researchers recruited study participants through daytime and late-night outreach at sex work locations and online solicitation spaces.

At enrollment and twice per year, trained interviewers administered questionnaires covering demographics; sex work history and patterns; social and community-level characteristics (such as social cohesion); and structural factors (including criminalization and access to health services). Outcome and exposure variables included: binary measures on accidental overdose and barriers to harm reduction. The researchers controlled for a number of potential confounders, including types of drugs used, demographic characteristics, mode of drug use and more. In addition, participants were regularly offered testing and, if necessary, treatment for HIV, Hepatitis C and other sexually transmitted infections.

The study’s analysis is based on 624 participants who reported use of drugs during the study period. This resulted in 3,703 observations and an average of 5 study visits at which participants had used drugs within 6 months. During the 7.5-year study period, nearly two-thirds of participants used non-injection opioids; almost all (96.3 percent) used non-injection stimulants; roughly two-thirds had injected opioids; and over half had injected stimulants.

At baseline, 7.7 percent reported a non-fatal overdose within the past six months; when the timeline was extended over the entire study period, 27.6 percent had experienced at least one. And 68.6 percent of participants said they had experienced police-related barriers to harm reduction strategies. Of these 1,248 events, participants most commonly reported: increased difficulty accessing drugs or harm reduction equipment; being hurried to smoke or inject; confiscation of harm reduction equipment; being searched or harassed.

Through statistical analysis, the authors found that having experienced police-related barriers to harm reduction strategies and resources was independently associated with non-fatal overdose risk. In fact, after adjusting for key confounders such as frequency of injection drug use or workplace violence, experiencing police-related barriers more than doubled the odds of non-fatal overdose.

Goldenberg et al. note that their findings are consistent with previous research that has shown that criminalizing drug use and sex work increases risk for HIV and other STIs, and reduces people’s abilities to engage in harm reduction. This study, they say, extends that knowledge to show that hindered access to harm reduction also affects overdose risk. The authors also argue that these results point to a need to enhance existing harm reduction and overdose prevention systems in ways that are friendly to sex workers and specifically aimed at reducing overdose risk. Such services, they write, should be “gender-sensitive, trauma-informed, and peer-led.”

Furthermore, the researchers highlight the importance of directly addressing the structural barriers to health and harm reduction services, including calling for the decriminalization of sex work and the support of non-harassment policies and physically moving policing away from areas where marginalized populations access social and health support.

In terms of the study’s weaknesses, the authors acknowledge its use of an observational (rather than experimental) design. While this does present limitations when drawing conclusions of causality, the fact that the data were collected prospectively and over 7.5 years greatly adds to the robustness of the findings. An additional challenge is that the researchers relied on self-report data collected from a highly stigmatized population. While this approach can result in participant hesitation to speak honestly about their experiences, the lengthy timeline and community-based collaborations during the design process help overcome potential biases.

Goldenberg et al. suggest that future studies should dive deeper into their findings using mixed and qualitative methods to further explain just how the experience of criminalization and policing shape sex workers’ engagement with harm reduction services and ultimately their overdose risk.