Study Claiming SSPs Increase Overdoses Overlooks Nuances of Real-World Drug Environments
Article: Analisa Packham, “Syringe exchange programs and harm reduction: New evidence in the wake of the opioid epidemic,” Journal of Public Economics 215 (November 2022).
Reviewed by: Stacey McKenna
Persistent and rising overdose rates across the United States have prompted a growing recognition of harm reduction as well as increased scrutiny of the approach. Harm reduction comprises a range of tools—from direct services to material resources to education—aimed at mitigating the health risks associated with certain behaviors, from sex to driving a car. When it comes to the use of opioids (which are driving the overdose crisis), the most common harm reduction intervention in the United States is the syringe services program (SSP). SSPs originated as a way to reduce the transmission of human immunodeficiency virus (HIV) and hepatitis C virus in the 1980s. Today, they may be community-based organizations, programs run through public health departments, or informal efforts launched by people who use drugs and their allies. As of June 2022, 38 states, Washington, D.C. and Puerto Rico allow SSPs, and an estimated 414 SSPs were operating across the country.
The programs distribute kits for safer injection—typically including safer-use supplies such as alcohol swabs, cookers, clean syringes, and needles and sharps containers—and work actively to meet clients where they are at in an effort to reduce stigma and support health-improving behaviors outside the expectation of abstinence. In many cases, these organizations also connect clients to an array of wrap-around services including housing, food banks and, if desired, treatment for substance use disorder. As potent synthetic opioids such as fentanyl and its analogs have driven a surge in overdose mortality across the United States over the last decade, SSPs have opened (or become legalized) in a growing number of communities, sometimes in the face of considerable social stigma and resistance.
Decades of data support the role of SSPs in reducing the spread of infectious disease and indicate that they do not encourage drug use, but rather facilitate the onset and maintenance of recovery. Although less is known about the direct role the programs play in combating overdose, many do provide overdose identification and response training as well as access to the overdose reversal medication, naloxone.
In a recent study published in the Journal of Public Economics, economist Analisa Packham sought to add to this knowledge base by examining the timing of the opening of SSPs in relation to two population-level health outcomes: HIV rates and overdose mortality. To do this, Packham compared data from counties that opened SSPs between 2009 and 2016 with data from counties that lacked an SSP during the same time period.
The resulting analysis indicated that the opening of SSPs was associated with a subsequent decline in countywide HIV rates and an increase in countywide overdose mortality, especially in rural counties and in the years following fentanyl’s emergence in the United States. These findings, and the media coverage that followed, have drawn considerable concern from researchers and on-the-ground harm reductionists across the country.
Packham’s conclusions about the impact of SSPs on HIV transmission are fairly consistent with the extensive research on SSPs and infectious disease, although they may underestimate the impact: Packham found that a newly opened SSP can reduce HIV rates by as much as 18.2 percent, but the U.S. Centers for Disease Control and Prevention suggest that the programs are associated with reductions of up to 50 percent.
However, it is Packham’s conclusions about the impact of SSPs on overdose mortality that have raised the most questions. Indeed, Packham acknowledges several methodological limitations of this study that should not be taken lightly. First, the study did not include SSPs that opened and subsequently closed during the study period. If SSPs closed because their services proved unnecessary, this could leave the so-called treatment group—those that kept their SSPs—only in areas with significant need, resulting in “survivor(ship) bias.” In this case, that would create a spurious correlation between the opening of SSPs and elevated rates of overdose death, giving a false impression that the programs were contributing to the deaths, rather than responding to and trying to prevent them.
In addition, Packham recognizes that she did not include details about SSPs’ operations, such as whether they allow unlimited syringe distribution or one-for-one exchange or what additional services they offer. Failing to include this information is highly problematic given the current, evolving risks associated with the illicit drug market. Indeed, although SSPs have long provided overdose education, they were not initially intended or designed to address overdose risk directly. As such, SSPs that opened in response to an increasingly toxic drug supply in their communities may not have had the resources or legal permissions to provide specific overdose-reversal and prevention tools such as naloxone or fentanyl test strips, especially in their early years of operation. Consequently, one would not expect to see an immediate plateau or decline in overdose deaths in the wake of the SSP’s opening. Recognizing this limitation, harm reductionists across the country have sought to add or adapt programs to provide a more overdose-specific response, though funding and legislation can hinder the optimal implementation of some of these called-for strategies.
In addition to the limitations cited by Packham, this study contains additional weaknesses that indicate a poor understanding of the broader drug use environments and undermine the author’s conclusion that SSPs lead to an increase in overdose mortality.
First, Packham does not recognize that many SSPs operate under the radar and, as such, may have been operating already before “opening” dates or could have escaped inclusion in this study. Second, the study does not appear to account for the highly localized emergence of fentanyl across the United States. Third, the study includes only counties with an SSP opening between 2009 and 2016. As this period constitutes the “early” days of fentanyl’s emergence on the illicit drug market, SSPs may not have had sufficient access to overdose-specific resources such as naloxone or fentanyl test strips.
Taken together, these oversights could lead even the most sophisticated statistical analysis to find an artificial correlation between sites opening and a rise in overdose deaths, especially if experts working on the ground used early insight about fentanyl in the local drug supply to justify launching the programs or to push harder for their legalization. This possibility has potential support in the study itself, which reported that overdose deaths seemed to jump significantly in year 0 (immediately after an SSP opened) and increased for one to two years before declining substantially. Although Packham implies that this may be because fentanyl had already “peaked,” outside evidence suggests that the drug’s saturation of the U.S. illicit drug market has only increased since 2016—the last year for which data are included in the study.
Another troubling aspect of Packham’s paper is one of the explanations she offers for her findings. Rather than drawing on data, she relies on a moral hazard argument, claiming that “if [syringe exchange programs] lower the costs of using opioids, we would expect opioid use and—potentially—opioid-related mortality to increase.” This assumption runs counter to a robust body of evidence indicating that SSPs do not encourage drug use and in fact improve treatment and recovery outcomes. On a related note, Packham fails to cite past studies that found that people who use drugs and who engage with SSPs are four to five times more likely than their counterparts who do not utilize SSPs to enter and maintain long-term recovery. This omission is especially relevant, as Packham found the strongest relationship between SSPs and overdose mortality in rural areas where she acknowledges that access to evidence-based treatment is especially lacking.
While the persistent overdose crisis and lack of research into the role SSPs play in preventing overdose at the population level highlight a need for more studies on this issue, Packham’s study contains too many substantial limitations to have conclusive implications. Furthermore, it serves as a reminder to lawmakers, journalists and experts on the ground: Whenever possible, new research, while essential to guide smart adaptations to ever-evolving circumstances, must be interpreted and understood within the context of the real-world environment and existing, substantiated knowledge.
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