Article: Assessing HIV and overdose risks for people who use drugs exposed to compulsory drug abstinence programs (CDAP): A systematic review and meta-analysis. (2021). Anh T. Vo, Christopher Magana, et al. International Journal of Drug Policy.

Reviewed by: Stacey McKenna

Illicit drug use is associated with increased risk for a number of negative health outcomes. Globally, people who inject drugs are approximately 22 times more likely to contract HIV than the general population. In the United States, more than 93,000 people died of an overdose in 2020. Fortunately, evidence-based medication-assisted treatment as well as harm reduction measures can reduce many of these risks and improve people’s quality and length of life.

Despite the demonstrated effectiveness of these strategies, many states rely on compulsory drug abstinence programs (CDAP), both through criminal justice and civil commitment systems. In fact, as of 2015, 32 U.S. states and the District of Columbia permitted “civil commitment of an adult for substance use treatment.” While the specifics of CDAP vary drastically across nations, communities and institutions, they all physically confine admitted patients without their consent. A robust body of research indicates that individuals who are incarcerated or recently released are at substantially increased risk for overdose and infectious disease. It follows that involuntary, abstinence-based programs may have similar consequences, even when not associated with traditional incarceration.

Anh T. Vo, et al. conducted a systematic review and meta-analysis of existing research to better understand the relationship between CDAP and relevant health outcomes among people who use drugs. The study, published in the International Journal of Drug Policy in 2021, analyzed the literature from two distinct searches. In both cases, CDAP was treated as the main exposure. The primary health outcomes were a) HIV incidence or seroprevalence and b) overdose (fatal or non-fatal).

The research team searched for studies examining the relationships between the primary exposure and outcome variables. Two authors then screened abstracts independently, compared their assessments and discussed discrepancies with senior team members. Those studies deemed eligible were reviewed in full. The first search (CDAP and HIV) returned 904 references, three of which were ultimately deemed to contain relevant data. The second search (CDAP and overdose) returned 1322 articles, five of which were included in the final analysis. These articles—eight in all—made up the basis of Vo et al.’s systematic review and, where possible, meta-analyses.

The authors began the review process by assessing the quality of all included studies using the NHLBI Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. All three studies of the relationship between CDAP and HIV outcomes and four of the five examining CDAP and overdose outcomes were found to be of poor quality. Weaknesses included reliance on self-report measures, insufficient control for confounders, and use of cross-sectional design, which hinders assessment of direction and causation. Furthermore, despite the small number of studies analyzed, there was significant variation in cultural and institutional contexts as well as outcome variables and measures used.

These challenges were particularly pronounced in the review of papers on CDAP and HIV outcomes, and findings were inconsistent across studies. Two of the three studies—both conducted in China—used blood testing at the time of data collection to measure associations between CDAP and HIV seroprevalence, but with conflicting results. However, when the researchers pooled the data from these two studies, their analysis indicated that overall, individuals who had been in CDAP were roughly 30 percent more likely to have HIV at the time of data collection, although this finding was not statistically significant.

Vo et al. also considered the risk variable of syringe sharing as this was assessed in all three CDAP and HIV papers. Unfortunately, the associations across studies were again inconsistent. While the two papers from China reported increased likelihood of syringe sharing among individuals who had never been in CDAP, the data from Mexico suggested the opposite.

The data on the relationship between CDAP exposure and overdose outcomes were somewhat more conclusive. Although the studies were geographically and institutionally diverse and used a range of exposure timelines, including “ever,” “6-months,” and “current,” all five found that individuals with exposure to CDAP had increased likelihood of overdose in their history as well. When Vo et al. pooled data from relevant studies, these trends held. CDAP exposure had an odds ratio of 3.67 for non-fatal overdose in the past 6 to 12 months and an odds ratio of 2.02 for risk of lifetime non-fatal overdose. Nonetheless, neither of these pooled findings were statistically significant.

Given the continued preference for CDAP over medication-assisted treatment in many contexts, the topic of this study is important both within the United States and globally.  Vo et al.’s systematic review and meta-analysis was a well-designed attempt to examine current knowledge on the issue, and highlights some key issues with reliance on CDAP.

As Vo et al. note, while the use of key terms can be limiting as a search mechanism, it is a standard way to search literature for relevant and related studies. Unfortunately, the greatest hinderances to their analyses are the dearth of original research on the relationship between CDAP and relevant health outcomes, and the poor quality of existing studies. The consistent use of cross-sectional design removes the ability to draw internal conclusions about direction or causation. Furthermore, the vast differences between context of the few extant studies make systematic comparisons difficult. Given the limited number of high-quality quantitative studies, the researchers might have added richness to their reviews (though not their meta-analyses) by opening up their search to incorporate qualitative and ethnographic research, which tends to be longitudinal and context-rich.

Despite these challenges, Vo et al. rightly posit that their analyses have some useful takeaways. In particular, while it is unclear whether CDAP actually increases risk for HIV risk behaviors and outcomes (as incarceration does), the authors argue that their “results indicated a lack of support for the role of CDAP in reducing potential injection risk behaviors.” Likewise, the authors were more confident in drawing conclusions regarding overdose, noting that while not all studies in this group reached statistical significance, all did find a similar magnitude of association between CDAP exposure and overdose risk.

However, given the limited number and quality of extant original research, the review findings primarily highlight the need for rigorous additional research rather than demonstrate anything conclusive about CDAP itself.