PrEP Use Low Among Commercially Insured Injection Drug Users

Despite its proven efficacy in preventing HIV infection, pre-exposure prophylaxis (PrEP) is underutilized among people who inject drugs (PWID). This challenge in mitigating the HIV epidemic prompted researchers from the Boston University School of Medicine and Boston Medical Center to evaluate the prevalence of PrEP use among commercially insured PWID for a study published in JAMA.

“Available estimates of HIV risk behaviors among PWID suggest that PrEP should be widely implemented in this population,” the study authors wrote. “However, PrEP uptake by PWID remains low, despite a growing body of data associated with successful delivery to those experiencing homelessness and with psychosocial vulnerabilities. Although PrEP implementation among US PWID has been inadequate, national HIV monitoring programs do not include data on PrEP, and specific trends in PrEP use are not well understood.”

The cross-sectional study analyzed 547,709 commercially insured individuals with opioid use disorder and/or stimulant use disorder. The average age of these individuals was 34.8 years and 61.4% were male. Data were analyzed from November 1, 2020-July 1, 2021. The researchers found 110,592 individuals with evidence of injection drug use (IDU) between January 1, 2010, and December 31, 2019.

The study’s primary outcome was receipt of tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) for PrEP determined by pharmacy claims using a multivariable logistic regression to assess the association of clinical and demographic characteristics with PrEP use. In the study period, PrEP was prescribed to 0.09% of the overall population (n = 508) and to 0.15% of individuals with evidence of IDU (n = 170).

Between 2010 and 2019, PrEP prescriptions rose from 0.001 to 0.243 per 100 person-years among the study population and 0.000 to 0.295 per 100 person-years among those with IDU. A multivariable analysis showed that PrEP use was more likely among males, people with IDU evidence, and people with evidence of sexual risk indicating them for PrEP.

Notably, PWID were older (mean [SD] age, 36.33 [13.91] vs 34.37 [12.84] years; P < .001), were more likely to be female (female, 62,092 [56.15%]; male, 274,008 [62.69%]; P < .001), had a longer enrollment period (mean [SD], 3.94 [2.64] vs 2.76 [2.27] years; P < .001), and were less likely to be administered a medication for opioid use disorder (32,072 [29.00%] vs 143,903 [32.92%]; P < .001) compared with those without evidence of IDU. The researchers defined medication for opioid use disorder by receipt of buprenorphine, naltrexone, or methadone based on pharmacy claims or in-office administration.

The researchers defined evidence of IDU by the diagnosis of injection-related infections, such as hepatitis C virus, soft tissue infection, infective endocarditis, and infective arthritis. Among the 508 individuals who received PrEP, 338 (0.08%) showed no evidence of IDU and 170 (0.15%) were PWID. After adjusting for individual characteristics and substance use diagnoses, the researchers found that having a pharmacy claim for TDF/FTC was associated with being male (aOR, 8.72; 95% CI, 6.39-11.89), evidence of IDU (aOR, 1.47; 95% CI, 1.21-1.79), and evidence of sexual risk behavior (aOR, 23.68; 95% CI, 19.57-28.66)

Incidence of a a pharmacy claim for TDF/FTC grew from 0.001 per 100 person-years in 2010 to 0.243 per 100 person-years in 2019 among the overall cohort. In those with evidence of IDU, the PrEP prescribing rate grew from 0 in 2010 with no PrEP prescriptions among PWID in the data set to 0.295 in 2019, which exceeded the rate of prescribing in the overall cohort.

“Although disappointing, our finding that outpatient pharmacy-filled prescriptions for HIV PrEP are rare among commercially insured patients with opioid and/or stimulant use disorder is consistent with previous literature on general PrEP prescribing rates,” the study authors wrote. “PrEP prescribing in our data is alarmingly low, even among persons with claims data indicating evidence of IDU.”

Study limitations included that these data were likely to be accurate for PrEP receipt among patients with a PrEP prescription billed to their commercial insurer; however, the study was not designed to capture PrEP prescriptions funded via other sources. As such, the findings may underestimate total PrEP coverage in this population, according to the authors.

“To achieve the public health goal of reducing new HIV infections by 75% by 2025 and at least 90% by 2030 and to stem the tide of HIV clusters and outbreaks among PWID across the country, no evidence-based prevention strategy can be overlooked,” the study authors wrote. “In this cross-sectional study, we found that the rate of PrEP among commercially insured PWID and other persons with opioid and/or stimulant use disorder is very low. Aggressive expansion of PrEP for PWID is urgently needed.”

Reference

Streed CG, Morgan JR, Gai MJ, Larochelle MR, Paasche-Orlow MK, Taylor JL. Prevalence of HIV Preexposure Prophylaxis Prescribing Among Persons With Commercial Insurance and Likely Injection Drug Use. JAMA Netw Open. 2022;5(7):e2221346. doi:10.1001/jamanetworkopen.2022.21346