Increasing patients' out of pocket costs for HIV pre-exposure prophylaxis (PrEP), medications, which have been shown to dramatically reduce the risk of HIV infection, could lead to a significant reduction in PrEP use and a rise in HIV infection rates, according to a new study co-led by researchers at the Perelman School of Medicine at the University of Pennsylvania and Johns Hopkins Bloomberg School of Public Health.

The study, published today in Health Affairs, was designed, in part, to explore the impact that out-of-pocket cost increases could have, depending on the outcome of an ongoing court case challenging certain provisions of the 2010 Affordable Care Act (ACA).

The researchers used a large, proprietary database of medical and pharmacy claims to determine the rates at which patients failed to fill (i.e., abandoned) insurer-approved PrEP prescriptions at different levels of out-of-pocket costs. Their findings suggest that even a small increase, from $0 to $10 in monthly PrEP out-of-pocket costs, would double the rate of PrEP prescription abandonment. Further, an increase in out-of-pocket costs to between $100 and $500 per month would result in nearly one-third of patients abandoning their PrEP prescriptions.

The analysis also highlighted the negative consequences of abandoning PrEP: The rate of new HIV infections in the year after the initial PrEP prescription was two to three times higher among those who never filled those prescriptions.

Our findings suggest that out-of-pocket cost increases for PrEP could upend the progress that has been made towards ending the HIV/AIDS epidemic in the United States."

Jalpa Doshi, PhD, study senior author, professor of Medicine and the director of Value-based Insurance Design Initiatives at the Center for Health Incentives and Behavioral Economics at Penn Medicine

To date, the FDA has approved two HIV PrEP products, each of which combines two standard antiretroviral drugs in a single pill. For the past decade, the U.S. Centers for Disease Control and Prevention (CDC) has recommended PrEP as a way of preventing HIV infection among higher-risk individuals. Expanding access to PrEP is also one of the central pillars of the CDC's Ending the HIV Epidemic in the U.S. (EHE) initiative, which seeks to reduce new HIV infections in the United States by 90% by 2030. In 2019, the U.S. Preventive Services Task Force (USPSTF), an independent group of experts on disease prevention, gave PrEP an "A" rating. Under a provision of the ACA, that rating has meant that, since 2021, most private insurance plans have been required to provide PrEP to policyholders without cost sharing.

However, an ongoing legal challenge (Braidwood Management, Inc. v. Becerra) may nullify that part of the ACA, allowing insurers to now require out-of-pocket costs for PrEP and other preventive therapies. Against this background, Doshi and her colleagues sought to gauge how out-of-pocket cost changes affect PrEP use.

The team reviewed a U.S.-wide database covering insurer-provided health care, including prescription records, dating from 2016-2018. They analyzed this dataset to determine the rate of PrEP prescription abandonment-;defined as a patient not picking up their newly-prescribed and insurer-approved PrEP prescription from the pharmacy within 365 days -;at different out-of-pocket cost levels. Their analysis covered 58,529 patients with new, insurer-approved PrEP prescriptions, and adjusted for differences among the patients. Refills did not feature in the analysis.

They found that both the rate of PrEP prescription abandonment and the rate of delayed prescription fills increased as out-of-pocket costs rose. Also, patients who abandoned their PrEP prescription were two to three times more likely to get infected with HIV in the following year, compared to those who filled their PrEP prescription.

Based on their analyses, the researchers estimated that raising monthly patient out-of-pocket costs for PrEP from $0 to the $1-$10 category would nearly double the prescription abandonment rate (from 5.6 percent to 11.1 percent), while moving to the $101-$500 category the abandonment rate would be 34.7 percent. At the $500+ category, they estimated, the abandonment rate would be about 42.6 percent, nearly eight times the rate at the $0 level.

Overall, the results suggest that even a modest increase in patient out-of-pocket costs for PrEP could result in a sharp increase in prescription abandonment-;and a subsequent large increase in the rate of new HIV infections.

The study was co-led by Lorraine Dean, ScD, Associate Professor at the Johns Hopkins Bloomberg School of Public Health. The research was supported by the National Institutes of Health (R21NR018387, R01NR017573, R25MH083620, and T32AI102623).