More young adults taking PrEP, but for shorter periods

Treatment episodes for HIV pre-exposure prophylaxis (PrEP) are shortening, despite increased dispensing and starting of PrEP among young adults, a study found.

To assess trends in PrEP dispensing to adults ages 18 to 25 years from 2016 to 2023, researchers conducted a cross-sectional study of retail pharmacy data to assess the quarterly PrEP dispensing rate (number of young adults with dispensed PrEP prescriptions per 100,000), quarterly PrEP initiation rate (number of young adults with a new dispensed PrEP prescription per 100,000), and quarterly mean PrEP persistence (number of days with an active PrEP prescription in the 180 days after the new PrEP prescription ended among those beginning therapy). Results were published May 9 by the Journal of General Internal Medicine.

The analyses included 1,450,296 PrEP prescriptions dispensed between January 2016 and December 2023 to 239,780 young adults. The quarterly PrEP dispensing rate increased sharply between 2016 and 2018, from 26.4 to 100.7 prescriptions per 100,000 people (quarterly percent change [QPC], 12.5%; 95% CI, 10.0% to 15.1%). This rate increased to 208.4 prescriptions per 100,000 people in 2023 (QPC, 3.5%; 95% CI, 2.7% to 4.3%). However, from 2016 to 2023, quarterly mean persistence decreased from 111.6 to 98.4 days (QPC, −0.4%; 95% CI, −0.6% to −0.2%).

Compared with patients ages 22 to 25 years, those ages 18 to 21 years had lower quarterly PrEP dispensing and initiation rates throughout 2016 to 2023. Persistence was lower in these younger patients in 2016, but the gap narrowed over time.

“Though more young adults are initiating PrEP therapy, they are remaining in therapy for shorter periods of time,” wrote the authors, who offered three explanations:

• changes in the characteristics of young adults who initiate PrEP, such as shorter periods of sexual activity resulting in less perceived need for prolonged PrEP,
• increasing barriers to follow-up after PrEP initiation, such as worsening primary care access, and
• use of PrEP on-demand rather than as a single daily dose.

The study authors said the findings should be considered in light of broader trends, including that from 2018 to 2022 new HIV infections among individuals ages 13 to 24 years decreased by 30%, possibly due to the increase in PrEP dispensing to young adults.

“Importantly, the decline in new HIV infections does not necessarily indicate that the number of young adults who would benefit from PrEP is decreasing, as this number is affected not just by HIV prevalence but also by the prevalence of behaviors that increase risk of HIV transmission among HIV-negative young adults,” the authors wrote. “Thus, our findings of increased PrEP dispensing should not be interpreted as definitive evidence that the gap between PrEP need and use is narrowing among young adults.”