Persistence on HIV pre-exposure prophylaxis drops off dramatically over a 2-year time period, with only 2 out of 5 users persisting on the treatment, according to a recent study from Emory University.
Persistence on pre-exposure prophylaxis (PrEP) medication for HIV prevention drops off significantly in both the first and second years of treatment, according to a recent study, suggesting that interventions are needed to increase persistence on PrEP treatment.
The study, published in the Journal of the International AIDS Society, examined pharmacy fill records of 7148 patients who initiated PrEP in 2015. It found that persistence was 56% in the first year, 63% in the second year, and 41% from initiation through the second year.
"What was surprising to me was that the drop-off in persistence in year 2 was also relatively high," study author Aaron Siegler, PhD, associate professor at the Rollins School of Public Health at Emory University, told Contagion®.
Dr. Siegler expected to see a high drop-off rate after the first year, which previous studies have found, but he expected that number to be more highly attenuated in the second year.
"Persistence in care at least up through year 2 remains a challenge and probably merits interventions to support individuals," he said of the results of the study, which is the largest to date to examine persistence on PrEP medication.
The study also revealed demographic differences, including that the youngest age group in the study, those ages 18 to 24, had lower persistence rates, with 43% persistence in year 1, 54% persistence in year 2, and 29% persistence from initiative through year 2.
"That age group is also especially important to retain in care because it's an age group that experiences among the highest HIV incidences," Dr. Siegler said in the interview.
Women also showed lower persistence, with rates of 34% in year 1, 49% in year 2, and 20% from initiative through year 2.
"It's clearly an area of research need that should be addressed," Dr. Siegler told Contagion®.
Persistence was highest among men, those older than 24, those with an average copay of $20 or less, those with commercial insurance, and those who accessed PrEP through a community-based specialty pharmacy.
"I think practitioners should be aware to keep in touch with their patients that are on PrEP and to try to maintain a close clinical bond and to be aware that there is substantial discontinuation to PrEP in the second year, not just in the first year," Dr. Siegler told Contagion®.
Although noting that the study doesn't include data to shed light on why people are dropping off of PrEP or what interventions may be effective in increasing persistence, Siegler suggested possible barriers to persistence may include financial barriers, changes in risk and risk perception, changes in insurance, and intolerance of the medication.
Dr. Siegler noted disparities between individuals' perceptions of whether PrEP was appropriate for them and US Centers for Disease Control and Prevention guidelines for the treatment. According to another Emory University study published March 7, which looked at young black men who have sex with men in Atlanta, 8 out of 11 of those who didn't perceive themselves as needing PrEP met CDC guidelines for the treatment.
Possible interventions that may help increase persistence include a home-based monitoring system using telemedicine to reduce the number of PrEP follow-up visits from 4 per year to 1 per year. Investigators at Emory University and other institutions developed PrEP@Home, and early studies of the system show promise. Using text-based reminders or mobile apps to help patients manage their treatment and ease the burden of access to care also may help.
The importance of regular screenings was underscored by a recent study that raised concerns about the possibility of drug resistance linked to prescribing PrEP to individuals with undiagnosed HIV infections.