SEATTLE – Female sex, young age, residing in a rural location, black race, and Medicaid insurance were all associated with reduced adherence to HIV pre-exposure prophylaxis in a from the Centers for Disease Control and Prevention.
Daily pre-exposure prophylaxis (PrEP) with emtricitabine/tenofovir () prevents infection, but not everyone sticks with it. The investigators wanted to find out who struggles the most with adherence to help focus future intervention efforts.
The team identified 7,250 commercially insured and 349 Medicaid PrEP users in IBM MarketScan databases during 2011-2016. They tracked them from their initial PrEP prescription until there was a gap of 30 days or more in their PrEP refills, at which point they met the study’s definition of nonpersistence.
Overall, “commercially insured nonpersistent PrEP users were young, female, and rural. Medicaid insured nonpersistent users were young, female, and black,” said lead investigator, a health scientist in the CDC Division of HIV/AIDS Prevention.
“It is concerning that some populations with low persistence were among those with the highest rates of HIV diagnosis, such as young, black men. Research is needed to understand reasons for discontinuing PrEP. Interventions tailored for priority populations are needed to improve PrEP persistence,” she said at the Conference on Retroviruses and Opportunistic Infections.
Her team found that commercially insured patients stuck with PrEP longer than did those on Medicaid, a median of 14.5 months, with 56% still filling their prescriptions after a year, versus a median Medicaid persistence of 7.6 months, with only a third of Medicaid patients still on PrEP after 12 months.
Men were more persistent with PrEP than were women in both groups, as were older people versus younger. The median length of adherence among commercially insured patients aged 45-54 years, for instance, was 20.5 months, versus 8.6 months among people aged 18-24 years. Older PrEP users persisted longer among Medicaid patients as well, a median of 10 versus 4 months.
Also in the Medicaid group, white patients stuck with PrEP longer than did black patients, a median of 8.5 months versus 4.1 months. There were no racial differences with commercial insurance.
The findings held even when the team used gaps of 60 and 90 days, instead of 30 days, to define nonpersistence.
The study says nothing about why people stopped PrEP, or why there were such stark differences between the groups.
Perhaps, in some cases, people quit risky behavior or entered new relationships. Maybe PrEP was too expensive for some, or transportation to the clinic was an issue. Side effects might have been a problem, or people could have lost their insurance coverage, or maybe didn’t want to deal with the hassle. It’s impossible to know from the data, Dr. Huang said.
She said her team wants to figure it out, so they can help people overcome barriers to treatment, which likely vary across subgroups.
The study also was limited to patients who were enrolled in coverage at least 6 months before and 6 months after their first PrEP prescription; the investigators want to exam the situation for people with less consistent coverage, and no coverage at all.
The work was funded by the Centers for Disease Control and Prevention. The investigators had no disclosures.
SOURCE: Huang YA et al. CROI 2019,