Study Explores Connection Between Adherence and Viral Suppression in Patients with HIV

HIV patients with medication adherence rates above 75% achieved similar rates of viral suppression as those with adherence rates above 90%, according to a new study conducted by researchers at Indiana University and Johns Hopkins. Thus, lower thresholds for evaluating pharmacy performance in medication adherence may be sufficient for achieving favorable real-world outcomes in HIV treatment. This research, published in the Journal of Managed Care + Specialty Pharmacy, could provide payers and healthcare providers valuable insights in assessing pharmacy performance and optimizing HIV treatment outcomes.

The main goal of HIV treatment is to suppress or stop the virus from multiplying in the body. Taking HIV medication regularly as prescribed is crucial for patients with HIV to achieve viral suppression — defined as a viral load below 200 copies per milliliter of blood.

One way to measure adherence is by calculating the proportion of days covered (PDC), which approximates adherence based on pharmacy claims data. In the past, antiretroviral therapy regimens for HIV were difficult to tolerate and required several types of pills multiple times per day. It was believed that very high levels of adherence (more than 95%) were necessary to maintain viral suppression. However, with the emergence of newer, simpler antiretroviral treatments and reduced pill burden, it’s unclear if such strict adherence is still necessary to achieve viral suppression.

Currently, only 57% of people living with HIV in the United States are virally suppressed, highlighting the continued need for better adherence to improve treatment outcomes.

Scott Canfield, Pharm.D.

The group of researchers, including Scott Canfield, Pharm.D., assistant director for Clinical Program Development at Johns Hopkins Home Care Group in Baltimore, sought to examine the correlation between medication adherence and achieving viral suppression in people living with HIV. The researchers also aimed to determine demographic factors affecting medication adherence levels and viral suppression.

The study included 1,629 adults with HIV who had been prescribed antiretroviral medications. Patients’ medication adherence was measured using PDC. The study found that patients with a PDC of at least 90% had a viral suppression rate of 96.6%, while those with a PDC lower than 50% had a viral suppression rate of 75.5%.

Age and insurance type were identified as significant factors impacting viral suppression. Patients with lower medication adherence (less than 50% or 50% to less than 75%) were less likely to achieve viral suppression compared with those with at least 90% adherence. However, patients with adherence rates above 75% achieved similar results as those with adherence rates above 90%.

The study emphasizes the importance of medication adherence for HIV patients to reach treatment goals and achieve viral suppression, and while adherence rates above 90% are ideal, it suggests that lower rates can still lead to high rates of viral suppression.

The authors also discussed the role of comprehensive HIV treatment clinics and programs such the Ryan White HIV/AIDS Program (RWHAP) in achieving viral suppression. Integrated health system HIV specialty pharmacy programs were shown to promote medication adherence and viral suppression. The RWHAP provides financial aid for healthcare services and support for people living with HIV, aiming to improve early diagnosis, connection to care, affordable treatment, and sustained viral suppression.

The Pharmacy Quality Alliance (PQA) endorses a PDC greater than 90% as a quality measure for pharmacy performance. Pharmacy performance measures are increasingly more common in healthcare. This study suggests that lower thresholds for evaluating pharmacy performance in medication adherence may be appropriate, and further guidance from the PQA is recommended. Managed care organizations may wish to consider their performance goals for evaluating pharmacy performance in HIV medication adherence. Using lower thresholds could still lead to positive real-world outcomes.