Antiretroviral Therapy Adherence Improved with Managed Problem Solving

The progression of treatable chronic diseases depends on patient adherence to pharmacotherapy; however, clinical nonadherence in patients with diabetes mellitus, hypertension, hypercholesterolemia, and HIV is common. Possible barriers to adherence include depression, substance abuse, complexity of the regimen, lack of a social support system, and low health literacy. Interventions designed to improve adherence have limited effect and tend to wane over time.

Noting that patients often have multiple barriers to medication adherence, researchers have developed Managed Problem Solving (MAPS) to address barriers to chronic pharmacotherapy adherence. The strategy is derived from Problem Solving (PS) Therapy, an effective intervention for depression. In the MAPS strategy, the interventionist and participant work together to solve specific adherence barriers using the PS framework.

The researchers recently conducted a study to determine whether MAPS resulted in improved adherence to therapy for HIV than usual care. They reported results of the study in JAMA Internal Medicine [2013;173(4):300-306].

The study was a randomized investigator blind trial of MAPS in HIV-infected individuals in 3 HIV clinics in Philadelphia, Pennsylvania. Eligibility criteria included plasma HIV-1 viral loads >1000 copies/mL and willingness to initiate or change therapy. MAPS involves 4 in-person and 12 telephone-based meetings with a trained interventionist, followed by 12 months of follow-up calls for 1 year.

The primary outcome measure of the current study was medication adherence as measured with electronic monitors; the secondary outcome measure was undetectable HIV viral load over 1 year.

The planned study size was 200 participants; however, recruitment was slower than anticipated and the target was decreased to 180. After applying eligibility requirements to a cohort of 218 individuals, 180 were enrolled; 91 were randomized to MAPS and 89 to usual care.

Of the original cohort of 180 individuals, 76% (n=136) received 3 drug regimens with 2 nucleoside reverse transcriptase inhibitors (NRTIs) and a boosted protease inhibitor or a nonnucleoside analog reverse transcriptase inhibitor. The remainder received various combinations of up to 6 drugs; the most commonly used NRTI combination was tenofovir and emtricitabine (88 participants [49%]).

Fifty-five participants were lost to follow-up: 33 in the MAPS group (36%) and 23 in the usual care group (26%). Common reasons for dropping out cited by those in the MAPS group included “not wanting to follow the protocol” and moving too far away to follow-up at the site.

In primary intention-to-treat analyses, the likelihood of being in a higher adherence category at any point during follow-up was 1.78 times greater for MAPS than usual care. In secondary analyses using an as-treated approach, the likelihood of being in a higher adherence category at any follow-up point was 2.33 times greater for MAPS than usual care.

In the intention-to-treat analysis of virologic suppression, the odds of having an undetectable viral load at any follow-up point was 1.48 times greater for MAPS than for usual care. In as-treated analyses, the effect of MAPS was stronger for both likelihood of being in a higher adherence category and having an undetectable viral load.

The researchers concluded by noting, “MAPS is an effective antiretroviral adherence intervention over the first year with a new regimen. It was equally effective at improving adherence in treatment experienced and naïve patients and did not lose effect over time. Implementation of MAPS should be strongly considered where resources are available.”