Personalized plans to address barriers to HIV drug adherence boost chances of successful therapy

"Nonadherence to medical therapy is a silent epidemic that undercuts physicians' efforts to treat diseases from high cholesterol and hypertension to HIV and diabetes," says the new study's lead author, Robert Gross, MD, MSCE, an associate professor of Infectious Diseases and Epidemiology. "We tend to view the problem as either a failure on our part or on the patient's part, but the results of our new study show that we can do our jobs better by sharing the planning role with them to overcome possible stumbling blocks to taking their prescribed drugs."

Antiretroviral drugs have turned HIV/AIDS into a manageable, chronic condition for many patients who would have died of the disease before the development of these medications, but they require lifelong adherence to be effective. The drugs have short half lives and need to be in the patients' system at all time in order to keep the virus from replicating, so frequently missing doses drastically cuts the chances that treatment will be successful. Predicting which patients will adhere to therapy has proven difficult.

"The barriers to taking these drugs properly are not universal -- for some patients, substance abuse or depression might undercut efforts to stay on track, and for others, the complexity of the dosing regimen may pose a problem. Side effects -- both real and perceived -- can impact adherence, and psychosocial issues like low health literacy or a chaotic lifestyle can interfere, too," Gross says. "We know from previous research that these issues cannot be overcome by simple education or simple technology alone, and financial incentives typically don't produce a sustained effect."

The researchers studied 180 patients receiving care at three Philadelphia HIV clinics, who were divided into two groups, one of which was randomized to a Managed Problem Solving (MAPS) group, and the other to usual care, which included a meeting with a pharmacist for drug regimen education and the provision of pill organizers. In order to study the benefit of the intervention, only patients who had detectable viral loads were enrolled.

With the help of a trained lay interventionist, MAPS participants received education about their newly prescribed drug regimen and then were taken through a process for identifying their personal barriers to adherence, brainstorming potential solutions, selecting the best option and monitoring its implementation. Potential solutions included memory and cognitive aids to remember to take and refill the drugs, ways to use social supports, and resources to seek help for depression or drug side effects. These plans were made during four initial in-person sessions and 12 telephone meetings that provided help for solving new problems and offering encouragement for obtaining refills and maintaining their regimens. Both groups' adherence to their drug regimen was recorded through the use of an electronically monitored pill bottle.

The results showed that the MAPS group was nearly twice (1.78 times) as likely as the usual care group to be at the better end of the adherence scale. Importantly, the researchers showed that this improvement in adherence translated to improvement in a key marker of survival. The MAPS group also had a 50 percent improvement in their viral suppression rate -- having no detectable HIV virus in the blood while on treatment. Although the findings showed that patients who had previously taken and failed antiretroviral regimens were only half as likely to be in the better adherence categories and have virologic suppression than those new to therapy, they were equally likely to benefit from the MAPS intervention. Gross notes that for every 25 percent increase in antiretroviral drug doses taken, a patient's chance of having treatment success was doubled in the study.

Patients whose viral loads are suppressed are at much less risk of transmitting HIV to others in the community, so efforts to improve adherence stand to benefit the population at large.

"Importantly, we found that this intervention was equally effective for both patients who were just beginning therapy and those who had already been taking the drugs and had problems adhering, and it continued to be effective over time, unlike many approaches in which patients eventually fall into less adherent behavior," Gross says. "The effect we found also persisted even though the population we studied has many life challenges, including poverty and unemployment."

He and his colleagues suggest that the same approach could be utilized to improve treatment adherence for patients with Hepatitis C, heart failure, and other diseases, particularly if the MAPS process could be scaled back to require less interaction with interventionist, and if patients who may require "booster" sessions could be identified.

The authors have made their Managed Problem Solving treatment manual available online for use by other clinicians, at http://www.med.upenn.edu/cceb/maps-form.shtml.