Patients who participated in an intervention that helped them identify barriers to taking their drugs properly and develop customised coping strategies took a significantly greater amount of their prescribed doses than those receiving standard care, a new study has found.

The study involved HIV patients, but the results, published this week in JAMA Internal Medicine, may point to a new strategy to improve adherence to medications for many other conditions, say the researchers, from the Perelman School of Medicine at the University of Pennsylvania.

"Non-adherence to medical therapy is a silent epidemic that undercuts physicians' efforts to treat diseases from high cholesterol and hypertension to HIV and diabetes," says study lead author Robert Gross, 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," he said.

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

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, says Dr Gross.

"Side effects, both real and perceived, can impact adherence, and psychosocial issues like low health literacy or a chaotic lifestyle can interfere too. 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," he adds.

The researchers studied 180 patients receiving care at three Philadelphia HIV clinics. They were divided into two groups, one of which was randomised 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 organisers. 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. They were then 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 and, importantly, that this translated into a key marker of survival. The MAPS group also had a 50% 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 virology suppression than those new to therapy, they were equally likely to benefit from the MAPS intervention. For every 25% increase in antiretroviral drug doses taken, a patient's chance of having treatment success was doubled in the study, Dr Gross notes.

"Importantly, we found that this intervention was equally effective for both patients who were just beginning therapy and those who have 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 behaviour. The effect we found also persisted even though the population we studied has many life challenges, included poverty and unemployment," he says.

Dr Gross and his colleagues suggest that the same approach could be utilised 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 interventionists, and if patients who may require "booster" sessions could be identified.

The authors have made their MAPS treatment available online for use by other clinicians, at: