December 3, 2014
Lack of Good Quality Evidence on How to Improve
Medication Adherence 

Hamilton, Ontario—Pharmacists constantly remind patients that if they don’t take their medications as prescribed, they’ll get little or no benefit from them.

Yet, only about half of all patients who are prescribed self-administered medication actually follow the drug regimens, according to a recent study published by The Cochrane Library. In addition to the many patients who don’t follow instructions for taking their drugs properly, some stop using them altogether, the authors lament.

So what are the best solutions? The Canadian study found that question very difficult to answer.

Looking at 182 trials—including 109 added since the last systematic review on medication adherence in 2007—the Cochrane researchers found it challenging to come to any firm conclusions. The studies differed widely according to medical condition, patient population, intervention, measures of adherence, and clinical outcomes.

“Pooling results according to one of these characteristics still leaves highly heterogeneous groups, and we could not justify meta-analysis,” study authors write. “Instead, we conducted a qualitative analysis with a focus on the RCTs [randomized controlled trials] with the lowest risk of bias for study design and the primary clinical outcome.”

“The studies varied so much in terms of their design and their results that it would have been misleading to try to come up with general conclusions,” added lead researcher, Robby Nieuwlaat, MSc, PhD, of the Department of Clinical Epidemiology and Biostatistics at McMaster University, in Hamilton, Ontario. “Based on this evidence, it is uncertain how adherence to medication can be consistently improved. We need to see larger and higher quality trials, which better take in account individual patient's problems with adherence.”

In fact, the researchers found that most trials were unreliable, casting doubt on the validity of the results; only 17 were of high quality, and each of those tested combinations of several different approaches, such as support from family members or pharmacists, education, and counselling.

Of those, just five of the studies demonstrated improvements in both medication adherence and health outcomes for patients.

“Current methods of improving medication adherence for chronic health problems are mostly complex and not very effective, so that the full benefits of treatment cannot be realized,” according to the study’s conclusions. “The research in this field needs advances, including improved design of feasible long-term interventions, objective adherence measures, and sufficient study power to detect improvements in patient-important clinical outcomes.”

As a result, the authors have created a database of the relevant trials and asked researchers in the field to add the information.

“By making our comprehensive database available for sharing we hope to contribute to the design of better trials and interventions for medication adherence,” Nieuwlaat said. “We need to avoid repeating the painful lessons of adherence research to date and begin with interventions that have shown some promise, or at least have not produced repeatedly negative results.”

U.S. Pharmacist Social Connect