What Is the Best Intervention for Improving Medication Adherence in Patients with Psoriatic Arthritis?

A new analysis of 14 clinical trials and 1 observational study concluded that multi-faceted interventions can lead patients with psoriatic arthritis and other immune-mediated inflammatory disorders to improve their adherence to treatment regimens.

Prior studies of patients with a wide range of chronic diseases have shown that only about half of them adhere fully to their prescribed treatments. A smaller body of research focused specifically on patients with immune-mediated inflammatory diseases suggests similarly low rates of patient adherence, wrote the authors of the new paper, who noted that such behavior leads to needlessly poor outcomes and high treatment costs.

A systematic search for high-quality efforts to test compliance-boosting strategies found only 15 papers, which collectively provided data on 1,958 patients, most of whom had either rheumatoid arthritis or inflammatory bowel disease. The authors of the new paper classified 7 of the 15 interventions as multifaceted and the rest as either educational (4), behavioral (2) or cognitive behavioral (2).

They also found that 9 of the 15 interventions were associated with significant improvements in treatment adherence rates. (Some of the other studies may have demonstrated significant benefits with more patients, wrote the authors of new analysis, who noted that 8 of 9 adequately powered studies, but only 1 of 6 underpowered studies, demonstrated significant improvements.)

Overall, 6 of the 7 multifaceted interventions demonstrated effectiveness, compared to only 1 of the 4 educational interventions, 1 of the 2 behavioral interventions and 1 of the 2 cognitive behavioral interventions.

“These results are consistent with previous reviews in other chronic conditions such as hypertension, hyperlipidemia, asthma, diabetes or heart failure,” the authors of the new analysis wrote in PLOS One. “A meta-analysis of intervention studies on medication adherence published between 1977 and 1994, showed that multidimensional approaches were more effective than uni-dimensional interventions.”

Multifaceted interventions also tended to produce larger increases in patient compliance than other interventions, though there were not enough studies to make meaningful comparisons. (Among interventions that showed any significant benefit, the relative “risk” of adherence among study-group patients ranged from 1.1 to 2.5.)

The authors of the new review concluded that existing research provides plenty of reason to believe that real-world medication adherence rates can be improved among patients with all types of immune-mediated inflammatory disorders. However, they also noted a need for more studies — and better studies.

“One major point of improvement should be the quality of study design, especially a priori sample size determination to ensure sufficient power to detect a clinically relevant effect. It is noteworthy that 6 out of 15 studies had a dramatic lack of power (<60%). Increasing the power of studies would avoid false negative results, which probably was the case for some of them,” they wrote.

“Another point of progress relates to the measure of adherence. Indeed, we observed that a large number of studies (8 out of 15) did not use standardized and validated instruments and are only based on the declaratives of patients... Future research should also attempt to clearly describe all the components of the intervention and to try to identify which specific component is necessary to enhance adherence. Some components may have additive effects, other may have synergistic effects.”