Value-based insurance design and medication adherence: opportunities and challenges

To evaluate the quality of existing value-based insurance design (V-BID) program evaluations on medication adherence, and to identify areas of expansion for future V-BID policy research.

Literature review.

A structured search of the peer-reviewed literature was performed using healthcare and economic databases for studies evaluating the impact of V-BID programs on medication adherence. Characteristics of V-BID programs that may result in biased estimates for V-BID effectiveness were assessed and evaluated.

A total of 20 studies assessing the effects of 17 V-BID programs were identified. Medication adherence generally improved after V-BID implementation (mean effect size 3.4% after 1 year). The V-BID evaluation literature suffers from several methodological issues, such as a lack of reporting on baseline and final adherence rates, or absolute adherence changes. Factors that may influence observed effect sizes include program characteristics, baseline adherence rates, disease category, and disease management programs. Effect sizes were much higher in studies where the primary author reported employment by the study firm or sponsor.

Many of the studies evaluating V-BID programs suffered from a lack of clarity when describing the methods used, or a lack of transparency when reporting results, and much of the evidence comes from studies where potential conflicts of interest exist. Authors should ensure that baseline and/or final adherence values are reported in addition to effect sizes, consistent terminology is used throughout a study, results are assessed for potential bias due to confounding factors, and due diligence has been performed to eliminate alternative explanations.