Do interventions that address patient cost-sharing improve adherence to prescription drugs? A systematic review of recently published studies.

INTRODUCTION: Poor prescription drug adherence is common, jeopardizing the benefits of treatment and increasing the costs of health care in the United States. A frequently reported barrier to adherence is patient out-of-pocket (OOP) costs. Areas Covered: This systematic review examines interventions that address patient cost-sharing to improve adherence to prescription drugs and reduce costs of care. Twenty-eight published studies were identified with 22 distinct interventions. Most papers were published in or after 2010, and nearly a third were published after 2014. Expert Opinion: Many of the interventions were associated with improved adherence compared to controls, but effects were modest and varied across drug classes. In some studies, adherence remained stable in the intervention group, but declined in the control group. Patient OOP costs generally declined following the intervention, usually as a direct result of the financial structure of the intervention, such as elimination of copayments, and costs to health plans for prescription drugs increased accordingly. For those studies that reported drug and nondrug costs, lower health plan nondrug medical spending generally compensated for increased spending on prescription drugs. With increasing health-care spending, especially for prescription drugs, efforts to improve prescription drug adherence in the United States are important. Federal policies regarding prescription drug prices may have an impact on cost-related nonadherence, but the content and timing of any policies are hard to predict. As such, employers and health plans will face greater pressure to explore innovative approaches to lowering costs and increasing access for beneficiaries. Value-based financial incentive models have the potential to be a part of this effort; research should continue to evaluate their effectiveness.