Using Adherence-Contingent Rebates on Chronic Disease Treatment Costs to Promote Medication Adherence: Results from a Randomized Controlled Trial

Marcel Bilger, Tina Wong, Jia Yi Lee, Kaye Howard, Filipinas Bundoc, Ecosse Lamoureux, Eric Finkelstein

Publication: Scientific journalJournal articlepeer-review

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BACKGROUND: Poor adherence to medications is a global public health concern with substantial health and cost implications, especially for chronic conditions. In the USA, poor adherence is estimated to cause 125,000 deaths and cost $US100 billion annually. The most successful adherence-promoting strategies that have been identified so far have moderate effect, are relatively costly, and raise availability, feasibility, and/or scalability issues. OBJECTIVE: The main objective of SIGMA (Study on Incentives for Glaucoma Medication Adherence) was to measure the effectiveness on medication adherence of a novel incentive strategy based on behavioral economics that we refer to as adherence-contingent rebates. These rebates offered patients a near-term benefit while leveraging loss aversion and regret and increasing the salience of adherence. METHODS: SIGMA is a 6-month randomized, controlled, open-label, single-center superiority trial with two parallel arms. A total of 100 non-adherent glaucoma patients from the Singapore National Eye Centre were randomized into intervention (adherence-contingent rebates) and usual care (no rebates) arms in a 1:1 ratio. The primary outcome was the mean change from baseline in percentage of adherent days at Month 6. The trial registration number is NCT02271269 and a detailed study protocol has been published elsewhere. FINDINGS: We found that participants who were offered adherence-contingent rebates were adherent to all their medications on 73.1% of the days after 6 months, which is 12.2 percentage points (p = 0.027) higher than in those not receiving the rebates after controlling for baseline differences. This better behavioral outcome was achieved by rebates averaging 8.07 Singapore dollars ($US5.94 as of 2 November 2017) per month during the intervention period. CONCLUSION: This study shows that simultaneously leveraging several insights from behavioral economics can significantly improve medication adherence rates. [...]
Original languageEnglish
Pages (from-to)841 - 855
JournalApplied Health Economics and Health Policy
Publication statusPublished - 2019

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