Behavioural Economics to Improve Antihypertensive Therapy Adherence (BETA): protocol for a pilot randomised controlled trial in Los Angeles

INTRODUCTION: Non-adherence to antihypertensive therapy is one of the major barriers to reducing the risk of cardiovascular disease. Several interventions have targeted higher medication adherence, yet most do not result in sustained adherence. Routinisation has emerged as a potential method for mitigating this problem, but requires high motivation during the relatively long habit formation phase. This pilot randomised controlled trial aims to test the feasibility, acceptability, and preliminary efficacy of behavioural economics-based incentives and text messages to support the routinisation of the medication-taking behaviour for promoting long-term medication adherence. METHODS AND ANALYSIS: This study will recruit and randomly assign 60 adult patients seeking care for hypertension at the Cedars-Sinai Medical Center in Los Angeles to one of the three groups, Control (n=20), Messages (n=20) and Incentives (n=20) in a 1:1:1 ratio. All participants will receive information about the importance of routinisation and will select an existing behavioural routine (‘anchor’) to which they will tie their pill-taking to, and the corresponding time. Additionally, participants in the Messages group will receive daily text messages reminding them of the importance of routines, while those in the Incentives group will receive daily text messages and conditional prize drawings. The interventions will be delivered over three months. Participants will be followed for six months post-intervention to measure behavioural persistence. Surveys will be administered at baseline, month-3 and month-9 visits. Primary outcomes include: (1) electronically measured mean medication adherence during the intervention period and (2) post-intervention period; and (3) mean timely medication adherence based around the time of the participants’ anchor during the intervention period, and (4) post-intervention period. ETHICS AND DISSEMINATION: The study was approved by the Cedars-Sinai Institutional Review Board (Study ID: Pro00057764). Findings will be published in scientific peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04029883.