A machine-learning assisted review of the use of habit formation in medication adherence interventions for long-term conditions

Adherence to medication in long-term conditions is around 50%. The key components of successful interventions to improve medication adherence remain unclear, particularly when examined over prolonged follow-up periods. Behaviour change theories are increasingly interested in the utility of habit formation for the maintenance of health behaviour change, but there is no documentation on how habit has been conceptualised in the medication adherence intervention literature, or what effect the key technique identified in habit formation theory (context dependent repetition) has in these studies. . To examine this, a machine-learning assisted review was conducted. Searches of MEDLINE, EMBASE and PSYCInfo and the reference list of a comprehensive systematic review of medication adherence interventions yielded 5973 articles. Machine learning-assisted title and abstract screening identified 15 independent RCTs published between 1976 and 2021, including 18 intervention comparisons of interest. Key findings indicate that conceptualisations of habit in the medication adherence literature are varied and intervention behaviour change techniques were diverse among these studies. Behaviour change technique coding identified only six studies which explicitly described using habit formation. Conclusions indicate that despite the potential utility of habits as a technique to support maintenance in medication adherence, randomised controlled trials of habit formation interventions are few. Future work should aim to develop this evidence base, drawing on contemporary habit theory and with explicit demonstration of what techniques have been used to promote habit formation.