John Alfred Weinman

Background Although previous systematic reviews have studied medication adherence interventions among people with Type 2 diabetes (PwT2D), no intervention has been found to improve medication adherence consistently. Furthermore, inconsistent and poor reporting of intervention description has made understanding, replication, and evaluation of intervention challenging. Purpose We aimed to identify the behavior change techniques (BCTs) and characteristics of successful medication adherence interventions among PwT2D. Methods A systematic search was conducted on Medline, Embase, CINAHL, PsycINFO, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus. Studies were included if they were randomized controlled trials with BCT-codable interventions designed to influence adherence to anti-diabetic medication for PwT2D aged 18 years old and above and have medication adherence measure as an outcome. Results Fifty-five studies were included. Successful interventions tend to target medication adherence only, involve pharmacists as the interventionist, contain “Credible source” (BCT 9.1), “Instruction on how to perform the behaviour” (BCT 4.1), “Social support (practical)” (BCT 3.2), “Action planning” (BCT 1.4), and/ or “Information about health consequences” (BCT 5.1). Very few interventions described its context, used theory, examined adherence outcomes during the follow-up period after an intervention has ended, or were tailored to address specific barriers of medication adherence. Conclusion We identified specific BCTs and characteristics that are commonly reported in successful medication adherence interventions, which can facilitate the development of future interventions. Our review highlighted the need to consider and clearly describe different dimensions of context, theory, fidelity, and tailoring in an intervention.