Purpose
Around half of prescribed medications for long-term conditions are not taken as directed. Automated two-way digital communication, such as text messaging and interactive voice response technology, could deliver interventions to improve medication adherence, and subsequently health. However, exploration of how such interventions may improve medication adherence is limited. This review aimed to explore how automated two-way digital communication can improve medication taking with or without using non-digital intervention components, such as phone calls with healthcare professionals.

Methods
A theory-informed narrative synthesis systematic review. Several databases were searched including CINAHL, Embase, Medline, and Web of Science using key words relating to ‘medication adherence’ and digital communication technologies. The Behavior Change Technique (BCT) coding using the BCT Taxonomy V1 and the Behavior Change Wheel were used to identify BCTs delivered within the included interventions.

Results
A total of 3,018 records were screened with 43 study reports included in the review. Four medication-taking behaviors: taking medication, obtaining medication, self-testing, and asking for support were identified as targets for behavior change within the included interventions. Most BCTs within the digital communication component aimed to increase motivation for medication adherence, with non-digital intervention components included to address other medication taking barriers, such as physical and psychological capability.

Conclusion
Automated two-way digital communication can detect barriers to medication adherence by monitoring performance of the taking medication behavior. Monitoring outcomes from taking medication may increase reflective motivation to take medicines. Addressing physical opportunity to taking medication by facilitating the behavior obtaining medication may also increase adherence.