Trial Summary

Study question and significance: Poor medication adherence is common among patients with chronic conditions, and poor adherence to cardiovascular medications is associated with higher rates of adverse health outcomes, including hospitalization and mortality.

Design and setting: Patient-level randomized trial embedded in 3 healthcare systems testing a variety of text messaging strategies to encourage patients to refill their cardiovascular medications from October 2019 to April 2022. The study enrolled 9051 patients who were aged 18 years to less than 90 years, had a diagnosis of 1 or more cardiovascular conditions, had a 7-day refill gap for any cardiovascular medication they had been prescribed, and did not opt out of the study.

Intervention and methods: Patients were randomly assigned to receive either usual care or 1 of 3 text message interventions: (1) a generic text message reminder to refill medication; (2) a text message reminder that incorporated "behavioral nudges"; and (3) a behavioral nudge text message reminder plus a chatbot that used preprogrammed algorithms to assess common barriers to medication adherence. The primary outcome was the proportion of days covered in the 365 days after randomization for all cardiovascular medication classes for which the patient had a refill gap at baseline.

Findings: There were no statistically significant differences in the proportion of days covered with medication between the study groups. There were also no differences in emergency department visits, hospitalizations, and mortality. In a post hoc analysis exploring medication adherence in the first 3 months after a refill gap, there was a modest improvement in refill adherence with the text messaging strategies compared with usual care.

Conclusions and relevance: Text messaging reminders to patients who delayed refilling their cardiovascular medications did not improve medication adherence compared with usual care. Because poor medication adherence may be due to multiple factors, future interventions may need to be designed to address these multiple factors.

NIH Project Information