Remote Monitoring App for Endocrine Therapy Adherence among Patients with Early-Stage Breast Cancer: A Randomized Clinical Trial

Importance: Adjuvant endocrine therapy (AET) use among women with early-stage, hormone receptor-positive breast cancer reduces the risk of cancer recurrence, but its adverse symptoms contribute to lower adherence. Objective: To test whether remote monitoring of symptoms and treatment adherence with or without tailored text messages improves outcomes among women with breast cancer who are prescribed AET. Design, Setting, and Participants: This nonblinded, randomized clinical trial (RCT) following intention-to-treat principles included English-speaking women with early-stage breast cancer prescribed AET at a large cancer center with 14 clinics across 3 states from November 15, 2018, to June 11, 2021. All participants had a mobile device with a data plan and an email address and were asked to use an electronic pillbox to monitor AET adherence and to complete surveys at enrollment and 1 year. Interventions: Participants were randomized into 3 groups: (1) an app group, in which participants received instructions for and access to the study adherence and symptom monitoring app for 6 months; (2) an app plus feedback group, in which participants received additional weekly text messages about managing symptoms, adherence, and communication; or (3) an enhanced usual care (EUC) group. App-reported missed doses, increases in symptoms, and occurrence of severe symptoms triggered follow-ups from the oncology team. Main Outcomes and Measures: The primary outcome was 1-year, electronic pillbox-captured AET adherence. Secondary outcomes included symptom management abstracted from the medical record, as well as patient-reported health care utilization, symptom burden, quality of life, physician communication, and self-efficacy for managing symptoms. Results: Among 304 female participants randomized (app group, 98; app plus feedback group, 102; EUC group, 104), the mean (SD) age was 58.6 (10.8) years (median, 60 years; range, 31-83 years), and 60 (19.7%) had an educational level of high school diploma or less. The study completion rate was 87.5% (266 participants). There were no statistically significant differences by treatment group in AET adherence (primary outcome): 76.6% for EUC, 73.4% for the app group (difference vs EUC, -3.3%; 95% CI, -11.4% to 4.9%; P =.43), and 70.9% for the app plus feedback group (difference vs EUC, -5.7%; 95% CI, -13.8% to 2.4%; P =.17). At the 1-year follow-up, app plus feedback participants had fewer total health care encounters (adjusted difference, -1.23; 95% CI, -2.03 to -0.43; P =.003), including high-cost encounters (adjusted difference, -0.40; 95% CI, -0.67 to -0.14; P =.003), and office visits (adjusted difference, -0.82; 95% CI, -1.54 to -0.09; P =.03) over the previous 6 months compared with EUC participants. Conclusions and Relevance: This RCT found that a remote monitoring app with alerts to the patient's care team and tailored text messages to patients did not improve AET adherence among women with early-stage breast cancer; however, it reduced overall and high-cost health care encounters and office visits without affecting quality of life. Trial Registration: ClinicalTrials.gov Identifier: NCT03592771.