Remote Monitoring App for Endocrine Therapy Adherence Among Patients With Early-Stage Breast Cancer

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