mHealth to Improve Medication Adherence Among Latina Breast Cancer Patients Experiencing Non-Medical Drivers of Health

Background: Hormonal therapy (HT) is highly effective for nearly all breast cancer patients with hormone receptor-positive tumors, which are about 80% of all breast cancer diagnoses. Long-term use of HT reduces cancer recurrence rates and cuts the risk of mortality nearly in half during the second decade after diagnosis. Despite proven benefits, 33% of women who are prescribed HT do not take it as prescribed (\<80% take their daily dosage). Latina patients are disproportionately affected by non-medical drivers of health (NMDoH) that keep them from adhering to HT and are at higher risk of breast cancer recurrence and mortality.

Objective: The goal of this 4-year randomized controlled study is to assess the effectiveness of the bilingual, culturally tailored, interactive HT Helper App, in combination with patient navigation (PN), on improving adherence to HT among Latina breast cancer patients experiencing any NMDoH barriers, such as income, health insurance, education, health literacy, and language, that impact their medication adherence. This theory-based intervention will increase patient education, enhance self-efficacy, facilitate communication with the medical team and coordination of resources to address NMDoH barriers, and help patients develop self-care skills for optimal adherence to HT, ensuring patients the most equitable treatment outcomes possible, including improvement in quality of life, survival, and life expectancy.

Specific Aims/Hypothesis: 1) Conduct a 3-group randomized study to assess the effectiveness of the HT Helper App + PN vs. PN alone vs. usual care, on HT adherence; and 2) Assess the effect of each study condition on patient self-efficacy to identify side effects, use self-care to manage side effects, and communicate with the medical team. We hypothesize that the HT Helper App + PN and the PN alone groups will have greater rates of HT adherence and higher patient self-efficacy than the usual care group; with the HT Helper App + PN achieving better results than both PN alone and the usual care groups.

Study Design. The proposed study involves a parallel 3-group randomized controlled trial with 5-time assessments (baseline, 3, 6, 12, and 18 months) and will enroll 159 breast cancer patients who are prescribed HT and are attending the breast clinic at the Mays Cancer Center at UT Health San Antonio. Intervention components are based on Social Cognitive Theory and elements of Motivational Interviewing.

Cancer Relevance. This innovative multi-level intervention will improve adherence to HT by addressing NMDoH and promote equitable breast cancer outcomes, including reduced recurrence and improved quality of life, overall survival, and life expectancy among underserved Latina patients. The anticipated outcome is a scalable, evidence-based, and easily disseminated intervention with potentially broad use to patients using oral anticancer medications.