Impact of telehealth utilization on adherence to endocrine therapies in privately insured breast cancer patients: A claims-based cohort study.

1648 Background: Adherence to endocrine therapies is essential for reducing recurrence and improving survival in breast cancer patients. However, nonadherence remains a significant challenge, particularly among young women. Telehealth has emerged as a promising tool to address barriers to care, yet its impact on long-term adherence to endocrine therapies is poorly understood. This study evaluated the association between telehealth utilization and adherence to endocrine therapies among privately insured women with nonmetastatic breast cancer. Methods: Using medical and pharmacy claims data from the Merative MarketScan database, we identified women under 65 years old who were newly diagnosed with nonmetastatic breast cancer in 2018 and were commercially insured for at least one year before diagnosis and five years after initiating endocrine therapy. Telehealth utilization was identified through billing codes, and adherence was measured by the proportion of days covered (PDC) with adherence defined as ≥80% prescription coverage. Generalized linear mixed models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) while adjusting for relevant patient-level covariates. Results: The study cohort included 1,141 patients with the majority (53%) aged 45-54 years and 92% exhibited moderate severity of comorbidities. All patients initiated endocrine therapy in 2018 with 34% receiving tamoxifen, 33% receiving an aromatase inhibitor, and 33% switching between agents during follow-up. Telehealth utilization increased sevenfold during the second year of treatment (coinciding with the COVID-19 pandemic) and peaked in the third year when 48% of patients used telehealth and 2,178 visits were recorded. Adherence rates declined steadily over time: from 75% in the first year to 36% by the fifth year. Patients who utilized telehealth were 58% more likely to be adherent compared to those who did not utilize telehealth (OR = 1.58; 95% CI: 1.31-1.91; p < 0.0001). Geographic region, insurance plan type, and endocrine therapy agent were also significant predictors of adherence. Conclusions: Telehealth utilization was significantly associated with improved adherence to endocrine therapies among privately insured breast cancer patients. These findings highlight the potential of telehealth to mitigate barriers to long-term treatment adherence. Future research should explore strategies to sustain adherence and evaluate the broader clinical and economic implications of telehealth in this population.