Does patient health literacy impact adherence to adjuvant endocrine therapy in breast cancer patients?

PURPOSE: Functional health literacy is critical for patients’ functional understanding and management of disease including adherence to medications and treatment recommendations. The purpose of this study was to determine if there is a relationship between self-reported health literacy and 1) decision to take adjuvant endocrine therapy and 2) adherence to adjuvant endocrine therapy at 2 years among women with breast cancer. METHODS: We initiated a prospective health literacy assessment to determine the relationship between health literacy and breast health outcomes. Among our overall cohort, we determined women who had estrogen receptor positive (ER+) disease and were recommended to take adjuvant endocrine therapy, those who initiated treatment, and those adherent at 2 years following diagnosis. Descriptive statistics and logistic regression were calculated to determine the relationship between health literacy and both initiation and adherence. RESULTS: Among the 340 patients in the sample who were recommended to take adjuvant endocrine therapy, 296 (87.1%) initiated the therapy. Two-year follow-up data are available in 136 patients with ER+ tumors. Among the patients with 2-year longitudinal data available, 108 (79.4%) were adherent and still taking the endocrine therapy at 2 years following diagnosis. In univariate logistic regression analysis, there was no statistical significance between health literacy and initiation of adjuvant endocrine therapy or adherence to adjuvant endocrine therapy at 2 years. CONCLUSION: Despite the underpinnings regarding health literacy and medication adherence supporting our hypothesis, we did not find an association between health literacy and the decision to initiate therapy or continued adherence at 2 years following diagnosis. Further study is needed to determine the nuances in adherence to adjuvant endocrine therapy for women with breast cancer.