Barriers to and facilitative processes of endocrine therapy adherence among women with breast cancer.

The treatment of chronic illness, and the prevention of disease progression and recurrence, often involve long-term adherence to prescription medications in breast cancer. Despite the survival benefit of endocrine therapies, nonadherence remains high. In this study, we examined barriers to and facilitators of endocrine therapy adherence among women with breast cancer (n = 1371). Participants currently taking tamoxifen or aromatase inhibitors were recruited from Dr. Susan Love Research Foundation's Army of Women(®) Registry. Participants responded online to open-ended and close-ended questions about thoughts, feelings, and behaviors relevant to endocrine therapy. Two weeks later, women were invited to complete a second online questionnaire regarding current endocrine therapy adherence. Approximately one-third (36 %) of participants reported the presence of factors that make endocrine therapy difficult; reporting any barrier to medication adherence was significantly associated with nonadherence (P < 0.001). In addition, 31 % of women used one or more strategies to maintain their motivation to adhere and the use of cognitive self-talk (e.g., thoughts regarding endocrine therapy efficacy) was related to higher adherence. Hierarchical linear regressions revealed a significant behavioral barrier × behavioral facilitator interaction (P < 0.05); participants who endorsed a behavioral barrier in the absence of a behavioral facilitator reported the lowest adherence. Findings suggest that a sizeable minority of women face barriers to taking endocrine therapy, which are associated with nonadherence.