Perceived barriers to treatment predict adherence to aromatase inhibitors among breast cancer survivors

Background: Although poor adherence to hormonal therapies such as aromatase inhibitors (AIs) is widely documented, to the authors' knowledge less is known regarding whether health beliefs predict treatment nonadherence. The objective of the current study was to evaluate the relationship between health beliefs (perceived susceptibility to breast cancer, perceived benefits of AI treatment, and perceived barriers to AI treatment) and adherence to AIs.

Methods: Postmenopausal women with early-stage, estrogen receptor-positive breast cancer who were currently receiving treatment with an AI completed the 3-factor Health Beliefs and Medication Adherence in Breast Cancer scale and questionnaires concerning their demographics and symptoms. Adherence data (treatment gaps and premature discontinuation) were abstracted from participants' medical charts. Logistic regression analyses were conducted to evaluate the relationship between health beliefs and adherence.

Results: Among 437 participants, 93 (21.3%) were nonadherent. Those who perceived greater barriers to their AI treatment were more likely to demonstrate AI nonadherence behaviors by the end of their treatment period compared with those who reported fewer barriers to AI therapy (adjusted odds ratio, 1.71; 95% confidence interval, 1.03-2.86 [P = .04]). In contrast, perceived susceptibility to cancer recurrence and perceived benefits of AIs did not appear to predict AI adherence. Minority individuals were found to have lower perceived susceptibility to breast cancer recurrence and higher perceived barriers to AI treatment (P<.05 for both).

Conclusions: Greater perceived barriers appeared to predict nonadherence to AIs. Interventions addressing women's negative beliefs regarding the challenges of AI treatment are needed to help optimize adherence in survivors of breast cancer. Cancer 2017;169-176. © 2016 American Cancer Society.