Understanding tamoxifen adherence in women with breast cancer: A qualitative study.

Objective: Non-adherence to tamoxifen is common in breast cancer survivors and is associated with poor clinical outcomes. This study aimed to understand womens' experiences of taking tamoxifen and to identify factors which may be associated with non-adherence.

Design: A qualitative study using semi-structured interviews.

Methods: Thirty-two breast cancer survivors who had been prescribed tamoxifen took part in interviews conducted face to face or over the telephone. They were transcribed verbatim and analysed using inductive thematic analysis with elements of grounded theory.

Results: A key theme identified in the data was weighing up costs and benefits of treatment, which resulted in women falling into three groups; tamoxifen is keeping me alive, tamoxifen is not worth the reduced risk of recurrence, or conflicting beliefs about the harms and benefits of treatment. Additional themes were living with risk of recurrence and information & support.

Conclusions: Women who believed that the necessity of tamoxifen outweighed its costs were more likely to be adherent, whereas women who thought that the benefits did not outweigh the side effects were more likely to have discontinued. A third more ambivalent group believed strongly in the importance of treatment, but were struggling with side effects and were often non-adherent. Patients sometimes felt unsupported and discussed a need for more comprehensive information. To increase adherence, future research needs to explore ways to increase beliefs around tamoxifen necessity and how to help women cope with side effects. Statement of contribution What is already known on this subject? Non-adherence to tamoxifen is associated with increased risk of recurrence and mortality. Up to 50% of patients are non-adherent to tamoxifen by the fifth year of treatment Few consistent predictors of tamoxifen non-adherence have been identified. What does this study add? Many women report not knowing how to manage their side effects. Non-adherence is related to how women weigh up their side effects against their medication beliefs. Interventions aiming to increase necessity beliefs and improve symptom management may be effective.