Development of a self-management intervention to improve tamoxifen adherence in breast cancer survivors using an Intervention Mapping framework

Objective: Up to 50% of women prescribed tamoxifen do not take it as prescribed for the full duration, which increases risk of recurrence and mortality. The current paper describes the development of a self-management intervention aiming to improve adherence in breast cancer survivors taking tamoxifen. Methods: The intervention was developed following an Intervention Mapping approach. The content of the intervention was determined by theories of health behaviour and empirical evidence. Development was an iterative process involving input from expert researchers, clinicians and patient representatives. Results: The intervention was designed to improve both intentional and unintentional non-adherence. Key features included modifying unhelpful illness and treatment beliefs, improving confidence for coping with side effects and developing strategies for remembering to take tamoxifen. Conclusion: Intervention Mapping proved a useful tool for developing an intervention which is grounded in theory and empirical evidence. The intervention has the potential to improve adherence in breast cancer survivors but needs to be trialled before the effectiveness of the intervention can be determined. Practice implications: If shown to be effective, the intervention could be rolled out at a low cost to improve adherence and support breast cancer survivors prescribed tamoxifen.