The relationship between risk factors and medication adherence among breast cancer survivors: What explanatory role might depression play?

OBJECTIVE: Despite the efficacy of clinical treatments (eg, adjuvant hormonal therapy) for breast cancer survivors (BCS), nonadherence rates remain high, increasing the risk of recurrence and mortality. The current study tested a theoretical model of medical nonadherence that proposes depression to be the most proximal predictor of medical nonadherence among BCS.

METHODS: Breast cancer survivors were recruited from radiation clinics in Missouri. Survey data were collected 12 months after the end of primary treatment. The sample size included 133 BCS.

RESULTS: Findings show substantial support for the model, demonstrating that depression mediated the relation between physical symptoms, cognitive symptoms, social support, and adherence to medication. This finding was replicated with a measure of mood disturbance.

CONCLUSIONS: These findings support the prediction that medication nonadherence among BCS multiply determined process and have compelling implications for healthcare providers and interventions designed to increase medication adherence among BCS.