Acceptability of acceptance and commitment therapy for medication-decision-making and quality of life in women with breast cancer: A qualitative process evaluation.

Objectives: Adjuvant endocrine therapy (AET) reduces breast cancer recurrence, but side effects and distress impact adherence. We co-designed an Acceptance and Commitment Therapy (ACT) intervention to support medication decision-making and quality of life in women prescribed AET (ACTION). In a qualitative process evaluation nested in the pilot trial, we aimed to elicit participant experiences of receipt and therapists experience of delivery of ACTION to enhance our understanding of acceptability.

Design: Remote semi-structured interviews were conducted with women with breast cancer who received ACTION (n = 20) and trial therapists (n = 3).

Methods: Interviews were guided by the Theoretical Framework of Acceptability (TFA). Rapid Assessment Procedure (RAP) sheets were completed after each interview to map responses onto TFA constructs, and sections of interviews were selectively transcribed. Individual RAP sheets were collated to identify key findings.

Results: ACTION was generally liked, in particular, the group format (affective attitude). Participants and therapists felt ACTION was low effort, but therapists acknowledged the burden associated with trial procedures (burden). Participants generally felt able to engage with ACTION, and therapists felt they were able to deliver it (self-efficacy). The perceived effectiveness of ACTION on well-being was good, but was mixed for impact on treatment adherence (perceived effectiveness). Participants and therapists understood the aims of ACTION (coherence), and ACTION generally aligned with therapists' values (ethicality). Therapists questioned who would be most appropriate to deliver ACTION (opportunity costs).

Conclusion: ACTION was acceptable to women with breast cancer and trial therapists. Rapid qualitative analysis can facilitate efficient process evaluations in time- and resource-limited contexts.