A mixed-methods process evaluation of internet-delivered self-help Acceptance and Commitment Therapy for family carers of people with dementia (iACT4CARERS): engagement, mechanisms, and contextual factors.

Objectives

A mixed-methods process evaluation was conducted alongside a randomised controlled trial of iACT4CARERS: an eight-session, online, self-help, Acceptance and Commitment Therapy (ACT) intervention with minimal therapist support for family carers of people with dementia. While the RCT evaluated its effects on anxiety, depression, and psychological flexibility, this study examined intervention implementation (fidelity and dose), contextual factors influencing engagement, and mechanisms of impact, focusing on how participants engaged with intervention content and therapist support to produce expected changes.

Methods

Data were collected from 249 intervention-group carers, including demographics, between-session ACT skill use, weekly values-based goal completion, and change in psychological flexibility (CompACT) from baseline to post-intervention. Platform analytics captured session completion and therapist interaction. Semi-structured interviews were conducted with a purposive sample of 28 carers (21% ethnic minority).

Results

iACT4CARERS was generally well received, with high completion, particularly among older, unemployed, and spousal carers. Engagement was shaped by carers' perceived need, reflecting subjective experience rather than dementia stage. Changes in psychological flexibility were influenced by carers' resonance with metaphors and case examples, and by their engagement with intervention content (e.g. note-taking) and therapists (e.g. therapeutic relationships).

Conclusion

iACT4CARERS largely operated as intended; identified refinements could further enhance engagement and benefits.