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Title: Development of a fidelity measure for Acceptance and Commitment Therapy
Author: O'Neill, Lucy Florence
ISNI:       0000 0004 7428 1095
Awarding Body: University of Leeds
Current Institution: University of Leeds
Date of Award: 2018
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Introduction: Acceptance and Commitment Therapy (ACT) is a third wave behavioural therapy with a developing evidence base to support its effectiveness. Studies have been criticised for lacking methodological quality and fidelity checks have been recommended for ACT to be considered a well-established treatment. There is a need for a practical and trans- diagnostic ACT fidelity measure that is coherent with contemporary ACT theory. Aim: This study aimed to develop a valid, practical and reliable measure of therapist fidelity to ACT. Delphi Method: Purposeful and snowball sampling was used to recruit a panel of ACT experts for a Delphi study. Participants completed three iterative rounds of online questionnaires, where analysis informed the construction of the following round. In the first two rounds, participants were asked to generate new items and rate each item for their opinion on its inclusion. They provided comments on the measure in general and item specific feedback. For the third round, participants were presented with the ACT Fidelity Measure (ACT-FM) in its useable format for final comments. Delphi Results: Half of the recruited panel members were recognised by the ACBS as a Peer reviewed ACT trainer and they had a mean of 11 years’ experience with ACT. Their ratings and comments resulted in a 24-item measure. Items were structured around therapist stance and the Tri-flex, with ACT consistent and inconsistent items. Eighty-three percent of items met the specified criteria for consensus. Field Study Method: ACT clinicians were recruited to use the ACT-FM to rate an ACT video. Inter-rater reliability was calculated and the clinicians provided feedback on the ease of use of the measure with suggestions. Field Study results: The ACT-FM was found to have moderate to excellent inter-rater reliability (ICC= 0.73). Participants rated the measure as easy to use, but identified 7 items that required clarification. The measure was revised in response to their suggestions. Discussion: A valid, practical and reliable ACT fidelity measure was created. Recruiting an expert panel for the Delphi study ensured the ACT-FM was high in content validity. It was considered practically useful by participants in the field study, and it achieved moderate to excellent inter-rater reliability.
Supervisor: Graham, Christopher ; Latchford, Gary Sponsor: Not available
Qualification Name: Thesis (D.Clin.Psy.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available