Physiotherapy informed by Acceptance and Commitment Therapy for chronic low back pain: A mixed-methods treatment fidelity evaluation.

Objectives: A randomized controlled trial of a new type of Physiotherapy informed by Acceptance and Commitment Therapy (PACT), found that it improved functioning in people with chronic low back pain compared to usual physiotherapy care. Fidelity evaluation is necessary to understand trial processes and outcomes. This study evaluated PACT treatment fidelity including delivery, receipt, and enactment.