Effectiveness and cost-effectiveness of a guided internet-based Acceptance and Commitment Therapy intervention (MobACT) for adults with Chronic Pain in Italy: study protocol for a randomized controlled trial

Background: Chronic Pain (CP) affects approximately one in five adults and is associated with emotional distress, disability, reduced productivity and substantial healthcare and societal costs. Acceptance and Commitment Therapy (ACT) has demonstrated effectiveness in improving emotional, behavioral and functional outcomes in individuals with CP, but access to ACT is frequently limited by geographic, organizational and workforce barriers. Internet-based interventions may help overcome these limitations by increasing accessibility, reducing treatment costs and improving scalability. Objective: This study evaluates the effectiveness and cost-effectiveness of MobACT, a guided internet-based ACT programme for Italian adults with CP. The primary effectiveness endpoint is the post-intervention assessment (T1). Methods and analysis: This two-arm randomized controlled trial will allocate adults with medically verified CP to either immediate MobACT or waitlist control (1:1). Participants in the waitlist control condition will receive access to MobACT only after completion of the T1 assessment, following the primary between-group comparison. A 6-month follow-up (T2) will be conducted in the intervention group only to examine maintenance of treatment effects. The primary outcome will be pain acceptance, assessed with the Chronic Pain Acceptance Questionnaire. Pain intensity and pain interference will be key clinical secondary outcomes. Additional secondary outcomes include quality of life, sleep quality, central sensitization, pain catastrophizing, psychological flexibility, self-efficacy, coping, anxiety, and depressive symptoms. Weekly assessments of sleep quality and changes in pharmacological treatment will also be collected during the active intervention period. The economic evaluation will compare the two conditions from healthcare and societal perspectives using service utilization data, productivity indicators, and EQ-5D-3L-derived quality-adjusted life years. Ethics and dissemination: Ethical approval was obtained from the Ethics Committee of Università Cattolica del Sacro Cuore, Milan (Approval No.: 146/24). Results will be disseminated through peer-reviewed publications, international conferences and stakeholder reports for patient organizations. Trial registration number: ClinicalTrials.gov Identifier: NCT07270588.