Self-guided Acceptance and Commitment Therapy-based Digital Smartphone Application for Management of Fibromyalgia

Introduction: Fibromyalgia (FM) is a prevalent syndrome that lacks curative treatment, imposing high healthcare and societal costs. The SMART-FM-Spain study investigates the effectiveness, physiological effects, and cost-utility of a self-guided digital intervention (STANZA-Spain) based on Acceptance and Commitment Therapy (ACT) for patients with FM. Methodology: Six-month, 3-arm randomized controlled trial (RCT) A total of 360 adult individuals meeting the 2016 American College of Rheumatology (ACR) criteria for FM will be recruited at Vall d'Hebron University Hospital (Barcelona, Spain), The Rheumatology Service of the Parc Sanitari Sant Joan de Déu (Sant Boi, Spain), The San Juan de Dios Hospital of Palma (Palma de Mallorca, Spain) and The San Juan de Dios Hospital of Aljarafe (Sevilla, Spain). They will be randomly allocated to one of the three study arms: Treatment as usual (TAU) plus STANZA-Spain, TAU plus digital symptom tracking (FibroST), or TAU. Participants will be assessed at baseline, post-treatment, and 6 month-follow-up. The primary outcome will be functional impairment, as measured by the FIQR; secondary outcomes will include patient impression of change, depression-anxiety-stress, and pain catastrophizing, among others constructs relevant to FM. Effectiveness and cost-utility analysis from a societal perspective will be computed, whereas ACT-related constructs, such as psychological flexibility, will be assessed to identify processes of change that will be analyzed with path analyses. Immune-inflamatory biomarkers will be assessed at baseline and post-treatment in 30-40 participants of each study arm. Additionally, a qualitative substudy using focus group thematic analysis will be conducted to deepen the understanding of STANZA app user experiences. Discussion: This study might represent a significant advancement in the management of FM in Spanish-speaking patients with FM, by examining the effectiveness, physiological effects, and cost-utility of a smartphone-based digital therapeutic with demonstrated empirical support in the United States of America.

Inclusion Criteria: * Fibromyalgia diagnosis according to the 2016 ACR criteria * Fibromyalgia Impact Questionnaire Revised (FIQR) total score within the range of 35-80 at baseline. * Willing to maintain their current pain treatment throughout the study. * Having a smartphone (iOS 12 or higher or Android OS 8 or higher). * Proficient understanding of Spanish. Exclusion Criteria: * Presence of cognitive impairment according to clinical records. * Diagnosis of severe medical or mental disorders such as cancer, psychotic disorder, and drug abuse according to medical records. * Patients at risk of suicide. * Being pregnant or planning a pregnancy during the study period, or currently breastfeeding. * Participation in other clinical trials during the study or within the previous 12 months. * Unable to use a smartphone. Exclusion criteria for biomarkers substudy (30-50 patients in each study arm): * Male sex * Comorbid rheumatologic disorders such as lupus or severe organ dysfunction. * History of fever (\> 38ºC) or infection within the last 2 weeks. * Vaccination within the last 4 weeks. * Recent physical trauma * Needle phobia. * Consumption of more than 8 units of caffeine per day. * Smoking more than 5 cigarettes per day. * Current use of oral or topical corticosteroids. * Current use of anti-cytokine biologic medications. * Current use of oral contraceptives.