Economic evaluation of the FIBROWALK multicomponent intervention in online and outdoor formats for fibromyalgia (The On&Out Study)

Fibromyalgia (FM) is a chronic condition with substantial healthcare and societal costs. Although multicomponent interventions are widely available, evidence of their economic impact remains scarce. This study evaluated the cost-utility and cost-effectiveness of the FIBROWALK intervention in online (FIBRO-On) and outdoor (FIBRO-Out) formats, compared to treatment as usual (TAU), for individuals with FM. An economic evaluation (n = 225) was conducted over six months from government (total costs) and healthcare (direct costs) perspectives. The follow-up assessment was conducted six months after baseline, which corresponds to three months after the end of the 12-week intervention. Direct and indirect costs were collected through the Client Service Receipt Inventory. Cost-utility was assessed with Quality Adjusted Life Years (QALYs) and cost-effectiveness with the Revised Fibromyalgia Impact Questionnaire (FIQR). FIBRO-On was superior to TAU in reducing specialized healthcare costs (Cohen's d = 0.71), improving perceived health (d = 0.50), and reducing FM severity (d = 0.56). Compared to FIBRO-Out, FIBRO-On also reduced healthcare costs and improved both QALYs and FIQR scores. In contrast, FIBRO-Out led to significantly higher costs than TAU and showed no significant benefit in QALYs or FIQR scores. Across intention-to-treat, complete case, and per-protocol analyses, FIBRO-On was also the more favorable intervention, particularly in comparison to FIBRO-Out. These findings suggest that FIBRO-On may be a cost-effective intervention for managing FM compared to TAU or FIBRO-Out. Furthermore, they underscore the potential benefits of exploring digital interventions such as FIBRO-On to improve accessibility and promote efficient use of healthcare resources to manage FM. TRIAL NUMBER: NCT05377567 PERSPECTIVE: Economic evaluations of interventions for fibromyalgia are crucial to guide healthcare decisions and optimize resource allocation. This study shows that the multicomponent FIBROWALK intervention in its online format (FIBRO-On) offers good value for money compared to TAU or the outdoor format (FIBRO-Out), based on cost-utility and cost-effectiveness analyses performed from a government and healthcare perspective.