Economic evaluation of a lifestyle intervention for individuals with overweight or obesity suffering from chronic low back pain (the BO2WL trial): a protocol for a health economic analysis.

Introduction Low back pain (LBP) is highly prevalent across the Western world, including Switzerland (CH) and Belgium (BE), with women experiencing higher disability rates than men. Chronic LBP (CLBP), persisting beyond 3 months, leads to diminished health-related quality of life and increased healthcare and societal costs. Evidence indicates a direct relationship between body mass index (BMI) and CLBP severity, with high BMI significantly driving LBP-related healthcare expenses. Current evidence supports combining pain neuroscience education (PNE) with cognition-targeted exercise therapy (CTET) to effectively manage CLBP.An economic evaluation alongside a randomised controlled trial, entitled 'Lifestyle Intervention in Overweight/Obese CLBP Patients: an International Multi-centre RCT' (BO2WL), will be conducted in CH and BE. It aims to evaluate the addition of a lifestyle intervention to PNE and CTET compared with PNE and CTET alone for treating individuals with CLBP and overweight or obesity. This protocol outlines the details of the economic evaluation of this trial. Methods And Analysis The trial consists of a 14-week intervention followed by a 52-week post-intervention follow-up. Primary outcomes include direct and indirect costs, as well as quality-adjusted life years and pain intensity. Cost data will be converted into 2026 Belgium € (BE) and 2026 Swiss Francs (CHF) for CH, with a discount rate of 3.5%. Incremental cost-utility and cost-effectiveness ratios will be calculated from a societal perspective for each country. Ethics And Dissemination Ethics approval was obtained by the local ethics committees (Bern, CH: project ID 2022-02210; Brussels and Geel, BE: BUN 1432022000296). Results of the main trial and economic evaluation will be submitted for publication in a peer-reviewed journal. Trial Registration Number NCT05811624.