ABSTRACT: BACKGROUND:Musculoskeletal pain is globally a leading cause of physical disability. Many musculoskeletal-related pain conditions, such as low back pain, often resolve spontaneously. In some individuals, pain may recur or persist, leading to ong-term physical disability, reduced work capacity, and sickness absence. Early identification of individuals in which this may occur, is essential for preventing or reducing the risk of developing persistent musculoskeletal pain and long-term sickness absence. The aim of the trial described in this protocol is to evaluate effects of an early intervention, the PREVSAM model, on the prevention of sickness absence and development of persistent pain in at-risk patients with musculoskeletal pain. METHODS:Eligible participants are adults who seek health care for musculoskeletal pain and who are at risk of developing persistent pain, physical disability, and sickness absence. Participants may be recruited from primary care rehabilitation centres or primary care healthcare centres in Region Västra Götaland. Participants will be randomised to treatment according to the PREVSAM model (intervention group) or treatment as usual (control group). The PREVSAM model comprises an interdisciplinary, person-centred rehabilitation programme, including coordinated measures within primary health care, and may include collaboration with participants' employers. The primary outcome sickness absence is operationalised as the number and proportion of individuals who remain in full- or part-time work, the number of gross and net days of sickness absence during the intervention and follow-up period, and time to first sickness absence spell. Secondary outcomes are patient-reported short-term sickness absence, work ability, pain, self-efficacy, health-related quality of life, risk for sickness absence, anxiety and depression symptoms and physical disability at 1 and 3?months after inclusion (short-term follow-up), and at 6 and 12?months (long-term follow-up). A cost-effectiveness analysis is planned and drug consumption will be investigated. DISCUSSION:The study is expected to provide new knowledge on the effectiveness of a comprehensive rehabilitation model that incorporates early identification of patients with musculoskeletal pain at risk for development of sickness absence and persistent pain. The study findings may contribute to more effective rehabilitation processes of this large patient population, and potentially reduce sickness absence and costs. TRIAL REGISTRATION:ClinicalTrials.gov Protocol ID: NCT03913325 , Registered April 12, 2019. Version 2, 10 July 2020. Version 2 changes: Clarifications regarding trial aim and inclusion process.