In this research project, the researchers will implement the Start-MSK tool, which is a screening instrument to support and facilitate the work of directing the right treatment to the right patient with musculoskeletal pain to promote recovery and improve health outcomes. The screening tool aims to identify prognostic factors to stratify patients into groups with different risks for long-term pain and disability. A total of 300 patients, 18 years and older, with musculoskeletal pain who seek primary care rehabilitation and a physiotherapist will be recruited. For this project, the investigaters are in contact with 10-15 primary care units in the Stockholm, Västra Götaland, Uppsala and Skåne Regions. Patients who are recruited will receive care from a physiotherapist and with a follow-up for 6 months. The primary aim is to investigate whether Start-MSK can predict the outcome (pain, quality of life) of the treatment at 3 months, and at long-term follow-up 6 months. The investigators will also conduct interview studies using focus groups with the physiotherapists and individual interviews with included patients who are part of the study to capture their experiences of using the Start-MSK; about how the participants feel the use has affected treatment and the measures they have received. Through Start-MSK, which is a step towards precision-based treatment for musculoskeletal pain, some of the long-term pain should be preventable.