British Axial Spondyloarthritis Inception Cohort (BAxSIC): a protocol for a multicentre real-world observational cohort study of early axial spondyloarthritis

Abstract

Objectives Timely diagnosis remains a challenge in axial Spondyloarthritis (axSpA). In addition, data are scarce on the impact of diagnostic delay and disease progression in affected individuals. The British Axial Spondyloarthritis Inception Cohort (BAxSIC) study aims to investigate the impact of newly diagnosed axSpA, the natural history of the disease and the effect of diagnostic delay on disease outcomes. Methods BAxSIC is a prospective, multi-centre, observational study. Eligible participants are adults (aged 16 years old or over), with a physician-confirmed diagnosis of axial Spondyloarthritis in the six months prior to study entry, recruited from secondary and tertiary rheumatology centres in the United Kingdom (UK). Participants will be followed up for 3 years, with in-person visits at baseline and 24 months. In addition, patient self-reported assessments (PROMs questionnaires) will be recorded remotely via the online electronic case report form (eCRF) at 6, 12, 18, 30 and 36 months. Results Trial status: The first patient was enrolled in BAxSIC in June 2023. Recruitment is currently ongoing and is planned to end in June 2026. Initial results will be available in 2027. Since opening, the trial has undergone two protocol amendments. Conclusion The BAxSIC study is the first inception cohort designed to investigate the impact of diagnostic delay on clinical presentation and long-term functional outcomes in patients with axSpA in the UK. With an innovative, patient-led virtual longitudinal data collection model, data generated from this study will help inform and improve the care of people newly diagnosed with axSpA.