Biological treatment in ankylosing spondylitis in the Nordic countries during 2010–2016: a collaboration between five biological registries

Objectives: Large-scale observational cohorts may be used to study the effectiveness and rare side effects of biological disease-modifying anti-rheumatic drugs (bDMARDs) in ankylosing spondylitis (AS), but may be hampered by differences in baseline characteristics and disease activity across countries. We aimed to explore the research infrastructure in the five Nordic countries regarding bDMARD treatment in AS.Method: This observational cohort...