Biological treatment of ankylosing spondylitis : A nationwide study of treatment trajectories on a patient level in clinical practice
Background: There is substantial evidence that patients with ankylosing spondylitis (AS) have high response rates to tumour necrosis factor inhibitors (TNFi), a low likelihood of successful treatment termination, but yet a limited drug retention. Whereas several reports have assessed drug retention rates for TNFi in AS, there are few, if any, studies investigating the actual treatment trajectories