Fig. 1.

a, b Current treatment after one to five whole years since starting a first TNFi. The figure describes the treatment status for bio-naïve patients with ankylosing spondylitis, 1–5 years after starting a first ever TNFi. (a) Patients who have either used > 3 different TNFi or cycled back to previous TNFi. (b) The solid black line indicates the percentage of the patients who are still on their first TNFi at the end of each year, and who have collected at least 75% of that year’s defined dose from a pharmacy. (c) The dotted black line indicates the percentage who were lost to follow-up (censored) due to death, emigration, “uncertain treatment status (see Methods)” or past the end of the study period. DDD = defined daily dose; csDMARDs = conventional synthetic disease-modifying anti-rheumatic drugs; TNFi = tumour necrosis factor alpha inhibitor; AS = ankylosing spondylitis