Objective. It is unknown if in axial spondyloarthritis (axSpA) patients' illness perceptions and coping strategies change when disease activity changes.Methods. Patients diagnosed with axSpA and... Show moreObjective. It is unknown if in axial spondyloarthritis (axSpA) patients' illness perceptions and coping strategies change when disease activity changes.Methods. Patients diagnosed with axSpA and with 1 or more follow-up visits (1 and/or 2 yrs in the SPACE cohort) were included. Mixed linear models were used for illness perceptions (range 1-5), coping (range 1-4), back pain (numeric rating scale range 0-10), health-related quality of life (range 0-100), physical and mental component summary (PCS and MCS; range 0-100), work productivity loss (WPL; range 0-100), and activity impairment (AI; range 0-100%), separately, to test if they changed over time.Results. At baseline, 150 axSpA patients (mean age 30.4 yrs, 51% female, 65% HLA-B27+) had a mean (SD) numeric rating scale back pain of 4.0 (2.5), PCS of 28.8 (14.0), MCS of 47.8 (12.4), WPL of 34.1% (29.8), and AI of 38.7% (27.9). Over 2 years, clinically and statistically significant improvements were seen in the proportion of patients with an Ankylosing Spondylitis Disease Activity Score (ASDAS) of low disease activity (from 39% at baseline to 68% at 2 years), back pain (-1.5, SD 2.2), AI (-14.4%, SD 27.2), PCS (11.1, SD 13.3), and WPL (-15.3%, SD 28.7), but MCS did not change (0.7, SD 13.9; P = 0.201). In contrast, illness perceptions and coping strategies did not change over a period of 2 years. For example, at 2 years patients believed that their illness had severe "consequences" (2.8, SD 0.9) and they had negative emotions (e.g., feeling upset or fear) towards their illness ["emotional representation", 2.5 (0.8)]. Patients most often coped with their pain by putting pain into perspective ["comforting cognitions", 2.8 (0.6)] and tended to cope with limitations by being optimistic ["optimism", 2.9 (0.7)].Conclusion. While back pain, disease activity, and health outcomes clearly improved over 2 years, illness perceptions and coping strategies remained remarkably stable. Show less