Abstract
Objective To explore residual disease, defined as substantial symptoms and disease burden despite a remission/low disease activity (described as 'LDA') state, in patients with axial spondyloarthritis (axSpA) and to determine which factors are associated with residual disease.
Methods For this cross-sectional observational study, one timepoint per patient was used from SpANet, a web-based monitoring registry for (ax)SpA. Patients with an Ankylosing Spondylitis Disease Activity Score (ASDAS)<2.1 (LDA) were included. Indicators of residual disease (outcomes) included fatigue (primary outcome), pain, physical functioning, health-related quality of life (HRQoL) and peripheral symptoms. Sex was the primary explanatory factor for residual disease. Other explanatory factors included demographics and disease-related factors. Associations between these factors and presence/extent of residual disease were explored using logistic/linear regression.
Results In total, 267 patients in an LDA state were included. Mean age was 50.6 (SD 14.3) years and 100 (37.5%) were female. Residual disease occurred frequently (n=114 [42.7%] had fatigue scores >4/10, n=34 [17.8%] pain >4/10), also in those in remission (ASDAS<1.3). Physical HRQoL was reduced in 27% and moderate/poor in 33%. Multivariable regression analyses showed that reported fatigue was more severe and prevalent in female patients (fatigue severity [0-10]: Bfemale=0.78, 95%CI 0.18-1.38; fatigue >4/10: ORfemale=3.29, 95%CI 1.74-6.20). Other indicators of residual disease (pain/peripheral symptoms/physical HRQoL) were also more severe and/or more prevalent in females.
Conclusion Residual disease is frequent in patients with axSpA who are in an LDA state, including remission. Especially female patients report this. Future studies should address how to prevent/manage residual disease in axSpA.
