Worse scores but similar patterns of disease activity: interpreting outcomes in women with axial spondyloarthropathy

Abstract

Objective The aim of this study was to evaluate the impact of sex on disease activity in axial spondylitis (axSpA). Method Data were extracted from the Ankylosing Spondylitis Registry of Ireland (ASRI). In this cross-sectional study, patients were analysed on the basis of sex, with a series of comparison analyses performed. Results Overall, 886 participants were enrolled in the ASRI [232 (26.2%) women, 644 (72.6%) men]. Females recorded significantly worse Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (4.57 vs 3.83, p < 0.01) and Ankylosing Spondylitis Quality of Life questionnaire (ASQoL) (7.51 vs 6.12, p < 0.01) scores than males. There was a stronger correlation in the Bath Ankylosing Spondylitis Functional and Metrology Indices (BASFI and BASMI) in females (rs = 0.619, p < 0.01) than in males (rs = 0.572, p < 0.01). Analysis of factors in BASDAI revealed that the higher total scores in females compared to males were due not to any single component, but to worse scores in all six components of the BASDAI combined. Ranking of components by severity between sexes revealed identical ranking in four of the six components of the BASDAI. Conclusions Women with axSpA reported significantly worse disease activity, quality of life, and functional ability than men. However, the BASDAI capturedsimilar patterns of disease activity. Limitation of spinal mobility in women with axSpA corresponded to greater impairment in functional ability. Further evaluation of disease monitoring tools is required to ensure that disease activity is accurately captured in men and women with axSpA.