Achieving inactive disease state in men and women with axial spondyloarthritis: results from a multi-country prospective observational study.

OBJECTIVE

To assess the probability of achieving low disease activity (LDA) and inactive disease (ID) in men vs women with recently diagnosed axial spondyloarthritis (axSpA).

METHODS

This 1-year post-hoc analysis of the PROOF study assessed patients with recently diagnosed (≤12 months) axSpA. Patients were classified as having radiographic (r) or non-radiographic (nr) axSpA using central radiograph readings. Demographics, disease characteristics, and treatment were assessed at baseline and annually thereafter. Disease activity at 1 year was assessed by Axial Spondyloarthritis Disease Activity Score (ASDAS).

RESULTS

1385 patients with baseline and year 1 data were included. Patients were classified as having nr-axSpA (n = 477 [34%]; 47% men) or r-axSpA (n = 908 [66%]; 71% men). Men had higher TNF inhibitor (TNFi) use vs women with nr-axSpA (15% vs 9%; P = 0.0238) and r-axSpA (20% vs 13%; P = 0.0118). At 1 year, TNFi use increased, remaining significantly higher for men with r-axSpA (34.9% vs 28.1%; P = 0.0497) but not nr-axSpA. Significantly more men with nr-axSpA achieved ASDAS LDA (46.0% vs 27.1%; P = 0.0002) and ID (21.7% vs 9.6%; P = 0.0013); no significant difference was observed in r-axSpA. Female sex was associated with significantly lower odds of achieving LDA and ID in nr-axSpA only (odds ratio, men vs women, LDA: 2.23 [95% CI, 1.45, 3.42]; ID: 2.40 [1.39, 4.12]).

CONCLUSION

Women with nr-axSpA, but not r-axSpA, were less likely to achieve LDA and ID after 1 year than men. These data stress the need to carefully evaluate the diagnosis and causes of pain in patients diagnosed with axSpA.