Background The Bath Ankylosing Spondylitis (AS) Disease Activity Index (BASDAI), an index of only patient-self-report measures, and AS Disease Activity Score (ASDAS)1, which adds patient global estimate and laboratory tests to BASDAI elements are widely used in Spondyloarthritis (SpA). Both indices are specifically designed to evaluate disease activity AS patients. Some studies have shown worse BASDAI in women, but sex-related differences by ASDAS remain unclear 2,3.
Objectives To analyze reports of sex-stratified disease activity measures -BASDAI and ASDAS- in patients with SpA.
Methods Data sources included PubMed (1950 to December 2016), Embase, Web Of Science, and manual searches of references lists. We included observational studies and randomized trials comparing disease activity scores, specifically BASDAI and ASDAS, between men and women with SpA. Studies quality was determined in line with the STROBE statement for observational studies and CONSORT statement for RCT, considering <50% positive items as low quality. Randomized effects were performed to report the mean difference (95% confidence interval) by gender, and heterogeneity was measured via I2 statistic in order to check the results robustness.
Results From 672 identified studies 18 cross-sectional studies, 3 cohort, 2 case-control studies, and 1 RTC reported sex-stratified BASDAI and ASDAS. ASDAS was evaluated in 3,758 patients (36.5% women) in 9 studies, and BASDAI included 12,329 patients (34.3% women) in 24 studies. In a metanalysis of mean difference BASDAI including 19 studies the mean difference was 0.56 (95% CI: 0.47, 0.66) and I2=43%, indicating a significantly higher disease activity in women (Figure). In a metanalysis of 7 studies ASDAS the mean difference was 0.06 (95% CI: -0.04, 0.16) and I2=41%, not showing statistically significant differences.
Conclusions We identified relevant sex differences in disease activity according to BASDAI with higher disease activity in women, but not according to ASDAS. In SpA, women present more peripheral arthritis and higher pain, which may influence the BASDAI score, mainly based on patient-self-report measures. It is important to recognize these differences that may influence management decisions based on disease activity measures.
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Acknowledgements Faculty of Health Sciences and University Institute for Gender Studies of the University of Alicante supported M. Blasco-Blasco.
Disclosure of Interest None declared