Influence of seasonal changes on disease activity and distribution of affected joints in rheumatoid arthritis

Table 2 Values of composite indices of disease activity in patients with rheumatoid arthritis by season in NinJa2016

	Total	Spring	Summer	Fall	Winter	p-value^#
	n = 12,839	n = 3250	n = 916	n = 1021	n = 7652
DAS28-CRP	2.3 ± 1.0	2.4 ± 1.1	2.3 ± 1.0	2.2 ± 1.0	2.3 ± 1.0	0.001
SDAI	5.1 [2.1, 9.7]	5.4 [2.1,10.2]	4.8 [1.9, 9.4]	4.3 [1.7, 8.1]	5.1 [2.1, 9.8]	< 0.001
CDAI	4.7 [1.8, 9.0]	5.0 [1.9, 9.7]	4.3 [1.6, 8.6]	4.0 [1.5, 7.6]	4.7 [1.9, 9]	< 0.001

^#Analysis of variance was used for the DAS28-CRP score. The Kruskal-Wallis test was used for the SDAI and CDAI scores. DAS28 Disease Activity Score with 28-joint counts (average value ± standard deviation), SDAI simplified disease activity index (median [interquartile range]), CDAI clinical disease activity index (median [interquartile range])

ISSN: 1471-2474