. 2020 Jul 1;7(3):105–111. doi: 10.5152/eurjrheum.2020.19199

Table 2.

Agreement in categorizing RA disease activity scores between the indices.

	R	Lo	Mo	Hi	R	Lo	Mo	Hi	R	Lo	Mo	Hi
DAS28-ESR	17	1^*	1^*	0^*	12	6^*	1^*	0^*	12	6^*	1^*	0^*	R
	19^*	9	1^*	0^*	7^*	20	2^*	0^*	5^*	23	1^*	0^*	Lo
	4^*	13^*	59	1^*	1^*	26^*	44	6^*	0^*	23^*	50	4^*	Mo
	0^*	0^*	26^*	24	0^*	0^*	13^*	37	0^*	0^*	19^*	31	Hi

Kappa 0.456 (p<0.001)	DAS28-CRP				20	20^*	0^*	0^*	17	23^*	0^*	0^*	R
ICC 0.882					0^*	18	5^*	0^*	0^*	19	4^*	0^*	Lo
(0.438, 0.955)					0^*	14^*	54	19^*	0^*	10^*	65	12^*	Mo
Agreement 62.3%					0^*	0^*	1^*	24	0^*	0^*	2^*	23	Hi
Incompatibility 37.7%

Kappa 0.506	Kappa 0.538	CDAI							17	3^*	0^*	0^*	R
(p<0.001)	(p<0.001)								0^*	48	4^*	0^*	Lo
ICC 0.202	ICC 0.190								0^*	1^*	59	0^*	Mo
(0.055, 0.339)	(0.043, 0.329)								0^*	0^*	8^*	35	Hi
Agreement 64.6%	Agreement 66.3%
Incompatibility 35.4%	Incompatibility 33.7%

Kappa 0.5215	Kappa 0.5887	Kappa 0.8717	SDAI
(p<0.001)	(p<0.001)	(p<0.001)
ICC 0.194	ICC 0.183	ICC 0.975
(0.47, 0.332)	(0.36, 0.323)	(0.854, 0.990)
Agreement 66.3%	Agreement 70.9%	Agreement 90.9%
Incompatibility 33.7%	Incompatibility 29.1%	Incompatibility 9.1%

Patients categorized into incompatible categories by two indices. The Kappa coefficient, ICC with its 95% CI levels of agreement, and percentage of incompatibly classified patients are also shown. Cutoff values are based on published criteria (14).

CDAI: clinical disease activity index; CI: confidence interval; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; Hi: high activity; ICC: intra-class coefficient; R: remission; Lo: low activity; Mo: moderate activity; SDAI: simple disease activity index.