Table 8. Agreement among disease activity indices.

Agreement between indices according to disease classification
	Weighted Kappa (CI 95%)
DAS28 ESR X DAS28 CRP	0.63 (0.59–0.67)
DAS28 ESR X SDAI	0.60 (0.57–0.64)
DAS28 ESR X CDAI	0.60 (0.57–0.64)
DAS28 CRP X SDAI	0.70 (0.67–0.73)
DAS28 CRP X CDAI	0.66 (0.63–0.69)
SDAI X CDAI	0.88 (0.86–0.90)

DAS28-CRP: Disease Activity Score 28- C reactive protein; DAS28-ESR: Disease Activity Score 28 -erythrocyte sedimentation rate; SDAI: Simplified Activity Index; CDAI: Clinical Activity Index.