Table 2 Correlations (Spearman r) between indices of disease activity and between disease activity indices and core measures, age and disease duration at both time points

		T1
		DAS28	SDAI	CDAI	RAPID3	RADAI	TJC	SJC	PhysGlob	PatGlob	MHAQ	Pain	ESR	CRP	Age	DisDur
T2	DAS28	X	0.89**	0.88**	0.62**	0.71**	(0.85)**	(0.75)**	0.77**	(0.57)**	0.51**	0.56**	(0.53)**	0.39*	0.24	0.00
	SDAI	0.88**	x	0.94**	0.66**	0.74**	(0.79)**	(0.75)**	(0.81)**	(0.66)**	0.45*	0.57**	0.24	(0.48)*	0.33	0.03
	CDAI	0.88**	0.95**	x	0.76**	0.79**	(0.87)**	(0.66)**	(0.79)**	(0.79)**	0.49**	0.68**	0.14	0.32	0.30	0.01
	RAPID3	0.70**	0.66**	0.74**	x	0.89**	0.59**	0.21	0.52**	(0.91)**	(0.73)**	(0.96)**	0.10	0.26	0.31	0.18
	RADAI	0.72**	0.80**	0.84**	0.81**	x	0.66**	0.33	0.63**	0.77**	0.67**	(0.86)**	0.24	0.35	0.37	0.22
	TJC	(0.72)**	(0.76)**	(0.86)**	0.51**	0.70**
	SJC	(0.79)**	(0.83)**	(0.78)**	0.38*	0.47*
	PhysGlob	0.78**	(0.84)**	(0.74)**	0.37	0.49**
	PatGlob	(0.62)**	(0.63)**	(0.72)**	(0.92)**	0.80**
	MHAQ	0.54**	0.50**	0.55**	(0.85)**	0.57**
	Pain	0.70**	0.67**	0.74**	(0.96)**	0.82**
	ESR	(0.42)*	0.11	0.00	0.16	0.06
	CRP	0.36	(0.42)*	0.29	0.41*	0.27
	Age	0.17	0.21	0.22	0.22	0.12
	DisDur	0.03	0.13	0.13	0.15	0.18

Figures in parentheses indicate that the variable is included for calculation of respective disease activity index.
*p<0.05, **p<0.01.
CDAI, Clinical Disease Activity Index; CRP, C-reactive protein; DAS28, 28-joint Disease Activity Score; DisDur, disease duration; ESR, erythrocyte sedimentation rate; MDC%, minimum detectable change; PatGlob, patient global assessment of disease activity; PhysGlob, physician/assessor global estimate of disease activity; RADAI, Rheumatoid Arthritis Disease Activity Index; RAPID3, Routine Assessment of Patient Index Data; SDAI, Simple Disease Activity Index; SDD, smallest detectable difference; SJC, swollen joint count; TJC, tender joint count.