Table 4

Spearman's correlation coefficient of DAREA with disease activity variables and composite scores at baseline

Source of data	N	DAS28_CRP	DAS28_ESR	SDAI	CDAI	Pain	PtGA	EGA	SJC28	TJC28	SJC66	TJC68	SF-36 pf	HAQ^†	PASI	CRP	ESR
IMPACT 2	180	0.85^***	–	0.89^***	0.89^***	0.25^**	0.32^***	0.30^***	0.59^***	0.80^***	0.63^***	0.89^***	0.26^**	–	0.002; NS	0.08; NS	–
IMPACT 2/DIP involvement^‡	40	0.89^***	–	0.93^***	0.93^***	0.12; NS	0.25; NS	0.54^***	0.66^***	0.80^***	0.71^***	0.84^***	0.15; NS	–	0.10; NS	0.27; NS	–
Observational	99	0.95^***	0.83^***	0.97^***	0.94^***	0.86^***	0.85^***	0.74^***	0.66^***	0.84^***	0.73^***	0.85^***	–	0.54^***	NS	0.34^**	0.27^*
Observational/DIP involvement^‡	41	0.87^***	.87^***	0.97^***	0.94^***	0.73^***	0.71^***	0.45^*	0.41^*	0.57^**	0.45^*	0.71^***	–	0.69^***	NS	0.52^**	0.50^*

Given are correlation coefficients (Spearman's r).
↵* p<0.05,
↵** p<0.01,
↵*** p<0.001.
↵† SF-36 pf for IMPACT 2, HAQ for observational set;
↵‡ DIP involvement: according to classification by Wright and Moll.3
CDAI, clinical disease activity index; CRP, C reactive protein; DAREA, ‘Disease Activity index for REactive Arthritis’; DAS28, disease activity score using 28 joint counts; DIP, distal interphalangeal joint; EGA, evaluator global assessment; ESR, erythrocyte sedimentation rate; HAQ, Health Assessment Questionnaire; IMPACT 2, Infliximab Multinational Psoriatic Arthritis Controlled Trial 2; PASI, psoriasis area and severity index; PtGA, patient global assessments; SDAI, simplified disease activity index; SJC, swollen joint count; TJC, tender joint count.