Table 4.

Multivariate analysis of disease activity measures for patients with RA alone or RA with FM

	RA alone	RA and FM
	Meana	Meana	P values
MBDA score	29.8	29.8	0.988
DAS28-CRP	2.6	3.2	0.008
SDAI	7.9	15.2	<0.001
CDAI	7.6	15.0	<0.001
RAPID3b	5.7	12.4	<0.001
Patient global, NRS	1.9	4.7	<0.001
Physician global, NRS	2.0	3.0	<0.001
Pain, NRS	2.0	5.0	<0.001
Physical functionb	1.3	2.2	<0.001
Tender joint count	4.1	6.7	0.153c
Swollen joint count	2.5	3.0	0.527c
CRP, mg/dl	0.2	0.1	0.431

^aMean values adjusted in multivariate analysis for non-redundant factors that were significantly different between the two groups (body mass index and non-biologic disease-modifying anti-rheumatic drug use).

^bPhysical function scores were available for all 198 patients; values were normalized for nine patients with RA alone and one patient with RA and FM, based on answers being available for only 8 or 9 of the 10 questions for physical function.

^cχ² test for tender joint count and swollen joint count; all others t-statistic.

NRS: numeric rating scale; RAPID3: Routine Assessment of Patient Index Data 3; MBDA: multibiomarker disease activity; SDAI: Simple Disease Activity Index; CDAI: Clinical Disease Activity Index.