. 2007 Nov 6;9(6):R116. doi: 10.1186/ar2323

Table 3.

Linear regression analysis of carotid intima-media thickness, rheumatoid arthritis features and cardiovascular risk factors in recent-onset rheumatoid arthritis patients

Variable	R²value	Standardized β coefficient	Standard error	t value	P value	Confidence interval
Univariate model
Number of swollen joints	0.12	0.391	0.041	2.25	0.032	0.008–0.174
Disease activity score (DAS4v)^a	0.16	0.431	0.079	2.74	0.01	0.056–0.377
C-reactive protein level (mg/l)^a	0.14	0.407	0.025	2.71	0.01	0.018–0.121
Rheumatoid factor presence^b			0.047		0.54	0.072–0.117
Age at onset of rheumatoid arthritis^a	0.56	0.759	0.001	7.19	<0.001	0.008–0.014
Male sex^b			0.066		0.018	-0.298 to -0.030
Pack-year history	0.10	0.320	0.001	2.09	0.044	0.000–0.005
History of smoking, ever^b			0.062		0.002	-0.329 to -0.079
Systolic blood pressure^a	0.27	0.540	0.184	3.63	<0.001	0.292–1.040
Cholesterol level	0.01	0.146	0.197	0.82	0.417	-0.564 to -0.239
Multivariate model
Age at onset of rheumatoid arthritis	0.64		0.002	6.11	<0.001	0.007–0.012
C-reactive protein level (mg/l)			0.001	2.18	0.038	0.000–0.004

Adjusted R²of the multivariate linear regression model = 0.69. ^aVariables entered into the multivariate model. Parameters determined by univariate linear regression analysis or t test^b.