Table 7.

Multivariate logistic regression analysis of predictors of atherosclerotic plaque in systemic sclerosis and systemic lupus erythematosus patients

Variable	Beta coefficient	Odds ratio (95% CI)	P value
Systemic sclerosis (n = 85)a
Age (per 5 years)	0.904	2.47 (1.61 to 3.78)	<0.001
Nicotine use (per 5 pack-years)	0.554	1.74 (1.13 to 2.68)	0.012
Prednisolone intake (per 5 mg/day over 5 years)	0.940	2.56 (1.09 to 6.04)	0.032
Systemic lupus erythematosus (n = 98)b
Age (per 5 years)	0.824	2.28 (1.61 to 3.22)	<0.001
Nicotine use (per 5 pack-years)	0.313	1.37 (1.05 to 1.78)	0.021
ssDNA antibody positive	-1.613	0.20 (0.05 to 0.83)	0.026
Duration of azathioprine use (per 5 years)	0.947	2.58 (0.93 to 7.13)	0.068

CI, confidence interval; ssDNA, single-stranded DNA.

^aFive observations excluded from model because of missing values. Events per variable: 27/3 = 9. Constant = -10.435. Nagelkerke R² = 65.6%. Hosmer–Lemeshow test P = 0.147. ^bTwo observations excluded from model because of missing values. Events per variable: 49/4 = 12.25. Constant = -8.507. Nagelkerke R² = 65.2%. Hosmer–Lemeshow test P = 0.914.