TABLE 2.

Univariate and multivariate logistic regression model for factors associated with exposure to silica among all study sample.

	Univariate logistic regression	Multivariate logistic regression
	Silica (N = 95)*	Silica
Variables	OR (95% CI)	Adjusted OR (95% CI)
Age ≥ 50 years	0.53 (0.33–0.84)	0.42 (0.22–0.75)
Male sex	6.63 (4.27–10.28)	7.87 (4.51–13.84)
Caucasian	1.15 (0.71–3.51)	–
Disease duration ≥ 5 years	0.75 (0.49–1.14)	–
Treatment with CYC or MMF	1.95 (1.03–3.45)	1.11 (0.45–2.48)
Smoking	1.69 (1.08–2.69)	1.05 (0.60–1.89)
Diffuse disease	1.96 (1.28–2.99)	1.49 (0.75–2.94)
Digital ulcer/pitting scars	1.28 (0.84–1.94)	–
Necrosis/gangrene/amputation	0.94 (0.60–1.44)	–
Nailfold capillaroscopy	0.76 (0.48–1.23)	–
Pulmonary arterial hypertension	0.93 (0.40–1.92)	–
Joint impairment	0.82 (0.49–1.31)	–
History of renal crisis	2.15 (0.87–4.60)	–
Cancer	1.05 (0.46–2.10)	–
ACA antibody	0.60 (0.36–0.97)	0.91 (0.48–1.66)
ATA antibody	1.54 (0.87–2.60)	–
U1RNP	1.36 (0.51–3.00)	–
Ro52	0.96 (0.57–1.56)	–
PDGFR	–	–
Ku	–	–
Nor90	0.52 (0.03–2.49)	–
Nucleolar antibodies	1.09 (0.62–1.83)	–
ILD	1.45 (0.93–2.22)	–
FVC < 70	2.20 (1.23–3.74)	2.08 (1.00–4.27)
GI_14	1.08 (1.02–1.15)	1.11 (1.01–1.21)
Rodnan score	1.03 (1.01–1.04)	1.00 (0.96–1.03)
Medsger—General	1.12 (0.95–1.31)	–
Medsger—Peripheral Vascular	1.18 (0.97–1.43)	–
Medsger—Skin	1.31 (0.99–1.72)	–
Medsger—Joint/Tendon	1.19 (0.99–1.41)	–
Medsger—Muscle	1.17 (0.90–1.47)	–
Medsger—GI tract	1.33 (1.01–1.79)	0.99 (0.69–1.43)
Medsger—Lung	1.24 (1.03–1.48)	1.08 (0.82–1.42)
Medsger—Heart	1.10 (0.89–1.33)	–
Medsger—Kidney	1.12 (0.77–1.48)	–

* Reference group no exposure to silica.

– Defines not available/not applicable.

Bold signifies significant values; Variable definitions as above.