Table 1.

Comparison of patient characteristics at the index visit between the exposed and unexposed groups

	Exposed (n = 47)	Unexposed (n = 254)	p
Patient characteristics
Median date of cohort entry, mm/yyyy	12/2008	02/2007
Age, mean ± SD	50.1 ± 10.4	55.1 ± 12.3	0.01
Female, n (%)	37 (81.5%)	207 (78.7%)	0.66
Ethnicity, n (%)			0.39
Caucasian	36 (76.6%)	204 (81.6%)
Aboriginal	1 (2.1%)	14 (5.6%)
Black	1 (2.1%)	3 (1.2%)
Asian	1 (2.1%)	5 (2.0%)
Latin America	2 (4.3%)	4 (1.6%)
Other	6 (12.8%)	20 (8.0%)
Past and/or current smoker, n (%)	27 (62.8%)	148 (60.2%)	0.50
Disease duration (years), mean ± SD	5.5 ± 7.4	11.7 ± 9.3	< 0.01
Interstitial lung disease, n (%)	31 (67.4%)	102 (40.3%)	< 0.01
Pulmonary hypertension, n (%)^	4 (8.7%)	17 (7.5%)	0.76
Inflammatory myositis, n (%)	7 (14.9%)	36 (14.2%)	0.89
Inflammatory arthritis, n (%)	13 (27.7%)	103 (40.6%)	0.01
Digital ulcers, n (%)	29 (61.7%)	164 (64.6%)	0.71
Prior SRC, n (%)	5 (10.6%)	14 (5.5%)	0.32
GI-14 score, mean ± SD	2.6 ± 2.5	2.6 ± 2.5	0.93
Auto antibodies, n (%)*
Anti-centromere	5 (12.5%)	64 (27.6%)	0.04
Anti-topoisomerase I	11 (27.5%)	40 (17.2%)	0.13
Anti-RNA polymerase III	11 (27.5%)	46 (19.8%)	0.27
Antinuclear antibody (titer ≥ 1/160)	38 (88.4%)	219 (92.4%)	0.37
CRISS variables
mRSS, mean ± SD	15.0 ± 9.4	13.1 ± 9.4	0.15
FVC%, mean ± SD	88.5 ± 18.7	91.4 ± 17.6	0.36
HAQ, mean ± SD	0.8 ± 0.7	0.7 ± 0.7	0.65
PTGA disease severity, mean ± SD	3.5 ± 2.6	3.2 ± 2.2	0.58
PGA disease severity, mean ± SD	4.2 ± 2.3	2.5 ± 1.9	< 0.01

SRC scleroderma renal crisis, GI-14 score Canadian Scleroderma Research Group 14 point score for gastrointestinal involvement, CRISS composite response index in diffuse systemic sclerosis, mRSS modified Rodnan skin score, FVC% percent of predicted forced vital capacity, HAQ Health Assessment Questionnaire, PTGA patient global assessment, PGA physician global assessment

^{^}Only 46 exposed and 227 unexposed patients had known pulmonary hypertension status

*Only 40 exposed and 232 unexposed patients had documented auto antibodies respectively