. Author manuscript; available in PMC: 2014 Jun 1.

Published in final edited form as: Arthritis Care Res (Hoboken). 2013 Jun;65(6):854–861. doi: 10.1002/acr.21928

Table 1.

Characteristics of 813 patients with rheumatoid arthritis (RA) and 813 subjects without RA.

Characteristic	RA N = 813	Non-RA N = 813	p-value
Age at incidence/index, years, mean ± SD	55.9 ± 15.7	55.9 ± 15.7	0.99
Sex, female, n (%)	556 (68%)	556 (68%)	1.0
Length of follow-up, years, mean ± SD	9.6 ± 6.9	10.9 ± 7.2	--
Smoking status at incidence/index, n (%)
Never	364 (45%)	435 (54%)	0.002
Current	178 (22%)	144 (18%)
Former	271 (33%)	234 (29%)
Body mass index at incidence/index, kg/m², mean ± SD	27.8 ± 6.2	27.8 ± 7.8	0.74
Herpes zoster prior to incidence/index, n (%)	58 (7%)	60 (7%)	0.85
Any malignancy prior to incidence/index, n (%)	53 (7%)	66 (8%)	0.22

N=number of patients, SD = standard deviation