Smoking–gender interaction and risk for rheumatoid arthritis

Table 1 Comparison between patients with rheumatoid arthritis and control individuals according to sex

	Women			Men
	RA cases (n = 777)	Controls (n = 1104)	P	RA cases (n = 318)	Controls (n = 426)	P
Age in years (mean ± SD)	62 ± 13	56 ± 15	<0.001	63 ± 12	53 ± 14	<0.001
Education in years (mean ± SD)	9.7 ± 3.8	10.9 ± 4.0	<0.001	8.6 ± 3.3	10.8 ± 4.2	<0.001
BMI (kg/m²; mean ± SD)	26 ± 4.6	25 ± 4.6	0.54	26 ± 3.8	27 ± 3.7	0.62
Proportion currently smoking (%)	7	14	<0.001	18	21	0.83
Proportion past smokers (%)	16	22	0.02	66	50	<0.001
HAQ disability index (mean ± SD)*	0.89 ± 0.8	0.30 ± 0.6	<0.001	0.68 ± 0.8	0.21 ± 0.5	<0.001
General health VAS (mean ± SD)^†	35.1 ± 22	22.4 ± 22	<0.001	31.8 ± 21	20.8 ± 22	<0.001
Pain VAS (mean ± SD)^†	34 ± 25	21 ± 25	<0.001	29 ± 23	19 ± 23	<0.001

*Health Assessment Questionnaire (HAQ) disability index (range 0–3); ^†visual analog scale (VAS; range 0–100, best to worst). BMI, body mass index; RA, rheumatoid arthritis.

ISSN: 1478-6362