Table 2.

Demographic features of MTX-exposed and non-MTX-exposed cases

Total		Total		Non-MTX exposed		MTX exposed		χ2 p value
		2692		1114		1578
Gender	Male	1804	67.0%	721	64.7%	1083	68.6%	0.034
	Female	888	33.0%	393	35.3%	495	31.4%
Age of RA onset	<55	1144	42.5%	436	39.1%	708	44.9%	<0.001
	55–64	723	26.9%	277	24.9%	446	28.3%
	65+	825	30.6%	401	36.0%	424	26.9%
Baseline smoking status	Never	991	36.8%	346	31.1%	645	40.9%	0.058
	Current	594	22.1%	179	16.1%	415	26.3%
	Ex-smoker	518	19.2%	172	15.4%	346	21.9%
	Other	25	0.9%	2	0.2%	23	1.5%
	Missing	564	21.0%	415	37.3%	149	9.4%
Baseline erosions	No erosions	1883	69.9%	808	72.5%	1075	68.1%	0.117
	Erosions	699	26.0%	276	24.8%	423	26.8%
	Missing	110	4.1%	30	2.7%	80	5.1%
Baseline RF	Negative	977	36.3%	462	41.5%	515	32.6%	<0.001
	Positive	1633	60.7%	628	56.4%	1005	63.7%
	Missing	82	3.0%	24	2.2%	58	3.7%
Baseline nodules	None	2515	93.4%	1057	94.9%	1458	92.4%	0.010
	Nodules	177	6.6%	57	5.1%	120	7.6%
Baseline DAS	<1.6	31	1.2%	5	0.4%	26	1.6%	<0.001
	1.6–2.59	298	11.1%	163	14.6%	135	8.6%
	2.6–3.2	345	12.8%	180	16.2%	165	10.5%
	>3.2–4.19	543	20.2%	243	21.8%	300	19.0%
	4.2–5.1	–	–	–	–	–	–
	>5.1	1415	52.6%	503	45.2%	912	57.8%
	Missing	60	2.2%	20	1.8%	40	2.5%

DAS, disease activity; MTX, methotrexate; RA, rheumatoid arthritis.