Table 5 Factors predicting occurrence of serious infection (all sites combined).

Factor	Univariate	Multivariate
	RR (95% CI) adjusted for age and sex	RR (95% CI) adjusted for age and sex
RA cumulative at 5th assessment:
Yes vs no	1.8 (1.2 to 2.6)	1.1 (0.6 to 2)
Rheumatoid factor*
Ever positive vs negative	2.2 (1.5 to 3.4)	2.0 (1.3 to 3.0)
Baseline smoking history†
Current or past vs never	1.5 (1.0 to 2.4)	1.2 (0.7 to 2.1)
Current only vs never	1.7 (1.2 to 2.6)	1.6 (1.0 to 2.5)
Steroid use
Ever vs never	2.3 (1.6 to 3.5)	2.2 (1.5 to 3.4)
DMARD use
Ever vs never	1.3 (0.9 to 1.9)	1.0 (0.6 to 1.6)
Erosive joints‡
Ever vs never	1.3 (0.9 to 1 .9)	1.0 (0.7 to 1.6)
Baseline HAQ
⩾1 vs <1	1.0 (0.7 to 1.5)	0.6 (0.3 to 1.1)
Five‐year HAQ
⩾1 vs<1	1.0 (0.7 to 1.5)	1.2 (0.8 to 2.0)
Mean HAQ
⩾1 vs <1	1.3 (0.9 to 1.8)	1.9 (1.0 to 3.4)

DMARD, disease‐modifying antirheumatic drug; HAQ, Health Assessment Questionnaire; RA, rheumatoid arthritis.

*Based on 93% complete data.

†Based on 94% complete data.

‡Based on 68% complete data.