Table 2.

HRs (95% CIs) from Cox proportional hazard models for incident RA (1976–2004) with distance to the closest A1–A3 road measured in 2000.

Distance to road (m)	Cases	Person-years	Basic modela	Adjusted modelb
Whole cohort (n = 90,297)
0 to < 50	52	136,205	1.33 (1.00–1.77)	1.31 (0.98–1.74)
≥ 50 to < 200	67	271,200	0.85 (0.66–1.09)	0.84 (0.65–1.08)
≥ 200	568	1,976,600	Reference	Reference
Nonsmokers (n = 40,128)c
0 to < 50	23	62,223	1.63 (1.06–2.52)	1.62 (1.04–2.52)
≥ 50 to < 200	21	117,291	0.79 (0.50–1.24)	0.78 (0.49–1.22)
≥ 200	200	883,025	Reference	Reference

^aAdjusted for current age in months and calendar year.

^bAdjusted for current age in months, race, smoking status (current, former, never), pack-years of cigarette smoking, age at menarche, parity, duration of lactation, menopausal status, menopausal hormone use, oral contraceptive use, race, physical activity, body mass index, mother’s and father’s occupation, education level, martial status, husband’s education, and census-tract-level median family income and house value.

^cNever-smokers at baseline (1976).