Table 2

OR and 95% CI of incident RA risk associated with an IQR increase in ambient air pollution

Timing relative to onset of RAPM10 (2 µg/m3)SO2 (8 µg/m3)NO2 (9 µg/m3)
OR (95% CI)OR (95% CI)OR (95% CI)
5th year before onset, (1307 cases, 2197 controls)
 Model 1*0.96 (0.90 to 1.03)1.17 (0.83 to 1.65)1.07 (0.96 to 1.19)
 Model 2†0.96 (0.89 to 1.03)1.04 (0.74 to 1.48)1.03 (0.92 to 1.15)
 Model 3‡0.98 (0.91 to 1.05)1.12 (0.79 to 1.59)1.07 (0.95 to 1.19)
10th year before onset, (1276 cases, 2138 controls)
 Model 1*0.98 (0.91 to 1.05)1.28 (1.06 to 1.55)1.10 (1.00 to 1.20)
 Model 2†0.97 (0.90 to 1.05)1.15 (0.95 to 1.39)1.06 (0.96 to 1.16)
 Model 3‡0.99 (0.92 to 1.07)1.18 (0.97 to 1.43)1.09 (0.99 to 1.19)
20th year before onset, (1168 cases, 1916 controls)
 Model 1*1.01 (0.94 to 1.09)1.12 (1.05 to 1.21)1.03 (0.97 to 1.10)
 Model 2†1.00 (0.93 to 1.08)1.07 (0.99 to 1.15)1.01 (0.94 to 1.08)
 Model 3‡1.02 (0.94 to 1.10)1.08 (1.00 to 1.16)1.02 (0.95 to 1.09)
Average exposure (1497 cases, 2536 controls)
 Model 1*0.95 (0.87 to 1.03)1.02 (0.95 to 1.10)0.99 (0.91 to 1.08)
 Model 2†0.94 (0.87 to 1.02)0.99 (0.92 to 1.07)0.96 (0.89 to 1.05)
 Model 3‡0.96 (0.88 to 1.04)1.01 (0.93 to 1.09)0.98 (0.90 to 1.07)
  • * Model 1 adjusted for age and gender.

  • Model 2 adjusted for age, gender, smoking status.

  • Model 3 adjusted for age, gender, smoking status, and educational attainment.

  • RA, rheumatoid arthritis.