Table 4

Risk of developing RA among workers exposed to organic dust from highest intensity compared with never exposed workers (n=1 41 917)

PercentilesAll RA casesSeropositive RASeronegative RA
Cases/controlsMean highest intensity (mg/m3)Median years since last occupation classified as exposedOR (95% CI)*OR (95% CI)*OR (95% CI)*
Wood dust
 Unexposed11971/123 4581.01.01.0
 ≤50275/20710.44251.1 (0.9 to 1.2)1.0 (0.9 to 1.2)1.2 (1.0 to 1.6)
 >50–≤75121/11921.24110.9 (0.7 to 1.1)0.9 (0.7 to 1.1)0.9 (0.7 to 1.3)
 >7583/8941.78210.9 (0.7 to 1.1)0.9 (0.7 to 1.1)0.8 (0.6 to 1.2)
 P value for trend0.2060.2030.678
Animal dust
 Unexposed12053/124 7281.01.01.0
 ≤50175/14540.01221.2 (1.0 to 1.4)1.1 (0.9 to 1.4)1.4 (1.1 to 1.7)
 >50–≤75136/11320.02241.2 (1.0 to 1.4)1.1 (0.9 to 1.4)1.3 (1.0 to 1.8)
 >75109/8420.19131.3 (1.1 to 1.6)1.4 (1.1 to 1.8)1.1 (0.7 to 1.6)
 P value for trend0.1140.0820.758
Paper dust
 Unexposed11650/120 3471.01.01.0
 ≤50311/31740.05201.0 (0.9 to 1.1)1.0 (0.8 to 1.1)0.9 (0.8 to 1.2)
 >50–≤75153/15010.09151.1 (0.9 to 1.3)1.0 (0.8 to 1.2)1.2 (0.9 to 1.5)
 >75168/14740.28231.1 (1.0 to 1.3)1.2 (1.0 to 1.5)0.9 (0.6 to 1.2)
 P value for trend0.6590.3770.591
Textile dust
 Unexposed12081/124 4551.01.01.0
 ≤50273/22800.11301.2 (1.0 to 1.3)1.2 (1.0 to 1.4)1.2 (0.9 to 1.4)
 >50–≤7522/2410.20390.9 (0.6 to 1.4)1.0 (0.6 to 1.6)0.8 (0.3 to 1.7)
 >7587/7440.25301.1 (0.9 to 1.4)1.2 (0.9 to 1.5)1.1 (0.7 to 1.6)
 P for trend0.0990.0660.779
Flour dust
 Unexposed12503/128 5871.01.01.0
 ≤5079/7481.17241.0 (0.8 to 1.3)1.0 (0.7 to 1.3)1.2 (0.8 to 1.7)
 >50–≤750/0
 >750/0
 P value for trend0.5380.7560.499
  • *Adjusted for county, age, sex, index year, education and silica dust.

  • RA, rheumatoid arthritis.