OR of RA together with 95% CI among workers classified as ever exposed to asbestos or silica in different censuses compared with workers classified as never exposed (n=126 534)
| All RA cases | Seropositive RA | Seronegative RA | |||||||
| Cases/controls | Median intensity for asbestos (fibre/cm3) and silica (mg/m3) | Median years since last occupation classified as exposed | Crude OR (95 % CI)* | Adjusted OR (95 % CI)† | Crude OR (95 % CI)* | Adjusted OR (95 % CI)† | Crude OR (95 % CI)* | Adjusted OR (95 % CI)† | |
| Asbestos | |||||||||
| Men | |||||||||
| Unexposed workers | 2151/24 033 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | ||
| Exposed from 1960 | 84/781 | 0.10 | 40 | 1.2 (1.0 to 1.5) | 1.0 (0.8 to 1.3) | 1.2 (0.9 to 1.6) | 1.0 (0.7 to 1.4) | 1.2 (0.8 to 1.7) | 1.1 (0.7 to 1.6) |
| Exposed from 1970 | 306/2148 | 0.11 | 35 | 1.7 (1.5 to 1.9) | 1.3 (1.1 to 1.5) | 1.7 (1.5 to 2.0) | 1.3 (1.1 to 1.6) | 1.5 (1.2 to 1.9) | 1.3 (1.0 to 1.7) |
| Exposed from 1975 | 83/711 | 0.17 | 32 | 1.3 (1.1 to 1.7) | 0.9 (0.7 to 1.2) | 1.5 (1.1 to 1.9) | 1.1 (0.8 to 1.5) | 1.0 (0.7 to 1.6) | 0.7 (0.4 to 1.1) |
| Exposed from 1980 | 1/10 | 0.02 | 27 | – | – | – | – | – | – |
| Exposed from 1990 | 0/5 | 0.04 | 20 | – | – | – | – | – | – |
| Silica | |||||||||
| Men | |||||||||
| Unexposed workers | 2956/32 361 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | ||
| Exposed from 1960 | 151/1018 | 0.10 | 35.0 | 1.6 (1.4 to 2.0) | 1.4 (1.1 to 1.7) | 1.9 (1.6 to 2.4) | 1.6 (1.3 to 2.1) | 1.2 (0.9 to 1.6) | 1.0 (0.7 to 1.4) |
| Exposed from 1970 | 233/1487 | 0.08 | 26.0 | 1.7 (1.5 to 2.0) | 1.4 (1.2 to 1.7) | 1.9 (1.6 to 2.2) | 1.5 (1.2 to 1.8) | 1.5 (1.2 to 2.0) | 1.3 (1.0 to 1.7) |
| Exposed from 1975 | 102/769 | 0.09 | 28.0 | 1.5 (1.2 to 1.8) | 1.2 (0.9 to 1.5) | 1.5 (1.2 to 2.0) | 1.2 (0.9 to 1.6) | 1.3 (0.9 to 1.9) | 1.1 (0.8 to 1.6) |
| Exposed from 1980 | 85/729 | 0.07 | 26.0 | 1.3 (1.0 to 1.6) | 1.1 (0.9 to 1.5) | 1.2 (0.9 to 1.6) | 1.1 (0.8 to 1.4) | 1.4 (1.0 to 2.0) | 1.3 (0.9 to 1.9) |
| Exposed from 1990 | 83/611 | 0.05 | 17.5 | 1.5 (1.2 to 1.8) | 1.3 (1.0 to 1.7) | 1.4 (1.0 to 1.8) | 1.2 (0.9 to 1.6) | 1.7 (1.1 to 2.4) | 1.6 (1.1 to 2.4) |
| Women | |||||||||
| Unexposed workers | 7558/77 370 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | ||
| Exposed from 1960 | 12/88 | 0.10 | 46.0 | 1.4 (0.8 to 2.6) | 1.2 (0.7 to 2.3) | 1.9 (1.0 to 3.5) | 1.6 (0.8 to 3.1) | – | – |
| Exposed from 1970 | 9/72 | 0.18 | 35.0 | 1.3 (0.6 to 2.6) | 1.1 (0.5 to 2.3) | 1.4 (0.7 to 3.1) | 1.1 (0.5 to 2.6) | – | – |
| Exposed from 1975 | 16/110 | 0.18 | 31.0 | 1.5 (0.9 to 2.5) | 1.3 (0.7 to 2.2) | 1.8 (1.0 to 3.2) | 1.5 (0.8 to 2.7) | – | – |
| Exposed from 1980 | 16/152 | 0.05 | 27.0 | 1.1 (0.6 to 1.8) | 0.9 (0.5 to 1.6) | 1.2 (0.7 to 2.2) | 1.0 (0.5 to 1.9) | – | – |
| Exposed from 1990 | 7/74 | 0.05 | 17.0 | 1.0 (0.4 to 2.1) | 0.8 (0.4 to 1.8) | 0.9 (0.4 to 2.3) | 0.8 (0.3 to 2.0) | – | – |
*Adjusted for county, age and index year.
†Adjusted for county, age, index year, pack-years of smoking and alcohol consumption. Asbestos and silica were adjusted for each other.
RA, rheumatoid arthritis.