2000 study (≥37 years of age) | Current study (≥40 years of age)a | ||||||
---|---|---|---|---|---|---|---|
Duration yearsb | N % | Cases | Silicosis prevalence % (95 % CI)c | Duration yearsb | N % | Silicosis prevalence (reader I) % (n-cases) (95 % CI)c | Silicosis prevalence (combined reading) % |
≤20 | 179 | 14 | 7.8 (4.3, 12.8) | ≤20 | 48 | 12.5 (6)(4.7, 25.2) | 8.3 |
21+ | 331 | 79 | 23.9 (19.4, 28.8) | 21+ | 182 | 20.3 (37)(14.7, 26.9) | 14.4 |
Crude | 510d | 93 | 18.2 (15.0, 21.9) | Overall | 230 | 18.7 (43)(13.9, 24.3) | 13.0 |
Adjustede | 20.5 |