Poisson regression analysis of risk of bladder cancer by cumulative exposure to PAHs (μg/m3×year), age, calendar period of diagnosis, and smoking
| Variable | Rate ratio | 95% CI | p Value test for trend |
| Age: | |||
| <60 | 1.0 | — | |
| 60–69 | 5.9 | 1.2 to 29.4 | |
| 70–74 | 8.4 | 2.2 to 32.7 | |
| 75–79 | 16.0 | 3.8 to 67.9 | |
| >80 | 7.9 | 1.5 to 42.7 | |
| Period of diagnosis: | |||
| 1953–74 | 1.0 | — | |
| 1975–95 | 3.7 | 1.3 to 10.6 | |
| Smoking: | |||
| Never and former smoker5-150 | 1.0 | — | |
| Smoker | 1.3 | 0.4 to 4.0 | |
| Unknown | 1.4 | 0.4 to 4.5 | |
| Cumulative exposure to PAHs (μg/m3×year), lag 3 y: | |||
| <50 | 1.0 | — | |
| 50–1500 | 0.7 | 0.3 to 2.0 | 0.2 |
| >1500 | 0.5 | 0.2 to 1.5 | |
↵5-150 No cases among the never smokers.