Respiratory diseases as intermediate variables between dust exposure and ischaemic heart disease (IHD)
| Response variable (Explanatory variable) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Bronchitis* (Dust) | IHD† (Bronchitis) | Emphysema, asthma* (Dust) | IHD† (Emphysema, asthma) | Pneumoconiosis* (Dust) | IHD† (Pneumoconiosis) | Pneumonia* (Dust) | IHD† (Pneumonia) | Other respiratory diseases* (Dust) | IHD† (Other respiratory diseases) | ||
| *Explanatory variables in model: dust exposure, age, and smoking; interaction between age and follow up time included. | |||||||||||
| †Explanatory variables in model: dust exposure, age, smoking, bronchitis, emphysema and asthma, pneumonia, pneumoconiosis, and other respiratory diseases; interaction between age and follow up time included. | |||||||||||
| ‡Only a few cases of this respiratory disease. | |||||||||||
| RR, rate ratio; 95% CI, 95% confidence interval. | |||||||||||
| Granite workers | RR | 1.0 | 2.2 | 1.0 | 1.1 | 1.0 | 1.2 | 1.0 | 1.4 | 1.0 | 1.7 |
| 95% CI | (1.00 to 1.01) | (1.52 to 3.27) | (0.99 to 1.00) | (0.72 to 1.73) | (1.01 to 1.03) | (0.74 to 2.08) | (0.99 to 1.01) | (0.86 to 2.27) | (1.00 to 1.03) | (0.95 to 3.14) | |
| Cotton mill workers | RR | 1.0 | 0.8 | 1.0 | 2.0 | –‡ | 6.5 | 1.0 | 2.0 | –‡ | 0.6 |
| 95% CI | (0.95 to 1.06) | (0.34 to 1.99) | (0.91 to 1.06) | (0.91 to 4.57) | –‡ | (1.36 to 31.37) | (0.89 to 1.10) | (0.93 to 4.27) | –‡ | (0.07 to 4.42) | |
| Foundry workers | RR | 1.0 | 2.3 | 1.0 | 1.1 | 1.0 | 1.1 | 1.0 | 1.3 | 1.0 | 1.3 |
| 95% CI | (1.00 to 1.04) | (1.59 to 3.40) | (0.95 to 1.01) | (0.70 to 1.79) | (0.99 to 1.05) | (0.69 to 1.89) | (0.95 to 1.01) | (0.77 to 2.24) | (0.92 to 1.05) | (0.51 to 3.07) | |
| Iron foundry workers | RR | 0.9 | 2.0 | 0.9 | 1.4 | 1.1 | 2.5 | 1.1 | 1.2 | 0.7 | 1.2 |
| 95% CI | (0.74 to 1.13) | (1.41 to 2.96) | (0.63 to 1.33) | (0.81 to 2.47) | (0.48 to 2.27) | (1.06 to 6.09) | (0.68 to 1.89) | (0.71 to 1.91) | (0.33 to 1.57) | (0.59 to 2.11) | |
| Metal products workers | RR | 1.2 | 0.8 | 1.6 | 1.1 | –‡ | 3.2 | 1.3 | 1.1 | 0.9 | 2.2 |
| 95% CI | (0.77 to 1.89) | (0.41 to 1.40) | (0.73 to 3.43) | (0.48 to 2.51) | –‡ | (0.38 to 26.56) | (0.64 to 2.66) | (0.59 to 2.11) | (0.23 to 3.16) | (0.78 to 6.16) | |
| Electrical workers | RR | 0.7 | 1.4 | 1.0 | 6.0 | –‡ | –‡ | 0.9 | 1.6 | 0.7 | 2.1 |
| 95% CI | (0.51 to 1.00) | (0.66 to 3.03) | (0.41 to 2.68) | (2.17 to 16.31) | –‡ | –‡ | (0.47 to 1.70) | (0.52 to 4.68) | (0.18 to 2.43) | (0.49 to 9.28) | |