Table 3 Respiratory symptoms according to the exposure category.
| Respiratory symptoms | ||||||
|---|---|---|---|---|---|---|
| Chronic cough+phlegm | Chronic wheeze | Breathlessness | ||||
| Prev | OR (95% CI)† | Prev | OR (95% CI)† | Prev | OR (95% CI)† | |
| Control | 4.7 | 1.00 | 3.8 | 1.00 | 3.1 | 1.00 |
| Exposed | ||||||
| Total | 2.5 | 0.61 (0.26–1.43) | 6.5 | 1.81 (0.82–4.00) | 1.9 | 0.64 (0.22–1.81) |
| Current status* | ||||||
| Production | 3.6 | 0.74 (0.25–2.22) | 7.8 | 2.14 (0.84–5.45) | 0.8 | 0.24 (0.03–2.03) |
| Development | 1.8 | 0.48 (0.10–2.27) | 7.0 | 1.91 (0.69–5.28) | 3.7 | 1.40 (0.37–5.30) |
| Maintenance | 2.4 | 0.57 (0.21–1.60) | 5.8 | 1.60 (0.66–3.84) | 1.8 | 0.67 (0.26–1.77) |
| Cumulative status | ||||||
| 1–10 | 3.0 | 0.78 (0.29–2.09) | 8.5 | 2.49 (1.07–5.81) | 1.6 | 0.54 (0.15–2.02) |
| 11–20 | 1.7 | 0.38 (0.12–1.15) | 5.1 | 1.43 (0.59–3.48) | 2.3 | 0.72 (0.23–2.23) |
| 21+ | 7.4 | 1.57 (0.31–7.82) | 3.8 | 0.92 (0.19–4.54) | 0 | – |
| Confounders | ||||||
| Age (/10 years) | – | 1.38 (0.88–2.16) | – | 1.05 (0.73–1.52) | – | 1.09 (0.61–1.95) |
| Smoking (/pack) | – | 2.28 (1.21–4.33) | – | 0.96 (0.74–1.23) | – | 1.26 (0.85–1.89) |
*Production: toner production; development: machine development; maintenance: machine maintenance.
†Prev: crude prevalence; OR: odds ratio; CI: confidence interval.
Values shown are the crude prevalence and odds ratio, estimated by logistic regression analysis, for each exposure category relative to those for the control group, after adjustment for age and smoking status. The effects of age and smoking as confounding factors in these regression models are also shown.