Prevalence of respiratory symptoms among respondents
| Symptoms | Charcoal workers | Controls | OR* | |||
| n (%) | n (%) | Crude OR | 95% CI† | Adjusted OR‡ | 95% CI§ | |
| Chronic cough | 14 (9.5) | 0 (0.0) | – | – | – | – |
| Productive cough | 20 (13.5) | 5 (3.6) | 8.50 | 1.96–36.79 | 2.45 | 0.30–20.25 |
| Wheeze | 13 (8.8) | 8 (5.4) | 2.67 | 0.70–10.05 | 4.22 | 1.37–12.99 |
| Breathlessness | 29 (19.6) | 20 (13.5) | 1.90 | 0.88–4.09 | 2.19 | 0.95–5.05 |
| Chest tightness | 13 (8.8) | 0 (0.0) | – | – | – | – |
| Nasal discharge | 51 (34.9) | 24 (16.2) | 2.33 | 1.40–3.89 | 1.41 | 0.61–3.27 |