Incidence rate ratios of LAA symptoms (with 95% confidence intervals) for workers (including non-atopic and atopic separately) with increasing hours per week of exposure to laboratory animals or their cages, from univariate Poisson regression
| Exposure to laboratory animals or their cages (hours/week) | Incidence rate ratio (95% CI) (all workers = 495) | Incidence rate ratio (95% CI) (non-atopic workers = 337) | Incidence rate ratio (95% CI) (atopic workers = 158) |
|---|---|---|---|
| 0 to 6 | 1.0 (referent) | 1.0 (referent) | 1.0 (referent) |
| >6 to 9 | 4.0 (1.6–10.3) | – | 6.7 (2.4–18.9) |
| >9 to 25 | 1.8 (0.9–3.6) | 1.8 (0.6–5.2) | 1.7 (0.7–4.4) |
| >25 | 2.7 (1.2–5.8) | 3.2 (1.1–9.4) | 2.5 (0.8–7.4) |