Table 3.
Results and value ranges for normosmic/healthy nasal function.
| Test | Purpose | Normal range | Results | Prevalence ratioa (95% CI) | |
|---|---|---|---|---|---|
| WTC | Controls | ||||
| Odor threshold (PEA) | Olfactory nerve (cranial nerve 1) function | Dilution step ≥ 7 | 22% < normal 9% anosmic 13% hyposmic |
10% < normal 3% anosmic 7% hyposmic |
1.96 (1.2–3.3) |
| Irritant threshold (n-butanol) | Trigeminal nerve (cranial nerve 5) function | Dilution step ≥ 4 | 74% < 4 | 23% < 4 | 3.28 (2.7–3.9) |
| Odor identification | Cranial nerve 1 and central olfactory function | Males ≥ 31/40 Females ≥ 34/40 |
20% < normal 8% severe |
17% < normal 1% severe |
1.15 (0.7–1.89) |
| Mucociliary transit test | Impaired nasal clearance from damaged cilia or mucus rheology | ≤ 30 min | 19% > 30 min | 20% > 30 min | 0.95 (0.6–1.78) |
| Acoustic rhinometry | Nasal congestion or obstruction | Mean cross-section area: 0.35–0.65 cm | 25% < 0.35 | 21% < 0.35 | 1.07 (0.5–1.94) |
a
Each ratio refers to the prevalence of all individuals scoring below normal for each outcome.