Sensitivity at 95% specificity of standard measures of airway reactivity and peak flow variability for doctor-diagnosed asthma
| Sensitivity at 95% specificity % | ||||
| All | 18–35 | 36–50 | >50 | |
| Airway reactivity | ||||
| PD20 | 57 | 56 | 65 | 39 |
| Regression slope | 52 | 53 | 63 | 36 |
| Two-point slope | 54 | 53 | 65 | 39 |
| Peak flow variability | ||||
| Amplitude%mean | 25 | 6 | 41 | 21 |
| std%mean | 22 | 9 | 35 | 10 |
| Two-lowest%mean | 20 | 6 | 39 | 8 |
PD20: prouocative dose of methacholine causing a 20% fall in forced expiratory volume in one seond