TABLE 1.
The ability of cough provocation tests with hypertonic aerosols to differentiate subjects with asthma from healthy subjects
| First author [Ref.] | Agent | Cut-off value | Subjects with asthma n | Sensitivity | Healthy subjects n | Specificity |
| Koskela [12] | Mannitol | ≥0.8 coughs/100 mg | 37 | 78%# | 10 | 100%# |
| Nurmi [48] | Mannitol | ≥17.2 coughs/100 mg | 11 | 91%# | 25 | 92%# |
| Johansson [45] | Mannitol | ≥48 coughs during the whole test | 16 | 80%# | 21 | 76%# |
| Koskela [20] | Hypertonic saline | ≤1428 mOsm·kg−1 to provoke 15 coughs | 26 | 62%# | 19 | 100%# |
| Purokivi [13] | Hypertonic saline | ≥0.0005 coughs·mOsm−1·kg−1 | 36 | 89%# | 14 | 93%# |
| Johansson [45] | Hypertonic saline | ≥5 coughs during the whole test | 16 | 100%# | 21 | 81%# |
| Koskela [18] | Hypertonic histamine | ≥12.2 coughs·mg−1·mL−1 | 32 | 62%# | 15 | 93%# |
| Purokivi [62] | Hypertonic histamine | ≥69.2 coughs·mg−1·mL−1 | 30 | 80% | 25 | 96% |
| Purokivi [13] | Dry air hyperpnoea | ≥0.085 coughs/MVV% | 36 | 75%# | 14 | 100%# |
| Johansson [45] | Dry air hyperpnoea | ≥11 coughs during the whole test | 15 | 60%# | 21 | 81%# |
#: Calculated from the original data, based on the largest obtainable Youden index. MVV%: minute ventilation level expressed as percentage of the predicted maximal voluntary ventilation.