Quality scores
| Random control | p-value | Spirometries with FEV1>20% | |
| Patients n | 314 | 345 | |
| Start-of-test | 1.87±0.50* | <0.001 | 1.69±0.72# |
| FEV1 repeatability | 1.96±0.21*, ¶ | NS | 1.94±0.30#, + |
| FVC repeatability | 1.81±0.49¶ | NS | 1.73±0.60+ |
| Total score | 5.63±0.83 | <0.002 | 5.36±1.13 |
FEV1: forced expiratory volume in one second; FVC: forced vital capacity. Differences between groups were tested by the Mann-Whitney U-test. Differences within groups were tested by the Wilcoxon test and are indicated with pairs of symbols (*, #, ¶, + <0.001).