| Visit 1 On CPAP | Visit 2 Off CPAP | Visit 3 On CPAP at 1 yr | |
| LCQ domains | |||
| Physical | 5.9 | 4.9 | 5.9 |
| Psychological | 6 | 6.1 | 6.1 |
| Social | 6.3 | 4.8 | 6.8 |
| Total | 18.2 | 15.8 | 18.8 |
| Cough challenge | |||
| C2 mM | 35.7 | 7.81 | >1000 |
| C5 mM | 42.4 | 40.7 | >1000 |
| VAS | 4 | 44 | 2 |
Assessments were performed on continuous positive airway pressure (CPAP) following initiation of therapy, off CPAP for 1 week and on CPAP at 1 yr of follow up. The LCQ is a health-related quality of life measure of chronic cough and is divided into three domains. Total LCQ scores range from 3 to 21, with higher scores representing better quality of life. The VAS was a 100-mm linear scale. Cough challenges were undertaken with citric acid. C2 is the concentration of citric acid eliciting two or more coughs and C5 that eliciting five or more coughs.