The prevalence (%) of respiratory symptoms among short, normal and long sleepers
| Short sleepers (<6 hours per night) n=462 | Normal sleepers (6–9 hours per night) n=5136 | Short compared with normal sleepers p Value | Long sleepers (≥9 hours per night) n=252 | Long compared with normal sleepers p Value | |
| Wheezing last 12 months | 35.7 | 23.2 | <0.001 | 25.4 | 0.951 |
| Woken with chest tightness last 12 months | 26.0 | 13.3 | <0.001 | 17.7 | 0.105 |
| Shortness of breath while at rest last 12 months | 14.0 | 6.8 | <0.001 | 7.9 | 0.291 |
| Shortness of breath after strenuous activity last 12 months | 33.1 | 21.7 | <0.001 | 30.2 | 0.006 |
| Woken with shortness of breath last 12 months | 15.3 | 7.7 | <0.001 | 8.1 | 0.152 |
| Woken by coughing last 12 months | 41.1 | 31.1 | 0.001 | 33.5 | 0.857 |
| Cough in morning during the winter | 18.7 | 10.8 | <0.001 | 17.1 | 0.102 |
| Cough during day or night during the winter | 27.4 | 15.1 | <0.001 | 19.1 | 0.928 |
| Phlegm in morning during the winter | 20.7 | 12.7 | <0.001 | 16.0 | 0.635 |
| Phlegm during day or night during the winter | 19.3 | 10.1 | <0.001 | 14.1 | 0.512 |
| Chronic bronchitis | 10.8 | 6.2 | 0.011 | 9.6 | 0.420 |
| nGOR | 20.0 | 14.0 | <0.001 | 14.5 | 0.984 |
| Asthma ever | 17.5 | 18.9 | 0.474 | 23.1 | 0.224 |
| COPD | 2.2 | 1.2 | 0.017 | 2.0 | 0.590 |
| Nasal allergies including hay fever | 33.4 | 33.9 | 0.899 | 34.7 | 0.551 |
| Nose blocked for >12 weeks last 12 months | 14.3 | 7.1 | <0.001 | 10.0 | 0.244 |
Significance (p<0.05) is marked as bold. p Values show comparisons of short sleepers versus normal sleepers and long sleepers versus normal sleepers.
COPD, chronic obstructive pulmonary disease; nGOR, nocturnal gastro-oesophageal reflux.