TABLE 1.
Demographics and characteristics of cases and controls included in the genome-wide association study of chronic sputum production
| Cases (n=9714) | Controls (n=48 471) | |
| Mean age (years) | 57.7 | 57.7 |
| Female (%) | 42.5 | 42.5 |
| Smoking status | ||
| Ever-smoker | 5306 (54.6) | 20 912 (43.1) |
| Current smoker | 983 (10.2) | 1569 (3.2) |
| Doctor-diagnosed chronic bronchitis | 407 (4.2) | 416 (0.86) |
| Doctor-diagnosed asthma | 2630 (27.1) | 5251 (10.8) |
| Cough on most days | 7022 (72.3) | 3999 (8.3) |
| Moderate-to-severe asthma | 520 (5.4) | 521 (1.1) |
| Self-reported chronic sinusitis | 181 (1.9) | 1057 (2.2) |
| Meets spirometry criteria for GOLD 1–4 | 1511 (21.8)# | 4766 (13.1)# |
Data are presented as n (%), unless otherwise stated. COPD: Global Initiative for Chronic Obstructive Lung Disease. #: ncases=6942 and ncontrols=36 321 with available spirometry that passed quality control.