TABLE 1.
Baseline characteristics of the study population
| Baseline characteristics | Total | Chronic cough cases | Non-cases | p-value |
| Subjects n | 9824 | 1073 | 8751 | |
| Age years | 66.0±10.8 | 67.8±10.6 | 65.8±10.8 | 0.392 |
| Age ≥70 years | ||||
| No | 6118 (62.3) | 579 (54.0) | 5539 (63.3) | <0.001 |
| Yes | 3706 (37.7) | 494 (46.0) | 3212 (36.7) | |
| Age (decades) | ||||
| 5th | 570 (5.8) | 39 (3.6) | 531 (6.1) | <0.001 |
| 6th | 2297 (23.4) | 209 (19.5) | 2088 (23.9) | |
| 7th | 3251 (33.1) | 331 (30.8) | 2920 (33.4) | |
| 8th | 2453 (25.0) | 338 (31.5) | 2115 (24.2) | |
| ≥9th | 1253 (12.8) | 156 (14.5) | 1097 (12.5) | |
| Female sex | 5725 (58.3) | 639 (59.6) | 5086 (58.1) | 0.369 |
| Smoking | ||||
| Never | 3133 (31.9) | 268 (25.0) | 2865 (32.8) | <0.001 |
| Past | 4915 (50.0) | 475 (44.3) | 4440 (50.8) | |
| Current | 1769 (18.0) | 329 (30.7) | 1440 (16.5) | |
| BMI kg·m−2 | 27.1 (24.7–29.9) | 27.2 (24.6–30.4) | 27.0 (24.7–29.8) | 0.475 |
| Obesity | 2114 (21.5) | 240 (22.4) | 1874 (21.4) | 0.154 |
| ACE inhibitors | 1837 (18.7) | 244 (22.7) | 1593 (18.2) | <0.001 |
| Comorbidities | 2420 (24.6) | 480 (44.7) | 1940 (22.2) | <0.001 |
| Chronic rhinosinusitis | 289 (2.9) | 57 (5.3) | 232 (2.7) | <0.001 |
| GORD | 1324 (13.5) | 196 (18.3) | 1128 (12.9) | <0.001 |
| Asthma | 522 (5.3) | 124 (11.6) | 389 (4.5) | <0.001 |
| COPD | 646 (6.6) | 213 (19.9) | 433 (4.9) | <0.001 |
| ACO | 21 (0.2) | 6 (0.6) | 15 (0.2) | 0.009 |
Data are presented as mean±sd, n (%) or median (interquartile range), unless otherwise stated. BMI: body mass index; ACE: angiotensin converting enzyme; GORD: gastro-oesophageal reflux disease; COPD: chronic obstructive pulmonary disease; ACO: asthma–COPD overlap.