Prevalence (n (%)) of symptoms by sex, age group, country, and smoking
| Chronic bronchitis | Usual cough or phlegm | Breathlessness | Recurrent chest illness | Pleuritic chest pain | n | |
| Sex: | ||||||
| Men | 23 (3.3) | 168 (24) | 22 (3.2) | 22 (3.2) | 12 (1.7) | 692 |
| Women | 2 (2.4) | 16 (20) | 7 (8.5) | 6 (7.3) | 1 (1.2) | 82 |
| Age: | ||||||
| <35 | 6 (2.4) | 48 (19) | 2 (0.9) | 9 (3.6) | 1 (0.4) | 247 |
| 35–44 | 5 (2.2) | 63 (27) | 11 (4.7) | 10 (4.3) | 7 (3.0) | 232 |
| 45–54 | 8 (4.3) | 41 (22) | 5 (2.7) | 5 (2.7) | 4 (2.2) | 195 |
| ⩾55 | 6 (5.5) | 32 (29) | 11 (10.0) | 4 (3.6) | 1 (0.9) | 110 |
| Country: | ||||||
| England | 6 (1.7) | 68 (19) | 7 (1.9) | 16 (4.4) | 4 (1.1) | 362 |
| France | 18 (5.1) | 93 (27) | 18 (5.1) | 6 (1.7) | 7 (2.0) | 351 |
| Germany | 1 (1.6) | 23 (38) | 4 (6.5) | 6 (9.8) | 2 (3.3) | 61 |
| Smoking: | ||||||
| Non-smokers | 6 (2.1) | 48 (16) | 7 (2.4) | 8 (2.7) | 5 (1.7) | 292 |
| Current smokers | 12 (4.3) | 103 (37) | 12 (4.3) | 12 (4.3) | 6 (2.1) | 282 |
| Ex-smokers | 6 (3.1) | 31 (16) | 10 (5.1) | 8 (4.1) | 2 (1.0) | 196 |