The basic characteristics of the subjects
| Characteristic | No current cough | Current cough | p-value |
| Subjects | 2720 | 976 | |
| Age years | 47.6 (47.2–48.0) | 48.7 (48.0–49.4) | 0.006 |
| Female sex | 82.2% | 83.9% | 0.24 |
| Body mass index kg·m−2 | 26.4 (26.2–26.6) | 27.2 (26.9–27.5) | <0.001 |
| Current smokers | 6.6% | 7.7% | 0.26 |
| Ever-smokers | 31.4% | 31.5% | 0.96 |
| Smoking history among ever-smokers pack-years | 6.16 (5.57–6.75) | 6.98 (5.92–8.05) | 0.17 |
| Family income per year income class# | 3.05 (3.02–3.08) | 2.97 (2.92–3.03) | 0.021 |
| Somatic symptom score¶ | 2.36 (2.29–2.43) | 3.50 (3.36–3.65) | <0.001 |
Data are presented as mean (95% CI) unless otherwise stated. #: income classes: 1, <€15 000 per year; 2, €15 000–40 000 per year; 3, €40 000–70 000 per year; 4, €70 000–120 000 per year; 5, >€120 000 per year. ¶: see main text for definition.