Characteristics of study population
| Characteristics | First examination | Second examination | ||
| n/N or mean | % or (SD) | n/N or mean | % or (SD) | |
| Male sex | 1908/3912 | 48.8 | – | – |
| Symptomatic study arm of ECRHS cohort | 550/3912 | 14.1 | – | – |
| Age completed full-time education | ||||
| <17 years | 689/3893 | 17.7 | – | – |
| 17–20 years | 1367/3893 | 35.1 | – | – |
| >20 years | 1837/3893 | 47.2 | – | – |
| Age in years (mean (SD)) | 43.2 | (7.1) | 54.3 | (7.1) |
| Height in cm (mean (SD)) | 170.4 | (9.6) | 169.8 | (9.6) |
| Weight in kg (mean (SD)) | 74.4 | (15.2) | 78.3 | (16.1) |
| BMI | ||||
| Continuous, in kg/m2 (mean (SD)) | 25.5 | (4.3) | 27.1 | (4.8) |
| <25 kg/m2 | 1980/3894 | 50.8 | 1414/3891 | 36.3 |
| 25–30 kg/m2 | 1399/3894 | 35.9 | 1575/3891 | 40.5 |
| >30 kg/m2 | 515/3894 | 13.2 | 902/3891 | 23.2 |
| Smoking | ||||
| Never | 1793/3912 | 45.8 | 1718/3616 | 47.5 |
| Ex-smoker with <15 pack-years | 747/3912 | 19.1 | 716/3616 | 19.8 |
| Ex-smoker with ≥15 pack-years | 392/3912 | 10.0 | 586/3616 | 16.2 |
| Current smoker with <15 pack-years | 395/3912 | 10.1 | 140/3616 | 3.9 |
| Current smoker with ≥15 pack-years | 585/3912 | 15.0 | 456/3616 | 12.6 |
| Second-hand smoke exposure at home or work | 1423/3893 | 36.6 | 727/3891 | 18.7 |
| Occupation | ||||
| Management/professional/non-manual | 1204/3912 | 30.8 | 1352/3912 | 34.6 |
| Technical/professional/non-manual | 717/3912 | 18.3 | 736/3912 | 18.8 |
| Other non-manual | 989/3912 | 25.3 | 856/3912 | 21.9 |
| Skilled manual | 394/3912 | 10.1 | 313/3912 | 8.0 |
| Semiskilled/unskilled manual | 360/3912 | 9.2 | 355/3912 | 9.1 |
| Other/unknown | 248/3912 | 6.3 | 300/3912 | 7.7 |
| Asthma | 613/3907 | 15.7 | 735/3901 | 18.8 |
| COPD* | 213/3781 | 5.6 | 356/3788 | 9.4 |
| Comorbidity† | 573/2651 | 21.6 | 1487/3863 | 38.5 |
*Defined as FEV1/FVC less than the lower limit of normal predicted using the Global Lung Initiative equations.29
†Report of either arthritis, hypertension, heart disease, diabetes, cancer and stroke. Only available for 19 out of 25 participating centres at the first examination. All centres collected this information at the second examination.
BMI, body mass index; ECRHS, European Community Respiratory Health Survey; n, number of cases; N, total available sample size.