Table 1. Characteristics of the study population.
| Characteristic | Main study population (ECRHS II, N = 2,347) |
Subsample with IPAQ data (ECRHS III, N = 671) |
|||
|---|---|---|---|---|---|
| n/N or mean | % or (SD) | n/N or mean | % or (SD) | ||
| Male sex | 1157/2347 | 49.3 | 333/671 | 49.6 | |
| Symptomatic study arm of ECRHS cohort | 422/2347 | 18.0 | 82/671 | 12.2 | |
| Age completed full time education | < 17 years | 504/2334 | 21.6 | 43/670 | 6.4 |
| 17–20 years | 732/2334 | 31.4 | 213/670 | 31.8 | |
| > 20 years | 1098/2334 | 47.0 | 414/670 | 61.8 | |
| Age in yearsa | 42.7 | (7.4) | 55.3 | (7.1) | |
| Height in cma | 170.1 | (9.8) | 170.2 | (9.7) | |
| Weight in kga | 74.0 | (15.1) | 76.2 | (15.6) | |
| BMI | < 25 kg/m2 | 1188/2344 | 50.7 | 304/669 | 45.4 |
| 25–30 kg/m2 | 842/2344 | 35.9 | 244/669 | 36.5 | |
| > 30 kg/m2 | 314/2344 | 13.4 | 121/669 | 18.1 | |
| Smoking habit | Never | 1000/2347 | 42.6 | 315/671 | 46.9 |
| Ex-smoker, < 15 pack-years | 357/2347 | 15.2 | 140/671 | 20.9 | |
| Ex-smoker, > = 15 pack-years | 254/2347 | 10.8 | 118/671 | 17.6 | |
| Current smoker, < 15 pack-years | 279/2347 | 11.9 | 30/671 | 4.5 | |
| Current smoker, > = 15 pack-years | 457/2347 | 19.5 | 68/671 | 10.1 | |
| Secondhand smoke exposure at home or work | 1000/2334 | 42.8 | 107/671 | 15.9 | |
| Occupation | Management/professional/non-manual | 754/2347 | 32.1 | 338/671 | 50.4 |
| Technical/professional/non-manual | 395/2347 | 16.8 | 155/671 | 23.1 | |
| Other non-manual | 549/2347 | 23.4 | 86/671 | 12.8 | |
| Skilled manual | 267/2347 | 11.4 | 29/671 | 4.3 | |
| Semi-skilled/unskilled manual | 240/2347 | 10.2 | 32/671 | 4.8 | |
| Other/unknown | 142/2347 | 6.1 | 31/671 | 4.6 | |
| Asthma | 412/2343 | 17.6 | 145/670 | 21.6 | |
| Pre-bronchodilator FEV1 in mla | 3455.2 | (810.1) | 2986.5 | (748.8) | |
| Pre-bronchodilator FVC in mla | 4320.7 | (992.4) | 4000.6 | (977.8) | |
| Physically active | ≥ 2 times and ≥ 1 hr per week | 856/2344 | 36.5 | -- | -- |
| Physical activity frequency | Low (< 1 a month) | 976/2347 | 41.6 | -- | -- |
| Medium (1–3 times a week) | 1016/2347 | 43.3 | -- | -- | |
| High (> 4 times a week) | 355/2347 | 15.1 | -- | -- | |
| Physical activity duration | Low (< 30 minutes) | 1013/2344 | 43.2 | -- | -- |
| Medium (1–3 hours) | 922/2344 | 39.3 | -- | -- | |
| High (> 4 hours) | 409/2344 | 17.4 | -- | -- | |
| Total physical activity (MET·min/week) | First tertile | -- | -- | 193/611 | 31.6 |
| Second tertile | -- | -- | 228/611 | 37.3 | |
| Third tertile | -- | -- | 190/611 | 31.1 | |
| Vigorous physical activity (MET·min/week) | First tertile | -- | -- | 320/665 | 48.1 |
| Second tertile | -- | -- | 117/665 | 17.6 | |
| Third tertile | -- | -- | 228/665 | 34.3 | |
| Moderate physical activity (MET·min/week) | First tertile | -- | -- | 223/646 | 34.5 |
| Second tertile | -- | -- | 178/646 | 27.6 | |
| Third tertile | -- | -- | 245/646 | 37.9 | |
| Walking physical activity (MET·min/week) | First tertile | -- | -- | 224/633 | 35.4 |
| Second tertile | -- | -- | 190/633 | 30.0 | |
| Third tertile | -- | -- | 219/633 | 34.6 | |
BMI = body mass index; ECHRS = European Community Respiratory Health Survey; FEV1 = forced expiratory volume in one second; FVC = forced vital capacity; IPAQ = International Physical Activity Questionnaire; MET = Metabolic Equivalent of Task; n = number of participants with characteristic; N = total number of participants available; SD = standard deviation
a The arithmetic mean and standard deviation are presented for these data which were normally distributed