Table 2 Frequency (%) of variables of interest at follow up and variation per centres in 3232 males and 3592 females.
| Males | Females | Centres with min and max frequencies | ||||
|---|---|---|---|---|---|---|
| Mean or % | Range by centres | Mean or % | Range by centres | |||
| Mean age (years) | 42.62 | (38.12–45.62) | 42.57 | (39.92–45.69) | Tartu | Grenoble |
| Smoking | ||||||
| Never, no passive smoking | 29.02 | (8.25–51.22) | 34.45 | (15.13–50.33) | Huelva | Umea |
| With passive smoking | 9.19 | (2.05–17.36) | 11.46 | (1.87–23.86) | Uppsala | Pavia |
| Former | 30.61 | (7.62–41.09) | 26.13 | (5.96–35.98) | Tartu | Grenoble |
| ⩽10/day | 13.40 | (4.46–37.14) | 14.45 | (6.82–31.79) | Uppsala | Tartu |
| 10–20/day | 11.34 | (2.44–25.22) | 10.69 | (3.54–21.01) | Uppsala | Oviedo |
| >20/day | 6.43 | (0.00–18.56) | 2.82 | (0.00–10.92) | Norwich, Umea | Huelva |
| Respiratory infections before 5 years | 9.04 | (2.78–13.64) | 10.24 | (2.91–24.00) | Huelva | Verona |
| Rhinitis | 25.87 | (10.11–34.92) | 29.84 | (11.38–43.40) | Galdakao | Paris |
| Any occupational exposure to biological or mineral dust, gas and fumes | ||||||
| None | 47.03 | (24.85–69.95) | 62.00 | (45.33–80.60) | Umea | Paris |
| Low | 27.53 | (18.00–33.70) | 33.18 | (19.40–47.20) | Turin | Uppsala |
| High | 25.44 | (7.25–46.15) | 4.82 | (0.00–8.89) | Paris | Galdakao |
| Social class (based on occupational group) | ||||||
| Professional and managerial (ref) | 31.03 | (10.71–52.02) | 24.25 | (8.57–44.26) | Huelva | Paris |
| Other non‐manual | 32.83 | (19.63–53.57) | 50.92 | (37.14–70.80) | Galdakao | Erfurt |
| Skilled manual | 17.95 | (3.54–28.99) | 2.81 | (0.00–7.24) | Paris | Albacete |
| Semi/unskilled manual | 12.93 | (5.05–22.47) | 7.32 | (2.13–18.40) | Paris | Galdakao |
| Unclassified | 5.26 | (0.00–17.36) | 14.70 | (1.25–37.08) | Norwich | Antwerp city |
| Educational level (years) | ||||||
| ⩽16 | 20.50 | (1.82–66.14) | 22.06 | (3.70–58.24) | Erfurt | Ipswich |
| 17–20 | 37.14 | (20.39–59.73) | 34.71 | (19.83–69.63) | Erfurt | Albacete |
| >20 | 42.36 | (12.60–59.36) | 43.23 | (12.94–70.61) | Ipswich | Uppsala |
| Reported traffic at home front door | ||||||
| Never | 45.64 | (17.36–68.93) | 39.33 | (15.25–64.04) | Antwerp–city | Pavia |
| Seldom | 19.14 | (8.74–29.75) | 20.67 | (12.10–37.93) | Pavia | South–Antwerp |
| Frequent | 15.78 | (9.96–31.31) | 17.29 | (10.11–28.85) | Goteborg | Huelva |
| Constant | 19.45 | (9.71–34.34) | 22.71 | (11.24–38.42) | Pavia | Antwerp city |
| Mean NO2 (μg/m3) | 38.00 | (5.86–78.37) | 38.44 | (6.18–76.16) | Umea | Barcelona |