Baseline characteristics of 5765 men aged 35–64 from the Collaborative study according to number of siblings. Values are age adjusted means or percentages
| Siblings | ||||||
|---|---|---|---|---|---|---|
| 0 | 1–2 | 3–4 | 5–6 | 7+ | p trend* | |
| *Using siblings as a continuous variable. †Not age adjusted. | ||||||
| Number of men | 489 | 2043 | 1535 | 915 | 783 | |
| Age† (y) | 46.4 | 47.1 | 48.6 | 49.7 | 49.9 | 0.0001 |
| % adult social class I and II | 48.6 | 45.6 | 28.2 | 17.7 | 12.3 | 0.0001 |
| % childhood social class I and II | 19.9 | 21.3 | 10.1 | 7.2 | 6.5 | 0.0001 |
| % upwardly socially mobile | 58.2 | 58.4 | 52.0 | 49.2 | 48.3 | 0.0001 |
| % downwardly socially mobile | 14.1 | 13.3 | 16.4 | 20.7 | 20.7 | 0.0001 |
| % regular car drivers | 63.8 | 59.6 | 48.7 | 43.7 | 39.3 | 0.0001 |
| % deprivation category 5–7 | 33.6 | 37.9 | 52.9 | 62.0 | 61.5 | 0.0001 |
| % left education ≤14 years | 30.0 | 35.1 | 57.3 | 66.4 | 74.3 | 0.0001 |
| % angina | 4.4 | 5.4 | 7.0 | 6.5 | 7.0 | 0.09 |
| % ECG ischaemia | 6.0 | 5.5 | 6.0 | 6.2 | 4.3 | 0.45 |
| % MRC bronchitis | 0.9 | 1.1 | 2.7 | 3.3 | 3.4 | 0.0001 |
| Height (cm) | 174.2 | 174.0 | 172.7 | 171.5 | 170.7 | 0.0001 |
| Body mass index (kg/m2) | 25.18 | 25.11 | 25.15 | 25.24 | 25.26 | 0.28 |
| % obese (BMI≥30 kg/m2) | 7.6 | 5.5 | 5.1 | 6.7 | 8.1 | 0.12 |
| Adjusted FEV1 (%) | 96.5 | 96.2 | 94.5 | 91.6 | 90.5 | 0.0001 |
| Adjusted FVC (%) | 97.8 | 98.0 | 97.1 | 95.4 | 94.3 | 0.0001 |
| Cholesterol (mmol/l) | 6.0 | 5.99 | 5.85 | 5.78 | 5.73 | 0.0001 |
| Systolic blood pressure (mm Hg) | 133.6 | 133.6 | 133.6 | 134.8 | 134.8 | 0.030 |
| Diastolic blood pressure (mm Hg) | 83.7 | 83.8 | 83.6 | 84.2 | 84.3 | 0.14 |
| % never smoked | 19.8 | 20.3 | 16.4 | 14.0 | 14.1 | 0.0001 |
| % current cigarette smoker | 52.4 | 49.6 | 57.0 | 62.0 | 64.2 | 0.0001 |
| Age started smoking (current) (y) | 19.1 | 18.7 | 17.8 | 17.5 | 17.6 | 0.0001 |
| Age started smoking (ex) (y) | 18.3 | 18.0 | 17.7 | 17.1 | 17.8 | 0.028 |
| Alcohol consumed per week (units) | 9.5 | 9.6 | 13.1 | 14.1 | 15.3 | 0.0001 |