Table 1 Characteristics of men and women in the 1966 Northern Finland Birth Cohort study.
| Characteristics | Men (n = 2684) | Women (n = 2706) |
|---|---|---|
| Early life factors | ||
| Birth weight (g) | 3592 (512) | 3467 (474) |
| Weight gain during first year (kg)* | 7.0 (1.1) | 6.5 (1.1) |
| Gestational age at birth (weeks) | 40.2 (1.5) | 40.3 (1.5) |
| % Parental social class III and IV at birth† | 47.5 (n = 222) | 40.9 (n = 220) |
| % Mothers smoking during pregnancy | 13.3 (n = 349) | 12.3 (n = 324) |
| % Childhood respiratory infection‡ | 6.7 (n = 181) | 5.0 (n = 135) |
| Factors at age 31 years | ||
| FEV1 (l) | 4.54 (0.62) | 3.41 (0.47) |
| FVC (l) | 5.48 (0.75) | 4.02 (0.55) |
| FEV1:FVC ratio (%) | 83.1 (6.4) | 85.0 (6.5) |
| FEV1 (% predicted) | 99.2 (11.7) | 101.8 (11.7) |
| Height (m) | 1.78 (0.8) | 1.65 (0.6) |
| Weight (kg) | 80.2 (12.7) | 65.6 (12.5) |
| BMI (kg/m2) | 25.2 (3.6) | 24.2 (4.7) |
| % Current cigarette smokers | 32.7 (n = 878) | 23.0 (n = 622) |
| % Known asthma at 14 or 31 years§ | 8.3 (n = 223) | 10.5 (n = 284) |
| % Known emphysema or chronic bronchitis§ | 5.4 (n = 144) | 5.9 (n = 160) |
| % Low physical activity level¶ | 42.9 (n = 1151) | 41.7 (n = 1129) |
| % Social class III and IV** | 66.0 (n = 308) | 50.7 (n = 249) |
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; BMI, body mass index.
Data presented as mean (SD) for all continuous variables.
*Measured between the 10th and 14th months; data available for 2262 men and 2295 women.
†Parental social class (III = unskilled/others, IV = farmers).
‡Hospital diagnosis of acute respiratory infection or pneumonia between 0 and 7 years.
§Physician diagnosis.
¶Participation in brisk activity of at least 20 minutes was less than twice a week.
**Adult social class (III = vocational, IV = no education beyond elementary school/unknown).