Table 1.
Sample construction from records of St. Helens Hospital and World War II enlistment files
| Sample | Number | Proportion of previous line | Mean birth weight (kg) (standard deviation) | Mean maternal age (standard deviation) | ||
|---|---|---|---|---|---|---|
| Specified group | Lost from above | Specified group | Lost from above | |||
| All births, 1907–1922 | 3166 | 27.89 (6.17) | ||||
| Births involving boys | 1566 | 0.49 | 27.86 (6.28) | 27.92 (6.07) | ||
| Live births | 1523 | 0.97 | 27.82 (6.25) | 29.24 (6.89) | ||
| Singleton births | 1496 | 0.98 | 3.53 (0.54) | 27.75 (6.23) | 32.70 (5.90) | |
| Found in birth registers | 1459 | 0.98 | 3.53 (0.54) | 3.54 (0.56) | 27.78 (6.26) | 26.35 (4.74) |
| Enlisted in World War II | 852 | 0.58 | 3.56 (0.50) | 3.48 (0.58) | 27.92 (6.37) | 27.52 (6.04) |
| Variables measured | ||||||
| Height | 789 | 0.93 | 3.56 (0.51) | 3.52 (0.50) | 27.97 (6.47) | 27.40 (5.18) |
| Blood pressure | 729 | 0.93 | 3.57 (0.51) | 3.49 (0.51) | 28.06 (6.45) | 27.15 (5.85) |
| Weight | 622 | 0.85 | 3.56 (0.50) | 3.57 (0.51) | 27.93 (6.62) | 27.89 (5.67) |
| All key variables | 599 | 0.96 | 3.56 (0.50) | 3.57 (0.51) | 28.03 (6.55) | 27.67 (5.94) |