All births in England linked to delivery HES records by sex, 2005–2014.
| Baby’s sex | Number of ONS birth records | Linked to HES delivery record | Never linked to HES delivery record | Linkage rate |
| Female | 3253 584 | 3149 797 | 103 787 | 96.81 |
| Male | 3423 327 | 3314 985 | 108 342 | 96.84 |
| Not stated | 1 | 0 | 1 | 0.00 |
| Total | 6676 912 | 6464 782 | 212 130 | 96.82 |
33.89542247 Pearson χ 2 statistic.
2 <- df = (rows−1)× (columns−1).
0.0000 <- getting the P value from the χ2 statistics and the df.
HES, Hospital Episode Statistics; ONS, Office for National Statistics.