Modelled estimates of annual live births by year ending date.
Official birth estimates from ONS are considered very accurate, but the lag between the end of the period covered and the publication of estimates is typically 9-12 months. To gain a more timely indication of birth trends, the GLA Demography team produces modelled estimates of annual births based on counts of infants registered with GP practices. Modelled birth estimates can be produced with the same frequency and latency that NHS Digital publishes patient count data - currently this is monthly and with a lag of 1-2 weeks.
The approach used to generate the modelled birth estimates was originally described in this 2016 technical note. The methodology relies on the correlation between the count of persons age 0 (i.e. yet to reach their first birthday) on the patient register and resident in an area with the number of births that have taken place in that area over the preceding year.
The data used to create these modelled birth estimates are:
- Modelled estimates of patient counts by age, sex, and local authority of residence
- Official estimates of annual live births by local authority of residence
A respository of the code used to generate the modelled birth estimates is available on GitHub. The repository's ReadMe provides more information about the methodology used to produce the estimates as well as a summary analysis of their past accuracy.
The outputs cover a range of geographies in England. Data for London show that annual births in London are predicted to have declined since the last official estimate, a continuation of recent trends in the official estimates.