Created 2 years ago, updated 10 days ago

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:

  1. Modelled estimates of patient counts by age, sex, and local authority of residence
  2. 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.

Within London there is variation in how annual births are predicted to have changed since the latest official estimates. The majority of boroughs show a decrease in annual births over the period of predicted data. Some boroughs do not follow the overall London trend and instead show an increase in annual births. The map below shows the percentage change between the latest official births estimates (01 Jan 2023) and the latest GLA modelled births estimate (01 May 2024) for London Boroughs.

File contents

Files containing the outputs from this modelling process are available for download below.

The downloads contain official ONS annual births estimates between 01 Jul 1992 and 01 Jan 2023, interpolated estimates at monthly intervals between official estimates, and predictions of annual births up to 01 May 2024. Predicted data are given alongside the upper and lower bounds of the 95% prediction interval.

The data are given for local authority districts, regions, country, and international territorial levels ITL2 in England using 2021 census boundaries.

These data are not currently split by sex.

The following are example rows to show the format of the csv data file downloads.

actual_and_predicted_births.csv
gss_code gss_name geography sex date type annual_births interval_lower interval_upper
E09000028 Southwark LAD21 persons 2022-12-01 interpolated 3448.9 NA NA
E09000028 Southwark LAD21 persons 2023-01-01 actual 3393 NA NA
E09000028 Southwark LAD21 persons 2023-02-01 predicted 3440.1 3363.5 3516.7
E09000028 Southwark LAD21 persons 2024-05-01 predicted 3400.5 3307.8 3493.2
birth_gp_ratios.csv
gss_code gss_name geography sex date ratio ratio_lower ratio_upper ratio_type gp_count actual_births
E09000028 Southwark LAD21 persons 2022-12-01 1.1 NA NA interpolated 3135.8 NA
E09000028 Southwark LAD21 persons 2023-01-01 1.103 NA NA actual 3075.4 3393
E09000028 Southwark LAD21 persons 2023-02-01 1.102 1.078 1.127 predicted 3120.5 NA
E09000028 Southwark LAD21 persons 2025-07-01 1.098 1.062 1.134 predicted NA NA

The plots.zip download contains png files of plots showing the actual and predicted annual births for each geographic area in the same format as the actual and predicted annual live births plot for London above. There are 3 plots for each different area which give different starting dates for the official estimates backseries to span a total of either 5, 10 or 15 years.

From
01/07/1991
To
File combining: official and modelled birth estimates. Data for English local authority districts, regions, and ITL 2 subregions.
  Other   Region   Local Authority
plots.zip  (84.99 MB)
Selected plots of actual and predicted recent births for English local authorities, regions, and ITL 2 subregions. Plots are labelled by their geographic code - a csv lookup of codes and names is included in the zip file.
  Region   Greater London   Other   Local Authority
From
01/01/2015
To
File containing: past birth estimates, modelled counts of patients age 0, actual and modelled ratios of births to patient counts. Data for English local authorities, regions, and ITL2 subregions.
  Local Authority   Region   Other   Greater London