Modelled estimates of recent births

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](https://digital.nhs.uk/data-and-information/publications/statistical/patients-registered-at-a-gp-practice) 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](https://data.london.gov.uk/dataset/estimating-births-using-gp-registration-data). 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](https://data.london.gov.uk/dataset/patients-registered-at-a-gp-practice) 2. [Official estimates of annual live births by local authority of residence](https://data.london.gov.uk/dataset/birth-estimates) A respository of the code used to generate the modelled birth estimates is [available on GitHub](https://github.com/Greater-London-Authority/nowcast-birth-estimates). 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 Jul 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 Jul 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 3440.2 3363.4 3516.9 … … … … … … … … … E09000028 Southwark LAD21 persons 2024-07-01 predicted 3358.3 3263.2 3453.4 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 1.102 NA NA interpolated 3130.3 NA E09000028 Southwark LAD21 persons 2023-01-01 1.105 NA NA actual 3070 3393 E09000028 Southwark LAD21 persons 2023-02-01 1.104 1.08 1.129 predicted 3115.1 NA … … … … … … … … … … … E09000028 Southwark LAD21 persons 2025-07-01 1.1 1.064 1.137 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.以统计截止日期为节点的年度活产数建模估计值。 英国国家统计局（ONS, Office for National Statistics）发布的官方出生估计数据被公认为精度极高，但从统计周期结束到估计数据正式发布通常存在9至12个月的滞后。为了更及时地掌握出生人口趋势，大伦敦管理局（GLA, Greater London Authority）人口统计团队基于全科医生（GP, General Practitioner）诊所注册的婴儿登记数量，构建了年度出生数的建模估计值。此类建模出生估计的生成频率与[NHS Digital](https://digital.nhs.uk/data-and-information/publications/statistical/patients-registered-at-a-gp-practice)发布的患者计数数据保持一致——目前为月度更新，数据滞后时长为1至2周。 用于生成该建模出生估计值的方法最初在[2016年技术报告](https://data.london.gov.uk/dataset/estimating-births-using-gp-registration-data)中进行了详细阐述。该方法论基于患者登记系统中0岁人群（即尚未年满一周岁的婴幼儿）的数量，与对应区域上一年度实际出生人口数之间的相关性建立模型。 用于创建上述建模出生估计值的原始数据包括： 1. [按年龄、性别及居住行政区划分的患者数建模估计值](https://data.london.gov.uk/dataset/patients-registered-at-a-gp-practice) 2. [按居住行政区划分的年度活产官方估计值](https://data.london.gov.uk/dataset/birth-estimates) 用于生成建模出生估计值的代码仓库已在[GitHub](https://github.com/Greater-London-Authority/nowcast-birth-estimates)公开。该仓库的README文件提供了更多关于估计值生成方法的细节，以及过往估计精度的汇总分析报告。 本次输出结果覆盖英格兰范围内的多种地理单元。伦敦区域的数据显示，自上一次官方估计发布以来，伦敦的年度出生数预计呈下降趋势，这与官方统计中近期的整体变动趋势一致。 在伦敦内部，不同行政区的年度出生数预计变化情况存在显著差异。大部分行政区的年度出生数在本次预测覆盖的时间段内有所下降，但仍有部分行政区并未遵循伦敦整体趋势，反而呈现年度出生数上升的态势。下图展示了伦敦各行政区最新官方出生估计（2023年1月1日）与最新GLA建模出生估计（2024年7月1日）之间的百分比变化。 **文件说明** 用户可通过以下链接下载包含本次建模流程输出结果的完整数据集。 下载包中包含1992年7月1日至2023年1月1日的英国国家统计局年度出生官方估计数据、官方估计值之间的月度插值估计结果，以及截至2024年7月1日的年度出生数预测结果。所有预测数据均附带95%预测区间的上下边界值。 数据以2021年英国人口普查的地理边界为基准，按地方政府行政区（LAD21）、区域、国家以及国际 territorial levels ITL2 等层级进行分类提供。 目前该数据集暂未按性别维度进行拆分。 以下为csv数据文件下载包的示例行格式： ### `actual_and_predicted_births.csv` 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,3440.2,3363.4,3516.9 ...,...,...,...,...,...,...,...,... E09000028,Southwark,LAD21,persons,2024-07-01,predicted,3358.3,3263.2,3453.4 ### `birth_gp_ratios.csv` csv gss_code,gss_name,geography,sex,date,ratio,ratio_lower,ratio_upper,ratio_type,gp_count,actual_births ...,...,...,...,...,...,...,...,...,...,... E09000028,Southwark,LAD21,persons,2022-12-01,1.102,NA,NA,interpolated,3130.3,NA E09000028,Southwark,LAD21,persons,2023-01-01,1.105,NA,NA,actual,3070,3393 E09000028,Southwark,LAD21,persons,2023-02-01,1.104,1.08,1.129,predicted,3115.1,NA ...,...,...,...,...,...,...,...,...,...,... E09000028,Southwark,LAD21,persons,2025-07-01,1.1,1.064,1.137,predicted,NA,NA `plots.zip` 下载包中包含各地理单元的实际与预测年度出生数折线图PNG文件，格式与上文展示的伦敦实际及预测年度活产数图表一致。每个地理单元对应3张图表，分别以5年、10年、15年为官方估计序列的起始时间跨度，覆盖不同长度的历史数据窗口。