Population estimates by output areas, electoral, health and other geographies, England and Wales: mid-2019

• There continues to be wide variation in the age structure of the population across England and Wales, with coastal and rural areas tending to have older populations than cities and urban areas; at the extremes, in the coastal Lower layer Super Output Area (LSOA) of Eastbourne 012B, the median age was 71.5 years whereas in the urban LSOA of Salford 016E the median age was 15.2 years.

• The proportion of people aged 65 years and over living in areas served by different Clinical Commissioning Groups (CCGs) in England ranged from 6.4% in NHS Tower Hamlets CCG to 28.3% in NHS Isle of Wight CCG.

• The proportion of people aged 85 years and over ranged from 0.8% in NHS Tower Hamlets CCG to 4.4% NHS Southport and Formby CCG.

• The population estimates in this release are consistent with the Mid-year population estimates published on 24 June 2020.

Super Output Areas (SOAs) are statistical geographies designed to improve the reporting of small area statistics. They are built from groups of census Output Areas, are of a consistent population size and are not subject to boundary changes between censuses.

Super Output Area (SOA) population estimates include:

• National Statistics for Lower layer Super Output Areas (LSOAs) by broad age groups and Middle layer Super Output Areas (MSOAs) by quinary (five-year) age groups

• supporting information for estimates at a greater level of disaggregation by age, including quinary age for LSOAs and single year of age for both SOAs

Middle layer Super Output Area population estimates (MSOA)

The age structures of populations at a local level can vary widely – indicating different requirements for public services provision – and median age provides a useful measure of this. The age structures of the 50 MSOAs with the highest median age and the 50 MSOAs with the lowest median age are shown in Figure 1.

In mid-2019, in the 50 MSOAs with the lowest median ages, 39.6% of the population were aged between 20 and 24 years, with a further 15.2% aged between 15 to 19 years; 1.9% were aged 80 years and over. A large number of the areas with the lowest median ages are home to large student populations. Conversely, the 50 MSOAs with the highest median ages are mostly in rural and coastal areas. In these MSOAs, 37.0% of the population were between 60 to 79 years and 13.1% were aged 80 years and over; 3.1% were aged 20 to 24 years.

Lower layer Super Output Area population estimates (LSOA)

There is still a wide variation in the age structure of the population across England and Wales. At Lower layer Super Output Area (LSOA) level, the highest median age was 71.5 years in Eastbourne 012B, and the lowest median age was 15.2 years in Salford 016E. In mid-2018 these two LSOAs also had, respectively, the highest and lowest median ages. Data on median age by LSOA is available from the single year of age LSOA population estimates.

At LSOA level, the proportion of children aged 0 to 15 years ranged from 52.0% in Salford 016E to 0.6% in Leeds 111A. The proportion of those aged 65 years and over ranged from 0.2% in Sheffield 073E to 61.3% in East Devon 012B and Eastbourne 012B. Across England and Wales as a whole the proportion of those aged 65 years and over was 18.5%, with 19.1% of the population aged 0 to 15 years.

Population density

Population density gives the population per square kilometre. It shows that areas in London and other major cities, particularly around Birmingham, are the most densely populated. Table 1 shows the LSOAs with the highest population densities in mid-2019.

Tower Hamlets 032D, located on the western side of Millwall Inner Dock on the Isle of Dogs in London, had the highest population density of 106,716 people per sq km. Most of the less densely populated areas were found in the North of England and Wales, particularly in areas covered by National Parks. The least densely populated area, an area partly covered by the Northumberland National Park and encompassing Kielder Water, was Northumberland 019C, with a population density of 2.5 people per sq km. Population estimates for National Parks are available.

LSOAs were designed to have similar population sizes and this means the land area they cover can vary considerably. The smallest in terms of land area, Kensington and Chelsea 021C (just under 2 hectares, an area including the World's End Estate), is around the twice the size of Trafalgar Square in London, while the largest, Northumberland 019C (67,284 hectares) is larger than the majority of local authorities.

Countryside and suburban areas have the highest proportions of those aged 85 years and over

One way of understanding how the population varies across England and Wales is to use the 2011 LSOA area classification; this classifies each LSOA in England and Wales according to its demographic characteristics based on the 2011 Census. Table 3 gives a summary of the population for each type of LSOA.

This supports the story that rural areas (described as Countryside living under the area classification) have older populations (26.5% aged 65 years and over) and much lower population densities (62 people per square km) but also shows that suburban areas (Suburban living) have a high proportion of older people (25% aged 65 years and over). Countryside living and suburban living also have the highest median ages of 50.1 and 48.1 years respectively.

LSOAs classified as Cosmopolitan student neighbourhoods have the lowest median ages (26.3 years) but also the lowest proportion of those aged 0 to 15 years (9.9%). The relatively low median age in these areas is explained by their high proportion of 18- to 22-year-olds (25.6%) compared with other areas.

Using this classification highlights the variation in population density in different parts of England and Wales. In areas classified as inner city cosmopolitan, the population density is nearly 172 times higher than in areas classified as countryside living.

Clinical Commissioning Groups (CCGs) are responsible for deciding how NHS funds are spent in their local area. Following a major reconfiguration in April 2020 there are 135 CCGs; prior to April 2020 there were 191.

At mid-2019, the average population of CCGs was 416,940, with population sizes ranging from 96,564 in NHS Surrey Heath CCG to 1,860,111 in NHS Kent and Medway CCG. The highest median age was 50.6 years in NHS Isle of Wight CCG and the lowest was 30.1 years in NHS Manchester CCG.

Annual population change

Between mid-2018 and mid-2019 the rate of population change varied across England and Wales. Of the 135 CCGs in England the population increased in 125 and decreased in 10. As with the year to mid-2018 the fastest increase, 2.5%, was in NHS Central London (Westminster) CCG. The largest percentage decrease was 0.5% in NHS Luton CCG; this follows a 0.3% reduction in population the year before.

Between mid-2018 and mid-2019 the two CCGs with the fastest population increases were in London, NHS Central London (Westminster) CCG (2.5%) and NHS Tower Hamlets CCG (2.2%). Of the remaining 10 CCGs with the greatest percentage increases in population, five are found in the East or West Midlands; this reflects the patterns of population growth shown in Mid-2019 population estimates release.

Table 5 shows the 10 CCGs with percentage decreases in population between mid-2018 and mid-2019. There are two distinct groups within the top 10, one along the south coast of England formed of NHS Fareham and Gosport CCG, NHS Southampton CCG and NHS Portsmouth CCG and one in West London formed of NHS Brent CCG, NHS Hammersmith and Fulham CCG and NHS Ealing CCG.

Wide variation in age structure of population across CCGs

The age distribution of the resident population in a CCG is likely to impact on both the overall level of demand for health services and the type of health services required. Areas with a large percentage of older people in their population are likely to have different demands on health services than those with younger populations.

Figure 2 shows the broad age structure for England, Barking and Dagenham (the CCG with the highest proportion of those aged 0 to 15 years) and the Isle of Wight (the CCG with the highest proportion of those aged 65 years and over), to highlight the variation in age structures between CCGs. Across England as a whole, 19.2% of the population were aged 0 to 15 years, with 62.4% aged 16 to 64 years and 18.4% aged over 65 years. However, in NHS Barking and Dagenham CCG the proportion of those aged 0 to 15 years is 27.2% and 9.3% were aged 65 and over. This contrasts with NHS Isle of Wight CCG where 28.3% of the population were aged 65 years and over and 15.5% were aged 0 to 15 years.

In mid-2019, the population aged 65 years or over in England was 18.4%. As Table 6 shows, 28.3% of the population in NHS Isle of Wight CCG was aged 65 years or over, the highest in any CCG. The CCG with the lowest proportion of people aged 65 years or older was NHS Tower Hamlets CCG (6.4%).

The percentage of the population who are children may also impact on requirements for health service provision. In mid-2019, the population of England aged 0 to 15 years was 19.2% but ranged from 27.2% in NHS Barking and Dagenham CCG to 15.4% in NHS Brighton and Hove CCG.

This bulletin has described estimates for LSOAs, MSOAs and Clinical Commissioning Groups but data for a range of other geographical entities are also available. As part of this release data for output areas and LSOAs by single years of age and sex is published. Using this data alongside geography lookups from the Office for National Statistics (ONS) Open Geography Portal enables estimates for additional geographic breakdowns to be produced.

Nomis

Population estimates for mid-2011 to mid-2019 are also available through Nomis. Nomis holds additional geographic breakdowns not published on the ONS website such as major towns and cities, built-up areas, Travel to Work areas (2011) and some data on historic ward boundaries.

Population estimates

Population estimates provide statistics on the current size and age structure of the population in the UK at country, region, county and local authority level. They are the official source of estimated population size in between censuses and inform a wide range of National Statistics.

Mid-year

Mid-year refers to 30 June of any given year.

Usually resident population

These data estimate the “usually resident population”. This is the standard UN definition and includes only people who reside in a country for 12 months or more, making them usually resident in that country. As such, visitors and short-term migrants are excluded.

Median age

Median age is the age that divides a population into two numerically equal groups (that is, half the people are younger than this age and half are older).

Population density

The number of people resident per square kilometre is the population density.

Ratio change method

While population estimates for local authorities are produced using the cohort component method, the main outputs in this release, Super Output Area (SOA) estimates, are produced using a ratio change methodology. This method uses the change in the population recorded in administrative sources as an indicator of change in the usually resident population, and it is used to produce SOA estimates in intercensal periods. For consistency, Lower layer Super Output Area (LSOA) mid-year population estimates are constrained to Middle layer Super Output Area (MSOA) estimates, which in turn are constrained to local authority estimates.

Producing output area estimates

LSOA population estimates are the starting point for calculating Output Area (OA) estimates. Administrative data sources are used to distribute the population, by single year of age and sex, between each OA within a single LSOA. Special populations (for example, prisoners and armed forces) are treated separately as they are static populations that are not included in the administrative data sources used to calculate OA estimates.

Aggregating to higher geographies

• Clinical Commissioning Group (CCG), Sustainability and Transformation Partnership (STP) and NHS England (Region) population estimates are direct aggregations of LSOA estimates

• Ward and Parliamentary constituency population estimates are based on aggregations of whole OA estimates; OA boundaries are not an exact fit (non-coterminous) for current ward or Parliamentary constituency boundaries and are therefore allocated using a best-fit approach

National Park estimates

National Park population estimates are provided for the exact boundaries of the National Park and therefore cannot be produced by aggregating whole OA estimates. The estimates are produced using a ratio change methodology that uses changes in the population of the wider area around the National Park (based on aggregations of OAs) as an indicator of the change in the true population of the National Park.

National Statistics and experimental statistics status

There are two broad types of small area population estimates, both of which are included in this release.

The main products are the estimates for Super Output Areas (SOAs), which are based on the 2011 Census and rolled forward annually using a ratio change methodology. This approach uses the change in the population recorded in the GP Patient Register as an indicator of the change in the true population. Estimates for LSOAs by broad ages and MSOAs by quinary age groups (five-year age groups) hold National Statistics status. Estimates at a greater level of disaggregation by age including quinary age for LSOAs and single year of age for both SOAs are supporting information only. More information can be found in Small Area Population Estimates: Summary of methodology review and research update.

The remainder of the small area population estimates products relate to a range of different geographic areas and are derived directly from the SOA figures. First, estimates for LSOAs are broken down to Output Area (OA) level using an apportionment approach. These OA estimates are then aggregated to produce estimates for electoral wards and Westminster Parliamentary constituencies on a best-fit basis. Estimates for National Parks are also calculated from the OA-level data. Electoral wards, Westminster Parliamentary constituencies and National Parks all hold Experimental Statistics status. Estimates for health geographies are aggregated directly from LSOAs and hold National Statistics status.

Upcoming changes – transformation of population statistics

It is our mission to provide the best insights on population and migration using a range of new and existing data sources to meet the needs of our users. Our ambition is to deliver a fully transformed system by 2023, making regular improvements to our statistics along the way as more administrative data become available. We will rigorously quality assure new methods and share the impact of any changes made. The Transformation of the population and migration statistics system: overview gives more information on this work. The resulting improvements will also be incorporated into future sets of population estimates.

Population estimates for mid-2020

The local authority population estimates for mid-2020 are planned for release in June 2021, these will be followed by population estimates for SOAs later in the year. The coronavirus (COVID-19) pandemic has disrupted the collection of several data sources (such as the International Passenger Survey) that underpin the production of population estimates. Further, the pandemic may have had impacts on how different groups, for example students, are captured on different data sources used in the population estimates. Over the coming months we will be working to further understand the impacts of these issues and will share our findings and consult with stakeholders as we progress.

Small area population estimates are used by both central government departments and local authorities for a range of purposes, including planning and monitoring of services and as denominators for the calculation of various rates and indicators. The Quality and Methodology Information (QMI) report has further information on the quality and use of these statistics.

Population estimates for LSOAs and MSOAs are often used for research and analysis as, unlike other small area geographies such as electoral wards, they are specifically designed for statistical purposes. Electoral ward population estimates are of particular interest to local government organisations. Parliamentary constituency estimates are of importance to Parliamentary organisations, researchers and Members of Parliament (MPs). Population estimates by health geographies are widely used within the health sector, and information on National Parks is valuable to both local government and the various National Park authorities.

The mid-2019 small area population estimates covered by this bulletin are fully consistent with population estimates for higher levels of geography including local authorities, regions and the national total for England and Wales. A full description of the methods used to calculate all small area population estimates is available in the methodology guide.

In some local authorities, the number of people included in the GP Patient Register data in 2019 has increased or decreased in a large number of LSOAs and MSOAs compared with 2018 data, which may be because of changes in administrative practices or may reflect genuine population change. The process of constraining LSOA and MSOA estimates to previously published local authority population estimates means that this pattern is not automatically reflected in the Office for National Statistics (ONS) Revisions policies on population statistics, including the small area population estimates, explains how we implement and categorise revisions to statistics, including following a census.