Counts of the number of resident males and females, and resident households, in an area.

Health area

The areas for administration of the health service have been subject to relatively frequent reorganisation in England, and separately in Wales, with a number of cases of uncertainty of definition at the time of the production of the 2001 Census results. The definitions and boundaries of the areas for which results are presented have the reference date of 31 December 2002 (for Primary Care Trusts) and 01 April 2003 (for Local Health Boards).

Local Health Board (LHB) (Wales)

Established generally in April 2003 as part of the restructuring of the health service in Wales, and correspond to the 22 Unitary Authorities in Wales. There are also three Regional Offices (North, \Mid and West, and South East).

Primary Care Trust (PCT) and Care Trusts

Established in April 2002 as part of the reorganisation of the health service in England. The 304 Trust areas comprise of groupings of electoral wards (as at 1 April 2002), and are grouped within Strategic Health Authorities.

Strategic Health Authority (SHAs)

Established in April 2002 as part of the restructuring of the health service in England. The 28 Authority areas comprise of individual, or groupings of local authorities.

2006 health geography reorganisation

Health administration in England was significantly restructured in 2006.

On 1 July 2006 the number of Strategic Health Authorities (SHAs) reduced from 28 to 10.

On 1 October 2006 the number of Primary Care Organisations (PCOs) reduced from 303 to 152. The PCOs are made up of 148 Primary Care Trusts and 4 Care Trusts. CTs are similar to PCTs, but with responsibilities for social as well as health care. PCOs report to the SHAs.


Measure of the extent of areas for which Census results are reported.

Measurements were calculated for each Output Area (OA), and aggregated to larger areas. They include all land within the Ordnance Survey mean high water mark, but exclude extensive areas of inland water and any additional areas of water included within the administrative boundaries.


Hyper Text Mark Up Language. The language used to develop web pages for display on, for example, the internet. Basic pages can be read by all standard internet browsers. The 2001 Census interactive CDs which accompany and supplement the printed reports use HTML pages to provide access to results on CD without the user having to install specialized software.

Key Statistics

Provide a summary of the main results of the 2001 Census, particularly to enable comparisons at local, regional, and national level.

Equivalents of all figures in the Key Statistics may be found in the more detailed Standard Tables, to facilitate comparison, although they are usually broken down into more categories.

Local authority

The general term for a body administering local government.

Local government is administered by either single tier or two tier local authorities in various parts of England. The single tier authorities are the Unitary Authority, the metropolitan district, and the London borough, largely in the major urban areas. The two tier authorities elsewhere are the county and the local authority district. There are single tier Unitary Authorities throughout Wales.

London; Greater London, Inner and Outer London, London borough

Greater London is the area of the Greater London Council set up in 1966, and abolished in 1986, but having some strategic functions and retained for the presentation of statistics.

It comprises of 32 London boroughs which administer local government in Greater London, with a status similar to metropolitan districts, together with the Corporation of the City of London which is treated as a borough for statistical purposes.

Inner London is the part of Greater London which formed the former London County from 1889 to 1965, and comprises of the City of London and thirteen boroughs. The remaining nineteen boroughs form Outer London, and the Inner/Outer division is frequently used for statistical purposes.

Look up files

A list which links one set of areas to another in exact or approximate terms, normally supplied as a computer file.

Output Areas (OAs) build exactly into the larger areas in the standard geographical hierarchy for 2001 Census output, and the 'constitution' of the standard geography is available as a look up file. Output for other areas is on a best fit basis, and similar look up files are available. There is also a file which lists the whole or part postcodes in each OA (around the time of the 2001 Census), mainly to allow data referenced by postcode to be linked to characteristics drawn from Census statistics.


MDB databases are files that are used in a variety of Microsoft products, in particular in Microsoft Access databases. The files are identified by a .DBF file extension.

Metropolitan district / county

Metropolitan district authorities administer local government in the former metropolitan counties of England.

The six former metropolitan counties were set up as upper tier authorities in 1974, together with 36 metropolitan districts, but were abolished in 1986, and the metropolitan districts became single tier authorities. The metropolitan counties, which approximate to the major agglomerations of population outside Greater London, have been retained as areas for the presentation of statistics.

MID/MIF format

A file format holding digitised boundaries for use in geographic software developed by MapInfo. The files are identified by .MID and .MIF file extensions.

Migration and migrants

The Census counts people who had a different address of residence one year before the Census as 'migrants'.

Figures on migration measured in this way are available for migrants to an area (wherever they lived a year before) and for migrants from an area (where they were enumerated in the UK). There are also origin/destination matrices giving 'flows' of migrants between areas.

Moving Group

A group of people who migrated together.

Defined as a group of people within a household or communal establishment who are migrants and had the same postcode or (overseas) country code for their address one year before Census day. A person moving by themselves or with no usual address one year before the Census is included as a moving 'group' for statistical purposes.

National Assembly for Wales constituency/region

Return members to the elected body responsible for the devolved administration of Wales.

The 60 members of the National Assembly for Wales are elected from 40 single member constituencies with the same boundaries as UK parliamentary constituencies, with the remaining 20 members being elected by proportional representation from five electoral regions that coincide with pre 1999 European Parliament constituencies.

National Park

An area of countryside, populated in part, designated for outstanding landscape value.

Each has a National Park authority to administer the special functions of the Parks, but each is also subject to the processes of the constituent local authorities. Reference maps for each park also showing the constituent local authorities, are on pages 398 to 408 of the Key Statistics for local authorities in England and Wales printed report.

The boundaries of the eight National Parks in England and the three in Wales are based on landscape quality and are generally not coterminous with other administrative boundaries or recognised in the creation of Output Areas, but the figures presented for each National Park as a whole are based on a count of the population within the exact boundary of the Park at the reference date of 31 December 2002 so that administration could be based on as accurate as possible facts about often distinctive socio-economic circumstances of the Park areas.