Scottish Index of Multiple Deprivation 2006: Technical Report

1. Summary

The Scottish Index of Multiple Deprivation ( SIMD) 2006 defines small area concentrations of multiple deprivation across all of Scotland in a consistent way. It consists of seven different domains or groups which each use the most appropriate and up to date information that was available at the time of compilation. The seven domains are Current Income, Employment, Health, Education Skills and Training, Geographic Access to Services, Housing and Crime. The latter is a new domain added since the SIMD 2004. The other major addition is the inclusion of new public transport sub-domain within the Geographic Access to Services domain. SIMD 2006 has National Statistics status.

The SIMD uses the 6,505 data zones across Scotland as its geographical base. It is a relative measure of deprivation which means the ranks can be used to compare data zones, the smaller the rank the more deprived the data zone. The data zone ranked one by the SIMD 2006 is the most deprived and the data zone ranked 6,505 is the least deprived. However the SIMD cannot be used to determine 'how much' more deprived one data zone is than another e.g. it is not possible to say that data zone X, ranked 50, is twice as deprived as data zone Y, ranked 100. However it is possible to say that X is more deprived than Y.

The SIMD can be used to identify Scotland's most deprived small areas on the overall index and each individual domain, commonly by applying a cut off such as 10%, 15% or 20%. The cut off should be informed by whether it aims to target areas with the very highest concentrations of deprivation or to be wider ranging. Users should consider applying sensitivity analysis to determine the effects of a slight change in cut off.

SIMD 2006 is an update with improvements on SIMD 2004 and uses the same geographical base as the SIMD 2004 of data zones. Each data zone's geographic size and boundaries have remained constant between SIMD 2004 and 2006 although the population size, gender or age distribution of a data zone may have changed. The SIMD 2004 represented information from 2001/2002 for most domains and used 2001 census based population estimates, whereas the majority of the SIMD 2006 data is from 2004/2005 and uses 2004 small area population estimates provided by the General Register Office for Scotland. The population size of each area should be taken into account before making direct comparisons between areas or over time.

Due to changed data sources and improvements to indicators and methodology, the overall SIMD and most domains are not directly comparable in absolute terms with those in the SIMD 2004.

Any decisions on changes to the methodology used to create the SIMD, and the indicators included in it, have been made in conjunction with data providers and the SCOTSTAT Measuring Deprivation Advisory Group ( MDAG). The MDAG is made up from users and analysts in local authority areas and other bodies (e.g. voluntary sector), experts in particular issues (e.g. access) and analysts within the Scottish Executive. The MDAG provides the Executive with advice on measuring deprivation as it works to implement the long term strategy for measuring deprivation. Advice covers: the needs of users; development priorities; methodological options; quality of outputs; dissemination and guidance on the use of outputs. Minutes and papers from all meetings with the MDAG are published on the Scottish Executive's website (see references in Annex c).

The major methodological improvements are listed in the methodology section. Some of the 37 indicators which are used to make up the domains are available as absolute measures through the Scottish Neighbourhood Statistics website and the SIMD background data, such as the changing pattern of health deprivation. Some indicators such as those contributing to the current income domain are not available individually due to confidentiality constraints and are subject to disclosure control. Details on comparing individual indicators over time are given within each relevant domain in this report.

Only the current income, employment and crime domains are based on absolute values and can therefore be used to identify the proportion of the population who are affected by these types of deprivation. Other domains are not straightforward summations of counts but are weighted scores so can only be used to compare the relative position of a data zone using the data zone rank.

The SIMD has been produced at data zone level and therefore cannot be used to compare levels of deprivation within local authority areas. The local authority area share of deprived data zones should not be used as a measure of a local authority area share of overall deprivation.

The SIMD can determine the national spread of deprived areas by showing the proportion of the most deprived data zones in Scotland which are in each local authority area. So for example; the national share of the 15% most deprived data zones by local authority area is the number of data zones in the 15% most deprived in Scotland in the local authority area as a proportion of the total number of data zones in the 15% most deprived in Scotland in total.

The SIMD can also be used as a measure of concentration of deprivation in a local authority area by showing the proportion of an authority's areas which are in the most deprived data zones in Scotland. So for example; the local share of the 15% most deprived data zones in Scotland is the number of data zones in the 15% most deprived in Scotland in the local authority area as a proportion of the total number of data zones in the local authority area.

1.1. Dissemination of the SIMD

Alongside this technical report the Scottish Executive have also published:

• A general report with summary analysis which is available on the SIMD website and in hard copy.
• Maps which show the spread of relative deprivation in Scotland across each local authority area for both the SIMD 2004 and SIMD 2006 are available from an interactive mapping website. The maps can be used to identify Scotland's most deprived areas and their location within each local authority area and to see how each authority's share of the most deprived areas in Scotland has changed between the two indices.
• Data behind the indicators have been published where possible, subject to confidentiality constraints, along with a statistical compendium containing tables, charts and other maps analysing the SIMD 2006 and change since SIMD 2004.
• A guidance leaflet providing information on how the SIMD can and cannot be used.
• In addition more detailed analysis of the SIMD 2006 can be carried out through comparison of the results with hundreds of socio-economic indicators on the Scottish Neighbourhood Statistics website.

1.2. Population Denominators

A number of the indicators included in the SIMD are rates or proportions of the population within a data zone and each domain uses the appropriate population denominators or weights in its construction. The SIMD 2004 used Census 2001 population information for such indicators and the SIMD 2006 used the latest population estimates available at the time of construction, which are from the General Register Office for Scotland's 2004 mid year small area population estimates ( SAPEs). For details on the methodology used to construct the estimates, see the GROS website (see Annex c). Population estimates are published at data zones level on Scottish Neighbourhood Statistics.

A small number of data zones have experienced large changes in the population size between SIMD 2004 and SIMD 2006. Generally such changes are due to either demolition or redevelopment within the data zone area. The SIMD takes into account absolute population change but not change in the population structure.

Some of the SIMD 2004 indicators were based on 2001 Census household populations which do not include communal establishment populations. More recent population estimates include communal establishment populations. Hence, for consistency, when calculating rates for indicators based on the household population, the population denominators were adjusted for those data zones which include a communal establishment.

1.3. Urban Rural Classification

The Scottish Executive Urban Rural Classification 2005-2006 updates the 2003-2004 version with the latest available population settlement and drive time estimates. The definitions of urban and rural areas underlying the classification are unchanged. Two main criteria have been used to produce the Scottish Executive urban rural classification: settlement size as defined by the General Register Office for Scotland ( GROS) and accessibility based on drive time analysis to differentiate between accessible and remote areas in Scotland. The changes between the 2003-2004 and the 2005-2006 classifications stem from settlements whose population fluctuates around the 10,000 and 3,000 marks as these are the population thresholds used to distinguish between urban and rural areas. More details are available in the Scottish Executive Urban Rural Classification 2005-2006 which can be found at http://www.scotland.gov.uk80f3fef7-2e45-417f-b929-2bcb24b13b02.

Change in number of data zones in each of the six- fold classifications between 2003/2004 and 2005/2006:

In 2005-2006 compared to 2003-2004, there are more data zones classified as being in remote rural, remote small towns and other urban areas and fewer data zones in less accessible rural and accessible small town areas. Reasons for the changes include: changes in population estimates, a change in the drive time software that altered a few on the edge of classifications, and changes to some settlement areas (for more detail see the 05/06 publication).