Scottish Index of Multiple Deprivation 2006: Technical Report

3. Updates to SIMD 2004 Domains and Indicators

Following ongoing work to implement recommendations made in the Long Term Strategy and changes to data sources, the SIMD 2006 contains more domains and indicators than SIMD 2004. Considerable improvements have also been made to data quality for many existing indicators. The SIMD 2006 now contains seven domains and 37 indicators, compared with the SIMD 2004, which contained six domains and 31 indicators.

The most recent SIMD 2006 indicators are based on mainly 2005 data, for the income and employment domains, two or three year averages up to 2004 or 2005 for the majority of the health and education data, 2001 for housing, 2006 data for the access to services data and 2004 data for the crime data. Unless otherwise stated in the technical notes for each indicator, population denominators were based on the 2004 mid-year data zone population estimates published by the General Register Office for Scotland.

Changes and additions are explained in full in the relevant sections for each domain; however the main changes are briefly described here.

3.1. New Domains

3.1.1. Crime Domain

The Long Term Strategy recommended that the Scottish Executive should work to develop a Crime and Social Order domain including a combination of crime incidence data, fear of crime measures and incidence of social disorder, incivilities and malicious fires. Until 2006, such data were unavailable at the small area level. For the first time, however, geo-referenced crime records are now available from Scotland's eight police forces and this has allowed the inclusion of a crime domain.

The SIMD crime domain contains indicators which provide the rate per 10,000 population for selected crimes of violence, domestic housebreaking, vandalism, drug offences and minor assault. There are no indicators on fear of crime, incivilities or social disorder. Fear of crime data are available from the Scottish Crime and Victimisation Survey, however, the sample size of the survey is insufficient for use at the data zone level. Data on incivilities and social disorder are unavailable at the small area level.

3.1.2. Physical Environment Domain.

The Scottish Executive intended to introduce a new Physical Environment domain in the SIMD 2006. The indicators considered, due to their availability at the data zone level, were: Air Pollution Concentrations, Proximity to Derelict Land and Proximity to Scottish Pollutant Release Inventory Sites. Considerable work has been undertaken to develop and quality assure these three indicators. The physical environment domain, however, will not be included in the SIMD at this time due to conceptual and methodological issues.

Factor analysis of the three indicators showed that, due to a lack of correlation at the data zone level, no two indicators could be combined to create sub-domains. Consequently, a physical environment domain would have to have been based on three individually weighted indicators. In effect, the physical environment domain would have consisted of three sub-domains, each containing just one indicator.

The work to date on these new and improved indicators, however, has been a significant development in both quality and relevance and add real value in their own right. They will be included in SNS in October 2006 if possible. The SE intend to build on this work and seek to improve the conceptualisation of the physical environment domain in the SIMD and will look to source and develop more suitable indicators for inclusion in the next update to the SIMD.

3.2. Overview of changes to existing domains

3.2.1. Current Income

Since 2003 there have been a series of changes to the benefits and credits systems which have had a major affect on indicators available for the income domain. As a result, some of the indicators used in the SIMD 2006 income domain are different to those used in the SIMD 2004. Further details on each indicator are included in the income domain chapter.

3.2.2. Employment

All indicators in the SIMD 2006 employment domain have remained the same as the 2004 domain. The domain scores and ranks from 2004 and 2006 are, therefore, directly comparable and can be used for analysis of both relative and absolute change over time.

3.2.3. Health

Several improvements have been made to indicators in the health domain and, as such, it is not directly comparable with the health domain from SIMD 2004. Firstly, as explained in the methodology chapter, shrinkage is no longer applied to any of the health indicators.

The second main difference is the change from direct to indirect age-sex standardisation in the Comparative Illness Factor ( CIF) and the Comparative Mortality Factor ( CMF). Following discussions with the Measuring Deprivation Advisory Group, the decision has also been made to age-sex standardise three other indicators which have a strong link to the age-sex structure of the population. These indicators are Hospital admissions due to alcohol use, Hospital admissions due to drug use and Emergency admissions to hospital.

Finally, in order to update the CIF, which used 2001 Census data in the SIMD 2004, the SIMD 2006 uses data on claimants of health related benefits from the Department for Work and Pensions.

3.2.4. Education

Several improvements have been made to indicators in the education domain and, as such, it is not directly comparable with the SIMD 2004 education domain. Firstly, as explained in the methodology chapter, shrinkage is no longer applied to any of the education indicators. Changes have also been made to each of the individual education indicators and these are described fully in the Education Chapter.

3.2.5. Geographic Access

This domain was previously known as the Geographic Access and Telecommunications domain; however, after extensive consideration of telecommunications data such as broadband coverage, the Scottish Executive has been unable to find a data source that is suitable at the small area level or for being conceptually appropriate for inclusion in the SIMD.

Following discussions with users and the Measuring Deprivation Advisory Group, several improvements have been made to the Geographic Access domain, including revising the list of services for the drive times and including public transport travel times to selected services where appropriate. The 2006 Geographic Access to Services domain consists of two sub-domains: drive times and public transport times.

3.2.6. Housing

The housing domain remains exactly the same as that in the SIMD 2004, which used 2001 Census data. Suitable housing data to replace Census indicators have not yet been developed. The housing domain has been retained, although it's weighting in the overall SIMD has been reduced. The housing domain is expected to be updated in future indices.