Study Number 5050 - English Longitudinal Study of Ageing: Wave 0 (1998, 1999 and 2001) and Waves 1-4 (2002-2009)

LEGAL AGREEMENT ON CONDITION OF USE

Acknowledgement:
The depositor has supplied the following text for users as an example of the acknowledgement that should be used in publications resulting from use of the ELSA study:

"The data were made available through the UK Data Archive. ELSA was developed by a team of researchers based at the National Centre for Social Research, University College London and the Institute for Fiscal Studies. The data were collected by the National Centre for Social Research. The funding is provided by the National Institute of Aging in the United States, and a consortium of UK government departments coordinated by the Office for National Statistics. The developers and funders of ELSA and the Archive do not bear any responsibility for the analyses or interpretations presented here."

Details of the bibliographic citation to be used may be found in the file "UKDA_Study_5050_Information.htm" that accompanies the dataset.

NEW EDITION INFORMATION

The original release of ELSA (March 2005) contained data and documentation from Wave 1. For subsequent editions, the following additions and changes have been made:

• For the second edition (June 2005), Pension Wealth Derived Variables data and documentation were added
• For the third edition (September 2005), Wave 1 Financial Derived Variables data and documentation were added
• For the fourth edition (August 2006), data and documentation for Wave 2 were added.
• For the fifth edition (November 2006) the following additions and updates were included: data and documentation from Wave 0; an updated version of the Wave 2 Nurse data; and the Wave 2 mortgage derived data with accompanying documentation (including a new version of the Wave 2 interview questionnaire).
• For the sixth edition (January 2007) the ELSA Index file and accompanying documentation were added. This file contains details of all age-eligible individuals within households identified from HSEs 1998, 1999 and 2001 (over 21,000 people). It also includes all ineligible individuals living in the same households as eligible individuals (a further 6,074 people). The variables comprise respondent status and some mortality information, as well as analytical identifiers.
• For the seventh edition (April 2007), a file containing self-completion data relating to personal beliefs and wellbeing, otherwise known as the 'Ryff' scale, were added. Accompanying documentation for the Ryff data and in addition, the questionnaire from the Nurse Visit, were added to the Wave 2 documentation.
• For the eighth edition (August 2007), some new items and updates to older materials were deposited. The new material comprised Wave 2 Pension Grid data and accompanying documentation; the Wave 1 Technical Report; a guide to the geographical variables used in ELSA; and a guidance document on applications for ELSA genetic data. Updates included a new version of the Wave 1 Pension Wealth Derived Variables data file and accompanying user guide, a revised core questionnaire and core user guide for Wave 1, and a revised core user guide for Wave 2. In addition, many existing files in the ELSA dataset underwent name changes at the request of the depositor: see the 'Useful Notes' section for details.
• For the ninth edition (January 2008), data and documentation from Wave 3 were added to the dataset (Wave 3 Phase 1 deposit).
• For the 10th edition (June 2008): the Wave 3 Phase 1 data file was replaced with a new version (Phase 2 - see Wave 3 documentation for details of deposit phasing) and accompanying documentation; previously unavailable Wave 3 Pension Grid data (with documentation) and Mortage Grid data (currently no documentation) were deposited; updated data and documentation for Wave 1 and 2 Pension Grid data, and updated documentation for the existing Wave 1 Pension Wealth Derived Variables file were deposited. In addition, syntax was supplied to correct variables labels for the SC module in the Wave 1 Core data. This has been applied to the Wave 1 Core file available from UKDA, and users are advised to either download a new version or run the syntax (see 'Useful Notes' section below) themselves on their existing file.
• For the 11th edition (June 2009), the Wave 3 Life History data and documentation were deposited (see also notes below on edits to 'Idauniq' variable in the Life History data file). In addition, Wave 2 Technical Report and Quality of Care documents, and a table describing the documentation currently available for ELSA (see documentation table in catalogue record or download zip package) were also deposited. Three duplicate cases, 111562 (Wave 0 1999 and Common files, and Wave 1 data), and 114707 and 116492 (Wave 0 2001 and Common files) have been removed, and some edits to Core data for Waves 1 and 2 (variable labels) have been made at the depositor's request.
• For the 12th edition (September/October 2009), several additions and amendments were made to the study. Users who obtained the 12th edition before 5 October 2009 are advised to download a new version, as some extra materials were added on that date. The 12th edition updates are as follows: a new document, the Wave 3 Technical Report, was added; a new data file containing Wave 2 Derived Variables, was added, with an accompanying user guide; an updated version of the Wave 3 Core Data (Phase 2 v.2) was added, with its user guide documentation updated accordingly (amendments to the data are detailed under 'Useful Notes' below); an updated version of the Index File (v.3) was added, again with with its user guide documentation updated accordingly; and some amendments were made to the Wave 2 Core data file (detailed under 'Useful Notes' below).
• For the 13th edition (January 2010), the Wave 4 Phase 1 data and documentation were deposited. Users should note that variables wpnlksmu to wpnlkm86, wplchmph to wplchm86 and wpwynmoh to wpwynm86 are not currently included in the data file, but may still be referenced in the Wave 4 Phase 1 documentation. It is hoped they may be reinstated for the Wave 4 Phase 2 deposit. Also, some variables in the Wave 3 Core data, with erroneous 'CH' prefixes that should have been 'CF', have been renamed as follows: chwhmeye=cfwhmeye; chwhmhea=cfwhmhea; chwhmtir=cfwhmtir; chwhmill=cfwhmill; chwhmcon=cfwhmcon; chwhmner=cfwhmner; chwhmmen=cfwhmmen; chwhmdis=cfwhmup; chwhmnoi=cfwhmnoi; chwhmlap=cfwhmlap; chwhmeng=cfwhmeng; chwhmref=cfwhmref. Previous users may wish to download a new copy of the Wave 3 Core data file, or make the changes themselves. In addition, a Derived Variable Guide for the Life History Data was received during February 2010; this has been added to the existing Life History documentation.
• For the 14th edition (August 2010), the following changes were made: the Wave 4 Core data was replaced with an updated version (Phase 2), and the User Guide updated accordingly; and the Wave 4 Nurse data, and Wave 3 Financial Derived Variables were added, both with accompanying documentation.
• For the 15th edition (April 2011), the following changes were made: the Wave 4 Core data was replaced with a version containing updated weighting variables (the updated weights were previously available on fast-track); the Wave 4 Financial Derived Variables (again, previously available on fast-track) were added to the main dataset and information covering Wave 1-4 Financial Derived Variables was added to the main documentation for each wave; the Wave 3 Core data file had value labels for variables scdri01 to scdri07 updated; self-completion weight variables (previously only available in the Index file) were added to Waves 1-3 core data files; and the Work and Pensions Module (WP) questionnaire was updated in the 'Wave 3 Phase 2 User Guides and Documentation' file.

DATA PROCESSING NOTES

The data were processed to the UK Data Archive's A standard. A rigorous and comprehensive series of checks was carried out to ensure the quality of the data and documentation.�Firstly, checks were made that the number of cases and variables matched the depositor's records. Secondly, checks were made that all variables had variable labels and all nominal (categorical) variables had value labels. Where possible, either with reference to the documentation and/or in communication with the depositor, absent labels were created. Thirdly, logical checks were performed to ensure that nominal (categorical) variables had values within the range defined (either by value labels or in the depositor's documentation). Lastly, any data or documentation that breached confidentiality rules were altered or suppressed to preserve anonymity.

All notable and/or outstanding problems discovered are detailed under the 'Data and documentation problems' heading below.

Data and documentation problems

All variables in the data files are labelled, but some values are not. These labels can be obtained from the documentation.

Useful Notes

DhDead variable
Although the DhDead variable is covered in the documentation, it is not released for analysis with each wave of ELSA, as the interview covers living respondents. If mortality within the ELSA sample is to be analysed, users should consult the variables MORTFIN, YRDEATH, AGEDEAD2, MAINCOD and MORTWAVE, which are available on the ELSA Index File.

Data conversion information

From January 2003 onwards, almost all data conversions have been performed using software developed by the UKDA. This enables standardisation of the conversion methods and ensures optimal data quality. In addition to its own data processing/conversion code, this software uses the SPSS and Stat/Transfer command processors to perform certain format translations. Although data conversion is automated, all data files are also subject to visual inspection by a UKDA data processing officer.

With some format conversions data, and more especially internal metadata (i.e. variable labels, value labels, missing value definitions, data type information), will inevitably be lost or truncated owing to the differential limits of the proprietary formats.�A UKDA Data Dictionary file (in rich text format), corresponding to each data file, is usually provided for viewing and searching the internal metadata as it existed in the originating format. These files are called: [data file name]_UKDA_Data_Dictionary.rtf

Important information about the data format supplied

The links below provide important information about the format in which you have been supplied the data. Some of this information is specific to the ingest format of the data, that is the format in which the UKDA was supplied the data in. The ingest format for this study was SPSS

Please click below to find out information about the format that you have been supplied the data in.

SPSS (*.por)

Electronic and paper documentation supplied with this study is usually incorporated into the UKDA User Guide (in PDF format). The conversion programmes used are the latest versions of Adobe PDF Writer for electronic documentation and Adobe Paper Capture (Acrobat 'plugin' version) for paper documentation. Occasionally, some�of the electronic documentation cannot be usefully converted to PDF (e.g. MS Excel files with wide worksheets) and this is supplied in�a more appropriate format. All User Guides are fully bookmarked.