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

The ELSA study is a longitudinal survey of ageing and quality of life among older people that explores the dynamic relationships between health and functioning, social networks and participation, and economic position as people plan for, move into and progress beyond retirement. The main objectives of ELSA are to:

• construct three waves of accessible and well-documented panel data
• provide these data in a convenient and timely fashion to the scientific and policy research community
• describe health trajectories, disability and healthy life expectancy in a representative sample of the English population aged 50 and over
• examine the relationship between economic position and health
• investigate the determinants of economic position in older age
• describe the timing of retirement and post-retirement labour market activity
• understand the relationships between social support, household structure and the transfer of assets

The current deposit comprises Waves 0, 1, 2 and 3 of the survey. Further files are also planned for future deposit. Further information may be found on the Insitute for Fiscal Studies English Longitudinal Study of Ageing web pages and the Natcen ELSA web pages (the latter are for ELSA respondents).

Joint ELSA/SHARE database: Users may request access to the ELSA portion of the data from a project to harmonise ELSA wave 2 and SHARE wave 1 (both 2004) data undertaken by Valeria Bordon at the University of Mannheim. Please contact longitudinal@esds.ac.uk for further details. The SHARE portion of this joint database can be accessed via CentERdata. Wave 3 Financial Derived Variables: These are currently available to registered UKDA users on a 'fast-track' basis only. Please contact the HelpDesk for further details. Latest edition of ELSA: For the 13th edition (January 2010), Wave 4 Phase 1 data and documentation were added to the study. Users should note that variables WPNLKMSU 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. See READ file for a full edition history. Main Topics:The ELSA dataset currently includes: Index file: This file contains details of all age-eligible individuals within households identified from the Health Survey for England (HSE) 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. See Index file documentation for further details. Wave 0 (1998, 1999 and 2001): These files comprise data for ELSA sample members who took part in the three different HSE studies used to construct the original ELSA sample. Three of the files include data for those variables which were measured at each of the three HSE study years (1998, 1999 and 2001). The fourth Wave 0 file comprises common variables included in all three survey years for all respondents. Wave 1:

• the Wave 1 core data file contains information obtained from the individual interviews and self-completion questionnaires. The individual interview comprised twelve modules: household demographics (completed by only one person in the household); individual demographics; health; social participation; work and pensions; income and assets (completed by one person in each financial unit); housing (completed by only one person in the household); cognitive function; expectations; psycho-social health; final questions; performance measures. The core file also contains some variables from HSE data for 1998, 1999 and 2001.
• the Wave 1 Pension Wealth Derived Variables file provides the discounted present value of the stream of income that an individual will receive from their pensions between starting to draw these pensions and death, under various alternative scenarios. These variables are derived from information on individuals' current and past circumstances from the Work and Pensions module of Wave 1, along with various assumptions about past and future behaviour.
• the Wave 1 Financial Derived Variables file includes derived summary variables for income and wealth, gathered from Wave 1. The variables are labelled and there is an accompanying Microsoft Excel spreadsheet included in the documentation that matches the derived variables to their source variables and provides further information specific to particular variables. A similar file is also available for Wave 2.

Wave 2:

• the ELSA Wave 2 interview covered a wide range of topics, which comprise the Wave 2 core data file. It was very similar to the questionnaire used in Wave 1, although every module was reviewed to ensure that it would provide data that measured change over time. This was achieved by repeating some measures exactly (for example, to measure income and assets), by asking directly about change (for example, to capture perceived changes in memory and concentration) and by adapting questions to allow people to update or amend past responses (for example, about work, pensions and specific health conditions). The Wave 2 interview was also expanded to answer a variety of additional research questions. The new items included: quality of health care received; household spending on leisure, clothing and transfers; perceptions of deprivation relative to others; perceptions of ageing; levels of literacy; perceived effort and reward for caregiving; voluntary activities.
• the Wave 2 Nurse data file includes information gathered from core sample members who also received a nurse visit. This was similar to the one that many respondents had as part of the HSE in 1998, 1999 or 2001 and included tests of blood pressure, lung function, blood tests, anthropometric measures and physical performance measures.
• the Wave 2 Mortgage data file includes mortgage data that have been manipulated into a series of 'loops' to facilitate easier analysis. For further details, see documentation.
• the Wave 2 Pension Grid data file includes one record for each private pension mentioned in Wave 2, and therefore contains multiple observations for some respondents, while for others (who have never had any private pensions), no observations are included. See documentation for further details.
• the Wave 2 Financial Derived Variables file includes derived summary variables for income and wealth, gathered from Wave 2. A spreadsheet is also available within the documentation; for details see the description given above for the Financial Derived Variables file for Wave 1.
• the Ryff self-completion data file comprises responses to a self-completion questionnaire based on the 'Ryff Scale of Psychological Wellbeing' (see Standard Measures below for full reference). Concepts covered include autonomy (independence and self-determination); environmental mastery (the ability to manage one's life); personal growth (being open to new experiences); positive relations with others (having satisfying, high quality relationships); purpose in life (believing that one's life is meaningful); and self-acceptance (a positive attitude towards oneself and one's past life). The Ryff questionnaire was distinct from the core self-completion questionnaires that ELSA respondents have been asked to complete at each wave, and was given to a sub-sample of respondents. For further details of methodology and sampling, see Wave 2 documentation.

Wave 3:

• as with previous waves, the Wave 3 main survey comprised a personal face-to-face interview and a self-completion questionnaire. Overall, the intention in Wave 3 was to collect data about the same topics as in Wave 2. There were, however, some additions to the content of the interview to respond to new areas of enquiry. Some questions from Wave 2 were omitted as it was decided that they did not need to be asked at every wave. Furthermore, several elements of the questionnaire were amended to take account of responses given at the previous wave. See documentation for further details.
• the Wave 3 Mortgage Grid file includes questions on mortgages, mortgage payments and related derived data
• the Wave 3 Pension Grid covers pensions and related derived data
• the Wave 3 Financial Derived Variables file includes derived summary variables for income and wealth, gathered from Wave 3. A spreadsheet is also available within the documentation; for details see the description given above for the Financial Derived Variables files for Waves 1 and 2.

Wave 4:

• The ELSA Wave 4 interview covered a wide range of topics. It was similar to the questionnaire used in Wave 3, although every module was reviewed to ensure that it would provide data that measured change over time. This was achieved by repeating some measures exactly, by asking directly about change and by adapting questions to allow people to update or amend past responses. The Wave 4 interview was also expanded to answer a variety of additional research questions. The new items included: dental health; help with daily activities the respondent may receive; access and use of both public and private transport; and questions on the state pensions forecasts that have been sent out by the government. See documentation for further details.
• At Wave 4, two further types of interview were conducted with specific sub-populations. An 'end of life interview' was sought with a relative, friend or carer of any core members who had died since responding to the first ELSA interview. An 'institution interview' was sought with core members who had moved from a private household after the first ELSA interview into a residential care home or similar institution, or with a proxy who could respond on their behalf. Users should note however that the data collected during these two types of interviews is not included with the Phase 1 deposit.

Standard Measures used in ELSA:

• Rose Angina Questionnaire: Rose, G. and Blackburn, H. (1986) Cardiovascular survey methods, World Health Organization Monograph
• Edinburgh Claudication Questionnaire: Leng, G. and Fowkes, F. (1992) 'The Edinburgh Claudication Questionnaire: an improved version of the WHO/Rose Questionnaire for use in epidemiological surveys', Journal of Clinical Epidemiology, 45, pp.1101-1109
• MRC Respiratory Questionnaire: Fletcher, C. et al. (1978) The natural history of chronic bronchitis and emphysema, Oxford: Oxford University Press
• CES-D Depression Scale (8-item): Rasloff, L.S. (1977) 'The CES-D Scale: a self-report depression scale for research in the general population', Applied Psychological Measurement, 1(3), pp.270-278
• General Health Questionnaire (12-item): Goldberg, D.P. Manual of the General Health Questionnaire, Windsor: NFER-Nelson, 1978
• CASP-19: Hyde, M. et al. (2003) 'A measure of quality of life in early old age: the theory, development and properties of a needs satisfaction model [CASP-19]', Ageing and Mental Health, 7, pp.186-194
• Ryff Scale of Psychological Wellbeing: Ryff, C.D. (1989) 'Happiness is everything, or is it? Explorations on the meaning of psychological wellbeing', Journal of Personality and Social Psychology, 57, pp.1069-1081, and Ryff, C.D. and Keyes, C.L. (1995) 'The structure of psychological wellbeing revisited', Journal of Personality and Social Psychology, 69(4), pp.719-727