Administrative data linkage Experiences from the English Longitudinal Survey of Ageing (ELSA) 19 July 2013

Contents Background Obtaining consent Rates of consent Procedures for accessing linked data

Background 1.

Key Facts People aged 50 and over and their partners Multi-disciplinary - health, economic and social circumstances Longitudinal Comparative - USA (HRS) and Europe (SHARE) Funding from US National Institute of Aging and consortium of UK government departments Reminder of the history to ELSA Study of people aged 50 and over in England. We know it as ELSA but also known on the doorstep as the “Health and Lifestyles of people aged 50 and over”. Carried out by NatCen in collaboration with UCL, Institute for Fiscal Studies and The University of Manchester Multi-disciplinary study that aims to interview the same group of people every two years to explore the health, social and financial situation of people as they grow older. The aim is to create a picture of what it means to age in England and understand the reasons behind any changes for better or worse. It is longitudinal – we hope interviews will be conducted every two years to understand change over time. Nurse visits every four years. ELSA is half funded by National Institute on Aging (NIA). NIA also funds sister studies - Health and Retirement Study in the States, and part funds Survey of Health and Retirement in Europe. This allows ELSA data to be compared with other countries. Half funded by UK government departments so there is a strong policy interest

Research Team Dept of Epidemiology and Public Health, UCL National Centre for Social Research Institute for Fiscal Studies Universities of Cambridge, East Anglia and Manchester There is a large research team behind ELSA

Research Questions Do people have enough savings to provide for their older age? How does people’s health and level of disability change over time? What is the relationship between these different factors? What explains who has good health in later life and who does not? How do people’s activities, relationships and quality of life change over time? How do changes in memory and concentration affect well being? Over time, the study will allow us to explore many questions, for example… When do people retire and how do they plan for their retirement?

History of ELSA Wave 1 - 12,099 Wave 2 - 9,432 Wave 3 - 9,771 Original sample interviewed in HSE 1998/1999/2001 Age 50+ on 1 Mar 2002 Wave 1 - 12,099 2002/3 Wave 2 - 9,432 Nurse visit 7,666 2004/5 Refreshment sample HSE 2001/02/03/04 Age 50-52 on 1 Mar 2006 Wave 3 - 9,771 Life-history 7,855 2006/7 Refreshment sample from HSE 2006 Age 50-74 on 1 Mar 2008 2008/9 Wave 4 - 11,050 Nurse visit 8,641 ELSA Wave 1 began in 2002, the original sample was taken from the Health Survey for England (HSE) – we call the HSE Wave 0 – those aged 50 and above on 1 March 2002. Wave 1 consisted of just a main interview ELSA Wave 2 took place in 2004, at this wave there was a core interview and a nurse visit. ELSA Wave 3 was carried out in 2006 and consisted of a core interview. As our sample ages it is no longer representative of those aged 50-52. So the sample was refreshed by the HSE 2001-04 sample at this wave. Life history interview asked about the respondents’ lives prior to joining ELSA – from early childhood to the date they joined ELSA. Information collected using a life grid – to aid recall. Includes questions on: Children - natural, adopt, foster, miscarriages, abortions, still births Partners - cohabiting and non-cohab (social networks) Accommodation - addresses for 6 months or more, Work - jobs for 6 months or more, changes in employer, pt or ft, salaries, activities between jobs, whether left because of ill health Health - injuries, childhood health (missed school, hospitalisation, list of conditions and when, impact on current life) - adult health (conditions lasting for more than 1 yr, age, long term effects) ELSA Wave 4 took place in 2008, there was a core interview and a nurse visit. The mainstage sample was refreshed by the HSE 2006 sample at this wave for those aged 50 – 74 years – replenish the sample. Wave 5 took place in 2010. Additional risk module which is a module of questions (or rather games) on attitudes towards financial risk. Games measure willingness to accept a delay in receiving money – deferred gratification and how risky or risk averse they are. Collected in combination with the financial data analyse people choice of pensions, assets etc. Only a sub-sample of just over 1,000 ELSA respondents aged 50 to 74 will be asked this module of questions. Wave 6 begins in ELSA May 2012. The sample is being refreshed this year from HSE 2009, 2010 and 2011. From our existing sample we are issuing a total of 11,577 individuals for the dress rehearsal who are living in 7,381 households. The refreshment sample contains 2,244 individuals, living in 1,310 households. Wave 5– 10,270 Risk module 1,065 2010/11 Refreshment sample from HSE 2009/10/11 Age 50-55 on 1 Mar 2012 Wave 6 – 10,448 Nurse visit c.7,720 2012/13

Obtaining consent 2.

Consent to what? Information about health and treatment from NHS health records (Hospital Episode Statistics – (HES)) Information about mortality from the NHS Central Cancer Register (original consent in HSE) Benefits and tax credit records from the Department of Work and Pensions (DWP) National Insurance Contributions from Inland Revenue (now HMRC) Mortality – basically when they died and what of. Not just cancer.

Actual data this relates to This is the flow of data showing who holds what and when in the process. This process ensures that external researchers never have data that can be linked to name address or date of birth information which would be highly disclosive.

At Wave 1 we asked about consent for linking to health records (hospital episodes statistics) and tax and benefits records. If respondents only wanted to consent to one they could cross out the other. Respondents were encouraged to give NI number to improve the accuracy of the linkage. ASK to GUESS HOW MANY GAVE NINO??? 62% gave a valid NINO at wave 1.

Wave 5 consents – from Wave 2 consent needed for new people for Cancer Register (mortality data) as well. This is the form on the left. The form on the right is an improved version of consent to the HES data and tax/benefits, which makes it clearer what has been consented to. The respondents ticks either yes or no.

Consent withdrawal wave 5 – every wave we remind people what they have consented to or not consented to in earlier waves and allow them the opportunity to opt in, or withdraw their consent. This form is for them to withdraw consent if they want to.

Rates of consent 3. Core Sexual activity

National Insurance and benefits data 9128 (76.8%) consent given 2224 (18.7%) consent refused 459 (3.9%) originally refused, but consented at a later wave 69 (0.6%) originally consented, but consent withdrawn at a later wave Figures based on all those who were productive at Wave 1 (prodw1 in indexfile=1) and frequencies from index file of coneco, conhe and connhs ASK WHETHER THEY THINK CONSENT TO HES DATA IS HIGHER OR LOWER

Hospital Episodes (HES) data 9559 (80.4%) consent given 1854 (15.6%) consent refused 399 (3.4%) originally refused, but consented at a later wave 71 (0.6%) originally consented, but consent withdrawn at a later wave Why is this higher than tax records? First on the form?

NHS central register (mortality data) 11424 (95.4%) consent given 543 (4.6%) consent refused 14 (0.1%) originally consented, but consent withdrawn at a later wave 98% consented to at least 1 data linkage People who refused in HSE not asked for consent again as high proportion consented already

Procedures for accessing linked data 4. So we have good consent rates and a lot of data we can link to, but where are we at with the various linkages? Linkage is an administrative and bureaucratic struggle, and even when you get the data the struggle does not end then.

NHS central register (mortality data) NatCen agreement with the NHS Information Centre and Office of National Statistics Data updates every 12 months Last update in March 2013 Used by team for reporting and sampling for future waves Information up to March 2012 available at UK Data Archive (Index File): Mortstat – whether dead or alive Yrdeath – year of death Agedead2 – age at death (90+ grouped) Maincod - Main cause of death (4 codes) Mortwave – when died in relation to ELSA wave Maincod – cancer, cvd, respiratory, other.

National Insurance and benefits data Administered by a separate committee - ELDAC Agreement with HMRC to link to National Insurance Contributions 10 applications already approved Work needed to update the data – NI data up to 2008 Agreement with DWP to link to benefits data New matching process underway to match data up to and including Q2 2011 Matched data due 2013 – detailed Information Security checks by DWP All ELDAC data available for analysis through NatCen and IFS data enclaves in London ELSA Linked data access committee

Hospital Episodes (HES) data NatCen agreement with the NHS Information Centre Linked data delivered to NatCen Complex cleaning and formatting about to start: Conversion from event based to person based data Ensure consistent formatting and labelling Linked analyses only possible in Data Enclave at NatCen in London Only people named on the HES application form can use it

Final thoughts ELSA ahead of its time in the UK in planning for linkage Possibility of linkage across a wide range of health and economic data Good procedures in place for gaining and checking consent Good consent rates – 98% consent to at least something Administrative and bureaucratic burden to get linkage to happen Large data management task to process admin data Different linked ELSA data at a variety of different stages

Where to get more information ELSA website: http://www.ifs.org.uk/elsa Data and associated documentation: http://www.esds.ac.uk/longitudinal/ longitudinal@esds.ac.uk elsadata@natcen.ac.uk To contact me... Andrew.phelps@natcen.ac.uk 22

Thank you If you want further information or would like to contact the author, Andrew Phelps Research Director T. 020 7549 7131 E. andrew.phelps@natcen.ac.uk Visit us online, natcen.ac.uk