Introduction to the Integrated Household Survey (IHS) Richard Clarke Caroline Jones ONS Social Surveys

Outline Background of the IHS How do these Social Surveys work then? Datasets – what and when! What are the results from the IHS?

Outline contd Dataset variables – End User License (EUL) vs. Special License (SL) Analysing the data – what to watch out for Questions and Answers

Background to the IHS ONS has several separate household surveys Different samples, fieldwork designs and processing systems All surveys have similar introductions Names, ages, work history Aim of the IHS is to integrate surveys into one modular survey with a core set of questions and survey modules bolted to the core Leading to ….. The largest social survey ever produced by ONS

Why ONS wanted to Integrate its Surveys Harmonisation of questions IHS consolidates existing work to harmonise questions over existing surveys Inter-Censal Data pressure to provide more accurate data between censuses Demand for Local Level Data increasing demand for more information, particularly at a local level within the UK

Surveys making up the IHS in 2009/10 Annual Population Survey (APS) 4 wave panel interview at 12 month intervals + waves of the Quarterly LFS Living Costs and Food Survey (LCF) single interview. Two week diary-keeping element. General Lifestyle Survey (GLF) 4 wave panel interview at 12 month intervals - longitudinal

Life Opportunities Survey (LOS) a longitudinal survey English Housing Survey (EHS) single interview + surveyor visit Opinions Survey (OPN) single interview (OPN left the IHS after Dec. 2010) Surveys making up the IHS in 2009/10 contd

IHS: 2009/ 2010 Sample Size by Component Survey Interview TypeApril 2009 to March 2010 Achieved Interviews GLF18,000 LCF12,000 OPN21,000 EHS41,000 APS +LFS334,000 LOS23,000 Annual Total449,000 The expected breakdown of the annual sample is as follows: Common set of core questions Continual sampling Adding up to large scale quarterly datasets.

What is The Survey Process? Design Prepare Test Conduct Survey / Collect Data Assemble and Check Data Disseminate Data

Development of the questions Most IHS questions were pre-existing ones originating on the APS/LFS Sponsored questions added: e.g. for smoking prevalence New questions undergo extensive checks – e.g. cognitive testing and field tests before going live Consult with stakeholders Program the questionnaire

What are the IHS Core Questions Household composition Accommodation Tenure Nationality Country of Birth National identity Ethnicity Sexual identity Religion Period at current address Health Smoking Government training scheme Work Looking for work Education

Find someone to ask it to…. The Royal Mail small user Postcode Address File (PAF) is the main sampling frame We only interview people living in private households Students in halls of residence or boarding schools should be included at their parents address Communal establishments are largely excluded Many are chosen.. Sadly not everyone will respond

Collecting the Data Data collected by CAPI (Computer Assisted Personal Interviewing) 65% of interviews by field interviewers in respondents home, remainder (mainly APS) done by telephone unit Respondents can answer for others in the household = Proxy Interviews Around 40% of IHS data collected in this way Exception is sexual identity which is only asked in person

An example of what the interviewer sees

An example of a showcard used by interviewers Please choose all that apply 1.Scottish 2.English 3.Welsh 4.Northern Irish 5.British 6.Other (please describe) 2 S

Data checks are built into the Questionnaire

Later, back in Newport The IHS team gets monthly data files from each survey Files are combined to give annual dataset Data cleaning Make sure all variable names are the same! Harmonise the questions e.g. GLF and APS have extensive education sections which are simplified into one highest qualification variable for the IHS

Later again….. Cases with missing data are imputed Weights are calculated Lots of derived variables are added The data set is checked Data is sent to GSS clients and to the UK Data Archive

What Datasets are available to you IHS releases data quarterly with a full years data April 2009 to March 2010 July 2009 to June 2010 October 2009 to September 2010 etc. Two type of publicly available datasets End User License (EUL) Special License Dataset (SL)

End User License vs. Special License Special License More disclosive personal data, e.g. sexual identity, relationship grid Smaller Geographic areas Down to local authority level Users need to apply & be accepted for approved researcher status End User License No disclosive information Large geographic areas Down to Government Office Regions Available after registration on ESDS website

Local authorities, counties Examples of Variables …. SL Country GOR Geography Sex, age Ethnicity, marital status, national identity, religion, 5 nationality categories, country of birth (3 categories UK, EU, other) Relation to other people in household, sexual identity, civil partnerships, other nationality categories(200+), country of birth (200+ countries) Identity SL EUL

Variables contd Industry & occupation codes Economic activity (top coded) Employment/training status Detailed levels of occupation/industry coding Work Many more variables (197 on SL file) – see User Guides on the IHS Website EUL SL

Analysing the IHS Data Points to bear in mind: Data has been imputed Missing data filled in using nearest neighbour approach Weighting Weights to equate numbers of responses to the population total Household Weight – for most analysis Non-Proxy weight – for analysing sexual identity (Will be Sexual Identity Weight on subsequent datasets) Sampling Errors With any sampling survey there are confidence limits on the data Given in appendix 2 of the IHS bulletin

Example Output 1 Results for GB and constituent countries – General Health, males aged 16+, Apr Mar 2010 Source: IHS

Example Output 2 Dichotomised Good General Health, adults aged by Economic Position, Wales Apr Mar 2010 Source: IHS

Media coverage The Daily Mirror The Sun City AM

IHS website from

Summary The IHS is the largest ONS Social Survey Made up from a common core on 6 other ONS surveys Annual Datasets updated every 3 months End User License File for higher level analysis Special User License File for more in-depth investigations See the IHS Website for User Guides

Any Questions?