Peter Craig Chief Scientist Office

1. The Scottish Health Survey-Scottish Morbidity Record Linked Datasets:Introduction to a new resource Peter Craig Chief Scientist Office

2. Outline • The Scottish Health Surveys • The Scottish Morbidity Record Linked Datasets • The SHS-SMR Linked Datasets • Examples • Further information and access to the data

3. The Scottish Health Surveys • Aims: to measure the health of the Scottish population, and to monitor changes in health, with a particular emphasis on cardiovascular disease and its risk factors • Three surveys carried out so far, in 1995-6, 1998-9 and 2003-4, and a fourth in progress

4. SHS - Design • Repeated cross-sectional survey, using a stratified, clustered random probability sample of individuals living in private households • Covers the whole of mainland Scotland plus the larger inhabited islands • Two-stage data-gathering: interview followed by a nurse visit

5. SHS - content Health: self-assessed general health, limiting longstanding illness, acute sickness; CVD and use of health services; respiratory health; asthma; accidents; food poisoning; use of dental services; psychosocial health (GHQ, SDQ*), health-related quality of life (SF-12)* Health behaviours: physical activity; eating habits; smoking; drinking; use of prescribed drugs, contraceptive pill, vitamin supplements and NRT; immunisations*; breastfeeding*; exposure to environmental tobacco smoke Measurements: height (length, demispan), weight; blood pressure; waist, hip, mid-upper arm circumference; salivary cotinine; blood analytes (total and HDL cholesterol, C-reactive protein, total and house dust mite specific IgE, etc.); urinary sodium*†, ECG*† *2003 only †subsample only

6. SHS - Content Household characteristics: size, composition, relationships; tenure, car ownership; receipt of state benefits; income*; economic status/occupation of household reference person*; Carstairs score; SIMD* Individual characteristics: age, sex; economic status, occupation; education (age left FTE, highest qualification); ethnic background, religion*; parental social class*; parental history of CVD *2003 only

7. SHS - changes • Content extended: household income; parental social class; fruit and vegetable consumption; HRQoL; SDQ; urinary sodium; ECG • Age range extended from 16-64 (1995) to 2-74 (1998) to all ages (2003) • Design modified • 1995, 1998 one adult per household interviewed • 2003 interviews attempted with all adults

8. SHS – non-response and weighting

9. SHS – non-response and weighting Weights • 1995, 1998 – single interview weight to take account of • disproportionate sampling within health regions • differing probabilities of selection within households of different sizes and within multi-occupied addresses • differential non-response • 2003 – interview, nurse visit and blood weights to take account of • disproportionate sampling within health regions • differing probabilities of selection within multi-occupied addresses • differential non-response at each stage of data-gathering

10. The SMR Linked Datasets • Records of hospital episodes (date of admission and discharge, diagnosis, etc.) linked to provide individual patient-based records • Contains information on acute and psychiatric hospital episodes, cancer registrations and deaths in Scotland from 1981-present

11. SHS-SMR Linked Datasets National Centre for Social Research SHS Survey data + encrypted serial number Names, postcodes, DoBs + encrypted serial number SMR01 data + encrypted serial number SHS Survey data + SMR01 data

12. SHS-SMR Linked Datasets • Currently include hospital episodes and deaths up to Sept 2006 and cancer registrations to December 2004 • Minimum datasets contain all survey data plus summary of SMR data – freely available • Full datasets contain survey data plus specified fields from the SMR01 catalogue – available subject to PAC approval

13. The ‘minimum datasets’ • All survey data for respondents who consent to linkage • Summary of SMR data • Death: date, cause • Psychiatric admissions: total number; date and diagnosis of 1st admission • Cancer registrations: total number; date and diagnosis of 1st registration for a range of sites • Cardiovascular disease: total numbers of AMI, CHD, stroke, angiography, PCTA, and CABG admissions; date of 1st admission for each cause • Emigration status

14. SHS-SMR Linked Datasets

19. SHS-SMR Linked Datasets • Strengths • Large, nationally representative samples • Numbers of events continually increasing • Easily accessible • Weaknesses • Non response and missing data • Exposure data not updated • Outcomes restricted to ‘major events’

20. SHS-SMR linked datasets • Examples of current uses • Modelling impact of public health interventions on health inequalities • Self-reported alcohol consumption and alcohol-related hospital admission • Social, biological and behavioural risk factors for hospital admission and death • Psychological distress as a predictor of cardiovascular disease and mortality • Developing models of cardiovascular risk and benefit to improving prescribing decisions

21. Further information To find out about the Scottish Health Survey www.scotland.gov.uk/Topics/Statistics/Browse/Health/scottish-health-survey To access the survey data www.data_archive.ac.uk To access the linked datasets, contact Catherine.storey@isd.csa.scot.nhs.uk David.clark@isd.csa.scot.nhs.uk