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 199519982003 Household--67 Individual interview 817660 Nurse visit716340

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 SHS Survey data + encrypted serial number Names, postcodes, DoBs + encrypted serial number National Centre for Social Research 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 1 st admission –Cancer registrations: total number; date and diagnosis of 1 st registration for a range of sites –Cardiovascular disease: total numbers of AMI, CHD, stroke, angiography, PCTA, and CABG admissions; date of 1 st admission for each cause Emigration status

14. SHS-SMR Linked Datasets 199519982003 Cases 7363830510470 Cancer registrations 560755500 Cancer registrations post survey 38945570 CHD admissions 367531441 CHD admissions post survey 291330121 Psych hospital admissions 260300167 Psych hosp. admissions post survey 14714035 Deaths 442618208

15. Deprivation quintile Hazard ratio Lower CI Upper CI P value Highest1.00 21.330.991.790.058 31.481.111.960.007 41.731.292.320.000 Lowest1.931.452.560.000

17. Self-assessed health Hazard ratio Lower CI Upper CI P value Very good1.00 Good1.441.111.870.006 Fair3.102.413.980.000 Poor4.983.756.620.000 Very poor5.803.629.280.000

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/scotti sh-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