Overview of key data sources: Scottish Health Survey

Organisation responsible: The Scottish Health Survey (SHeS) is commissioned by the Scottish Government Health Department and is carried out by the Scottish Centre for Social Research (ScotCen), in collaboration with the Department of Epidemiology and Public Health at University College London (UCL) and the MRC Social and Public Health Sciences Unit at the University of Glasgow.

Background and purpose: The SHeS was introduced in 1995 to provide information about the health and lifestyles of people all over Scotland. This information is essential for the Scottish Government's forward planning, for identifying gaps in health service provision and for identifying which groups are at particular risk of future ill-health. Specifically the SHeS aims to:

• estimate the prevalence of particular health conditions in Scotland;
• estimate the prevalence of certain risk factors associated with these health conditions and to document the pattern of related health behaviours;
• look at differences between regions and between subgroups of the population in the extent of their having these particular health conditions or risk factors, and to make comparisons with other national statistics for Scotland and England;
• monitor trends in the population's health over time;
• make a major contribution to monitoring progress towards health targets.

In 2007, the SHeS was redesigned and now adopts a core and modular design. In addition, the survey has moved from a one-off administration every 3-5 years to a continuous format with annual reporting.

Survey years / frequency: One-off surveys were carried out in 1995, 1998 and 2003. Fieldwork for the redesigned SHeS began in January 2008 and will run continuously until 2011.  There is no commitment to continue it beyond 2011 as yet.

Survey content: The previous surveys (1995, 1998, 2003) consisted of an interview including questions on general health, cardiovascular disease, respiratory symptoms, eating habits, smoking, drinking, physical activity and accidents as well as height and weight measurements. All respondents were asked if they would consent to a follow-up nurse visit. The nurse visit collected additional information and further measurements including blood pressure, lung function, saliva and blood samples, and a urine sample or an ECG reading on a sub-sample of respondents.

The survey now has a core and modular structure with a core set of questions going to the whole sample and two modules of questions which go to a proportion of the sample. Module A contains a range of questions on cardiovascular disease, asthma, eating habits, physical activity, mental health, dental health and accidents. Most of these questions will be asked every second year although some will be asked annually. Module B, the Knowledge, Attitudes and Motivations to Health (KAM) module, contains questions on health-related knowledge, attitudes and motivations to health. The module is funded by NHS Health Scotland to replace the previous Health Education Population Survey. The follow-up nurse visit is now only offered to around one sixth of the adult sample. A pictorial representation of the new design structure is available from the survey website.

Target population: The target population is people living in private households in Scotland. The age range has extended over the survey series: 16-64 years in 1995, 2-74 years in 1998, individuals of all ages from 2003.

Sample size: For the 2008-2011 survey, the target achieved sample size for the core is around 6,400 adults and around 2,000 children each year. In 2008 and 2009, three Health Boards boosted their samples - Borders, Fife and Grampian - each by an additional 200 adults, increasing the core sample size to a total of 7,000 adults. Module A will be asked of around 2,500 adults and 1100 children each year. Module B will be asked of around 2,200 adults (one per sampled household) each year.  The 2008 Scottish Health Survey achieved 6,465 individual interviews with adults and 1,750 with children aged 0-15.

Response rate: The 1995 and 1998 surveys sampled one adult per household but in 2003 the design was altered to include all adults per household. Thus in 1995 and 1998 there was no difference between household and individual response rates - 81% in 1995 and 76% in 1998. In 2003, the household response rate declined to 68% and individual response rate to 60%.  In the 2008 survey, the household response rate was 61% and individual response rate 49%.

Method of data collection: Interviews are conducted using Computer Assisted Personal Interviewing (CAPI).

Smallest geographical unit reported: All previous surveys were designed to provide data at national and regional levels, with regional results reported for seven 'health regions' based on amalgamations of the 15 health boards which existed at the time. A key change to the 2008-2011 survey is the ability to report at the level of every individual health board (of which there are now 14) after 4 years.

Availability of results and further information: National results from the 2008 Scottish Health Survey were published in September 2009. Supplementary web tables from the report were published in November 2009. Results at health board level will not be available for most boards until 2012. Further information about the survey and previous reports are available from the Scottish Health Survey. The SHeS datasets are available from the UK Data Archive. For further SHeS queries, email the SHeS team at: ScottishHealthSurvey@scotland.gsi.gov.uk.