Scottish Health Survey 2012 - volume 1: main report

Scottish Health Survey 2012 - main report

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Introduction

Lisa Rutherford

Policy Context

Health features prominently in the Scottish Government's National Performance Framework (NPF)[5,6]. The Government's core purpose, to create a more successful Scotland, is underpinned by five strategic objectives, one of which is to create a healthier Scotland. The objective is driven, in part, by the recognition of the considerable need to help people to sustain and improve health, particularly in disadvantaged communities. Of the 16 national outcomes allied to the Government's strategic objectives, those of greatest relevance to health are:

We live longer, healthier lives.

We have tackled the significant inequalities in Scottish society.

Many of the 50 national indicators that track progress towards the national outcomes have relevance to health. The addition of 2 indicators relating to health to the recently refreshed NPF[6], highlights the Government's ongoing commitment to improving the health of the population and tackling inequalities.

The Scottish Health Survey (SHeS) is used to monitor progress towards the following national indicators:

Improve mental wellbeing

Increase physical activity

Improve self-assessed general health

Increase the proportion of healthy weight children

As a study of public health, SHeS plays an important role in assessing health outcomes and the extent of health inequalities in Scotland and how these have changed over time. Each of the chapters included in this volume addresses an aspect of health that relates either directly or indirectly to the Government's objective of improving health in Scotland.

The Scottish Health Survey Series

The Scottish Health Survey (SHeS) comprises a series of surveys, of which the 2012 survey is the eighth. The survey has been carried out annually since 2008 and prior to that was carried out in 1995, 1998 and 2003.

The series is commissioned by the Scottish Government Health Directorates to provide regular information that cannot be obtained from other sources on a range of aspects concerning the public's health, and many factors related to health. The series was designed 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

The 2012 -2015 surveys are being carried out by ScotCen Social Research, the MRC/CSO Social and Public Health Sciences Unit (MRC/CSO SPHSU) based in Glasgow, The Centre for Population Health Sciences at the University of Edinburgh and The Public Health Nutrition Research Group at Aberdeen University.

The 2012 Survey

Topics

Each survey in the series includes core questions and measurements (height and weight and, if applicable, blood pressure, waist circumference, urine and saliva samples), plus modules of questions on specific health conditions that vary biennially.

The principal focus of the 2012-2015 surveys is cardiovascular disease (CVD) and related risk factors. The main components of CVD are coronary heart disease (CHD) and stroke. As noted in Chapter 8, CHD is Scotland's second biggest cause of death and is the focus of a significant number of health policies, many of which have a specific emphasis on reducing the significant health inequalities associated with CVD in Scotland. The SHeS series now has trend data going back for over a decade, and providing the time series is an important function of the survey.

Many of the key behavioural risk factors for CVD are in themselves of particular interest to health policy makers and the NHS. For example, smoking, poor diet, lack of physical activity, obesity and alcohol misuse are all the subject of specific strategies targeted at improving the nation's health. SHeS includes detailed measures of all these factors and these are reported on separately in Chapters 3-7.

Sample

The sample for the 2012-2015 surveys was designed to yield a representative sample of the general population living in private households in Scotland every year. Estimates at the NHS Board level are possible after four years of data collection.

A random sample of 4459 addresses was selected from the small user Postcode Address File (PAF), using a multi-stage stratified design. The PAF is a list of nearly all the residential addresses in Scotland and is maintained by The Royal Mail. The population surveyed was therefore people living in private households in Scotland. People living in institutions, who are likely to be older and, on average, in poorer health than those in private households, were outwith the scope of the survey. This should be considered when interpreting the survey estimates. The very small proportion of households living at addresses not on PAF (less than 1%) was not covered.

Where an address was found to have multiple dwelling units, one was selected at random. Where there were multiple households at a dwelling unit, a single household was selected at random. Each individual within a selected household was eligible for inclusion. Where there were more than two children in a household, two were randomly selection for inclusion, to limit the burden on households.

In addition, two further samples were selected for the survey in 2012: a child boost sample (4140 addresses) in which up to two children in a household were eligible to be interviewed but adults were not, and a Health Board boost sample (956 addresses) where some Health Boards opted to boost the number of adults interviewed in their area.

Fieldwork

A letter stating the purpose of the visit was sent to each sampled address before the interviewer visited. The interviewer sought the permission of each eligible selected adult in the household to be interviewed and both parents' and children's consent to interview selected children aged up to 15.

Interviewing was conducted using Computer Assisted Interviewing (CAI). The content of the interview and full documentation are provided in Volume 2. Children aged 13-15 were interviewed themselves, and parents of children aged 0-12 were asked about their children.

In addition, those aged 13 and over were asked to complete a short paper questionnaire on more sensitive topics. There were four such booklets: one for adults aged 18 and over, one for young adults aged 16-17 (with the option of using it for those aged 18-19 at the interviewer's discretion), and one for teenagers aged 13-15. Parents of children aged 4-12 years, included in the sample, were also asked to fill in a self completion booklet about the child's strengths and difficulties designed to detect behavioural, emotional and relationship difficulties in children.

Height and weight measurements were taken from those aged 2 and over at the end of the interview.

In a sub-sample of households, interviewers sought permission from adults (aged 16 and over) to take part in an additional 'biological module'. This module was carried out by specially trained interviewers. In the biological module, participants were asked questions about prescribed medication and anxiety, depression and self-harm. The interviewer also took participants' blood pressure readings and waist measurement as well as samples of saliva and urine. Further details of these samples and measurements are available in the Glossary and Volume 2.

Survey response

In 2012, across all sample types, interviews were held in 6602 households with 4815 adults (aged 16 and over), and 1787 children aged 0-15. 1020 adults also completed the biological module. More detailed information can be found in Volume 2, Chapter 1.

The following table sets out the numbers of participating households and adults in the four most recent survey years. Further details of all the 2012 figures are presented in Volume 2, Chapter 1.

Numbers participating:
Participating households (main & health board boost sample) 3183
Adult interviews 4815
Adults eligible for biological module 1516
Adults who completed biological module 1020
Child interviews 1787
Response rates:
% of all eligible households (main & health board boost sample) 66
% of all eligible adults 56

Ethical Approval

Ethical approval for the 2012 survey was obtained from the REC for Wales committee (reference number 11/WA/0246).

Data Analysis

Weighting

Since addresses and individuals did not all have equal chances of selection, the data have to be weighted for analysis. SHeS comprises of a general population (main sample) and a boost sample of children screened from additional addresses. Therefore slightly different weighting strategies were required for the adult sample (aged 16 or older) and the child main and boost samples (aged 0-15). Additional weights have been created for use on combined datasets (described below). A detailed description of the weights is available in Volume 2, Chapter 1.

Statistical information

The SHeS 2012 used a clustered, stratified multi-stage sample design. In addition, weights were applied when obtaining survey estimates. One of the effects of using the complex design and weighting is the standard errors for the survey estimates are generally higher than the standard errors that would be derived from an unweighted simple random sample of the sample size. The calculations of standard errors shown in tables, and comment on statistical significance throughout the report, have taken the clustering, stratifications and weighting into account. Full details of the sample design and weighting are given in Volume 2.

Analysis variables

As in all previous SHeS reports, data for men and women are presented separately where possible. Many of the measures are also reported for the whole adult population. Survey variables are tabulated by age groups and, usually, Scottish Index of Multiple Deprivation (SIMD), National Statistics Socio-Economic Classification (NS-SEC), and equivalised household income.

Presentation of trend data

Trend data are presented, where possible, for the eight surveys in the series to-date (1995, 1998, 2003, 2008-2012). In some cases trend data are restricted to those aged 16-64 (the age range common to all eight surveys), for some measures trends are available for the 16-74 age range (common to the 1998 survey onwards). Trends based on the surveys from 2003 onwards can be presented for all adults aged 16+.

Presentation of results

Commentary in the report highlights differences that are statistically significant at the 95% confidence level. It should be noted that statistical significance is not intended to imply substantive importance.

A summary of findings is presented at the beginning of each chapter. Chapters then include a brief introduction to the relevant policy initiatives in the area. These should be considered alongside the higher level policies noted above and related policy initiatives covered in other chapters. Following the chapter introduction and details of methods and key definitions, the results are outlined in detail. Tables are at the end of each chapter and show the results discussed in the text.

Availability of further data

As with surveys from previous years, a copy of the SHeS 2012 data will be deposited at the UK Data Archive. Furthermore, additional 2012 data are presented in web tables on the Scottish Government's SHeS website along with trend tables showing data for variables collected every year for adults and children.

Content Of Report

This volume contains chapters with substantive results from the SHeS 2012, and is one of two volumes based on the survey, published as a set as 'The Scottish Health Survey 2012:'

Volume 1: Main Report

Volume 2: Technical report

Volume 1 contents:

1. General health and mental wellbeing

2. Dental health

3. Alcohol consumption

4. Smoking

5. Diet

6. Physical activity

7. Obesity

8. Long-term conditions

9. Gambling

Both volumes are available from the Scottish Government's SHeS website. A summary report of the key findings from the 2012 report and a set of web tables are also available on the survey website. (www.scotland.gov.uk/scottishhealthsurvey).

Contact

Email: Julie Landsberg

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