Scottish Health Survey 2017 - volume one: main report

Introduction

Joanne McLean and Shanna Christie

Policy Context

In July 2018, the Scottish Government launched a completely revised National Performance Framework (NPF)^[1], developed together with the public, practitioners and experts to reflect the values of the people and the aspirations held for the future of people living in Scotland. The overarching core purpose guiding the NPF is 'to focus on creating a more successful country with opportunities for all of Scotland to flourish through increased wellbeing, and sustainable and inclusive economic growth'. Related to this is the value that 'we are a society which treats all our people with kindness, dignity, and compassion, respects the rule of law, and acts in an open and transparent way'. There are eleven National Outcomes which contribute to measuring progress towards this vision for Scotland of which one is focussed solely on health - 'we are healthy and active'. Underpinning this National Outcome are a number of national indicators:

• Healthy life expectancy
• Mental wellbeing
• Healthy weight
• Health risk behaviours
• Physical activity
• Journeys by active travel
• Quality of care experience
• Premature mortality

In addition the National Outcomes have been designed to link with a number of the United Nation's Sustainable Development Goals. The specific goals that this health outcome relates to are:

• Gender equality
• Reduced inequalities
• Responsible production and consumption
• Good health and well-being

Many of the National Indicators that track progress towards the national outcomes have relevance to health^[2]. The Scottish Health Survey (SHeS) is used to monitor progress towards the following National Indicators:

• Healthy Life Expectancy
• Mental Wellbeing
• Healthy Weight
• Health Risk Behaviours
• Physical Activity

• Child wellbeing
• Food insecurity

The Scottish Government's Programme for Government: Delivering for Today, Investing for Tomorrow 2018-19^[3], published on 4^th September 2018, sets out the need to close the gap between the health of the wealthiest communities and the poorest as well as improve population health overall. It includes action to reform the way we respond to and treat mental ill-health, tackle poor diet and obesity and increase physical activity.

As a study of public health, the Scottish Health Survey plays an important role in assessing health outcomes, health risks and the extent of health inequalities in Scotland and how these have changed over time. As well as being the official source for measuring progress on a number of NPF indicators, SHeS is used to monitor numerous health strategies, programmes and initiatives.

Each of the chapters included in this volume addresses an aspect of health that relates either directly or indirectly to the Government's objective that 'we are healthy and active'.

The Scottish Health Survey Series

The Scottish Health Survey has been carried out annually since 2008 and prior to this was carried out in 1995^[4], 1998^[5], and 2003^[6]. The 2017 survey was the thirteenth in the series.

Commissioned by the Scottish Government Health Directorates, the series provides regular information on aspects of the public's health and factors related to health which cannot be obtained from other sources. The SHeS 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

Each survey in the series includes a set of 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 and health risk factors that vary from year to year. Each year the main sample has been augmented by an additional boosted sample for children. Since 2008

NHS Health Boards have also had the opportunity to boost the number of adult interviews carried out in their area.

The 2012-2017 surveys were 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 2017 Survey

Topics

Cardiovascular disease (CVD) and related risk factors remains the principal focus of the survey. The main components of CVD are ischaemic heart disease (IHD) (or coronary heart disease) and stroke, both of which are clinical priorities for the NHS in Scotland^[7][8][9]. Diseases of the circulatory system are the second most common causes of death in Scotland after cancer, accounting for 26% of deaths in 2017. This includes 12% of deaths which are caused by IHD, with a further 7% caused by cerebrovascular disease (e.g. stroke)^[10]. Early mortality from heart disease and stroke have both improved in recent years (surpassing targets in both cases), but concern remains about continuing inequalities in relation to morbidity and mortality linked to these conditions^[7]. The SHeS series now has trend data going back over two decades, and providing time series data remains 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 problematic alcohol use are all the subject of specific strategies targeted at improving the nation's health. SHeS includes detailed measures of all these factors which are reported on separately in Chapters 4-8. There are two chapters which focus on specific health conditions - General Health, Long-Term Conditions and Cardiovascular Disease (Chapter 1) and Mental Health and Wellbeing (Chapter 2). The remaining chapters report Dental Health and Services (Chapter 3) and Gambling (Chapter 9).

Sample

The Scottish Health Survey is designed to yield a representative sample of the general population living in private households in Scotland every year.

The current survey design also means that estimates at NHS Health Board level are available by combining four consecutive years of data. NHS board results for the period 2014-2017 have been published at the same time as this report.

Those 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 borne in mind when interpreting the survey findings.

A random sample of 4,445 addresses was selected from the Postcode Address File (PAF), using a multi-stage stratified design. 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 selected for inclusion, to limit the burden on households. The individuals interviewed at these addresses form the 'main sample'.

Two further samples were selected for the survey in 2017: a child boost sample (4,584 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 (482 addresses) for those Health Boards which 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 in advance of the interviewer visit. Interviewers sought the permission of each eligible adult in the household to be interviewed, and both parents' and children's consent to interview up to two children aged 0-15.

Interviewing was conducted using a combination of Computer Assisted Interviewing (CAI), where the questionnaire answers are input directly to a laptop, and self-completed paper questionnaires. The content of the interview and full documentation are provided in the accompanying technical report.

Adults (aged 16 and over) and children aged 13-15 completed the interview themselves. Parents of children aged 0-12 completed the interview on behalf of their child.

Those aged 13 and over were also asked to complete a short paper self-completion questionnaire on more sensitive topics during the interview. Parents of children aged 4-12 years selected for interview 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.

Towards the end of the interview height and weight measurements were taken from those aged 2 and over.

In a sub-sample of households, interviewers sought permission from adults (aged 16 and over) to take part in an additional 'biological module'. The biological module was administered by specially trained interviewers. In the module, participants were asked questions about prescribed medication and anxiety, depression, self-harm and suicide attempts. In addition, the interviewer also took participants' blood pressure readings and waist measurement, as well as samples of saliva and urine. Data from the biological module are reported every second year to allow two years of survey data to be combined. Data from the 2016 biological module combined with 2017 biological module data are included in this report. Further details of these samples and measurements are available both in the Glossary and in the accompanying technical report.

Survey response

In 2017, across all sample types, interviews were held in 3,062 households with 3,697 adults (aged 16 and over), and 1,603 children (aged 0-15). Of these, 938 adults completed the biological module. The number of participating households and adults in 2017 is listed in the table below. Further details on survey response in 2017 are presented in Chapter 1 of the technical report.

Main and Health Board boost samples
Participating households	2,483
Eligible households responding	57%
Adult interviews	3,697
Eligible adults responding	50%
Adults eligible for biological module	1,449
Adults who completed biological module	938
Child boost sample
Participating households	579
Eligible households responding	66%
Child interviews (child boost sample only)	885
Child interviews (main and child boost sample combined	1,603

Ethical Approval

Ethical approval for the 2017 survey was obtained from the REC for Wales committee (reference number 12/WA/0261).

Data Analysis

Weighting

Since addresses and individuals did not all have equal chances of selection, the data had 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 the biological module and for use on combined datasets (described below). A detailed description of the weights is available in Chapter 1 of the technical report.

Weighted and unweighted data and bases in report tables

All data in the report are weighted. For each table in the report both weighted and unweighted bases are presented. Unweighted bases indicate the number of participants involved. Weighted bases indicate the relative sizes of sample elements after weighting has been applied.

Standard analysis variables

As in all previous SHeS reports, data for men, women, boys and girls are presented separately where possible. Many of the measures are also reported for the whole adult or child population. Survey variables are tabulated by age groups and in some cases also by Scottish Index of Multiple Deprivation (SIMD).

Statistical information

The SHeS 2017 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 the technical report, Chapter 1.

Presentation of trend data

In this report trends based on the nine surveys from 2003 onwards are presented for all adults aged 16 and over. Prior to this the survey eligibility criteria was set at a maximum age of 64 in 1995 and then a maximum age of74 in 1998. Trends for children are based on the 2-15 years age group from 1998 onwards, and 0-15 years from 2003 onwards.

Presentation of results

Commentary in the report highlights differences that are statistically significant at the 95% confidence level. Statistical significance is not intended to imply substantive importance. A summary of findings is presented at the beginning of each chapter. Each chapter then includes a brief overview of the relevant policy area. These overviews should be considered alongside the higher level policies noted above and related policy initiatives covered in other chapters. A description of the methods and key definitions are also outlined in detail in each chapter. Tables showing the results discussed in the text are presented at the end of each chapter.

Availability of further data and analysis

As with surveys from previous years, a copy of the SHeS 2017 data will be deposited at the UK Data Archive along with copies of the combined datasets for 2015/2017, 2016/2017 and 2014/2015/2016/2017. In addition, trend tables showing data for key variables are available on the Scottish Government SHeS website along with a detailed set of web tables for 2017, providing analysis by age, area deprivation, socioeconomic classification, equivalised income and long-term condition for a large range of measures^[11].

Comparability with other UK statistics

Guidance on the comparability of statistics across the UK is included in the introductory section of individual chapters.

Content of this Report

This volume contains chapters with substantive results from the SHeS 2017, and is one of two volumes based on the survey, published as a set as 'The Scottish Health Survey 2017':

Volume 1: Main Report

1. General Health, Long-Term Conditions and Cardiovascular Diseases
2. Mental Wellbeing
3. Dental Health and Services
4. Alcohol
5. Smoking
6. Diet
7. Physical Activity
8. Obesity
9. Gambling

Volume 2: Technical Report

Volume 2 includes a detailed description of the survey methods including: survey design and response; sampling and weighting procedures; and, information on laboratory analysis of urine and saliva samples.

Both volumes are available from the Scottish Government's SHeS website. A summary report of the key findings from the 2017 report and a set of web tables are also available on the survey website: www.gov.scot/scottishhealthsurvey.