The Scottish Health Survey 2023 - volume 1: main report

Introduction

Victoria Wilson

Policy Context

As a study of public health, the Scottish Health Survey (SHeS) 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. While some positive changes have been recorded, Scotland continues to record a significantly lower life expectancy compared to other countries in the UK and Western Europe, as well as continued disparity in health outcomes between those living in the most and least deprived areas^[1]. Improving the health and wellbeing of Scotland’s population continues to be a key challenge at both the local and national level.

In 2018, the Scottish Government launched six inter-related public health priorities designed to improve the health of the population and reduce health inequalities in Scotland over the next decade^[2]. In the same year, a revised National Performance Framework (NPF)^[3] was also launched containing eleven National Outcomes that link with several of the United Nation’s Sustainable Development Goals^[4], including several health outcomes. Underpinning the outcome focused exclusively on health - ‘we are healthy and active’ - are a number of National Indicators. SHeS is used to monitor progress towards indicators relating to mental wellbeing, healthy weight, health risk behaviours, physical activity, child wellbeing and happiness, and food insecurity.

A review of the National Outcomes (as required every 5 years by the Community Empowerment (Scotland) Act 2015) is due to conclude in early 2025, subject to Parliamentary procedure. To ensure the indicator set remains fit for purpose and focused on measuring progress towards the updated National Outcomes, national indicators will be revised to reflect the changes agreed with parliament to the National Outcomes.

The SHeS Series

SHeS has been carried out annually since 2008 and prior to this was carried out in 1995^[5], 1998^[6], and 2003. Due to disruption to the survey at the onset of the pandemic, the survey data collected in 2020 was published as experimental statistics and was not comparable with the time series^[7]. This data has not been included in the survey trends.

Commissioned by the Scottish Government Health Directorates, the SHeS series aims to provide 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 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 subgroups of the population in the extent of their having these particular health conditions or risk factors, and to make comparisons with other official 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 SHeS series includes modules of questions on health conditions and health risk factors together with height and weight measurements and, for a proportion of households measurement of blood pressure and waist circumference and a saliva sample. Some question modules vary from year to year. Each year the main sample is augmented by an additional boosted sample for children.

The 2018 to 2023 surveys were undertaken by the Scottish Centre for Social Research, with the Office of National Statistics (ONS) sharing fieldwork. Survey contributors have included 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 2023 Survey

Interviews for all sample types for the 2023 survey were undertaken using a primarily in-home face-to-face approach with a telephone contingency for respondents who were not willing to have an interviewer in-home. The Community Health Index (CHI) was again used to identify households with children, significantly improving the sample efficiency and response.

Further details on the fieldwork approach can be found in Chapter 1 of the Scottish Health Survey 2023 - volume 2: technical report.

The SHeS series now has trend data going back over two decades and providing time series data remains an important function of the survey. The impact of COVID-19 restrictions means that caution should be applied when comparing the 2021 survey data, which were collected via a telephone approach, with other SHeS surveys. Further details on the fieldwork approach in 2021 and information on the differences between the 2021 survey data and previous years can be found in the Scottish Health Survey 2021- volume 2: technical report.

Topics

Cardiovascular disease (CVD) and related risk factors remains the principal focus of the survey. The main components of CVD are ischaemic heart disease (or coronary heart disease) and stroke, both of which remain clinical priorities for the NHS in Scotland^[8], ^[9], particularly in light of the impact of the COVID-19 pandemic. CVD is one of the leading causes of death in Scotland. A key risk factor for CVD is hypertension (high blood pressure) where the additional pressure on the blood vessels, the heart and other organs can lead to chronic or even life-threatening conditions^[10].

Many of the key behavioural risk factors for CVD are in themselves of particular interest to health policy makers, public health professionals and the NHS; poor diet, obesity, lack of physical activity, smoking, levels of alcohol consumption and drugs are all the subject of specific strategies targeted at improving Scotland’s health. SHeS includes detailed measures of all these factors which are reported on separately in Chapters 5-9. The other four chapters focus on health conditions and experiences which have the potential to influence health outcomes - Mental Health and Wellbeing (Chapter 1), General Health, Cardiovascular Disease and CPR (Chapter 2), Respiratory Conditions (Chapter 3) and Dental Health (Chapter 4).

Sample

SHeS 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 and Local Authority level are available, usually by combining four consecutive years of data. Due to disruption of the survey in 2020 and comparability issues with the results collected from the short telephone survey conducted that year, NHS board results have been produced using data from the 2019, 2021, 2022 and 2023 surveys combined. These have been published within the survey dashboard 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 total of 8,724 addresses in the main sample (main sample version A and main sample version B) were issued for the whole of the 2023 fieldwork period. A total of 2,504 CHI-linked Child Boost addresses were also issued for this period.

Fieldwork

For the main sample, all adults aged 16 and over in responding households were eligible for interview. To ease respondent burden, for child interviews for both the main and the child boost samples a maximum of two children were interviewed at each household. If a household contained more than two children, then two were randomly selected for interview.

Data collection involved a main computer assisted personal (CAPI) or telephone (CATI) interview, and online or paper self-completion questionnaire.

No height and weight measurements or biological measures could be taken for interviews conducted by telephone. For these interviews, participants were therefore asked to estimate their own height and weight during the interview.

The key differences between the main version A and version B interviews were a slightly longer interview for version A to cover the rotating modules (those not asked every year) and a slightly longer self-completion for version B to cover the depression, anxiety, self-harm and attempted suicide questions and additional bio measurements (blood pressure, waist circumference and saliva samples).

More information on fieldwork is available in the Scottish Health Survey 2023- volume 2: technical report.

Survey response

In 2023, across all sample types, interviews were held in 4,089 households with 4,949 adults (aged 16 and over), and 2,184 children (aged 0-15). The number of participating households and interviews in 2023 is presented separately for the main and child boost samples in the tables below. Further details on survey response in 2023 are presented in the Scottish Health Survey 2023 - volume 2: technical report.

When considering the household response rate, households classed as “responding” were those where at least one eligible person opted-in/consented to interview and was interviewed.

It should be noted that whilst 2023 response rates are improved upon those seen in 2022 for the main sample, they remained lower than typical pre-pandemic rates.

Ethical Approval

Ethical approval for the 2023 survey was obtained from the REC for Wales committee (reference number 17/WA/0371).

Data Analysis

Weighting

Since addresses and individuals did not all have equal chances of selection, the data had to be weighted for analysis. The address selection weights were calculated to compensate for unequal probabilities of selection of addresses in different survey strata. Additional weights have been created for use on combined datasets and for adult self-completion data due to reduced response rates in 2023. A detailed description of the weights is available in the Scottish Health Survey 2023- volume 2: 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 males and females 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 by Scottish Index of Multiple Deprivation (SIMD) or other variables such as mental wellbeing.

Statistical information

SHeS 2023 used a partially 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 that standard errors for survey estimates are generally higher than the standard errors that would be derived from an unweighted simple random sample of the same size. Confidence intervals are shown in the survey dashboard and comments on statistical significance throughout the report, have taken the clustering, stratification and weighting into account. Full details of the sample design and weighting are given in the Scottish Health Survey 2023 - volume 2: technical report.

Presentation of trend data

In this report, trends based on the sixteen surveys from 2003 onwards are presented for all adults aged 16 and over. Prior to this the survey eligibility criteria were set at a maximum age of 64 in 1995 and then a maximum age of 74 in 1998. Unless specified otherwise, 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 all findings is presented at the beginning of this report and topic-specific summaries can be found within each chapter. Each chapter 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 detailed in Chapter 2 of the Scottish Health Survey 2023 - volume 2: technical report. A link to the tables showing the results discussed in the text is included at the end of each chapter.

Availability of further data and analysis

As with surveys from previous years, a copy of the SHeS 2023 data will be deposited at the UK Data Archive along with copies of the combined datasets for 2021/2023, 2022/2023 and 2019/2021/2022/2023. The survey dashboard, providing analysis by sex, age, area deprivation, equivalised income, long-term conditions and local areas for a large range of measures is also available.

Further breakdowns for smoking, long-term conditions, general health, and caring indicators can be found in the Scottish Survey Core Questions, which asks harmonised questions across the three major Scottish Government household surveys.

Comparability with other UK statistics

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