The Scottish Health Survey 2024 - Volume 2: Technical Report

1.1 Introduction

1.1.1    The Scottish Health Survey (SHeS) series

The SHeS series was established in 1995 to provide data about the health of the population living in private households in Scotland. It was repeated in 1998 and 2003 and has been carried out annually since 2008. 

The 2024 survey was conducted by the Scottish Centre for Social Research. Since 2023, SHeS saw a return to the standard SHeS methodology, following some disruption to the survey during the COVID-19 pandemic.

Fieldwork for SHeS 2020 was suspended in March 2020 and, whilst data for some of the key measures from SHeS were collected via a telephone survey in August and September 2020, due to the different methodology, these results were published as experimental statistics and have not been included in time series analysis presented in the main report.  Whilst the 2021 survey included most of the usual SHeS questions and key indicators, interviews were still conducted by telephone and this, along with the different approach to sampling, is likely to have impacted the responses received and thus comparability with the SHeS data from other survey years. The 2022 survey was a transitional year moving from pandemic approaches back to the usual SHeS methodology. 

Details of the approaches used for the 2024 survey can be found below.

1.1.2     The SHeS 2024 Fieldwork 

The SHeS 2024 launched in February 2024. Interviews for all samples were undertaken using primarily an in-home face-to-face approach. Potential respondents were contacted by letter and invited to take part in an in-home interview. A telephone contingency was retained for respondents unwilling to have the interviewer enter their home due to health concerns.

In 2024, fieldwork for the child boost sample continued to utilise a sample linked to the Community Health Index (CHI) database, an approach that has been approved by the Scottish Government’s Public Benefits and Privacy Panel. The transition to the use of the CHI database was undertaken to increase the efficiency of the sample. Prior to the suspension of fieldwork at the outset of the COVID-19 pandemic, the child boost sample was drawn without any indication as to whether there may be children under 16 living in the sampled households. This meant that approximately four-fifths of households visited did not have children under the age of 16 living in them. The transition to sampling via CHI database linkage was used to try and identify households with children under 16 living in them and while a margin for error remains with this approach, it was found to be much more efficient than the previous sampling approach. 

1.1.3     Aims of the SHeS

The purpose of SHeS is to provide information at national level about the health of the population and the ways in which lifestyle factors are associated with health. This level of information is not available from administrative or operational databases, as hospitals and GPs are not able to collect detailed information about peoples’ lifestyles and health- related behaviours. In addition, it is crucial that the Scottish Government has information about the health of the population, including people who do not access health services regularly.

The specific aims of SHeS are:

• To estimate the prevalence of particular health conditions in Scotland.
• To estimate the prevalence of certain risk factors associated with these health conditions and to document the pattern of related health behaviours.
• To 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, England, Wales and Northern Ireland.
• To monitor trends in the population’s health and health related behaviour over time.
• To make a major contribution to monitoring progress towards health targets.

Each survey in the SHeS series has a set of main questions and measurements (height and weight and, if applicable, blood pressure, waist circumference 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.

The SHeS series now has trend data going back 29 years and providing this time series is an important function of the survey.

1.1.4    The 2024 survey

The 2024 SHeS was designed to provide data at national level about the population living in private households in Scotland. The survey covered all ages, with the target sample sizes for the 2024 survey the same as those for 2018-2023.

The flowchart overleaf shows the total number of addresses drawn from the postcode address file (PAF) for each sample type (main and child boost).

The sample for the 2024 survey was drawn on the basis of being worked as primarily face-to-face in-home.

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

Standardised interviewer-administered height and weight measurements were reintroduced as part of in-home interviews in 2022 and have continued since. For interviews conducted by telephone, no height and weight measurements or biological measures could be taken. Participants were asked to estimate their own height and weight during these interviews. 

The main version B sample completed a biological module, and these addresses were only assigned to trained bio interviewers. Version B interviews included a slightly longer self-completion to cover the depression, anxiety, self-harm and attempted suicide questions which are included in the biological module.

1.1.5    The 2024 SHeS annual report

The 2024 report consists of two volumes:

• Volume 1 presents results for adults and children on a variety of health topics and includes a summary of key results.
• Volume 2 (this report) provides methodological information and survey documentation.

Both volumes are available on the Scottish Government’s SHeS website. An interactive data dashboard is also available presenting key indicators for Scotland, NHS Boards and local authority areas.

1.1.6    Comparisons with previous surveys in the SHeS series

In the 2024 report, comparisons are made with data collected earlier in the series (1998-2019 and 2021-2023 for children and 2003-2019 and 2021-2023 for adults). However, it should be noted that, due to the difference in method for 2021, caution should be applied when comparing results from this survey year to 2024. For more information, see Chapter 2 of this report.

In addition, the report and/or dashboard include analysis from combined datasets 2021/2022/2023/2024, 2022/2023/2024, 2023/2024 and 2022/2024.

This is to aid analysis of small subsamples of the population and/or for questions which are included in the survey every second year. Combining data across years in this way allows for a more detailed analysis of subgroups in the sample and allows for analysis of questions with small sample sizes in one survey year.

1.1.7    Health Board and local authority level analysis

Since 2008, the SHeS sample has been designed to be representative of adults at Health Board level (for all Health Boards) following four years of data collection and in 2018 the sample size was increased to allow analysis by local authority. Analysis of the 2021, 2022, 2023 and 2024 data combined by NHS Health Board and by local authority is published via the SHeS dashboard. Areas with larger samples may be able to analyse data at their area level based on fewer years of data collection and users should consult the SHeS website for further guidance on sub-geographies analysis.

Changes in the sample design for the 2012 survey mean that users are not advised to combine data for periods spanning 2011 and 2012. Since 2012, however, the sample has been designed to be representative of the population of Scotland at Health Board level for every four-year period. Hence the survey can be analysed using combined data from:

• 2012/2013/2014/2015,

• 2013/2014/2015/2016,
• 2014/2015/2016/2017,
• 2015/2016/2017/2018,
• 2016/2017/2018/2019,
• 2017/2018/2019/2021,
• 2018/2019/2021/2022,
• 2019/2021/2022/2023 and
• 2021/2022/2023/2024.

It should be noted that no data for 2020 is available by Health Board or Local Authority.

1.1.8    Access to SHeS data

Data from the 2024 survey will be deposited at the UK Data Service (UKDS) along with combined 2021/2022/2023/2024, 2022/2023/2024, 2022/2024 and 2023/2024 datasets. The datasets from earlier years in the series are also deposited at the UK Data Service.