The Scottish Health Survey 2023 - Volume 2: Technical Report

Chapter 2 Methods and Definitions

Victoria Wilson, Julie Landsberg, Morag Shepherd, Xanthippi Gounari

2.1. General survey definitions

Age standardisation

Age standardisation has been used in some analysis in order to enable groups to be compared after adjusting for the effects of any differences in their age distributions.

When different sub-groups are compared in respect of a variable on which age has an important influence, any differences in age distributions between these sub-groups are likely to affect the observed differences in the proportions of interest.

Age standardisation was carried out, using the direct standardisation method. The standard population to which the age distribution of sub-groups was adjusted was the mid-2021 population estimates for Scotland. All age standardisation has been undertaken separately within each sex.

The age-standardised proportion p' was calculated as follows, where p_i is the age specific proportion in age group i and N_i is the standard population size in age group i:

Therefore p' can be viewed as a weighted mean of p_i using the weights N_i. Age standardisation was carried out using the age groups: 16-24, 25-34, 35-44, 45-54, 55-64, 65-74 and 75 and over. The variance of the standardised proportion can be estimated by:

Clusters

A cluster sampling approach was used whereby addresses across Scotland were divided into smaller groups (or clusters) before then using a random sample selection approach to select a sample to approach for the survey.

Household

A household was defined as one person or a group of people who have the accommodation as their only or main residence and who either share at least one meal a day or share the living accommodation.

Household Reference Person (HRP)

The HRP is defined as the householder (a person in whose name the property is owned or rented) with the highest income. If there is more than one householder and they have equal income, then the household reference person is the oldest.

Local Authority

32 elected councils make up the Scottish Local Government, which are referred to as Local Authorities.

Mean

Most means in this report are arithmetic means (the sum of the values for cases divided by the number of cases).

NHS Health Board

The National Health Service (NHS) in Scotland is divided up into 14 geographically based local NHS Boards and a number of National Special Health Boards. Health Boards in this report refers to the 14 local NHS Boards.

Percentile

The value of a distribution which partitions the cases into groups of a specified size. For example, the 20^th percentile is the value of the distribution where 20 percent of the cases have values below the 20^th percentile and 80 percent have values above it. The 50^th percentile is the median.

Primary sampling unit

A primary sampling unit (or PSU) is the first stage of the sampling process. All primary sampling units (data zones on the islands, intermediate geographies elsewhere) in Scotland were randomly allocated to one of four sets. One of these sets is used in each year of fieldwork. This means that the sample is drawn from one quarter of PSUs each year.

P-value

A p value is the probability of the observed result occurring due to chance alone. A p value of less than 5% is conventionally taken to indicate a statistically significant result (p<0.05). It should be noted that the p value is dependent on the sample size, so that with large samples differences or associations which are very small may still be statistically significant. Results should therefore be assessed on the magnitude of the differences or associations as well as on the p value itself. The p values given in this report take into account the clustered sampling design of the survey.

Quintile

Quintiles are percentiles which divide a distribution into fifths, i.e., the 20th, 40th, 60th and 80th percentiles.

Sample

The survey sample represent a proportion of the whole population living in Scotland. It is not possible to survey every household in Scotland, therefore, a proportion of addresses are selected, or sampled, each year in such a way as to be as representative of the whole population as possible. See chapter 1 of the 2023 technical report for more information on the sampling approach used.

Scottish Index of Multiple Deprivation (SIMD)

The SIMD is the Scottish Government’s official measure of area based multiple deprivation. It is based on 37 indicators across 7 individual domains of current income, employment, housing, health, education, skills and training and geographic access to services and telecommunications. SIMD is calculated at data zone level, enabling small pockets of deprivation to be identified. The data zones are ranked from most deprived (1) to least deprived (6,505) on the overall SIMD index. The result is a comprehensive picture of relative area deprivation across Scotland.

This report uses the SIMD 2020 for the 2019, 2021, 2022 and 2023 data (see Scottish Index of Multiple Deprivation 2020).

Self-completion booklet

A portion of the survey questions included in SHeS are asked via a self-completion booklet, including some questions that could be viewed as more sensitive. These paper booklets were handed to respondents who completed them without interviewer assistance (unless this was requested). The booklets were returned to the interviewer before leaving the household.

Significance testing

Where differences in relation to a particular outcome between two subgroups, such as males and females, are highlighted in the main report, the differences can be considered statistically significant, unless otherwise stated.

Statistical significance is calculated using logistic regression to provide a p-value based on a two-tailed significance test. One-tailed tests are used when the difference can only be in one direction. Two-tailed tests should always be used when the difference can theoretically be in either direction. For example, even though previous research has shown a higher prevalence of hazardous levels of alcohol consumption among males than among females, and we may expect this to be true in the most recent survey, a two-tailed test is used to confirm the difference.

Unweighted bases

The unweighted bases presented in the report tables provide the number of individuals upon which the data in the table is based. This is the number of people that were interviewed as part of SHeS and provided a valid answer to the particular question or set of questions. The unweighted bases show the number of people interviewed in various subgroups including sex, age and Scottish Index of Multiple Deprivation.

Weighting

While SHeS is designed to have as representative a sample as possible, it is not possible to obtaining a fully representative sample as participation is on a voluntary basis. Therefore, statistical adjustments are undertaken to ensure that the data is representative of the population of Scotland, according to the most up-to-date population estimates. For more information on the weighting approach used, see chapter 1 of the 2023 technical report.

Weighted bases

The weighted bases are adjusted versions of the unweighted bases which involves calculating a weight for each individual so that their representation in the sample reflects their representation in the general population of Scotland living in private households. Categories within the table can be combined by using the weighted bases to calculate weighted averages of the relevant categories.

2.2. Chapter definitions

2.2.1 Chapter 1 – Mental health and wellbeing

Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS)

The WEMWBS was developed by researchers at the Universities of Warwick and Edinburgh, with funding provided by NHS Health Scotland, to enable the measurement of mental wellbeing of adults in the UK. It was adapted from a 40 item scale originally developed in New Zealand, the Affectometer 2. The WEMWBS scale comprises 14 positively worded statements with a five item scale ranging from ‘1 - None of the time’ to ‘5 - All of the time’. The lowest score possible is therefore 14 and the highest is 70; the tables present mean scores. The 14 items are designed to assess positive affect (optimism, cheerfulness, relaxation); and satisfying interpersonal relationships and positive functioning (energy, clear thinking, self-acceptance, personal development, mastery and autonomy)^[1].

The scale was not designed to identify individuals with exceptionally high or low levels of positive mental health, so cut-off points have not been developed^[2].

General Health Questionnaire (GHQ-12)

GHQ-12^[3] is a scale designed to detect possible psychiatric morbidity in the general population. GHQ-12 is a widely used standard measure of mental distress and mental ill-health consisting of 12 questions on concentration abilities, sleeping patterns, self-esteem, stress, despair, depression, and confidence in the previous few weeks. Responses to each of the GHQ-12 items are scored, with one point allocated each time a particular feeling or type of behaviour is reported to have been experienced 'more than usual' or 'much more than usual' over the previous few weeks.

These scores are combined to create an overall score of between zero and twelve. A score of four or more (referred to as a high GHQ-12 score) has been used here to indicate the presence of a possible psychiatric disorder. A score of zero on the GHQ-12 questionnaire can, in contrast, be considered to be an indicator of psychological wellbeing. GHQ-12 measures deviations from people's usual functioning in the previous few weeks and therefore cannot be used to detect chronic conditions.

Loneliness

A question was included in the adult and young adult self-completion questionnaires to measure levels of loneliness experienced in the week prior to being interviewed, with five answer options ranging from ‘none or almost none of the time’ to ‘all or almost all of the time’. This differs from the question used prior to 2021 where the period asked about was two weeks.

Strengths and difficulties questionnaire (SDQ)

The child Strengths and Difficulties Questionnaire (SDQ) aims to measure behavioural, emotional and relationship difficulties in children. It asks about 25 attributes which are used to devise a total SDQ score and scores for 5 sub-scales related to emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems and prosocial behaviour.

Stress at work

A series of rating scale questions are asked of adults aged 16 and over who are in work in version A of the survey every second year. These questions cover general levels of stress, as well as work life balance and circumstances or conditions at work that may cause stress.

2.2.2 Chapter 2 – General health, cardiovascular conditions, CPR training and caring

General health

Long-term conditions & limiting long-term conditions

Long-term conditions were defined as a physical or mental health condition or illness lasting or expected to last 12 months or more. The wording of this question changed in 2012 and is now aligned with the harmonised questions for Scottish Government surveys. Long-term conditions were coded into categories defined in the International Classification of Diseases (ICD), but it should be noted that the ICD morbidity and mortality statistics are coded by clinicians using the codes for diseases, whereas SHeS asks respondents to self-report if they have any of these conditions. A long-term condition was defined as limiting if the respondent reported that it limited their activities in any way.

Self-assessed general health

Each year, participants who are aged 13 and over are asked to rate their health in general with answer options ranging from ‘very good’ to ‘very bad’. For children under the age of 13 the question is answered by the parent or guardian completing the interview on their behalf.

Cardiovascular conditions

Blood pressure/hypertension

Participants were defined as having self-reported doctor-diagnosed hypertension if they stated during the interview that they had been told by a doctor or nurse that they had high blood pressure.

Cardiovascular disease (CVD)

Participants were asked whether they had ever suffered from any of the following conditions: diabetes, angina, heart attack, stroke, heart murmur, irregular heart rhythm, or ‘other heart trouble’. If they responded affirmatively to any of these conditions, participants were asked whether they had ever been told they had the condition by a doctor and whether they had experienced the conditions in the previous 12 months. For the purpose of this report, participants were classified as having a particular condition only if they reported that the diagnosis was confirmed by a doctor.

It is important to note that no attempt was made to verify these self-reported diagnoses objectively. It is, therefore, possible that some misclassification may have occurred because some participants may not have remembered (or not remembered correctly, or not known about) diagnoses made by their doctor.

Any CVD condition

Participants were classified as having ‘any CVD’ if they reported ever having any of the following conditions confirmed by a doctor: angina, heart attack, stroke, heart murmur, abnormal heart rhythm, or ‘other heart trouble’^[4].

Diabetes

Participants were classified as having diabetes if they reported a confirmed doctor diagnosis. Females whose diabetes occurred only during pregnancy were excluded from the classification. In 2018, a new question was introduced asking participants to report if they had been told they had Type 1 or Type 2 diabetes. Prior to 2018 no distinction was made between Type 1 and Type 2 diabetes in the interview.

Any CVD condition or diabetes

A summary measure of the above conditions is presented in the tables as ‘any CVD condition or diabetes’.

Ischaemic heart disease (IHD)

IHD is also known as coronary heart disease. Participants were classified as having IHD if they reported ever having angina, a heart attack or heart failure diagnosed by a doctor.

Stroke

Participants were classified as having a stroke if they reported ever having had a stroke confirmed by a doctor.

IHD or Stroke

A summary measure of the above conditions is presented in the tables as ‘IHD or stroke’.

Cardiopulmonary Resuscitation (CPR) Training

CPR is an emergency procedure that combines chest compressions with artificial ventilation in an effort to manually preserve brain function in a person who is in cardiac arrest.

Participants were asked whether they had ever had any type of training in CPR or learned CPR either through instructor led sessions or self-instruction using DVD/online instruction. Those who reported they had CPR training were asked to provide details of the time interval since the first training, whether they had attended refresher training and the type of CPR training.

Unpaid caring

Unpaid caring is defined for the purposes of this survey as looking after, or giving any regular help or support to family members, friends, neighbours or others because of either long-term physical, mental ill-health, disability; or problems related to old age, apart from anything done as part of paid employment.

2.2.3 Chapter 3 – Respiratory

Asthma

Participants (including parents of children aged 0-12, and children themselves aged 13-15) were asked if a doctor had ever told them they had asthma. This question was asked in the 1998, 2003, 2008 and 2010 surveys, and has been included every year since 2012. No objective measures were used to confirm these reported diagnoses.

In 2023, an annual question asking about wheezing or whistling in the chest in the last 12 months (TweWz) was unintentionally excluded from the survey and therefore no data is available for this question.

Chronic Obstructive Pulmonary Disease (COPD)

COPD is defined by the World Health Organisation as ‘a pulmonary disease characterised by chronic obstruction lung airflow that interferes with normal breathing and is not fully reversible’. It is associated with symptoms and clinical signs that in the past have been called ‘chronic bronchitis’ and ‘emphysema,’ including regular cough (at least three consecutive months of the year) and production of phlegm.

Each year since 2008, adult participants have been asked if they had ever had COPD, chronic bronchitis or emphysema and, if so, whether a doctor had told them they had one of these conditions. Those who reported doctor-diagnosed COPD were also asked what treatment or advice they had received. No objective measures were used to confirm these reported diagnoses.

Long COVID

Questions asked whether participants had had or thought they had had COVID-19 and how long their symptoms lasted. Long COVID was defined as currently experiencing symptoms more than 4 weeks after they first had COVID-19 that were not explained by something else.

It should be noted that due to changes in the question wording, the long-COVID data is not equivalent with that calculated and reported in the 2022 report, which reported on ever having had long covid. However, figures are comparable with those reported in the 2021 report.

2.2.4 Chapter 4 – Dental Health

Data on dental health is collected from adults aged 16 and over. In addition to collecting data on the number of natural teeth and presence of pain, a list of answer options from which participants can select as many as apply is used to collect data on issues they may be having with their mouth, teeth or dentures.

Questions on dental services are rotated in every two years and asked of adults aged 16 and over as part of the version A sample only. A list of answer options are provided to collected data on denture wearing, timing of last dental visit and issues that may affect their ability to visit a dentist.

2.2.5 Chapter 5 – Diet and Food insecurity

Adult dietary data Intake24, an online dietary tool, was introduced as a means of collecting and analysing data on adult dietary intakes for the 2021 survey. This replaced previous methods of obtaining adult dietary data that were used in SHeS and will be repeated every three years, next to be included in 2024. Therefore, no adult dietary data was collected or reported in 2023.

Fruit and vegetable consumption (children)

Data on fruit and vegetable consumption among children was measured using survey questions, as in previous years. It is recommended that children eat at least five portions of fruit and vegetables per day[5].

Food insecurity

Food insecurity is ‘the inability to acquire or consume an adequate quality or sufficient quantity of food in socially acceptable ways, or the uncertainty that one will be able to do so’. In their self-completion questionnaire, participants answered three routed questions on food insecurity asking whether they had worried about running out of food, had eaten less than they should have or had actually run out of food in the last 12 months.

2.2.6 Chapter 6 – Physical Activity

UK Chief Medical Officers (CMO) Physical Activity Guidelines (2019)

Age group

Early years – children under 5 years

Guidelines

Infants (less than 1 year):

Physical activity is recommended several times a day (the more activity the better) in a variety of ways including interactive floor-based activity, e.g. crawling.

Where infants are not yet mobile, at least 30 minutes of tummy time spread across the day and while awake is recommended along with movements such as reaching and grasping, pushing and pulling themselves over independently, or rolling over; more is better.

Toddlers (1-2 years):

At least 180 minutes (3 hours) per day of physical activity of any intensity is recommended for toddlers, including active and outdoor play.

Pre-schoolers (3-4 years):

At least 180 minutes (3 hours) per day of activity is also recommended for pre-school aged children, including a variety of active and outdoor play physical activities spread throughout the day. For this age group, this should include at least 60 minutes per day of moderate-to-vigorous intensity physical activity.

Age group

Children and young people aged 5 to 18

Guidelines

It is recommended that children and young people in this age group engage in moderate-to-vigorous intensity physical activity for an average of at least 60 minutes per day. The activities undertaken include those undertaken in a variety of settings such as school-based physical education, active travel, after school activities, play and sporting activities.

Engagement in a range of activities and intensities over the course of a week is recommended in order to develop movement skills, muscular fitness and bone strength.

This activity should be accompanied by as minimal an amount of sedentary time as possible, with any long periods of inactivity broken up with some physical activity, even if this is light in nature.

Age group

Adults aged 19-64

Guidelines

Daily physical activity is recommended for both physical and mental health benefits - the more the better but any activity is encouraged.

This includes activities to develop and strengthen the major muscle groups, which can be achieved through activities such as heavy gardening, carrying heavy shopping, or resistance exercise. It is recommended that muscle strengthening activities are done on at least two days a week, but any strengthening activity is better than none.

On a weekly basis, adults should undertake:

• at least 150 minutes (2 1/2 hours) of moderate intensity activity (such as brisk walking or cycling)
• or 75 minutes of vigorous intensity activity (such as running)
• or even shorter durations of very vigorous intensity activity (such as sprinting or stair climbing);
• or a combination of moderate, vigorous and very vigorous intensity activity.

Sedentary time should be minimized as far as possible, breaking this up with at least light physical activity.

Age group

Adults aged 65 and over

Guidelines

Daily physical activity is also recommended for older adults for the maintenance of good physical and mental health, wellbeing, and social functioning. Even light activity offers greater health benefits than being sedentary, although the more daily physical activity that is undertaken, the better.

Older adults should also undertake activities aimed at improving or maintaining muscle strength, balance and flexibility on at least two days a week, either on their own or combined with moderate aerobic activity. This should be accompanied by 150 minutes (two and a half hours) of moderate intensity aerobic activity, building gradually up to this where activity levels are currently lower.

Those who are already regularly active can achieve these benefits through:

• 75 minutes of vigorous intensity activity
• or a combination of moderate and vigorous activity

Weight-bearing activities offer additional benefit in helping to maintain bone health.

Where physically able, long periods of being sedentary should be broken up with light activity, or at least with standing.

Adult physical activity questionnaire

The SHeS questionnaire^[6] asks about four main types of physical activity:

• home-based activities (housework, gardening, building work and DIY)
• walking
• sports and exercise
• activity at work

Information is collected on the:

• time spent being active
• intensity of the activities undertaken
• frequency with which activities are performed.

Adherence to adult physical activity guidelines

The activity guidelines advised adults to accumulate 150 minutes of moderate activity or 75 minutes of vigorous activity per week or an equivalent combination of both, in bouts of 10 minutes or more. These guidelines are referred to as the Moderate or Vigorous Physical Activity guidelines (MVPA). To help assess adherence to this guideline, the intensity level of activities mentioned by participants was estimated.

Activities of low intensity, and activities of less than 10 minutes duration, were not included in the assessment. This allowed the calculation of a measure of whether each SHeS participant adhered to the guideline, referred to in the text and tables as “adult summary activity levels”, see the table below. A more detailed discussion of this calculation is provided in the 2012 report^[7].

Adult summary activity levels^a

Meets MVPA guidelines

Reported 150 mins/week of moderate physical activity or 75 mins vigorous physical activity, or an equivalent combination of these.

Some activity

Reported 60-149 mins/week of moderate physical activity, or 30-74 mins/week vigorous physical activity, or an equivalent combination of these.

Low activity

Reported 30-59 mins/week of moderate physical activity, or 15-29 mins/week vigorous physical activity or an equivalent combination of these.

Very low activity

Reported less than 30 mins/week of moderate physical activity, or less than 15 mins/week vigorous physical activity, or an equivalent combination of these.

^a Only bouts of 10 minutes or more were included towards the 150 minutes per week guideline.

Muscle strengthening

A second summary measure was calculated, to assess whether adults are meeting the guideline to carry out activities that develop or maintain strength in the major muscle groups on at least 2 days a week.

Nine different sports (swimming, athletics, canoeing, climbing, horse riding, rowing, sailing, skiing and waterskiing) were classed as always muscle strengthening, and other sports or exercises were classed as muscle strengthening if the participant reported that the effort was enough to make the muscles feel some tension, shake or feel warm. If the participant carried out such activities for at least 10 minutes on 2 or more days a week, on average, they were deemed to meet the muscle strengthening guideline. As this only includes muscle strengthening through sporting activity, reported levels may be an underestimate.

Child Physical Activity Questionnaire

The questions on child physical activity are slightly less detailed than those for adults^[8]. No information on intensity is collected (with the exception of asking those aged 13-15 about their walking pace). The questions cover:

• sports and exercise
• active play including housework and gardening
• walking

Where appropriate, data are collected and reported for physical activity undertaken at and outside of school.

Sedentary time

Data are collected for adults and children on sedentary time on weekdays and weekends. Sedentary time is calculated from questions on time spent sitting at work, watching TV/another type of screen and/or time spent sitting doing other activities such as eating a meal, reading, napping etc. Sedentary time excludes those without a limiting illness or disability who said they were sedentary for more than 14 hours a day.

2.2.7 Chapter 7 – Smoking

Questions on smoking behaviour

Questions on smoking have been included in SHeS since 1995. Some small changes were made to the questions in 2008 and 2012. These are outlined in the relevant annual reports^[9],[10].

The current questions in the survey focus on:

• current smoking status
• frequency and pattern of current smoking
• the number of cigarettes smoked by current smokers
• exposure to second-hand smoke
• past smoking behaviour, current and ex-smokers
• quit attempts and desire to give up smoking
• medical advice on giving up smoking
• nicotine replacement therapy (NRT) use (including questions on NRT that led to successful cessation)
• Nicotine Vapour Products (NPVs) e.g. e-cigarettes/vapes (including as part of a quit attempt)

Adults aged 20 and over were asked about their smoking behaviour during the main interview. For those aged 16 and 17, information was collected in a self-completion questionnaire offering more privacy and reducing the likelihood of concealing behaviour in front of other household members. Those aged 18 and 19 could answer the questions either during the interview or via the self-completion, at the interviewer’s discretion.

The self-completion questions were largely similar to those asked in the interview. However, given the age of the participants completing the self-completion questionnaire, questions on past smoking behaviour, desire to give up smoking and medical advice to stop smoking were excluded.

Smoking status

Smoking status categories reported are:

• current cigarette smoker
• ex-regular cigarette smoker
• never regular cigarette smoker
• never smoked cigarettes at all

Information on cigar and pipe use is collected in the survey but as prevalence is low these are not considered in the definition of current smoking.

Nicotine Vapour Products (Electronic cigarettes/e-cigarettes/vapes)

Electronic cigarettes or e-cigarettes are battery-powered handheld devices which heat a liquid that delivers a vapour. The vapour is then inhaled by the user, which is known as ‘vaping’. E-cigarettes typically consist of a battery, an atomiser and a cartridge containing the liquid. Earlier models, often referred to as ‘cigalikes’, were designed to closely resemble cigarettes but there is now a wide variety of product types on the market. The liquid is usually flavoured and may not contain nicotine, although in most cases e-cigarettes are used with nicotine. Unlike conventional or traditional cigarettes, they do not contain tobacco and do not involve combustion (i.e. they are not lit).

SHeS has gathered information on the use of e-cigarettes among the Scottish adult population since 2014, in response to their increased availability and high profile. The questions ask whether participants have ever used an e-cigarette as well as whether they currently use an e-cigarette. The questions about e-cigarettes were amended in 2016 to include the term ‘vaping devices’.

Exposure to second-hand smoke

Exposure to second-hand smoke in adults was measured by asking respondents to self-report where they have been exposed to second-hand smoke. The analysis of cotinine levels from the saliva samples provides an alternative measurement of exposure to second-hand smoke. Analysis of cotinine levels is not presented in the report this year as two year of data combined are generally required for reporting and the saliva samples were only reinstated part way through the 2022 survey year due to pandemic restrictions.

Exposure to second-hand smoke for children is measured by the following:

• whether there is someone who regularly smokes inside the accommodation where the child lives, and
• parents’ and older children’s (aged 13-15) reports of whether children are exposed to smoke at home.

Nicotine Replacement Therapy (NRT)

The remedial administration of nicotine to the body by means other than tobacco, usually as part of smoking cessation. Common forms of nicotine replacement therapy include nicotine patches and nicotine gum.

2.2.8 Chapter 8 – Alcohol and Drugs

UK Chief Medical Officers’ Alcohol Guidelines

The UK CMO alcohol guidelines consist of three recommendations:

• a weekly guideline on regular drinking;
• advice on single episodes of drinking; and
• a guideline on pregnancy and drinking

According to the weekly guideline, adults are safest not to regularly drink more than 14 units per week, to keep health risks from drinking alcohol to a low level. If you do drink as much as 14 units a week, it is best to spread this evenly over three days or more. On a single episode of drinking, advice is to limit the total amount drunk on any occasion, drink more slowly, drink with food and alternate with water. The guideline on drinking and pregnancy, or planning a pregnancy, advises that the safest approach is not to drink alcohol at all^[11].

Questions on alcohol

Questions about drinking alcohol have been included in SHeS since its inception in 1995. Questions are asked either face-to-face via the interviewer or included in the self-completion questionnaire if they are deemed too sensitive for a face-to-face interview (e.g. if being interviewed with a parent). All those aged 16-17 years are asked about their consumption via the self-completion, as are some of those aged 18-19 years, at the interviewers’ discretion. The way in which alcohol consumption is estimated in the survey was changed significantly in 2008. A detailed discussion of those revisions can be found in the chapter on alcohol consumption in the 2008 report^[12].

In 2023, the SHeS questionnaire covered the usual weekly consumption of alcohol.

Weekly consumption

Participants (aged 16 years and over) were asked preliminary questions to determine whether they drank alcohol at all. For those who reported that they drank, these were followed by further questions on how often during the past 12 months they had drunk each of six different types of alcoholic drink:

• normal strength beer, lager, stout, cider, and shandy
• strong beer, lager, stout, and cider
• spirits and liqueurs
• sherry and martini
• wine
• alcoholic soft drinks (alcopops)

From these questions, the average number of days per week the participant had drunk each type of drink was estimated. A follow-up question asked how much of each drink type they had usually drunk on each occasion. These data were converted into units of alcohol and multiplied by the amount they said they usually drank on any one day^[13].

Calculating alcohol consumption

The guidelines on lower risk drinking are expressed in terms of units of alcohol consumed. Detailed information on both the volume of alcohol drunk in a typical week and on the heaviest drinking day in the week preceding the survey was collected from participants. The volumes reported were not validated. In the UK, a standard unit of alcohol is 10 millilitres or around 8 grams of ethanol (pure alcohol). In this chapter, alcohol consumption is reported in terms of units of alcohol.

There are numerous challenges associated with calculating units at a population level, not least of which are the variability of alcohol strengths and the fact that these have changed over time. The table below outlines how the volumes of alcohol reported in the survey were converted into units (the 2008 report provides full information about how this process has changed over time)^[14]. Those who drank bottled or canned beer, lager, stout or cider were asked in detail about what they drank, and this information was used to estimate the amount in pints.

Alcohol unit conversion factors

Type of drink	Volume reported	Unit conversion factor
Normal strength beer, lager, stout, cider, shandy (less than 6% Alcohol By Volume (ABV)	Half pint	1.0
	Can or bottle	Amount in pints multiplied by 2.5
	Small can (size unknown)	1.5
	Large can / bottle (size unknown)	2.0
Strong beer, lager, stout, cider, shandy (6% ABV or more)	Half pint	2.0
	Can or bottle	Amount in pints multiplied by 4
	Small can (size unknown)	2.0
	Large can / bottle (size unknown)	3.0
Wine (including champagne and prosecco)	250ml glass	3.0
	175ml glass	2.0
	125ml glass	1.5
	750ml bottle	1.5 x 6
Sherry, vermouth and other fortified wines	Glass	1.0
Spirits	Glass (single measure)	1.0
Alcopops	Small can or bottle	1.5
	Large (700ml) bottle	3.5

Problem drinking – Alcohol Use Disorders Identification Test (AUDIT)

Since 2012 the AUDIT questionnaire has been used to assess problem drinking. AUDIT is widely considered to be the best screening tool for detecting problematic alcohol use.

It’s comprised of ten indicators of problem drinking; three indicators of consumption, four of use of alcohol considered harmful to oneself or others, and three of physical dependency on alcohol. Given the potentially sensitive nature of these questions, they were administered in self-completion format for all participants. In line with the World Health Organisation guidelines on using the tool, responses to each of the ten AUDIT questions were assigned values of between 0 and 4^[15]. Scores for the ten questions were summed to form a scale, from 0 to 40, of alcohol use.

The WHO guidelines^[16] for interpreting AUDIT scale scores are as follows:

Score	Category description
0 to 7	low-risk drinking behaviour, or abstinence
8 to 15	medium level of alcohol problems, with increased risk of developing alcohol-related health or social problems (sometimes described as hazardous drinking behaviour)
16-19	high level of alcohol problems, for which counselling is recommended (harmful drinking behaviour)
20 or above	warrants further investigation for possible alcohol dependence

Drug use

Respondents completing the adult and young adult self-completion questionnaires were presented with 21 drugs and asked to indicate whether they had taken each of these or not in the last 12 months. This list included several substances not regulated under the misuse of drugs act (poppers, solvents and nitric oxide), as well as prescription only painkillers that were not prescribed for the respondent.

While under-reporting of drug taking can be a factor in surveys such as SHeS, people may report taking particular drugs when they have not actually done so. The list of drugs included in the survey therefore includes ‘semeron’, a fictitious drug. Any respondents select semeron are excluded from the final data outputs and reporting for the drugs questions.

The drugs were categorised in the data tables according to their composite group within the Drugs Wheel[17]: cannabinoids, stimulants, opioids, depressants, psychedelics, dissociatives, empathogens, prescription painkillers and an additional category of steroids and by their classification: A, B or C (as defined by the Misuse of Drugs Act 1971^[18]), as shown in the table overleaf.

Drug	Drugs Wheel Category	Drug Class
Amphetamine (speed, sulph, uppers, Billy, base)	Stimulants	B
Methamphetamine (crystal meth, ice, glass, Tina, yabba, crystal)	Stimulants	A
Cannabis (weed, pot, grass, hash, skunk, ganja, blunt, dope, blow, spliff, smoke, green, edibles, joints, marijuana, oil, resin, pollen, shatter)	Cannabinoids	B
Synthetic cannabis (K2, spice, black mamba, incense, fake weed, Yucatan, genie)	Cannabinoids	B
Cocaine (coke, Charlie, white, flake, ching, posh, petrol)	Stimulants	A
Crack (rock, sand, stone, pebbles, freebase, wash)	Stimulants	A
Ecstasy/MDMA Powder (‘E’, ‘X’, eccies, ‘XTC’, MDMA, swedgerz, pingers, sweeties, pills, Mandy, madman)	Empathogens	A
Heroin (smack, skag, ‘H’, morphine, fentanyl, brown, junk, gear, kit)	Opioids	A
LSD (acid, tabs, trips, blotters)	Psychedelics	A
Magic mushrooms (mushies, psilocybin, shrooms, liberty caps)	Psychedelics	A
Methadone/Physeptone without prescription (phy, meth, linctus, juice, turtle, green)	Opioids	A
Semeron (sems, ‘S’)*	N/A	N/A
Anabolic steroids without prescription (steroids, roids)	Steroids	C
Poppers (amyl nitrate, liquid gold, TNT)	Stimulants	NC**
Ketamine (K, special K, KET)	Dissociatives	B
Glues, solvents, gas or aerosols (to sniff or inhale)	Depressants	NC**
Mephedrone (M-Cat, 4MMC, ‘bubbles’, drone, meph)	Stimulants	B
Tranquilisers: Benzodiazepines without prescription (temazepam, nitrazepam, diazepam, etizolam, Valium, Xanax, blues, yellows, benzos, jellies, scoobies)	Depressants	C
GHB/GBL (G, GINA, LIQUID E, LIQUID X)	Depressants	C
Nitrous Oxide (laughing gas, whippets, NOS)	Dissociatives	NC**
Prescription only painkillers that were not prescribed for you (morphine, codeine, co-codamol, oxycontin, tramadol, gabapentin, pregabalin)	Prescription painkillers	NC**

* Fictitious drug included for quality assurance purposes

** Not classified/class not determined

Problem drug and alcohol use

Adults aged 16 and over are asked, in the self-completion booklets, whether they have ever had a problem with alcohol and if they consider themselves to still have a problem. Similar questions are then asked about drugs. These are subjective questions that are answered according to the respondent’s own view on whether any alcohol and/or drug use is problematic.

2.2.9 Chapter 9 – Obesity

Body Mass Index (BMI)

BMI is a widely accepted measure that allows for differences in weight due to height. It is defined as weight (kg)/square of height (m²). This has been used as a measure of obesity in SHeS since its inception in 1995. BMI has some limitations and does not, for example, distinguish between mass due to body fat and mass due to muscular physique^[19].

In 2023, standardised height and weight measurements were largely administered by an interviewer in-home. For the small proportion of interviews conducted by telephone, participants provided estimated measurements.

For adults, both interviewer-administered and self-reported measures have been used to calculate estimated BMI. The self-reported data has been adjusted using adjustment factors based on a study of data from the Health Survey for England (HSE) and Active Lives Surveys which found that, on average, participants overestimated their height and underestimated their weight^[20].

Based on their BMI (calculated from self-reported height and weight), adult participants were classified into the following groups based on the World Health Organisation (WHO) classification^[21]:

BMI (kg/m2)	Description
Less than 18.5	Underweight
18.5 to less than 25	Normal
25 to less than 30	Overweight, excluding obesity
30 to less than 40	Obesity, excluding morbid obesity
40+	Morbid obesity

The child BMI data included in the report and data tables is based only on those with interviewer administered measurements. Based on their BMI, child participants were classified into the following groups based on the World Health Organisation (WHO) classification^[22].

Although the BMI calculation method is the same, there are no fixed BMI cut-off points defining overweight and obesity in children. Instead, overweight and obesity are defined using several other methods including age and sex specific BMI cut-off points or BMI percentile cut-offs based on reference populations.

Children can be classified into the following groups:

BMI (percentile)	Description
Above 2nd and below 85th	Within healthy range
At or below 2nd, at or above 85th	Outwith healthy range
At or above 85th, below 95th	At risk of overweight
At or above 95th	At risk of obesity

Waist Circumference

Waist circumference is a measure of deposition of abdominal fat. It is measured during the biological module. A raised waist circumference has been defined as more than 102cm in males and more than 88cm in females. In 2022, it was only possible to collect accurate information for waist circumference (WC) for a proportion of the version B sample interviews; therefore, some caution when making comparisons to 2022 due to the reduced sample size is advised.

Health risk category

Health risk categories are organised according to the SIGN guidelines on obesity which cite that an individual’s risk of conditions such as type 2 diabetes and CVD is better estimated using a combination of both BMI and WC than either measure on their own [23].

The classification categories suggested by SIGN are set out in the following table. BMI, derived from height and weight data collected in the main interview, in combination with waist measurements collected in the biological module have been used to estimate the proportion of adults who fall into each of the risk categories. This combined classification designates those with a raised WC as 'very high' WC, while those towards the upper end of the 'not raised' WC range are designated 'high' WC. As the table indicates, the health risk is similar for adults with very high WC and class I obesity and for adults with high WC and class II obesity. The SIGN guidance notes that increased WC can be a marker for disease even among people of normal weight. The analysis presented in this chapter classifies people with normal weight and a very high WC as at increased risk of disease.

Assessment of health risk from obesity

BMI Classification	'High' WC Males WC 94-102cm Females WC 80-88cm	'Very high' WC Males WC >102cm Females WC >88cm
Normal weight (BMI 18.5 - <25(kg/m2))	-	-
Overweight (BMI 25 - <30(kg/m2))	Increased	High
Obese
I - Mild (BMI 30 - <35(kg/m2))	High	Very high
II - Moderate (BMI 35 - <40(kg/m2))	Very high	Very high
III - Extreme (BMI 40+(kg/m2))	Extremely high	Extremely high

Source: based on Table 3, P11, in SIGN 115²³.

2.3. A note about bases for males and females in the 2023 tables

From 2022, a question on participant’s sex has been included in the survey self-completion questionnaires for adults in addition to the usual approach of the household reference person providing this information for everyone in the household as part of the main CAPI interview.

Where the respondent completed a self-completion questionnaire, their response to the sex question here took precedence over the CAPI data. However, in the self-completion questionnaire, the sex question included the option of ‘prefer not to say’. In addition, respondents could choose not to answer the question. Any such cases where the sex data was missing or ‘prefer not to say’ had been selected are not included in the breakdowns for males and females in the data tables but are included in the ‘All adults’ totals. As such, base numbers for all adults may be greater than the sum of the men and women base numbers where these are reported separately.

For children, sex is provided by the household reference person. In cases where the sex question has not been answered the data is not included in the breakdowns for males and females in the data tables but are included in the ‘All children’ totals. As such, base numbers for all children may be greater than the sum of the males and females base numbers where these are reported separately.

References and notes

1 Kammann, R. and Flett, R. (1983). Sourcebook for measuring well-being with Affectometer 2. Dunedin, New Zealand: Why Not? Foundation. Information on measuring mental wellbeing using WEMWBS is available online from: https://warwick.ac.uk/fac/sci/med/research/platform/wemwbs Further information about WEMWBS is available at: www.healthscotland.com/scotlands-health/population/Measuring-positive-mental-health.aspx

2 Stewart-Brown, S and Janmohamed, K (2008). Warwick-Edinburgh Mental Well-being Scale (WEMWBS). User Guide Version 1. Warwick and Edinburgh: University of Warwick and NHS Health Scotland. Available at: http://www.healthscotland.com/documents/2702.aspx

3 Goldberg, D and Williams, PA (1988). A User's Guide to the General Health Questionnaire. Windsor: NFER-Nelson.

4 Diabetes and high blood pressure are not included in the definition of ‘any CVD condition’ as they are risk factors for CVD.

5 See https://www.nhs.uk/live-well/eat-well/5-a-day/portion-sizes/#:~:text=Children%20should%20also%20eat%20at,the%20palm%20of%20their%20hand.

6 The questions used in the survey since 1998 are based on the Allied Dunbar National Fitness Survey, a major study of physical activity among the adult population in England carried out in 1990. For further details see: Health Education Authority. Allied Dunbar National Fitness Survey. Health Education Authority and Sports Council, London. 1992

7 Bromley C. (2013) Chapter 6: Physical Activity. In Rutherford L, Hinchliffe S and Sharp C (eds.) Scottish Health Survey 2012 – Volume 1: Main Report. Edinburgh: Scottish Government. Available at: https://www.gov.scot/publications/scottish-health-survey-2012-volume-1-main-report/pages/10/

8 The questions on child physical activity included in SHeS since 1998 are based on the 1997 Health Survey for England (HSE) children’s physical activity module.

9 Gray L & Leyland AH (2009). Chapter 4: Smoking. In: Bromley, C., Bradshaw, P. and Given, L. (eds.) The 2008 Scottish Health Survey – Volume 1: Main Report. Edinburgh: Scottish Government. 2009. www.gov.scot/Publications/2009/09/28102003/0

10 Gray L & Leyland AH (2013). Chapter 4: Smoking. In: Rutherford, L., Hinchliffe, S. and Sharp, C. (eds.) The Scottish Health Survey 2012 – Volume 1: Main Report. Edinburgh: Scottish Government. Available at: www.gov.scot/Publications/2013/09/3684

11 See: https://www.drinkaware.co.uk/alcohol-facts/alcoholic-drinks-units/latest-uk-alcohol-unit-guidance/

12 Reid S (2009). Chapter 3: Alcohol consumption. In: Bromley C, Bradshaw P and Given L. (eds.) The 2008 Scottish Health Survey – Volume 1: Main Report. Edinburgh: Scottish Government. 2009. Available at: www.gov.scot/Publications/2009/09/28102003/31

13 For participants aged 16 and 17, details on alcohol consumption were collected as part of a special smoking and drinking self-completion questionnaire. Some aged 18 and 19 also completed the self-completion if the interviewer felt it was appropriate. For all other adult participants, the information was collected as part of the face-to-face interview. The method of estimating consumption follows that originally developed for use in the General Household Survey and is also used in the Health Survey for England. For six types of alcoholic drink (normal strength beer/lager/cider/shandy, strong beer/lager/cider, spirits/liqueurs, fortified wines, wine, and alcoholic soft drinks), participants were asked about how often they had drunk each one in the past twelve months, and how much they had usually drunk on any one day. The amount given to the latter question was converted into units of alcohol, with a unit equal to half a pint of normal strength beer/lager/cider/alcoholic soft drink, a single measure of spirits, one glass of wine, or one small glass of fortified wine. A half pint of strong beer/lager/cider was equal to 1.5 units. The number of units was then multiplied by the frequency to give an estimate of weekly consumption of each type of drink. The frequency multipliers were:

Drinking frequency	Multiplying factor
Almost every day	7.0
5 or 6 times a week	5.5
3 or 4 times a week	3.5
Once or twice a week	1.5
Once or twice a month	0.375
One every couple months	0.115
Once or twice a year	0.029

The separate consumption figures for each type of drink were rounded to two decimal places and then added together to give an overall weekly consumption figure.

14 See: https://www.gov.scot/publications/scottish-health-survey-2008/pages/29/

15 AUDIT questionnaire

Questions	0	1	2	3	4
1. How often do you have a drink containing alcohol?	Never	Monthly or less	2-4 times a month	2-3 times a week	4 or more times a week
2. How many drinks containing alcohol do you have on a typical day when you are drinking?	1 or 2	3 or 4	5 or 6	7 to 9	10 or more
3. How often do you have six or more drinks on one occasion?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
4. How often during the last year have you found that you were not able to stop drinking once you had started?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
5. How often during the last year have you failed to do what was normally expected of you because of drinking?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
6. How often during the last year have you needed a first drink in the morning to get yourself going after a heavy drinking session?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
7. How often during the last year have you had a feeling of guilt or remorse after drinking?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
8. How often during the last year have you been unable to remember what happened the night before because of your drinking?	Never	Less than monthly	Monthly	Weekly	Daily or almost daily
9. Have you or someone else been injured because of your drinking?	No		Yes, but not in the last year		Yes, during the last year
10. Has a relative, friend, doctor, or other health care worker been concerned about your drinking last year?	No		Yes, but not in the last year		Yes, during the last year

16 Babor, T.F., Higgins-Biddle, J.C., Saunders, J.B. and Monteiro, M.G (2001). AUDIT – The Alcohol Use Disorders Identification Test – Guidelines for Use in Primary Care, Second Edition. Geneva: World Health Organization.

17 See http://www.thedrugswheel.com/

18 See https://www.legislation.gov.uk/ukpga/1971/38/contents

19 Romero-Corral, A. et al (2008). Accuracy of body mass index in diagnosing obesity in the adult general population. International Journal of Obesity, 32: 959–966.

20 See https://fingertips.phe.org.uk/documents/2.12%20Adult%20excess%20weight%20method%20details%202015-16.docx

21 These cut-offs differ to those used in the previous surveys. In 1995 and 1998 the normal weight range was defined as 20-25 kg/m², in 2003 it was changed to 18.5-25 kg/m². From 2008 onwards the ranges are defined as set out below. This brings the definition in line with WHO recommendations. The impact of the change of definition is very marginal as very few people have a BMI measurement that is exactly 18.5, 25, 30 or 40 kg/m².

	2003	2008 onwards
Underweight	18.5 or under	Less than 18.5
Normal weight	Over 18.5 – 25	18.5 to less than 25
Overweight	Over 25 – 30	25 to less than 30
Obese	Over 30 – 40	30 to less than 40
Morbidly obese	Over 40	40+

22 These cut-offs differ to those used in the previous surveys. In 1995 and 1998 the normal weight range was defined as 20-25 kg/m², in 2003 it was changed to 18.5-25 kg/m². From 2008 onwards the ranges are defined as set out below. This brings the definition in line with WHO recommendations. The impact of the change of definition is very marginal as very few people have a BMI measurement that is exactly 18.5, 25, 30 or 40 kg/m².

	2003	2008 onwards
Underweight	18.5 or under	Less than 18.5
Normal weight	Over 18.5 – 25	18.5 to less than 25
Overweight	Over 25 – 30	25 to less than 30
Obese	Over 30 – 40	30 to less than 40
Morbidly obese	Over 40	40+

23 See https://www.sign.ac.uk/assets/sign115.pdf