Long-term monitoring of health inequalities: December 2018 report

Annex 2: Data sources and quality

Data quality

Except where the source data is held by Scottish Government (i.e. the mental wellbeing, the limiting long terms conditions and the self-assessed health indicators), aggregate data is provided by National Records of Scotland for the mortality and alcohol mortality indicators, and by ISD Scotland for all other indicators in this report. Scottish Government statisticians carry out quality assurance checks on the aggregate data, comparing it with past trends and against other published data, such as national level data published by NRS or ISD. For the mental wellbeing, limiting long terms conditions and self-assessed health indicator, Scottish Government statisticians quality assure the aggregate data in the same way but take the additional step of double checking the programming methods used to derive the figures within the responsible team.

ISD Scotland and NRS are responsible for the quality assurance of their own datasets. Detailed information on the quality control of the relevant ISD datasets is available online^[4]. National Records of Scotland have published detailed information on the quality of data on deaths^[5]. Analysts at both ISD and NRS are provided with income-employment decile-datazone lookups and population estimates before a request for aggregate data is submitted.

Pre-release access

In accordance with the Pre-release Access to Official Statistics (Scotland) Order 2008, pre-release access to these statistics was provided to Scottish Government policy and communications officials 5 working days before release for the purposes of briefing ministers. NHS Health Scotland colleagues were also provided pre-release access from 5 working days before release for the purposes of making a statement or issuing a press release at the time of, or shortly after, publication.

Indicators

Premature Mortality (from all causes, aged under 75 years)

Source: National Records of Scotland.

Definition: European age-standardised rates of deaths from any cause amongst those aged under 75 years.

Mental Wellbeing (adults aged 16 years and over)

Source: Scottish Health Survey (2008-2017).

Definition: Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS). This has been developed as a tool for measuring positive mental wellbeing at a population level. The scale comprises fourteen separate statements describing feelings related to mental wellbeing; respondents are asked to indicate how often they have felt such feelings over the last two weeks.

Results are presented as average WEMWBS score for the population concerned, and are age-standardised using the age distribution for the Scotland population each year. WEMWBS scores for individuals can range from 14 (for the lowest possible score for each of the fourteen statements) to 70 (for the maximum possible score for each of the fourteen statements).

An additional indicator based on the proportion of adults with ‘below’ average wellbeing is also included. This takes ‘below average’ WEMWBS scores to be at least on standard deviation below the population mean, which equates for scores of 41 or lower in all years.

In order to improve the precision of the estimates of mean and below average WEMWBS scores, data has been presented for two year combined periods in this report (2008/2009 to 2016/2017), together with confidence limits around each estimate.

Coronary Heart Disease - first ever hospital admission for heart attack aged under 75 years

Source: NHS Information Services Division (ISD); SMR01 records (all inpatient and daycase discharges).

Definition: European age-standardised rates of first ever hospital admission for acute myocardial infarction (heart attack) amongst those aged under 75 years. The following World Health Organisation International Classification of Disease coding was used: ICD10 ‘I21-I22’; ICD9 ‘410’.

Coronary Heart Disease - deaths aged 45-74 years

Source: NHS Information Services Division (ISD); using deaths data from National Records of Scotland.

Definition: European age-standardised rates death from coronary heart disease amongst those aged 45-74 years. The following World Health Organisation International Classification of Disease coding was used: ICD10 ‘I20-I25’; ICD9 ‘410-414’. Because of the dynamic nature of the linked database, previous years’ data are sometimes updated in subsequent publications.

Cancer - incidence rate aged under 75 years

Source: NHS Information Services Division (ISD); Scottish Cancer Registry.

Definition: European age-standardised rates of new cases of cancer amongst those aged under 75 years.

All Cancers- cancer defined as all malignant neoplasms excluding non-melanoma skin cancer. The following World Health Organisation International Classification of Disease coding was used: ICD10 ‘C00-C96’ excluding ‘C44’ (the Scottish Cancer Registry does not use code ‘C97’).
Prostate cancer (males only) - ICD-10 C61
Breast cancer (females only) - ICD-10 C50
Cancer of the trachea, bronchus and lung- ICD-10 C33-C34
Colorectal cancer- ICD-10 C18-C20

Cancer - deaths aged 45-74 years

Source: NHS Information Services Division (ISD); Scottish Cancer Registry.

Definition: European age-standardised rates of deaths from cancer amongst those aged under 45-74 years.

All cancers- cancer defined as all malignant neoplasms excluding non-melanoma skin cancer. The following World Health Organisation International Classification of Disease coding was used: ICD10 (2000 onwards) ‘C00-C97’ excluding ‘C44’.
Prostate cancer (males only) - ICD-10 C61
Breast cancer (females only) - ICD-10 C50
Cancer of the trachea, bronchus and lung- ICD-10 C33-C34
Colorectal cancer- ICD-10 C18-C20

Alcohol - first hospital admission aged under 75 years

Source: NHS Information Services Division (ISD).

Definition: European age-standardised rates of first hospital admission for alcohol related conditions amongst those aged under 75 years. These rates include hospitals discharges where alcohol-related problems are recorded as either primary or secondary reasons for admission to hospital and will cover first admission in the last ten years. These figures exclude private hospitals, mental illness hospitals, psychiatric units and maternity hospitals and include Scottish residents only. Caution is necessary when interpreting these figures. The recording of alcohol misuse may vary from hospital to hospital. Where alcohol misuse is suspected but unconfirmed it may not be recorded by the hospital. The following revised World Health Organisation International Classification of Disease coding was used: ICD10: F10, K70, X45, X65, Y15, Y90, Y91, E244, E512, G312, G621, G721, I426, K292, K860, O354, P043, Q860, T510, T511, T519, Y573, R780, Z502, Z714, Z721.

Alcohol - deaths aged 45-74 years

Source: National Records of Scotland.

Definition: European age-standardised rates of death from alcohol related conditions amongst those aged 45-74 years. The definition of alcohol related deaths includes deaths where there was any mention of alcohol related conditions on the death certificate, rather than just as the main cause of death. The following World Health Organisation International Classification of Disease coding was used: ICD10 F10, G31.2, G62.1, I42.6, K29.2, K70, K73, K74.0, K74.1, K74.2, K74.6, K86.0, X45, X65, Y15; ICD9 291, 303, 305.0, 425.5, 571.0, 571.1, 571.2, 571.3, 571.4, 571.5, 571.8, 571.9, E860.

All-cause mortality aged 15-44 years

Source: National Records of Scotland.

Definition: European age-standardised rates of deaths from any cause amongst those aged 15-44 years. Specific breakdowns for deaths from assault, drug related deaths and suicide are also provided, as the major causes of death for which there are large inequalities amongst young people. There may be some double counting in these breakdowns. The following World Health Organisation International Classification of Disease coding was used: Assault ICD10 ‘X85-Y09’, ‘Y87.1’ ICD9 ‘E960-969’; Drug-related ICD10 ‘F11-16’, ‘F19’, ‘X40-44’, ‘X60-64’, ‘X85’, ‘Y10-Y14’; Suicide (intentional self-harm + undetermined intent) ICD10 ‘X60-84’, ‘Y87.0’ ICD9 ‘E950-959’, ‘E980-989’.

Low Birthweight

Source: NHS Information Services Division (ISD); SMR02 maternity dataset.

Definition: The figures are presented as a percentage of all live singleton births (not including home births or births in non-NHS hospitals). Low birthweight is defined as <2,500g - the standard World Health Organisation definition.

Healthy Birthweight

Source: NHS Information Services Division (ISD); SMR02 maternity dataset.
Definition: A baby is considered to be of healthy birthweight (a weight appropriate for its gestational age) when it lies between the 5th and 95th centile for weight at its gestational age. Gestational age is a way of expressing the age or development of a baby. It is typically based on an antenatal ultrasound scan. However, it may also be estimated from the number of weeks since the mother's last normal menstrual period.

Note: In previous publications, data on appropriate birthweight for gestational age were produced using standard tables derived from Scottish data on all births from the years 1998-2003 by Sandra Bonnellie (Napier University) and Jim Chalmers (ISD).

Details of the way in which the standards were derived are available here: http://www.biomedcentral.com/1471-2393/8/5.

ISD recently updated their methodology and data on appropriate birthweight for gestational age are now produced using tables based on the UK-WHO child growth standards developed by the Royal College of Paediatrics and Child Health, see: https://www.rcpch.ac.uk/resources/growth-charts

Figures presented in this publication are calculated using the new methodology.

Self-assessed health (adults aged 16 years and over)

Source: Scottish Health Survey (2008-2017)

Definition: The indicator expresses the percentage of adults responding either ‘bad’ or ‘very bad’ to the following question from the Scottish Health Survey:

How is your health in general? Would you say it was…
1. … very good 2. good 3. fair 4. bad, or 5. very bad

Results are presented as percentage of adults self-reporting ‘poor’ or ‘very bad’ health, and are age-standardised using the age distribution for the Scotland population each year

In order to improve the precision of estimates, data has been presented for two year combined periods in this report (2008/2009 to 2016/2017), together with confidence limits around each estimate.

Limiting long-term conditions (adults aged 16 years and over)

Source: Scottish Health Survey (2008-2017)

Definition: The indicator expresses the percentage of adults responding ‘yes’ to the first question below and then either ‘yes, a lot’ or ‘yes, a little’ to the second question.

Do you have a physical or mental condition or illness lasting, or expected to last 12 months or more?
1. Yes 2. No

Does (condition) limit your activities in any way?
1. Yes, a lot 2. Yes, a little 3. Not at all

Results are presented as percentage of adults with a limiting long term condition, and are age-standardised using the age distribution for the Scotland population each year.

In order to improve the precision of estimates, data has been presented for two year combined periods in this report (2008/2009 to 2016/2017), together with confidence limits around each estimate.