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What are these statistics?

These statistics present quarterly information about sickness absence of staff in the NHS in Wales by NHS organisation and staff group.

Source of data and methodology

The data in this release and the accompanying StatsWales tables comes from the Electronic Staff Record (ESR), provided by Health Education and Improvement Wales (HEIW). The ESR is a payroll and human resources system for NHS employees in Wales and England. A monthly extract is downloaded from the ESR Data Warehouse detailing the number of Full Time Equivalent (FTE) calendar days available and the number of FTE calendar days of sickness absence for each member of NHS staff in Wales on the ESR. Sickness absence rates are then calculated for the whole Welsh NHS, staff groups and individual organisations. This rate is derived by dividing the FTE number of days sick by the FTE number of days available.

Sickness absence rates are calculated using FTE calendar days and include non-working days, which is 365 days of the year (366 days for a leap year). This may result in a slight under count of sickness absence rates calculated in this way when compared to sickness absence rates calculated using FTE worked days only, as non-working days such as weekends are included in both the numerator (if they are included in a period of reported sickness) and denominator. Typically not all non-working days lost to sickness will have been reported by an employee and therefore captured on the ESR.

The use of the term FTE in this context means, for example, that if a full time member of staff is off sick for 5 days (including any non-working days) then the numerator for the rate=5, and the denominator=365. However, if a half time member of staff is off sick for 5 days (including any nonworking days) then the numerator=5 and the denominator=182.5.

This methodology is consistent throughout this publication series so that different NHS organisations and staff groups can be compared accurately over a time series. The same methodology is also used by NHS Digital for reporting NHS Sickness Absence Rates in England. However, care should be taken when comparing these rates to those using different methodologies.


Sickness absence statistics relate to all staff directly employed by the NHS in Wales during the recording periods. Such staff are recorded on the ESR which acts as a data source for both the quarterly NHS Staff statistics and the Sickness Absence statistics.

Statistics are presented on a quarterly basis from the start of a calendar year onwards.

Data included in the release are published on StatsWales.

For data relating to the period of the coronavirus pandemic, NHS staff who are self-isolating are not counted as being off sick and are therefore not included in the statistics.

What are the potential uses of these statistics?

These statistics will be used in a variety of ways. Some examples of these are:

  • advice to ministers
  • to inform debate in the Welsh Parliament and beyond
  • to monitor and evaluate staffing levels in the NHS in Wales

Who are the key potential users of this data?

The main users are:

  • ministers, members of the Welsh Parliament, and the Members Research Service in the Welsh Parliament
  • NHS organisations
  • the Health and Social Services Group in the Welsh Government
  • other areas of the Welsh Government
  • the research community
  • students, academics and universities
  • individual citizens and private companies

If you are a user and do not feel the above list adequately covers you, or if you would like to be added to our circulation list, please let us know by e-mailing

Strengths and limitations of the data


  • Data has coverage for all NHS organisations for staff employed by the NHS in Wales.
  • Data is available by staff group although some differ slightly to those used for quarterly reporting on NHS Staff numbers.
  • A 12 month moving average is shown within reports to provide clearer information on long term changes to the rate of sickness absence as there is wide seasonal variation throughout the year.
  • Although data is published quarterly, the sickness absence rates provided via our StatsWales website are monthly data.


  • Sickness absence is subject to marked seasonal variation however reports show a 12 month moving average to more clearly show long term trend.
  • While lower sickness absence rates, in general, indicate lower levels of sickness absence it should be noted that lower rates can also indicate under reporting of sickness absence.

Data processing cycle

Data is submitted from HEIW on Excel spreadsheets via Afon, the Welsh Government secure web data transfer system.

Validation checks are performed by Welsh Government statisticians and queries referred to HEIW and NHS contacts where necessary.

Once validated, data is published in line with statement on confidentiality and data access each quarter.

Statistics are currently published in an html webpage with brief analysis and commentary, in addition to open data format tables which are published on StatsWales.

Data is published by staff group at aggregated local health board and national level, with minimal risk of disclosing information about any individual. All figures are shown to one decimal place.

Quality information

Our statistics are produced to high professional standards set out in the Code of Practice for Statistics. They undergo regular quality assurance reviews to ensure that they meet customer needs. They are produced free from any political interference.

Data on the number of Staff directly employed by the NHS in Wales (also known as the NHS staff census data) is published on a quarterly basis. The staff groups included in the sickness absence and staff census data differ slightly in that:

  • locums are removed from the staff census data on the basis of their occupation code, however some locums remain in the sickness absence data.
  • since 2018 most health care assistants (HCAs) working in nursing services have been re-categorised, moving from the HCA and other support workers group to nursing support staff. Those support staff working in nursing services that have not been re-coded remain within the HCA and other support staff group within the sickness absence data, but from 2009 they are shown as nursing support staff in the staff census data to make comparisons over that time period more meaningful.
  • other staff (i.e. general payments and other non-medical staff) are added to the ‘administration and estates’ staff group within the sickness absence release; they are shown separately in the staff census release and data.


In 2009, the Wales Audit Office conducted a review of sickness absence in NHS Wales. This report made a number of key recommendations, including the recommendation that sickness absence trends should be published and also the trends for organisation and staff group.

These statistics can be used for monitoring of sickness absence levels by NHS organisation in Wales, and comparisons with other public sector and non-public sector organisations although care should be taken to ensure methodologies are comparable.

We encourage users of the statistics to contact us to let us know how they use the data.


As the Electronic Staff Record is a live system and data extracts are taken from it, data presented may be revised in future editions of the statistical release. In particular, revisions may occur in data by staff group, as work is ongoing to improve occupational coding of staff in NHS Wales.

Each edition of the release presents data for the latest quarter and revised data for the previous quarter.

From the publication of the release for the quarter ended 31 March 2016, the process behind producing the sickness absence release and StatsWales tables was revised. The methodology remains the same for calculating the rates. However as a result of the change in process the data available on StatsWales was revised slightly and further subsets of the data became available i.e. sickness absence rate by organisation and staff group.

Data by staff group is based on mapping occupational codes for individual staff. Information on staff groups is available from the NHS Occupation Code Manual.

In the unlikely event of incorrect data being published, revisions would be made and users informed in conjunction with our Revisions, errors and postponements arrangements.

Timeliness and punctuality

Statistics are published as soon as possible after the relevant time period. All outputs adhere to the Code of Practice by pre-announcing the date of publication through the Upcoming calendar. Furthermore, should the need arise to postpone an output this would follow our Revisions, errors and postponements arrangements.

Coherence and comparability

The sickness absence data is collected through the same HR/payroll system, Electronic Staff Record (ESR), which covers all NHS organisations in Wales and includes all staff directly employed by the NHS in Wales.

Health Education and Improvement Wales (HEIW) was established on 1 October 2018 as a Special Health Authority within NHS Wales. Inclusion of sickness absence rates for this organisation may impact on the breakdown of sickness absence rates by staff group.

Note that health service provision for residents of Bridgend local authority moved from Abertawe Bro Morgannwg to Cwm Taf on 1 April 2019. As set out in a written statement, from this date, Cwm Taf University Health Board became Cwm Taf Morgannwg University Health Board and Abertawe Bro Morgannwg University Health Board became Swansea Bay University Health Board. Both the old and new LHBs appear on StatsWales, as appropriate for the periods covered.

Prior to January 2021 all NHS Wales Shared Services Partnership (NWSSP) staff were recorded under Velindre NHS Trust. Between January and May 2021 certain NWSSP staff (including foundation dentists, F1 trainees and specialty registrars) were recorded separately as NWSSP staff. From June 2021 all NWSSP staff were recorded separately. Data at the all Wales level is unaffected by these changes.

Data for Digital Health and Care Wales (DHCW), a Special Health Authority, is available from 1 April 2021.

Changes over time to the NHS occupation codes and the resultant re-codes of staff may impact on figures by staff group but the overall rates are not affected.

These statistics can be used for monitoring of sickness absence levels by NHS organisation in Wales, and comparisons with other public sector and non-public sector organisations although care should be taken to ensure methodologies are comparable.

NHS Digital publishes sickness absence rates in the English NHS. The English rates are calculated using the same methodology as the Welsh figures in this release.


The statistics are published in an accessible, orderly, pre-announced manner on the Welsh Government website at 9.30am on the day of publication. Outputs are publicised on Twitter and are available to download for free.

More detailed data is available at the same time on the StatsWales website and this can be manipulated online or downloaded into spreadsheets for use offline.

Plain English in used in our outputs as much as possible and adhere to the Welsh Government’s accessibility policy.

All our webpage headlines are published in Welsh and English.


A brief statistical release is published with high level summaries and further interactive data tables are published on StatsWales.


We welcome feedback on any aspect of these statistics which can be provided by email to