About this release

This release by Public Health Scotland and the Scottish Intensive Care Society Audit Group (SICSAG) provides a summary of the activity, interventions and outcomes of critical care services in NHSScotland during 2021.

Revision 8 December 2022. An error was identified in Appendix 4, Table 7: ICUs and combined unit profiles (2021) and Table 8 : HDU profiles (2021) with the heading description of Column 5.  The data is for the whole WTE of each unit and not per level 3 or 2 bed as previously published. The impact of this is would result in the over counting of nurses per each unit. Please note no figures within the Tables have required updating and as at 8/12/22 the correct heading has been published.

Main points

  • The COVID-19 pandemic continued to impact on critical care units, affecting case-mix, unit configuration and staffing levels.
  • There were 16,036 admissions to intensive care units (ICUs) and combined units. There were 23,091 admissions to high-dependency units (HDUs).
  • Mortality in ICUs/combined units was 12.7%. After allowing for differences in case-mix and illness severity, no ICU/combined unit had a significantly higher standardised mortality ratio than the national average.
  • Delayed discharges have continued to be challenging, with almost half of patients delayed for more than 4 hours. This continues the trend reported in previous years.
  • All ICUs achieved the Scottish Intensive Care Society minimum standards and quality indicators (MSQIs) for the majority of patients.
  • General HDUs not meeting MSQIs (6 out of 26) have provided a summary of how they plan to achieve these in the coming year.


Critical care units are specialist hospital wards for the most severely ill or injured patients. They treat patients with a high level of complexity. This audit includes all ICUs and the majority of HDUs in NHSScotland during 2021.

It is not possible to provide an accurate figure on the number of HDUs due to differing provisions across all specialties and Health Boards. However, it is estimated that more than 95% of all HDUs participated in this audit. The audit covers nearly 40,000 patients admitted to critical care units in NHSScotland during 2021.

SICSAG aims to improve the quality of care delivered to critical care patients by monitoring and comparing activities and outcomes. The audit of critical care is a coordinated quality improvement programme which provides data, analysis and feedback to raise standards and continued improvement in patient outcomes.

Critical care units have provided detailed comments where any MSQIs were not fully met.

Specific COVID-19-related data are available in the 10 COVID-19 reports published in 2020, 2021 and 2022.

Further information

The next release of this publication will be 08 August 2023.

General enquiries

If you have an enquiry relating to this publication, please email phs.sicsag@phs.scot.

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Older versions of this publication

Versions of this publication released before 16 March 2020 may be found on the Data and Intelligence, Health Protection Scotland or Improving Health websites.

Last updated: 21 March 2024
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