As at 15th March 2022 This release by Public Health Scotland is the tenth report on data from the Scottish Intensive Care Society Audit Group (SICSAG – chaired by Dr Naz Lone) relating to patients admitted to intensive care units (ICUs) and high dependency units (HDUs) across Scotland with COVID-19. This report focuses on patients who are admitted to critical care units with a positive PCR test for SARS-CoV-2, comparing characteristics and outcomes for those with a clinically coded diagnosis of COVID-19 compared with those with a non-COVID-19 clinical diagnosis. In this report Wave 1 is defined as 01 March 2020 to 31 July 2020, wave 2 is defined 01 August 2020 to 17 May 2021, and wave 3 is defined as starting from 18 May 2021. The Omicron variant became the dominant strain in ICUs at the end of December 2021. The report uses 01 January 2022 as the date to mark this transition. This tenth report includes ICU activity up to 13 March 2022. Main Points Taken From the Report During the period 01 March 2020 to 13 March 2022 there were 3,303 patients with a positive PCR test for SARS-CoV-2 admitted to intensive care units (ICUs) in Scotland. Of these, 296 patients have been admitted to ICUs since 01 January 2022, when the Omicron variant became the predominant variant in Scottish ICUs. During the period 01 March 2020 to 13 March 2022 there were 2,279 patients with a positive PCR test for SARS-CoV-2 admitted to high dependency units (HDUs) in Scotland. Of these patients, 251 were admitted since 01 January 2022. Since the Omicron variant became the predominant strain in ICUs in Scotland, the definition of critical care COVID-19 cases used by SICSAG, which relies on PCR testing to identify cases, no longer identifies patients admitted with COVID-19 disease with sufficient accuracy. Since 1 January 2022, only 26% of ICU admissions defined using the previous definition, had COVID-19 as the primary reason for admission to critical care on clinical case note review. In a further 14%, COVID-19 may have contributed to the reason for admission, though was not the primary reason. In 60% of admissions, the positive PCR test was coincidental to the reason for admission. Using the coded reason for admission to critical care in the SICSAG database to identify cases of COVID-19, out of 54 admissions that had COVID-19 coded as the admission diagnosis, 93% (50) had this diagnosis confirmed on case note review as the primary reason for admission, However, a further 17 cases of COVID-19 were not identified as they had a non-COVID-19 coded reason for admission A revised method to identify critical care COVID-19 cases using the coded reason for admission to critical care recorded in the SICSAG database would correctly identify 75% of all cases of COVID-19, but would not capture cases in which COVID-19 contributed to the reason for admission. Furthermore, it would not reflect the resource implications associated with isolating patients with a positive SARS-CoV-2 test from other patients. Using this revised method to identify cases, only 29% of ICU admissions and 27% of HDU admissions admitted since 01 January 2022 with a positive SARS-CoV-2 PCR test are defined as COVID-19 admissions. Read the full Report Publication date 11 May, 2022