Changes to the severity of COVID-19 and impact on hospitals in Scotland
As at 28 June 2022

About this release

This release by Public Health Scotland (PHS) presents data on the changes to the severity of COVID-19 and the impact on hospitals in Scotland from January 2022 to April 2022. Since January 2022, our understanding of the effect the virus is having on deaths and severe disease has changed, with implications for the type of robust epidemiological evidence required to inform future COVID-19 policy and decision making in Scotland. This report aims to inform future approaches to COVID-19 reporting and surveillance.

Main Points

• During the first wave of the pandemic (March-June 2020), in those deaths where there was a positive COVID-19 result, 94% were considered to be caused by the virus. However, from January to April 2022 this has decreased to 43%. Public Health Scotland (PHS) now no longer reports this measure of deaths and National Records Scotland is now the source information of COIVD-19 related deaths in Scotland.
• An analysis of existing data show that the proportion of all COVID-19 emergency hospital admissions who acquired their infection in the community decreased from 78% in the week ending 07 November 2021, to 59% in the week ending 01 May 2022.
• Even this may be an overestimate, as data from NHS Grampian (an NHS Board able to routinely monitor cause of admission in real time) showed that the proportion of patients admitted because of SARS-CoV-2 infection declined from 57% in the first week of January 2022 to 20% in April 2022. In addition, there was a reduction in the seven-day average number of persons admitted with symptomatic SARS-CoV-2 infection from 31 per day in March 2022 to 21 in April 2022.
• Data from Intensive Care Unit (ICU) admissions shows that the percentage of patients positive for SARS-CoV-2 in ICU with a clinical diagnosis of COVID-19 disease has declined from over 80% in the early phases of the pandemic to 29% since 01 January 2022. With less than 30% of people who are SARS-CoV-2 positive being admitted because of the virus, ICU clinical auditors have concluded that a positive PCR test on its own is insufficiently accurate to identify patients suffering with COVID-19 disease and will over-estimate the number of cases. A clinical diagnosis of COVID-19 disease should be used going forward.
• Using the numbers of people in hospital with SARS-CoV-2 at any one time was also problematic and affected by the emergence of cases that had a probable or definite hospital onset (nosocomial cases). The median length of stay prior to a positive test, ranged from 21 days and 67 days in acute and non-acute settings, respectively and around 62% of nosocomial cases were asymptomatic at the time of testing. The nosocomial cases often had extended lengths of stay before acquiring SARS-CoV-2 and many are not taking up an additional bed due to COVID-19. Therefore, increasing numbers of nosocomial cases do not necessarily translate into additional bed occupancy due to COVID-19.

Background

The Omicron variant of SARS-CoV-2 was first detected in Scotland in December 2021 and has since become the dominant variant in circulation.