Coronavirus (COVID-19): modelling the epidemic (issue no.87)

Latest findings in modelling the COVID-19 epidemic in Scotland, both in terms of the spread of the disease through the population (epidemiological modelling) and of the demands it will place on the system, for example in terms of health care requirement.

This document is part of a collection


1 Modelling the Epidemic Issue 31. All historical versions of this publication can be found here Coronavirus (COVID-19): modelling the epidemic - (

2 Modelling the Epidemic Issue 31

3 Seven-day moving averages of cases by specimen date (left-hand axis) and deaths and hospital admissions (right-hand axis). Source:

4 Public Health Scotland COVID-19 Statistical Report

5 BLOG: Tracking the Delta variant in Scotland - Our blog - Public Health Scotland

6 Coronavirus (COVID-19): additional data and information - (

7 Coronavirus (COVID-19) Infection Survey headline results, UK - Office for National Statistics

8 Deaths projections were not provided between May and August 2021. In this period, the number of new deaths had fallen to very low levels. Projecting forwards is difficult when numbers fall to very low levels, therefore SPI-M-O decided to pause producing medium-term projections where this was the case. The small numbers can also introduce apparent inconsistency as regions are aggregated.

9 Modelling the Epidemic Issue 37

10 Based on S gene dropout, which is a proxy for the Alpha variant.

11 The Early Pandemic Evaluation and Enhanced Surveillance of Covid-19 (EAVE) 2 Study Group[11] linked individual patient-level data from all primary, secondary, mortality and virological/serological testing data in Scotland. They used this national dataset to investigate the temporal progression of Covid-19 in the Scottish population and the development of Covid-19 morbidity and mortality in individuals.

12 Modelling the Epidemic Issue 48

13 Joint Committee on Vaccination and Immunisation: advice on priority groups for COVID-19 vaccination (

14 Modelling the Epidemic Issue 49

15 Interim findings from first-dose mass COVID-19 vaccination roll-out and COVID-19 hospital admissions in Scotland: a national prospective cohort study - The Lancet

16 Modelling the Epidemic Issue 62

17 Modelling the Epidemic Issue 72

18 Modelling the Epidemic Issue 76

19 These figures are produced by Public Health Scotland as “experimental statistics” and may be subject to future revision as the new method for counting combined PCR and LFD tests evolves.


21 Using data to 24th January.

22 Particular care should be taken when interpreting this estimate as it is based on low numbers of cases, hospitalisations, or deaths and / or dominated by clustered outbreaks. It should not be treated as robust enough to inform policy decisions alone.

23 The cyan bars use Covid-19 test data and purple bars use multiple sources of data. The estimate produced by the Scottish Government is on the left (yellow). The UKHSA consensus range is the right-most (red). Data to 24th January 2022. R, incidence and growth rate as of 11th January.

24 See Figure 6

25 All projections are based on current vaccine roll-out plans and efficacy assumptions. Data to 5th January 2022.

26 The actual positive tests are adjusted to coincide with the estimated day of infection.

27 Actual data does not include full numbers of CPAP. ICU bed actuals include all ICU patients being treated for Covid-19 including those over 28 days.

28 For this graph, a wastewater Covid-19 average using the last 7 days of data is computed at every sampling date.

29 Advancements in detection and interpretation practices allow us to identify when outlying results are anomalous rather than indicators of spikes in Covid-19 levels. Table 2 provides population weighted daily averages for normalised WW Covid-19 levels with the outliers removed. See Technical Annex in Issue 60 of these Research Findings for further details.

30 Coverage as for week beginning 18th January 2022.



Back to top