Coronavirus (COVID-19): framework for decision making - assessing the four harms

Sets out the four harms process for assessment used to establish when coronavirus restrictions could be safely lifted after lockdown and the scientific evidence underpinning the decisions.

Harm 1


Harm 1 is the tragic harm that COVID-19 can cause to people's health. We saw this in the first phases of the pandemic in Scotland, with the daily growth in number of new cases; number of new hospitalisations; number of people requiring treatment in Intensive Care Units; and sadly, the number of deaths related to the virus. Lockdown helped us to bring these numbers under control, but as we move through a second wave and into the winter, we have a renewed focus on the direct harm of COVID-19.

COVID-19 causes direct and tragic harm to people's health. We are tracking daily the extent of the direct health harm being caused by the virus. Data is published every day on the Scottish Government Coronavirus webpages.[40]

Assessing the risk of Harm 1

We are concerned with the impact on R and the prevalence of the virus within the community when we look at Harm 1. Many different factors come into play when we assess risks with this harm. We take into account the science behind the virus, the setting, indoors or outdoors, the number of people potentially affected, the duration of the activity and the proximity of the people involved, the likelihood of droplet/aerosol production and spread and of touching surfaces and finally the possibility and ease of mitigations available.

In order to assess how risky an activity or setting is for the spread of transmission of the virus, we consider:

a. Whether the activity is indoors or outdoors. As stated previously, in poorly ventilated indoor spaces transmission of the virus through aerosols is increased, therefore outdoor activities are considered less risky;

b. How many people will be involved in an activity at any one time. Where people come together in crowds, you are more likely to come into close contact with someone that has COVID-19 and it is more difficult to maintain physical distance. The more interactions there are between different people, the greater the opportunities the virus has to spread; therefore, the higher the number of people attending any event/setting/activity the higher the risk;

c. How long people will be in close contact with each other is also important as the virus is only likely to spread from people who are in contact for more than 15 minutes although this is dependent on the closeness of contact[41];

d. The environment that the activity will take place in and whether it is possible to reduce contact with surfaces and whether surfaces will be easy to clean are also relevant;

e. The age group of people involved in the activity. The evidence shows that the risk of COVID-19 to younger children is very small and they are not a high risk for transmission of the virus. However, young adults, although not as susceptible to the risks of the disease, do play an important role in transmission; and

f. In order to allow for tracing to work effectively, we need to be able to trace anyone that has been included in an activity and therefore we consider the ease of identifying who took part in an activity and the numbers taking part.

Ease of mitigation

We take into consideration how easy it would be to put mitigation into place in any venue or event against the spread of COVID-19. We consider how many people will be likely to attend, how much space is likely to be available, whether a venue is well ventilated, whether it is an indoor or outdoor venue or a combination of the two, how well staff and customers are able to physically distance and whether face coverings are likely to give an increased level of protection in a given situation. In regulated settings, it is easier to ensure that mitigations, such as physically distancing measures and barriers, are put in place and being adhered to. We can also carry out monitoring and inspection of businesses and ensure that mitigation measure are in place. In informal situations such as family gatherings or house parties, the risks are greater. When people are very familiar with each other, they are less inclined to physically distance from one another and these situations are more challenging to regulate, inspect or ensure mitigation measures are being appropriately used.

Compliance and attitudes

To control the virus in Scotland, everyone has to play their part and, for that reason, it is important that we use a range of data and analysis to look at changes in people's behaviour. This evidence helps us to understand the extent that people are adhering to the guidelines and the areas where they are finding it difficult.

A range of analytical approaches help with this. We have data that tells us about the number of cars on the road and foot fall in town centres. We have data from the police, health, schools and other public services that tell us about issues such as use of public service and school attendances. We also have data from weekly public attitudes surveys and polls (including research undertaken by YouGov and Ipsos MORI) that provides information directly from people, about their levels of knowledge and awareness, and their behaviours in different social settings, such as work, school, travelling, healthcare, shopping and businesses. Questions asked in our surveys vary from week to week but enable us to monitor the success of measures, such as avoiding gatherings and meetings with people from other households, minimising the use of shared workplaces and offices by working from home, and using personal protective equipment in relevant situations.

A range of other studies are being carried out in Scotland and the UK to understand people's behaviours during the pandemic. The COVID-19 Health and Adherence Research in Scotland (CHARIS) group at the University of Aberdeen have been running weekly surveys to assess the rates of adherence, the mental and general health of the public, and the triggers for changes in adherence. The UK-wide COVID-19 Social Study (UCL) asks to what extent respondents are following the recommendations from government such as social distancing and staying at home and the factors associated with compliance including mental health, wellbeing and confidence in government.

Some of these studies are 'opt-in', which means that those likely to volunteer to take part will have some level of interest in the virus and are potentially more likely to adhere to guidance. Whilst bearing this in mind, evidence suggests a high level of reported compliance on a national and general level. 79% in Scotland reported 'complete' or 'almost complete' compliance (i.e. people who rated themselves 6-7 on a scale of 1-7) (YouGov 1-2 Dec). Self-reported willingness to comply and compliance with self-isolation is also high. The vast majority (85%) agree that they would self-isolate and book a test through Test and Protect straightaway at the first sign of Covid-19 symptoms (YouGov 24-25 Nov). Of respondents who had to self-isolate at some point during the last 7 months (n=196), almost three quarters (72%) said they didn't leave home at all during the isolation period, although a quarter (26%) left home at least once (YouGov, 27-28 Oct). Other data from the UK has, however, shown a lower estimate. In regular and repeated surveys undertaken between March and August across the UK, only 18% of people who reported having experienced symptoms of COVID-19 in the last week had not left their home since developing symptoms. This figure does not relate to those who had confirmed cases of coronavirus or who are contacted through Test & Protect.

Data from other sources such as Police Scotland and PHS also provide insight into compliance. Police Scotland report the number of COVID-19 interventions on a weekly basis, and this has been higher during October and November than it was in the previous months. Public Health Scotland also present data on the number of people who they contact, following a positive test result or who need to quarantine following their entry into Scotland. Since 22 June, only a small proportion of individuals with a positive test and confirmed contacts have not been contactable.

A final source of data that provides another perspective on compliance is the 'Scottish Contact Survey'. This shows that the average contacts per day are approximately three quarters higher than the level at the beginning of lockdown (UK comparison 2.8), but less than half of the level pre-lockdown (UK comparison 10.8). Data also show a decrease in the number of people visiting locations, particularly other people's homes. This is down to 28% (26 Nov-2 Dec) from 58% (6-12 Aug).



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