The Forgotten Principles of the Risk Assessment

Being able to carry out risk assessments is a core skill for many clinicians, and in this pandemic era, many individuals, businesses, community groups, schools, and institutions of higher education are also being tasked with carrying out risk assessments for their own activities. However, it is a failure of health communications that most have received little direction in how to do this.

These risk assessments can themselves have significant negative outcomes. Risk assessments are intended to help evaluate and encourage strategies that mitigate risk. However, if carried out inappropriately, they can instead serve to entrench anxiety and encourage actions that do not, in fact, reduce the risk, and can cause significant harm.

The following principles should be adhered to when considering any risk assessment:

1) The actual risk needs to be identified

Rather than taking actions to ‘appear’ safe or careful, the actual risk that is being targeted needs to be identified. In the context of the Covid-19 pandemic, the key risk that groups and individuals wish to avoid is Covid-19 transmission taking place at an event and an individual becoming seriously ill or dying as a result of that transmission.

2) The likelihood of a risk occurring needs to be estimated

In order for the risk of someone becoming seriously ill to take place, a chain of events needs to take place, which includes an individual attending who has a Covid-19 infection, then transmitting the virus, and the person to whom they are transmitting to then become seriously ill. 

These risks can be estimated, in numerical terms, on the basis of the prevalence of Covid-19, and the likelihood of serious illness. In areas of the world where there is significant uptake of the vaccination programme in people who are vulnerable to serious illness, combined with significant levels of infection-acquired immunity, the likelihood of serious illness in any individual will be very low.

3) Any risk reduction strategies need to be targeted to a specific risk

All mitigation strategies need to be targeted to an actual risk. If the mitigation strategy does not, in fact, reduce the risk, then it should not be adopted.

4) Risk reduction strategies should be proportionate to the risk that is posed

Given that the risk of serious illness in a group, which already has significant vaccination and infection-acquired immunity, is very low, this may mean that many of the risk reduction strategies at reducing viral transmission are not proportionate to the risk that is posed.

5) The efficacy of risk reduction strategies should be evaluated, using techniques of critical appraisal

An attempt should be made to evaluate the efficacy of any risk reduction strategy, using the ‘hierarchy of evidence’ model, such that randomised controlled trials are considered a superior standard of evidence to observational data, which is considered superior to modelling, with the least weight given to “expert opinion.” Almost all of the risk mitigation strategies adopted to reduce the risk of viral transmission, such as masking, providing ventilation equipment, social distancing, one-way systems, Perspex screens, sit at the level of ‘expert opinion’ or ‘modelling’ and therefore the evidence for the efficacy of such interventions would be considered to be weak.

6) Potential harms of any risk reduction strategy needs to be identified

All interventions have potential harms. These will range from the specific (e.g. masking can make communication more difficult for people with sensory and cognitive deficits) to the more existential (the consequences if risk reduction measures make it impossible for a particular organisation to function). These harms, including potential discriminatory impacts, should be specifically listed on a risk assessment.

If these principles are followed, then individuals and communities will be better skilled to evaluate for themselves what the effective interventions are likely to be. These principles will direct us to introduce interventions where they might be most effective. Ultimately, if those that are at risk of serious illness are either not present (as may be the case in young persons’ activities), or have been offered vaccination, then the risk of any individual becoming seriously unwell with a Covid-19 infection becomes very low, and therefore the benefits of any risk reduction strategy become insignificant. Risk assessments, when properly carried out, encourage us to consider the harms and evaluate the strength of evidence for the efficacy of proposed interventions.

These principles can also help individuals and communities to think through the purpose of the risk reduction measures. Given that the purpose of all of the risk reduction strategies is to reduce the risk of serious illness or death, then it is not a failure of risk assessment if asymptomatic or mild cases result from any particular event. The purpose of risk reduction strategies is not to remove all possibilities of viral transmission resulting in mild illness.

As Covid-19 becomes endemic, some of these principles should be reapplied to other public health measures that have been widely adopted, including mass testing, border restrictions, and testing to travel. Most of these measures are not targeting any specific risk, have a weak or nonexistent evidence base, and therefore their use should be reevaluated.

These principles can help risk assessments function as intended – as a tool to help individuals and communities evaluate risk and put in place targeted measures, to contain and ultimately reduce anxiety, and to move away from more performative measures that simply serve to entrench anxiety and cause harm, without any benefit.