Letter to Professor Chris Whitty: Negative consequences of public testing for COVID19

Mass public testing for COVID19 is likely to impact negatively on compliance with social isolation and other protective behaviours.

News that home/community testing for COVID19 will soon be possible seems really positive, and as a family who developed mild symptoms we, like others, would be keen to have this test to know if we have immunity.  However, as Professors, HCPC Registered Health Psychologists and experts in behavioural science, we are very concerned about the likely effect of mass public testing for COVID19 on people’s reactions to public health messages to stay at home and socially isolate. It may well be that these issues are already being given careful consideration, in which case we apologise for taking up your valuable time, but we felt compelled to write in case they are not.

While perceived risks for self, loved ones and community members and understanding of the potential severity of COVID19 are some of the drivers of the behaviour to stay at home and socially isolate, they are not the only ones.  Social norms to isolate are also extremely important.  We saw this last weekend (21st/22nd March) when large numbers of people went out to tourist locations.  Clearly the government expected that people would make rational assessments of personal/family risk and that, once they realised that physical separation would not be possible in a tourist location, they would turn around and go back home.  But they did not.  A likely reason for this seemingly contrary behaviour is that other people being out and about created a social norm that this was OK and safe: ‘if other people are doing it, then it’s probably safe for me as well’.

When the COVID19 tests become available, and assuming due attention has already been paid to the issue of panic buying, there will broadly be three groups of people:

  • Group A who test positive for having had COVID19 who presumably have some immunity.
  • Group B who test negative for having had COVID19.
  • Group C who have not yet had the test and who do not know their COVID19 status.

We expect, and perhaps you are planning, that Group A will be able to recommence activities. We would want people in Groups B and C to continue to stay at home and self-isolate given that they could still contract and spread COVID19, but this will largely depend on how people react to positive and negative COVID19 tests (Groups A and B), and on Group B and C’s perceptions of what Group A are doing.  For example:

  • In the community, we cannot tell who is in Groups A, B or C.  If Group A starts undertaking normal activities this will create norms for social contact/leaving home that may impact on Groups B and C: ‘if other people are doing it, then it’s probably safe for me as well’.
  • Some people who are in Groups B and C who, for various reasons, want to stop socially isolating could pretend to be in Group A.  Authorities will not be able to tell the difference between A, B and C and it will therefore be much more difficult to enforce isolation.
  • If it is not the case that people in Group A will be able to recommence activities, how will they be persuaded to continue to self-isolate?
  • People in Group B are likely to feel at lower risk, at least immediately after testing, and may therefore engage in less social isolation, putting both themselves and the people they are in contact with at risk.

Making tests easily available in the community could therefore have detrimental effects on public social isolation and therefore on the spread and containment of COVID19.  We therefore urge careful planning on how this testing will be managed to avoid the problems outlined above.  We would welcome the opportunity to work with you on this if you feel it would be helpful.

Yours sincerely,

Professor Madelynne Arden & Professor Christopher Armitage

Behavioural Science Consortium

Sent by email to Chris Whitty, Matt Hancock, Jon Ashworth, Duncan Selbie and other COVID19 response leaders on 28th March 2020