Poor studies on long Covid are sensationalized by the media
OPINION: The media are overdramatising poor studies concerning the long-term effects of Covid-19.
Many recent reports in the media have given the impression that people are experiencing major long-term effects after having even mild Covid-19. This impression does not correspond with the knowledge we have accumulated so far.
We must dedramatise the long-term effects of Covid-19, often referred to as long Covid. The media have a responsibility in this regard. They must become more critical of the research methods used in the studies they refer to.
Most infectious diseases with severe symptoms will to some extent be accompanied by long-term effects. Most infectious diseases with mild symptoms will cause few short-term effects.
More and more studies are showing that this is probably also the case for Covid-19. It is vital that more high-quality studies are carried out to examine this problem.
Nordic register data provides many answers
Data from the Norwegian Institute of Public Health’s emergency preparedness register (BeredtC19) includes around two million Norwegians who have been tested for SARS-CoV-2. It shows a short-term and temporary rise in the number of contacts with general practitioners – GPs and emergency medical centres – after mild Covid-19.
The study suggests there has been no increase in use of the specialist health service when compared with those who have tested negative.
The media have overdramatised studies which have not included suitable comparison groups.
The fact that the effects can exclusively be investigated and treated by GPs means that most effects are likely to be mild, even though they might seem unpleasant for the people concerned.
This Norwegian data is supported by a major Danish register study, which found a low risk of serious complications after mild Covid-19.
Sharp increase in mental health problems
The studies have a number of strengths, but of particular importance in this context is that they include one or more comparison groups. Such a group could for example consist of those who tested negative for Covid-19 during the same time period.
An example of the importance of having a comparison group is that we find a sharp increase in mental health problems amongst those who have had Covid-19 in Norway between March and November 2020.
This would typically have led to a headline along the lines of "Mild Covid-19 causes mental health problems”. However, when we study a comparison group consisting of people who tested negative over the same period of time, we find an even greater increase.
Intimidation and unnecessary fear are the last thing we need.
This means that both those who have had and those who have not had Covid-19 may have suffered long-term mental health problems as a result of isolation and loneliness during lockdown, rather than of having had Covid-19. Instead, the headline would then be "Mild Covid-19 does not give rise to mental health problems”.
Examples of the media overdramatizing studies without suitable comparison groups include headlines and articles such as: New coronavirus research: Over half of young people with mild symptoms suffered long-term effects or 60 percent of coronavirus patients struggle with long-term effects.
Journalists must familiarise themselves with research methodology
The example of mental health problems shows that having a suitable group to draw comparisons with is key to understanding the consequences of having had Covid-19 disease.
Journalists must get better at asking researchers critical questions regarding whether such a group exists and, if so, how it is composed or constructed.
Comparison groups are useful precisely when they are comparable. In other words, the group that has had Covid-19 must be as similar as possible to the group that has not had it.
This is about the lives and health of many people. Intimidation and unnecessary fear are the last thing we need.
So, when the next study of long-term effects is published and journalists consider using the headline “Mild Covid-19 can cause death after six months”, perhaps they could start by asking themselves the question: Did the study also investigate deaths after six months amongst those who have not had Covid-19?
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