Christmas market in Cologne: During the pandemic, masks were compulsory in many places
Photo: Ying Tang / NurPhoto / Getty Images
There it is again, the mask fight.
Since the beginning of the pandemic, there have been repeated discussions about how useful masks are or not.
The most recent reason: An analysis by the Cochrane Collaboration concludes that it has not been clearly proven how well masks prevent the spread of respiratory viruses.
Some media think there is a “swatter for German corona policy”, there is talk of the “hardest blow” against Health Minister Karl Lauterbach.
But much of what is currently being said about the study does not give it at all.
To make it short: According to the work, the effectiveness of masks can currently neither be proven nor disproved.
So what exactly did the scientists investigate?
The Cochrane Collaboration is internationally recognized.
The independent, non-profit organization has set itself the goal of publishing fact-based information on medical issues.
So your judgment counts.
Reliability rated as "moderate".
On more than 300 pages, the experts have compiled knowledge from dozens of studies on the benefits of masks and hand hygiene.
The studies analyzed were not only about Covid-19, but also about diseases caused by other viruses, such as the Sars pandemic a good twenty years ago.
The current study is therefore not fundamentally new, but an update that bundles the known knowledge and also takes current studies into account.
From the time of the corona pandemic, two relevant studies in particular were added, writes the team of authors.
However, these would hardly have influenced the overall result.
The assessment is based primarily on work on other diseases up to 2016. A total of 78 studies were included in the meta-analysis.
Result: "Based on the studies we evaluated, we are unsure whether wearing medical masks or FFP2 masks slows the spread of respiratory viruses." Some analyzes indicated that the effect of masks is marginal, but the team of authors themselves have their doubts on their validity and that of their own investigation.
Reliability is rated as "moderate".
That is, by definition: the true effect is likely to be close to the estimated effect, but there is a possibility that it deviates significantly.
In other words: you don't know anything for sure.
One reason for the inaccuracy is the type of study that was selected: so-called randomized controlled studies are considered to be particularly reliable, but in reality they do not always provide clear results.
Too many factors play a role in everyday life that can distort the results.
Physically proven: Masks protect against infections
An analysis from December 2021 shows how uncertain such analyzes can be.
It is one of the few studies on the corona pandemic that the Cochrane team used - and speaks for the effectiveness of masks.
For the study, masks were distributed free of charge in some towns in Bangladesh and people were encouraged to wear them.
In fact, significantly more people wore masks in the villages than in comparable areas where no intervention had taken place.
There have also been fewer reports of illnesses similar to Covid-19, especially among the elderly.
However, it cannot be ruled out that factors other than mask wearing are decisive for the observed differences.
Perhaps less virus was simply brought into the regions where masks were worn more often - and that led to fewer diseases?
In the same way, randomized controlled trials have uncertainties concluding that masks have little or no benefit.
Were the masks worn over the mouth and nose?
And did the people in the comparison groups stick to other protective measures such as keeping their distance?
All of this can hardly be checked outside of laboratory conditions and easily leads to the comparison of unequal comparison groups.
"Our confidence in these results is generally low to moderate," the Cochrane Collaboration concludes.
It is difficult to draw clear conclusions, the study situation remains ambiguous in many points.
Further investigations are urgently needed.
In other words, the analysis neither concludes that masks are effective nor refutes their effectiveness.
"In my view, the study is not meaningful and does not allow for the conclusion that was drawn," said Eberhard Bodenschatz, Director at the Max Planck Institute for Dynamics and Self-Organization in the "Tagesspiegel".
In fact, several studies have shown that masks retain virus particles, and there is a reason why they are considered standard protective clothing in hospitals when dealing with respiratory infections.
It has been physically proven that masks protect against infections, says Bodenschatz, and there is absolutely no doubt about that.