Correlation Between Mask Compliance and COVID-19 Outcomes in Europe.
Spira B (April 19, 2022) Cureus 14(4): e24268. doi:10.7759/cureus.24268
Masking was the single most common non-pharmaceutical intervention in the course of the coronavirus disease 2019 (COVID-19) pandemic.
Most countries have implemented recommendations or mandates regarding the use of masks in public spaces.
The aim of this short study was to analyse the correlation between mask usage against morbidity and mortality rates in the 2020-2021 winter in Europe.
Data from 35 European countries on morbidity, mortality, and mask usage during a six-month period were analysed and crossed.
Mask usage was more homogeneous in Eastern Europe than in Western European countries. Spearman's correlation coefficients between mask usage and COVID-19 outcomes were either null or positive, depending on the subgroup of countries and type of outcome (cases or deaths).
Positive correlations were stronger in Western than in Eastern European countries.
These findings indicate that countries with high levels of mask compliance did not perform better than those with low mask usage.
While no cause-effect conclusions could be inferred from this observational analysis, the lack of negative correlations between mask usage and COVID-19 cases and deaths suggest that the widespread use of masks at a time when an effective intervention was most needed, i.e., during the strong 2020-2021 autumn-winter peak, was not able to reduce COVID-19 transmission.
Moreover, the moderate positive correlation between mask usage and deaths in Western Europe also suggests that the universal use of masks may have had harmful unintended consequences.