Polish scientists have attempted to explain whether the size, function and geographical location of 20 cities in Poland have an impact on the course and intensity of the epidemic. Association studies did not show statistical significance between the infection rate and population density in selected cities, or a higher level of health care and lower mortality as a result of COVID-19. The obtained results therefore indicate the individual nature of the spread and trajectory of the epidemic in each city and the possible influence of other features not included in the study.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8940580/pdf/main.pdf