Correlation between PCR Examination Rate among the Population and the Containment of Pandemic of COVID-19

We investigated the relation between PCR examination rate among population and the success of containment of COVID-19 for each country. Although there was moderate correlation, multiple regression revealed that the success of containment was solely explained by Gross Domestic Product per capita (GDP), which may well be related to the strict compliance to social distancing. Close inspection of individual countries supported this hypothesis. The social distancing must be the largest factor to achieve containment, and the contribution of broad PCR tests is small.