Abstract
Background: We conducted data analysis to determine whether there are
distinguishing characteristics depending on the success or failure of
control for COVID-19 by country in the trend of the daily number of
confirmed cases and the number of tests. Methods: We obtained the number
of confirmed cases and tests per day for almost every country in the
world from Our World in Data. We applied the Pearson correlation between
the two time series was calculated according to the time delay to
analyze the relationship between the number of tests and the number of
cases with a lag. Results: For each country, we obtained the time lag
that makes the maximum correlation between the number of confirmed cases
and the number of tests for COVID-19. It can be seen that countries
whose time lag lies in a special section between about 15 and 20 days
are generally successful in control COVID-19. It looks like a trench on
the battlefield. Conclusion: We have seen the possibility that the
success in mitigating COVID-19 can be expressed as a simple indicator of
the time lag of the correlation between confirmed cases and tests. This
indicator can be presumed to be a sign of an effort to actively tracing
infected person.