Doubling Time and its Interpretation for COVID 19 Cases

摘要

Doubling time is the number of days required for the number of cases in an epidemic to double, based on the rate of cumulative increase in number of cases. The doubling time is a crude estimate of the current rate of spread of the virus. It is comparable across time as well as countries at different stages of spread, and additionally, it is not affected by the proportion of true cases that are being identified, as long as this proportion does not change substantially. For uncontrolled exponential growth, we expect the doubling time to remain constant. If measures are being effective, we should see the doubling time increasing.