No Excess Mortality of COVID-19 in Japan until April, 2020

Kurita, J.; Sugawara, T.; Sugishita, Y.; Ohkusa, Y.

Background: As of the end of June, 2020, the COVID-19 outbreak exhibited its highest peak on April 3. Nevertheless, no remarkable excess mortality attributable to COVID-19 has been observed. Object: We sought to quantify excess mortality in April using the National Institute of Infectious Diseases (NIID) model. Method: We applied the NIID model to deaths of all causes from 1987 up through April, 2020. Results: Results show no significant excess mortality in March or April, 2020, when the COVID-19 outbreak affected Japan most. Discussion and Conclusion: Because changes in application rule of the International Classification of Diseases in 2017 affected the number of pneumonia deaths drastically, we were unable to use pneumonia deaths to estimate excess mortality. it might be important to continue to monitor excess mortality of COVID-19 carefully after May 2020.