In the event of a major infectious disease epidemic, case fatality and mortality risk factors are estimated in real time using statistical methods.For example, analysis of data on thousands of people infected with SARS (Severe Acute Respiratory Syndrome), which was prevalent in Hong Kong around 2002, revealed these risks.On the other hand, the MERS epidemic in South Korea has a small number of patients of 185, and it has been clarified that the case fatality rate of all patients is about 20%. It was difficult to find out.

　Associate Professor Nishiura et al. Have improved the case fatality rate even in the case of a small number of patients by combining the survival analysis method used in the conventional case fatality rate estimation method with the method of predicting the risk of death.When analyzed using this for patients aged 60 years or older with underlying disease and other groups, the case fatality rate was about 48% for elderly patients with disease, whereas it was less than 15% for the other groups. It turned out that there is a big difference.In addition, when we investigated the change in case fatality rate over time, it became clear that the case fatality rate was as high as 40% at the beginning of the epidemic, but eventually decreased to about 3%.It is believed that government measures have contributed to lowering the case fatality rate.

　With conventional methods, even if emerging infectious diseases begin to spread, it remains unclear who should be vigilant until a large number of infected people appear.The new analytical method will help to quickly derive epidemic control guidelines and encourage government action.