Moving-average based index to timely evaluate the current epidemic situation after COVID-19 outbreak

Yun-ting He; Hao He; Jing Zhai; Xiao-jin Wang; Bing-shun Wang

A line chart of the EEI over date can indicate the epidemic situation. The upper and lower limit represent the worst and the best estimates of the epidemic situation, respectively. If the EEI is higher than 1.0, it suggests that the epidemic is still developing. High level restriction measures should be maintained. If the EEI drops below 1.0, it can be judged that the epidemic has entered the period of decline. It's time to plan to phase out some stringent preventive and control measures. If the EEI remains below 1.0 for more than 7 days (one time interval of LMA), it indicates that the epidemic has entered a stable remission period. It is possible to phase out highly stringent restrictions and then resume production gradually.. If the upper limit of the EEI is less than 1, indicating that under the worst circumstance, the EEI is also at a low level. It can be said with greater confidence that the epidemic will soon be completely eliminated. If there are very few daily new confirmed cases (<5), the EEI will become not applicable. In this scenario, we should evaluate the epidemic situation based on suspected cases or other indicators.