Results . Analysis of the pattern of hepatitis E incidence before the COVID-19 outbreak . Typically, the monthly incidence of hepatitis E in China from 2013 to 2018 was assumed to be trend stationary and nonrandom (Fig.? 1 ), which was verified by the Box-Ljung test ( χ 2?=?252.73, df ?=?24, p ?<?0.001) and the augmented Dickey-Fuller test ( Dickey-Fuller ?=?-5.9816, lag order ?=?4, p ?<?0.01). The difference analysis of the original series showed that ndiff ?=?0; h...