Department of Mathematics, University of Manchester, Manchester, M13 9PL, UK.
Department of Statistics, Federal University of Technology, Akure, Nigeria.
Sci Rep. 2023 Jul 4;13(1):10814. doi: 10.1038/s41598-023-37722-9.
We provide an extreme value analysis of daily new cases of COVID-19. We use data from Benin, Burkina Faso, Cabo Verde, Cote d'Ivoire, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone and Togo, covering a period of 37 months. Extreme values were defined as monthly maximums of daily new cases. The generalized extreme value distribution was fitted to them with two of its three parameters allowed to vary linearly or quadratically with respect to month number. Ten of the sixteen countries were found to exhibit significant downward trends in monthly maximums. The adequacy of fits was assessed by probability plots and the Kolmogorov-Smirnov test. The fitted models were used to derive quantiles of the monthly maximum of new cases as well as their limits when the month number is taken to infinity.
我们对 COVID-19 每日新增病例进行了极值分析。我们使用了来自贝宁、布基纳法索、佛得角、科特迪瓦、冈比亚、加纳、几内亚、几内亚比绍、利比里亚、马里、毛里塔尼亚、尼日尔、尼日利亚、塞内加尔、塞拉利昂和多哥的数据，涵盖了 37 个月的时间。极值定义为每日新增病例的月度最大值。广义极值分布的三个参数中有两个允许随月份数线性或二次变化，以此对其进行拟合。在 16 个国家中，有 10 个国家的月度最大值呈显著下降趋势。通过概率图和柯尔莫哥洛夫-斯米尔诺夫检验来评估拟合的准确性。使用拟合模型得出了月度新增病例最大值的分位数以及当月份数趋于无穷大时的限值。
