Detection of outlier prefectures on the mortality due to COVID-19 in Japan

Kentaro Iwata; Chisato Miyakoshi

doi:10.1016/j.jiac.2023.01.016

Detection of outlier prefectures on the mortality due to COVID-19 in Japan

J Infect Chemother. 2023 Apr;29(4):427-429. doi: 10.1016/j.jiac.2023.01.016. Epub 2023 Jan 24.

Authors

Kentaro Iwata¹, Chisato Miyakoshi²

Affiliations

¹ Division of Infectious Diseases, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe, Japan. Electronic address: kentaroiwata1969@gmail.com.
² Department of Research Support, Center for Clinical Research and Innovation, Kobe City Medical Center General Hospital, Kobe, Japan.

Abstract

Japan has suffered from COVID-19 with significant mortality, but its prefectural differences are not well investigated. Since the mortality due to COVID-19 was likely to be associated with the number of infected cases, the population density, and the proportion of the elderly population, we tried to detect the outlier prefectures by multiple linear regression analyses. With the use of the Hampel identifier, we found that Hokkaido and Hyogo were the outlier prefectures with higher mortality after adjusting the variables above. Further studies should delineate the causes of these differences.

Keywords: COVID-19; Hampel identifier; Japan; Mortality.

MeSH terms

Aged
COVID-19*
Humans
Japan / epidemiology
Regression Analysis