日本における高齢者の異状死に関する過去20年間の研究動向： KH CoderによるText Mining

The purpose of this study was to determine the current state of research on unnatural deaths　in older adults in Japan. We searched original articles published in Japan from 2000 to 2020 by using the key terms“ older adult” and“ unnatural death” and identified 32 articles. We analyzed the articles by quantitative text mining with KH Coder （ver.3.0） software. The most frequently extracted words were“ death,”“ many,”“ discovery,”“ suicide,”“ cause of death,” and“ autopsy.” In the co-occurrence network analysis of words,“ death,”“ many,”“ suicide,” and“ man” had high mediation centrality. We used subgraph detection to classify the top 50 words into 5 groups: “Time delay before discovery of single older adult men after death,”“ Trend for unnatural deaths of missing older adults,”“ Relationship between mental illness and solitary death,”“ Investigation of cause of death by forensic autopsy,” and “Measures for preventing solitary death of older adults isolated from society.” Currently, studies are limited regarding possible measures to prevent solitary deaths among older adults isolated from society. In Japan, there is an urgent need to support older adults at risk of social isolation, such as single men and people with mental illnesses, to help maintain or improve their social integration.