Koritsu-shi (Solitary Death) and Its Actual Situation
Department of Legal Medicine, Nippon Medical School
Koritsu-shi (solitary death) refers to cases of death in which the deceased was living in a one-person household. In Japan, koritsu-shi cases have received significant attention as a major social problem because the aging population has led to an increase in single-person households. However, because the definition of koritsu-shi is unclear and carrying out a national level survey of households where the occupant has died is difficult, the actual situation surrounding koritsu-shi has not been elucidated. As koritsu-shi is legally treated as an unnatural death, statistics on koritsu-shi have been reported in many areas (Tokyo, Osaka, Kobe) under the medical examiner system. Of these areas, statistics from the Tokyo ward area have revealed the most information and show that the proportion of unnatural deaths involving koritsu-shi has been increasing year after year, with 36% of cases being koritsu-shi in 2016. Each year showed that koritsu-shi was higher in men than women. Although the deceased were predominantly male in cases of middle-aged koritsu-shi, both sexes are affected more evenly in single-elderly cases. However, the overall incidence was higher in men when the numbers of middle aged and elderly people are tallied against the higher numbers of elderly women. In men, the characteristic cause of death is chronic alcoholic liver injury with other cases mostly being categorized as unknown due to postmortem damage. Even within the densely populated Tokyo ward area, spatial clustering was detected with regard to the incidence of koritsu-shi per ward. There are many points that are consistent between reports of koritsu-shi in the Tokyo ward area and other areas. However, it is not easy to compare results among different regions due to the unclear definition of koritsu-shi and insufficient bias exclusion. Koritsu-shi cases are expected to increase in Japan in the future. Future efforts should focus on finding the deceased as soon as possible after death, or even pursuing the possibility of preventing koritsu-shi in cases when an individual living in a one-person household suddenly collapses at home. In addition, to reduce the effect of loneliness and social isolation among those living in single-person households to improve health outcomes, it is important that medicine and public health efforts address the problem of koritsu-shi.
日医大医会誌 2018; 14(3), 100-112
koritsu-shi, solitary death, loneliness, social isolation
Yoshimasa Kanawaku, Department of Legal Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan