A descriptive study of solitary death in Yokohama City.

BACKGROUND: The solitary death rate in Japan is expected to continue increasing because of its growing super-aged society and the rapid growth of home care in the country. To accurately determine the actual status of solitary deaths, we used a novel analysis method of combining vital statistics and ambulatory care information in Yokohama City.

METHODS: Data of persons who died at home in 2013 were obtained from death certificate notifications. We also obtained the emergency transportation records that matched the cases of these death certificate notifications. Then, we gathered information regarding age, gender, marital status, and cause of death for the matched cases.

RESULTS: There were 1890 "suspected unnatural deaths," in which most solitary deaths could be included, among all citizens who died at home (n = 4847). We were able to match 1503 of these cases with emergency transportation records. These 1503 cases were divided into two groups, "solitary death" (n = 349) and "un-solitary death" (n = 1154) according to the postmortem interval until finding (PMI-f). Pearson's χ2 tests conducted for the two groups revealed that there were significant differences regarding the proportion of persons who were elderly, unmarried, male, and had a hepatic disease and senility. A logistic regression analysis also showed that an increased likelihood of a prolonged PMI-f was associated with males and an unmarried status with hepatic diseases.

CONCLUSIONS: Unmarried, male sex, and liver diseases are independent risks for solitary death in Yokohama City.