Factors that delay discovery in cases of death at home in Japan

In Japan, solitary deaths have become a social issue, with an increasing number of cases in which the body is discovered long after death. This study aimed to clarify the factors underlying such delays. Cases of death at home were extracted from forensic autopsies. In each case, we collected information about the deceased and their living conditions. The postmortem interval until finding (PMI-f) was calculated by measuring the time between death and discovery. We classified the cases into long PMI-f (LPMI-f; having PMI-f of ≥3 days) and short PMI-f (SPMI-f; having PMI-f of <3 days), and examined the factors that lead to LPMI-f. The characteristics of the group living alone with a PMI-f of <24 h and living with family or acquaintances with an LPMI-f were also analyzed. Among the 420 cases included, 244 (58.1%) were in the LPMI-f group. The LPMI-f group had higher number of males; older individuals; those living alone; those found inside their homes; single, retired, or non-employed individuals; those without long-term care certification; and those with drinking habits. Forty-seven individuals lived alone and had PMI-f of <24 h. Regular visits from relatives living separately led to early detection after death. In the LPMI-f group, 56 individuals lived with family or acquaintances. The absence of regular visits can result in delayed discovery after death; however, the time between death and discovery could be shortened by implementing systems such as allowing neighbors to check the person's safety by noticing uncollected mail.