Development of Prevention Strategies Against Bath-related Deaths Based on Epidemiological Surveys of Inquest Records: A Model Study in Kagoshima Prefecture

Sudden death in the bathroom (bath-related death) occurs more frequently in Japan than in other countries, especially among the elderly. To clarify the epidemiological characteristics of bath-related deaths, we reviewed inquest records of deaths in Kagoshima Prefecture from 2006 to 2019. We identified 2,689 cases of bath-related death. Of these cases, 90% were among people aged ≥65 years. The majority of cases occurred in a home bathtub between 16:00 and 20:00. Most deaths (52.0%) occurred in winter (December to February), and there was a significant negative correlation with the environmental temperature (maximum, minimum, and mean) on the day of death. We identified the environmental temperature that bath-related deaths were likely to occur in each region of Kagoshima. The causes of death were cardiac death in 1,231 cases and drowning in 855 cases. Forensic autopsies were performed in only 29 cases. Although autopsies are essential to elucidate the pathogenesis of bath-related deaths, it is difficult to increase the rate of autopsies under the current Japanese death investigation system. Therefore, we suggest that the best way to prevent bath-related death is establishing an “Alert system” based on our results, and to have people refrain from bathing on dangerous days.