Analysis of the Effect of Climate on Mortality over Time

Malignant neoplasms, cardiac disease, and cerebrovascular disease are Japan's most common causes of death, with cardiac disease and cerebrovascular disease increasing during the winter season. The indoor environment of Japanese houses is poor in winter. To reduce medical costs for the further aging of the population, it is essential to study the relationship between mortality and the indoor environment. This paper analysed mortality rates by location, age group, year of death, and energy efficiency classification to clarify the relationship between climate and mortality rates in each region. Data were constructed by merging mortality data with climate data. Mortality sensitivity measures the mortality rate increases when the outside temperature falls by 1 ˚C. We also found that mortality among those who died in residential settings was more strongly affected by the cooler outside temperature environment than in nonpresidential settings. It suggests that the mortality rate was more strongly affected by residential areas, which tend to have cooler indoor temperatures during the winter, than non-residential buildings such as hospitals and elderly care facilities. The analysis by age group showed that the sensitivity was higher for older age groups and warmer energy efficiency classification categories in Kyushu and Okinawa.