Children’s death survey using death certificates in the Chiba prefecture

In recent years, Child Death Review (CDR) has attracted attention in Japan. It is necessary to consider not only hospital deaths but also out-of-hospital deaths. However, recommending preventive measures may be difficult because statistics on Japanese child mortality are limited. We examined cause of death (COD) and its application in preventive medicine based on death certificates (DCs) in the Chiba Prefecture. Death documents (DDs) and death slips (DSs) were created for individuals aged under 20 years who died between January 2012 and December 2016. They were based on DCs submitted to the Chiba Prefecture. We examined the trend of COD, occurrence of extrinsic mortality, and characteristics of doctors and compared CODs mentioned in DCs with autopsy results. For 1149 cases, the descriptions of DSs and DDs matched. Half of the extrinsic and undetermined deaths, which were examined by police doctors, occurred out-of-hospital. The autopsy rate was 13.5%. The COD mentioned in DCs did not match the autopsy results for 26 out of 69 autopsies performed at our institute. Approximately 70% of sudden infant death syndromes were diagnosed without autopsy. Low autopsy rate, incorrect writings, and errors during the death diagnosis cannot be ignored while conducting CDR. As more than half of the preventable deaths occurred out-of-hospital and there is no system to collect detailed information on them, the Japanese CDR system may not be reliable. It is necessary to improve the death investigation system by promoting autopsies for children and constructing a comprehensive database.