Medicolegal death diagnosis in Tokyo Metropolis, Japan (2010): Comparison of the results of death inquests by medical examiners and medical practitioners

PurposeJapanese methods of death inquests are still in developmental stages and many problems have been uncovered since an inspection error was reported in 2007. In this study, we investigated the latest results of medicolegal deaths in the Tokyo Metropolis, which is composed of areas with and without the medical examiner system, and compared the results of inquests performed by official medical examiners with those by medical practitioners to re-evaluate the effectiveness of the medical examiner system for the Japanese death inquiry system.MethodsBy using death certificates as inquest records in the Tokyo Metropolis, 2010, we made a comparison of the autopsy rates, causes of death and the numbers of death certificates containing defects between the inquests performed by official medical examiners and those by medical practitioners.ResultsAge distributions and male to female ratios were not different between the two groups. The autopsy rate of the medical practitioners’ cases was only 5.5%, whereas that of official medical examiners’ cases was 21%. The proportion of deaths due to circulatory system disease was higher in medical practitioners’ cases than in official medical examiners’ cases (P < 0.01), and the proportion of deaths from cerebrovascular disease in medical practitioners cases was twice as high as that in official medical examiners’ cases. The number of ambiguous causes of death, such as unspecific heart failure and arrhythmia, certified without autopsies was much higher in medical practitioners’ cases than in official medical examiners’ cases. For accidental deaths, the proportion of deaths by poisoning and heatstroke was lower in medical practitioners’ cases than in medical examiners’ cases (P < 0.01). The proportion of death certificates containing defects was much higher in medical practitioners’ cases (24.1%), especially in the rural areas (45.4%), as compared to official medical examiners’ cases (1.3%).ConclusionsThe lower autopsy rate and the higher frequency of defects in death certificates in medical practitioner’s cases likely led to the differences in the mortality statistics between the two groups. On the other hand, the medical examiner system leaves room for further improvement, such as in the autopsy rate. This study supports the necessity for implementation and improvement of the medical examiner system, and for reinforcement of under/postgraduate medicolegal education in Japan.