he number of deaths from pulmonary embolism (PE) has been increasing in Japan, 1 and the incidence of PE in autopsy cases is also reported to have increased from 1958 to 1986. 2,3 Population-based analysis shows that deaths from PE are increasing in older age groups but PE is often misdiagnosed. 4,5 There are no reports on the incidence of PE in autopsy cases after 1986 in Japan and the following remain to be solved: (1) to what degree does PE contribute to death in different ages and genders and (2) what factor (s) contributes to diagnosis of PE before death. Therefore, our aims in the present study were to examine the incidence of PE in autopsy cases after 1986, and to clarify these 2 unsolved questions.
MethodsThe subjects of the present study included PE cases confirmed by autopsy in Japan between 1987 and 1998. 6-17 We excluded cases of pulmonary microembolism with disseminated intravascular coagulation from our analysis.
Circulation Journal Vol.71, November 2007PE was defined as critical (critical PE) when it was the primary cause of death or the main diagnosis and it includes all types of PE. The term "all PE" was used to indicate the total number of thrombotic PEs, tumor PEs, bacterial PEs, mycotic PEs and other emboli (eg, fat, amniotic fluid, etc). 18 To make it possible to compare our data with those reported by Mieno et al, 3 we analyzed our PE cases according to Mieno's criteria in which cases less than 1 year old and those with non-thrombotic PE were excluded.
Statistical AnalysisStatistical analysis was performed using SPSS 13.0 (SPSS Inc, Chicago, IL, USA). Non-ordinal categorical data using the chi-square test. The results of the logistic regression models and Poisson regression analysis 19 are presented as estimated odds ratios (ORs) with the corresponding 95% confidence intervals (CIs).Circ J 2007; 71: 1765 -1770 (Received April 18, 2007 revised manuscript received July 9, 2007; accepted July 24, 2007