Annual Increase of Acute Inpatients with Both Cancer and Cardiovascular Diseases in Japan 2011-2015: Analysis From National Database of Health Insurance Claims and Specific Health Checkups of Japan.

Background: Patients with cancer were able to live longer due to improvements in cancer treatment. Additionally, cardiovascular disease (CVD) is the second leading cause of mortality in cancer survivors. However, epidemiological data on onco-CVD have not been sufficiently provided. We aimed to investigate the clinical characteristics of cancer in CVD patients using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB).

Method and results: The NDB sampling dataset used in this study was randomly sampled 10% from the whole Diagnosis Procedure Combination (DPC) records from every January, April, July, and October from 2011 to 2015. The significance of the increase trend in the percentage of records in each disease group to the total number of all DPC records from 2011 to 2015 was checked with Chi-square test with a Bonferroni correction. The percentage of records in cancer with the CVD group to the total number of all DPC records significantly increased over time, and their average age also increased since 2011. Their proportion over 75 years was approximately 56 % in 2015. There was no difference in the cancer sites. However, the prevalence of heart failure dramatically elevated.

Conclusion: We were able to assess the increase in cancer among CVD patients using DPC inpatient records obtained from the NDB. Both cardiologists and oncologists should be more aware of this phenomenon.