The National Health Insurance Research Database (NHIRD) in Taiwan offers a nationwide
population-based database for research purposes. All of the patients with a diagnosis of CHD or
malignancy register with the NHIRD and obtain a catastrophic illness certification, which helps
reduce their medical expenditures under the National Health Insurance (NHI) program. These
features make the NHIRD appropriate for analyzing the risk of developing cancer [
30
–
40
]. To
date, there has been no large-scale study examining various malignancies reported in patients
with CHD. The aim of this study was to use the nationwide population-based database to explore
the association between CHD and malignancies, including all and specific cancer types, and to
examine the risk factors for cancer after a diagnosis of CHD.