Chang Gung Research Database: A multi-institutional database consisting of original medical records

Background: The Chang Gung Research Database (CGRD) is a de-identified database derived from original medical records of Chang Gung Memorial Hospital (CGMH), which comprises seven medical institutes located from the northeast to southern regions of Taiwan. The volume of medical services performed in CGMH is large, and clinical and scientific studies based on the CGRD are reported to be of high quality. However, the CGRD as a useful database for research has not been analyzed before. The objective of the study was to analyze the CGRD with regard to its characteristics and coverage of Taiwan's population. Methods: We performed a nationwide cohort study using population-based data from the Taiwan National Health Insurance Research Database (NHIRD). All patients who had any medical record of outpatient visits or admission between January 1, 1997, and December 31, 2010, were included, and the sex ratio, age distribution, socioeconomic status, urbanicity, severity of illness, prevalence of specific disease, and coverage of the CGRD were analyzed. Results: The sex ratio, age distribution, socioeconomic status, and urbanicity of the population of the CGRD are different from those of Taiwan NHIRD and medical centers in Taiwan (all the pairwise p < 0.05). The severity of comorbidities, and prevalence of specific diseases of the population of the CGRD are significantly higher than those of Taiwan NHIRD and medical centers in Taiwan for both outpatient and inpatient samples (all the pairwise p < 0.05). The overall coverage of the CGRD was 21.2% for outpatients and 12.4% for inpatients. The disease-specific coverage of the CGRD was 27-34% for outpatients and 14-21% for inpatients. Conclusions: The CGRD is a multi-institutional, original medical record-based research database with high overall and disease-specific coverage of Taiwan. The population of the CGRD has significantly higher severity of comorbidities, and prevalence of specific diseases than those of Taiwan NHIRD and medical centers in Taiwan.