Population diversity of cardiovascular outcome trials and real-world patients with diabetes in a Chinese tertiary hospital

Background: Recent cardiovascular outcome trials (CVOTs) changed the therapeutic strategy of guidelines for type 2 diabetes. We compared the characteristics of patients from real-world hospital settings with those of participants in recent pragmatic randomized trials. Methods: This electronic medical record (EMR)-based retrospective observational study investigated the data of patients with diabetes from inpatient and outpatient settings in West China Hospital of Sichuan University from January 1, 2011, to June 30, 2019. We identified patients meeting the inclusion criteria of a pragmatic randomized trial (EMPA-REG OUTCOME) based on EMRs and compared their baseline characteristics with those of the trial participants. The cutoff for the clinical significance of each characteristic was set as its minimal clinically important difference based on expert consultation. Results: We included 48,257 inpatients and 36,857 outpatients with diabetes and found that 8389 (17.4%) inpatients and 2646 (7.2%) outpatients met the inclusion criteria for the EMPA-REG OUTCOME trial. Compared with the trial population, the real-world inpatients meeting the eligibility criteria of the EMPA-REG OUTCOME had similar age, blood pressure, and lipid profiles but comprised of fewer males, metformin users, anti-hypertensive drug users, and aspirin users, and had a lower body mass index. The group of outpatients meeting the eligibility criteria had fewer males, similar age, fewer metformin users, fewer insulin users, fewer anti-hypertensive drug users, and fewer aspirin users compared with the trial population. Conclusions: The trial population in EMPA-REG OUTCOME represents only a small portion of patients with diabetes from the inpatient and outpatient departments of a Chinese tertiary medical center. Evidence localization in different clinical settings and validation are essential to enabling extrapolation of the results from CVOTs in patients with diabetes to Chinese clinical practice.