Data source

The study data were obtained from electronic medical records of four tertiary hospitals on the Big Data Platform of Medical Data Research Institute of Chongqing Medical University. At present, the platform has collected more than 40 million electronic medical records from seven tertiary hospitals of Chongqing, and anonymized all information related to patient privacy. A total of 50 patient records were collected from the Yongchuan Hospital of Chongqing Medical University, 360 from the Second Affiliated Hospital of Chongqing Medical University, and 470 from the University-Town Hospital of Chongqing Medical University. Patients from above the three centers were divided into the training. The patient records collected from the Third Affiliated Hospital of Chongqing Medical University (n = 185) were used as the external validation set.

The Ethics Committee of the Affiliated Banan Hospital of Chongqing Medical University approved the study. Written informed consent for participation was not required for this study due to its retrospective design, and the study was undertaken in accordance with national legislation and institutional requirements.