In this Multi-center study performed from January 2018, we reviewed data on infants whose gestational ages were below 36 weeks. we collected data containing maternal diseases and neonatal clinical features. LASSO regression was used to select variables for the risk model. Then, we used multivariable logistic regression to build the prediction model incorporating these selected features. Discrimination was assessed by the C-index, and and calibration of the model was assessed by and calibration curve and the Hosmer-Lemeshow test.

Inclusion Criteria:

• Patients were recruited from Multi-center Collaborative Group Hospital Neonatal Intensive Care Unit (NICU) Department.
• Patients with gestational age <36 weeks
• admitted to the NICU within 24 h after birth
• the length of stay was more than 1 week

Exclusion Criteria:

• patients with inherited disease, metabolic disorders and multiple malformations.

Patients were recruited from Multi-center Collaborative Group Hospital Neonatal Intensive Care Unit (NICU) Department. The data was collected from medical records. Patients with GAs <36 weeks, and who were admitted to the NICU within 24 h after birth were included, and the length of stay was more than 1 week.patients with inherited disease, metabolic disorders and multiple malformations were excluded.