3.1 Characteristics of the patients
Eight NICUs (6 level III NICUs and 2 level II NICUs, comprising 1 children’s hospital, 2 maternal and child health hospitals and 5 comprehensive hospitals), including 6 of the 17 NICUs we contacted and 2 NICUs who contacted us, participated in the retrospective, multicenter study. In total, 2051 newborns admitted to the participating hospitals were sampled and enrolled, 1770 of whom were evaluable and 281 were excluded due to incomplete demographic data (10 neonates) and unqualified prescriptions (271 neonates) (Table 1). Among the evaluable patients, 1035 (58.47%) were male and 735 (41.53%) were female. The mean body weight was 2.98 kg (SD = 0.80, range 0.78-6.0) and the majority of patients (68.14%) resulted to be the normal body weight (2.5~<4.0 kg). Of the patients, 41.52% were diagnosed with suspected/proven infections, followed by gastrointestinal diseases (25.88%) and respiratory diseases (7.57%). Intravenous injection was the most common route of administration, accounting for 73.11% of all the prescriptions, followed by oral administration (11.89%) and intramuscular injection (10.39%).