This survey included 20 general hospitals across the country, 10,881 beds (424–759 in each hospital), 10,209 inpatients (330–758 in each hospitals) including 4408 patients from eight medical specialties (108–1319), 5208 patients from nine surgical specialties (138–953), and 593 patients from the ICU. The average age of the enrolled patients was 58.15 ± 17.31 years, the proportion of males was 57.48%, and 22.58% of the patients suffered from fatal diseases (including ultimately fatal and rapidly fatal diseases defined by the McCabe classification), of which hematology, oncology, nephrology and rheumatism, tumor surgery, and ICU encompassed 70.34%, 69.93%, 50.00%, 47.83%, and 45.15% of patients, respectively. Immunosuppressed individuals accounted for 15.05% (of which 84.41% and 78.20% were in hematology and oncology departments, respectively) of patients. The proportion of males, fatal diseases, and immunosuppressed individuals were higher in internal medicine than in surgical patients. Of the patients, 3777/10209 (37.00%) received antimicrobial agents, 1630/5208 (31.30%) received surgical operations, 1249/1630 (76.63%) received prophylactic antibiotic, 1935 patients had CAI, and 387 (427 cases) were HAI (Table 1).

Of the inpatients, 22.7% had an infection diagnosis (CAI: 18.95%, 1935/10209; HAI: 3.79%, 387/10209). The major infections were respiratory tract infection (RTI, 48.04%), urinary tract infection (UTI, 13.87%), and gastrointestinal/abdominal infection (9.16%). The number of patients with an infectious disease diagnosis was far lower than that of the total number of patients receiving antimicrobials (37.00%, 3777/10209). The prevalence of antimicrobial use in medical, surgical, and ICU patients was 38.84% (1712/4408), 32.07% (1670/5208), and 66.61% (395/593), respectively. There were 6151 antibacterial prescriptions in total, 2487 prescriptions for internal medicine, 2989 for surgery, and 675 for ICU. Among them, the proportion of prescriptions for treatment and prophylaxis was 67.66% (4162/6151) and 26.55% (1633/6151), respectively. Of the prescriptions, 5.79% (356/6151) lacked a recorded indication. Targeted and empiric therapy accounted for 10.43% (434/4162) and 85.25% (3548/4162) of prescriptions, respectively. Administration of medication without a recorded indication was higher in surgery patients than those in the ICU and in internal medicine. Infectious disease departments had the highest antimicrobial use without indication in internal medicine (9.14%, 31/339), and general surgery (21.41%, 79/369) and urology (12.56%, 81/645) was the highest in surgery. The proportion of patients receiving surgical clean incision was 31.29% (510/1630), and the antibiotic prophylaxis rates in surgical patients was 76.63% (1249/1630), of which ob-gynecology, orthopedics, and tumor surgery had rates higher than 90% (Tables 2 and 3).

The overall intensity of antimicrobial use in hospitals was 61.25 DDDs/100 patient days, while that of internal medicine, surgery, and the ICU was 67.79, 45.81, and 124.45 DDDs/100 patient days, respectively. The intensity of use in infectious disease departments, respiratory departments, urology, hepatobiliary pancreatic surgery, and gastrointestinal surgery was higher than that of internal medicine or surgery as a whole.

The overall quality of antimicrobial prescriptions was low. Only 11.62% (715/6151) of prescriptions had a reason described in the patient record. Of prescriptions, 8.44% (210/2487), 14.19% (424/2989), and 12% (81/675) had a described reason in internal medicine, surgery, and the ICU, respectively. Worryingly, in respiratory departments, orthopedic, neurosurgery, and ob-gynecology rates of described prescription indication were less than 10%. Considering cases of therapeutic antibiotic use, empirical, targeted, and purpose unclarified therapeutical administration accounted for 84.33% (3810/4518), 10.03% (453/4518), and 5.64% (255/4518), respectively. Rates of empiric antimicrobial therapy in internal medicine, surgery, and the ICU were 89.21% (2150/2487), 83.34% (1231/1477), and 69.13% (383/554), respectively. Furthermore, over 90% of antimicrobial therapies were empiric in respiratory departments, endocrinology, hepatobiliary, and pancreatic surgery. The review and stop dates recorded for antimicrobial therapy was 43.73% (1976/4518), and that of internal medicine, surgery, and ICU was 34.86% (867/2487), 58.23% (860/1477), and 44.94% (249/554), respectively. Further, the respiratory department (26.74%) and orthopedics (5.95%) were the lowest specialties in internal medicine and surgery. During the survey, 65.41% (2988/4518) of patients were treated with antimicrobials for less than 7 days, with 64.97% (1616/2487), 69.12% (1021/1477), and 63.35% (351/554) of patients in medical, surgical, and ICU departments, respectively, receiving less than 7 days of therapy. Of the therapeutic drugs, 91.98% (5128/5575) was administered intravenously. The frequency of combination therapy was 38.07% (1438/3777), with internal medicine, surgery, and ICU presenting with combination therapy rates of 38.26% (655/1712), 36.95% (617/1670), and 42.03% (166/395), respectively. Only 41.72% (1885/4518) of patients were treated with antibiotics following reference to microbiological or biomarker examination (Tables 2 and 3).

The classes of specific antimicrobial agents prescribed was limited. The majority of antimicrobial classes prescribed (69.00% of total prescriptions) encompassed third generation cephalosporins (3GC) and their combination with β-lactamase inhibitors (CLI) (22.05%, 1356/6151), second-generation cephalosporins (2GC; 19.61%, 1206/6151), quinolones (14.50%, 892/6151), and broad-spectrum penicillins combined with β-lactamase inhibitors (BPLI; 13.41%, 825/6151). The antimicrobial classes most frequently used in internal medicine, surgery, and the ICU were quinolones (24.13%, 600/2487), 2GC (31.33%, 930/2989), and 3GC (26.96%, 182/675), respectively. 2GC was used most frequently (43.78%, 715/1633) for surgical prophylaxis, but 3GC (18.25%, 298/1633) and nitroimidazoles (12.25%, 200/1633) also accounted for a large proportion of prescriptions. Carbapenems were mainly used in the ICU, hematology, respiratory departments, infectious disease departments, and neurosurgery. Antifungal agents for systemic use were mainly used in hematology and ICU (Figs. 1 and 2).

Proportion of prescribed antibiotic classes for systemic use in internal medicine and intensive care units. ID, Infectious disease; Pulm, Pulmonary department; Hema, hematology department; Onco, oncology department; Endo, endocrinology department; Neur, Neurology department; Ne-Rh, Nephrology & Rheumatology department; ICU, intensive care unit

Proportion of prescribed antibiotic classes for systemic use in surgeries. GenS, general surgery; Urol, urology; NeurS, neurosurgery; Gyn, gynecology; HepaB, hepatobiliary surgery; Ortho, orthopedics; GiS, gastrointestinal surgery; OncoS, oncological surgery

The proportion of the top 20 antimicrobial agents prescribed was 75.06% (4617/6151), encompassing 77.97% (1932/2478), 83.64% (2500/2989), and 66.21% (435/657) of patients in internal medicine, surgery, and the ICU, respectively. The frequency of prescriptions of the top four individual antimicrobial agents were cefuroxime (8.93%), levofloxacin (8.50%), cefoperazone/sulbactam (7.87%), and piperacillin/tazobactam (5.33%), which accounted for 30.63% in total. The top four agents accounted for 37.27% of prescriptions in internal medicine (levofloxacin, 14.15%; moxifloxacin, 9.13%; cefoperazone/sulbactam, 7.44%; and piperacillin/sulbactam, 6.55%), 32.55% in surgery (cefuroxime, 15.02%; cefoperazone/sulbactam, 6.32%; ornidazole, 6.02%; and metronidazole, 5.19%), and 36.75% in the ICU (cefoperazone/sulbactam, 16.30%; cefuroxime, 8.15%; piperacillin/sulbactam, 6.52%; and meropenem, 5.78%). The composition of antimicrobial use across clinical specialties varied markedly (Figs. 3 and 4).

Proportion of the most frequently prescribed 20 antibiotic agents for systemic use in internal medicines and intensive care units. ID, Infectious disease; Pulm, Pulmonary department; Hema, Hematology department; Onco, Oncology department; Endo, Endocrinology department; Neur, Neurology department; Ne-Rh, Nephrology & Rheumatology department; ICU, Intensive care unit

Proportion of the most frequently prescribed 20 antibiotic agents for systemic use in surgeries. GenS, General surgery; Urol, Urology; NeurS, Neurosurgery; Gyn, Gynecology; HepaB, Hepatobiliary surgery; Ortho, Orthopedics; GiS, gastrointestinal surgery; OncoS, oncological surgery

The top three antibacterial drugs used to treat CAI were 3GC [24.27%, including cefoperazone/sulbactam (8.90%)], quinolones [19.54%, including levofloxacin (11.38%)], BPLI [19.33%, including piperacillin/tazobactam (7.07%)]. By contrast, the main drugs used for treatment of HAI were 3GC [28.48%, including cefoperazone/sulbactam (18.70%)], carbapenems [13.71%, including meropenem (6.09%)] and BPLI [9.92%, including piperacillin/tazobactam (6.30%)]. With the exception of central nervous system infections (CNSI), the prescriptions of antibacterial drugs for other infections followed a comparable pattern. The main classes of antibacterial agents used for treatment of CNSI were carbapenems (24.24%, 16/66) and 3GC (25.76%, 17/66) (Figs. 5 and 6). Among the 20 most commonly prescribed antibacterial agents, 16 were highlighted as restricted by the AMS strategy. Prescriptions with non-therapeutic purposes accounted for 22.50% (784/3484), including prescription of ceftriaxone, cefminox, ceftazidime/sulbactam, ornidazole, voriconazole, and vancomycin in 49.03% (101/206), 44.81% (69/145), 29.69% (19/64), 56.61% (107/189), 31.71% (26/82), and 23.33% (14/60) of cases, respectively (Fig. 7).

Proportion of prescribed antibiotic classes for systemic use in different infections and for surgical prophylaxis. CNS, Central nerve system infection; RTI, Respiratory tract infection; GI/IAI, Gastroenterological infection and intra-abdominal infection; SSTI Skin and skin structure infections; UTI Urinary tract infection; SP Surgical prophylaxis

Proportion of the most frequently prescribed 20 antibiotic agents for systemic use in different infections. CNS, Central nerve system infections; RTI, Respiratory tract infections; GI/IAI, Gastroenterological infection and intra-abdominal infection; SSTI, Skin and skin structure infections; UT, Urinary tract infection

Proportions of indications for the most frequently prescribed restricted or special antimicrobials. CAI, Community acquired infection; HAI, Healthcare associated infection; MP, Prophylaxis in internal medicine; SP, Surgery prophylaxis; NA, Not applicable