OBJECTIVE To investigate the changes of etiological submission rates before the antimicrobial therapy after a series of intervention measures were taken so as to optimize the use and management of antibiotics.

METHODS A total of 97, 146 patients who were hospitalized and treated with antibiotics in the First Affiliated Hospital of Soochow University from Jul. 2021 to Jun. 2024 were recruited as the research subjects. Jan. 2023 was set as the time node of intervention, the time period from Jul. 2021 to Dec. 2022 was assigned as the pre-intervention group, and the time period from Jan. 2023 to Jun. 2024 was assigned as the post-intervention group. The etiological submission rates before the antimicrobial therapy were observed by interrupted time series before and after the intervention measures were taken. The changes of isolation rates of multidrug-resistant organisms and incidence of hospital-associated infections were estimated by chi-square test.

RESULTS The etiological submission rates before the antimicrobial therapy, etiological submission rates before combined use of major antibiotics and etiological submission rates relating to diagnosis of hospital-associated infections were higher after the intervention than before the intervention(all P < 0.05). The interrupted time series analysis showed that from the perspective of long-term benefit, the intervention measures could raise the etiological submission rates before the use of restricted, special grades of antibiotics and general antibiotics, and the net benefits were 0.85%, 0.67% and 0.68%, respectively (all P < 0.05); there was no significant difference in the etiological submission rate before the combined use of major antibiotics. After the intervention, the incidence of multidrug-resistant organisms infection decreased from 0.46% to 0.27% (P < 0.001); the isolation rate of multidrug-resistant organisms was 25.73% after the intervention, 27.47% before the intervention, and there was no significant difference.

CONCLUSIONS Scientific and reasonable interventions may effectively raise the etiological submission rates before the antimicrobial therapy, however, the etiological submission rate for combined use of major antibiotics and the isolation rate of multidrug-resistant organisms are not improved remarkably. It is necessary to further formulate targeted intervention measures so as to push forward high-quality development of infection control.