China launched a 3-year rectification scheme for the clinical use of antibiotics in 2011, and a specific scheme for carbapenem use in 2017. The aim of this study was to investigate the effects of government policies on carbapenem use, and their correlation with carbapenem-resistant Pseudomonas aeruginosa (CRPA). The study was divided into four stages: preintervention (2010), antimicrobial programme (2011–2013), post-antimicrobial programme (2014–2016) and carbapenem programme (2017). A point-score system was proposed for evaluating the rationality of carbapenem use, and evaluated based on the indications, microbial culture, single dose, interval, and duration. Any prescription without a global score of 10 points was judged as irrational. The trend was analyzed by regression analysis, and Spearman correlation analysis was used for testing the correlation. The rate of rational use of carbapenems was 29.7% in 2010, and increased by 55.5, 45.2, and 51.5% during the subsequent three stages. The rationality declined slightly during the post-antimicrobial programme (2014–2016) while the consumption of carbapenems was markedly increased. These two parameters improved slightly in 2017. Moreover, the prevalence of CRPA was significantly negatively correlated with the rate of rational carbapenem use (Coefficient = − 0.553, P < 0.05), and not with the consumption of carbapenems (P > 0.05). The rational application of carbapenems was related to government policies in this study, with irrational carbapenem use possibly related to the development of CRPA. The current point-score system could be a useful tool for performing assessments.

Introduction: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is rapidly emerging as a life-threatening nosocomial infection. In this study, we aimed to identify risk factors, especially antibiotic use and co-carriage with other bacteria for CRPA infection or colonization. Methodology: A retrospective study was conducted in the First Affiliated Hospital of Xi’an Jiaotong University, which involved a cohort of patients with Pseudomonas aeruginosa infection or colonization from January 2014 to June 2016. Univariate analysis and multivariate analysis were performed to estimate the risk factors of CRPA occurrence. Results: Eight hundred and eighty-eight patients were included in the study. More than 50% of the risk factors were associated with CRPA infection or colonization according to univariate analysis (P < 0.05), such as invasive procedures, co-carriage with Gram-negative pathogens, and prior treatment with some antibiotics. However, only prior exposure to carbapenems (OR: 8.005; CI:4.507-14.217, P<0.001), the days of carbapenems treatment (OR: 1.190; CI: 1.073-1.272; P < 0.001), and co-carriage with Escherichia coli (OR: 1.824; CI: 1.005-3.310, P = 0.048) were considered independent risk factors by multivariate analysis. A higher mortality was found among patients with CRPA infection or colonization (P < 0.05). Conclusions: Risk factors for CRPA infection or colonization were prior exposure to carbapenems, the days of carbapenems treatment, and co-carriage with Escherichia coli. The prevalence of CRPA could be influenced by Gram-negative pathogens, especially in Escherichia coli, and it need more researches. Moreover, restrictions in the clinical use of carbapenems should be taken into account.