THE IMPACT OF AN ANTIMICROBIAL STEWARDSHIP PROGRAM ON BROAD-SPECTRUM ANTIBIOTIC USE, BACTERIAL SUSCEPTIBILITY PATTERNS, AND ANTIBIOTIC COSTS IN THE INTENSIVE CARE UNIT OF A LARGE TERTIARY HOSPITAL: A PRE-POST INTERVENTION STUDY

Abstract

Introduction: Antibiotics are the drugs most often used in intensive care units (ICUs). More than two-thirds of critically ill patients receive antibiotics, which lead to increasing rates of resistant pathogens, along with a few new antibiotics, making the ICU an ideal setting for carrying out antimicrobial stewardship programs (ASPs). The implementation of ASPs is crucial because they facilitate the rational use of antibiotics, leading to reduced utilization, lower rates of antibiotic resistance, and alleviation of the financial burden. The aim of this study was to evaluate the impact of ASPs on broad-spectrum antibiotic utilization, direct costs, and antibiotic sensitivity before and after ASP implementation. Method: A retrospective, prepostintervention study design was utilized to evaluate the impact of an ASP over two years prior to and two years following its introduction at An-Najah National University Hospital, a tertiary care facility in the West Bank, Palestine. Data on antibiotic consumption metrics, such as DDD and DOT/1000 patient days, direct cost/1000 patient days and antibiotic sensitivity, were compared between the two groups. Results: There was a statistically significant decrease in the number of patients who consumed meropenem, tigecycline, colistin, ceftriaxone and quinolones after ASP. The mean total DDD/1000 patient-days decreased from 517.74 to 481.67 (6.97%), and the mean total DOT/1000 patient-days also decreased from 612.31 to 519.27 (15.19%). However, ceftriaxone DDD significantly decreased, whereas vancomycin, piperacillin/tazobactam, and levofloxacin consumption significantly increased. Furthermore, a significant increase in the sensitivity of Pseudomonas aeruginosa and K. pneumoniae to meropenem, imipenem, piperacillin/tazobactam and amikacin after ASP, levofloxacin and linezolid susceptibility significantly decreased for Enterococcus faecalis. The total direct cost/1000 patient-days decreased by 40.99% after ASP implementation. There was also a significant reduction in the median cost per 1000 patient-days for meropenem, tigecycline, piperacillin/tazobactam, vancomycin, ceftazidime, ceftriaxone and quinolones. The median length of stay decreased significantly, by 18.18% (p=0.010); however, the mortality rate did not significantly change. Conclusion: In conclusion, introducing an antimicrobial stewardship program in the ICU led to clearer, more appropriate use of broad-spectrum antibiotics. Overall, antibiotic use and related costs went down, and improvements in the susceptibility of several key pathogens were observed. Importantly, these benefits were achieved without compromising patient safety, as hospital mortality did not change and the length of hospital stay was noticeably shorter. Together, these findings underscore the importance of antimicrobial stewardship in promoting more responsible antibiotic use, enhancing microbiological outcomes, and mitigating avoidable costs in intensive care settings, even in resource-constrained environments.