Outcomes of Antimicrobial De-escalation with Emphasis on Antimicrobial Utilisation in a Tertiary Care Hospital at South India

Background: Research and literature on antimicrobial de-escalation are often confined to assessment of safety and efficacy of de-escalation for patients with infection and, not antimicrobial utilization. Evidence suggests that the key intervention to stop further emergence of antimicrobial resistance (AMR) is to optimize antimicrobial de-escalation and improve antimicrobial stewardship (AMS) practices. An audit of antibiotic use in infection and measuring antibiotic consumption is the basic area of an Antimicrobial stewardship AMSP. This study aimed to assess the clinical outcomes of antibiotic de-escalation on length of stay (LOS), days on IV antibiotics, along with antibiotic utilization and duration of antibiotic therapy.

Methods: This prospective observational study included in-patients with antibiotic prescriptions. Data collected included patient demographics, empiric, de-escalated or non-de-escalated antibiotic regimens, microbiological reports and final diagnoses were collected. The outcomes of de-escalation and non-de-escalation were compared. Statistical analysis was done using SPSS software and the p value < 0.05% was considered significant.

Results: Out of the 360 patients, 226 patients were de-escalated and 134 patients had their therapy non-de-escalated. The de-escalated population had a shorter LOS (mean: 4 days vs. 6 days, p <.05), shorter DOT (mean: 11.3 days vs. 13.9 days, p = .05), and fewer days on IV antibiotics (median: 3 days vs. 5 days, p = .05) compared to the non-de-escalated group.

Conclusion: De-escalation resulted in a:

Reduction of 2.6 DOT (Days of Therapy) units of antimicrobial use (p value= .05), despite similar durations of antimicrobial therapy (LOT).
Reduction of 2 days of intravenous antimicrobial (p value= .05).
Reduction of 1.7 days in the Length of hospital Stay (p value < .05).