Assessment of Antibiotic De-escalation by Spectrum Score in Patients With Nosocomial Pneumonia: A Single-Center, Retrospective Cohort Study

Background Hospital-acquired and ventilator-associated pneumonia (HAP/VAP) cause significant mortality. Guidelines recommend empiric broad-spectrum antibiotics followed by de-escalation (DE). This study sought to assess the impact of DE on treatment failure. Methods This single-center retrospective cohort study screened all adult patients with a discharge diagnosis code for pneumonia from 2016 to 2019. Patients were enrolled if they met predefined criteria for HAP/VAP ≥48 hours after admission. Date of pneumonia diagnosis was defined as day 0. Spectrum scores were calculated, and DE was defined as a score reduction on day 3 versus day 1. Patients with DE were compared to patients with no de-escalation (NDE). The primary outcome was composite treatment failure, defined as all-cause mortality or readmission for pneumonia within 30 days of diagnosis. Results Of 11860 admissions screened, 1812 unique patient-admissions were included (1102 HAP, 710 VAP). Fewer patients received DE (876 DE vs 1026 NDE). Groups were well matched at baseline, although more patients receiving DE had respiratory cultures ordered (56.6% vs 50.6%, P = .011). There was no difference in composite treatment failure (35.0% DE vs 33.8% NDE, P = .604). De-escalation was not associated with treatment failure on multivariable Cox regression analysis (hazard ratio, 1.13; 95% confidence interval, 0.96-1.33). Patients receiving DE had fewer antibiotic days (median 9 vs 11, P < .0001), episodes of Clostridioides difficile infection (2.2% vs 3.8%, P = .046), and hospital days (median 20 vs 22 days, P = .006). Conclusions De-escalation and NDE resulted in similar rates of 30-day treatment failure; however, DE was associated with fewer antibiotic days, episodes of C difficile infection, and days of hospitalization.