O06 – Empiric Azoles Are Not Beneficial in Surgical Patients: A Propensity-Matched Cohort Study
Author(s):
Background: Broad-spectrum empiric antibacterials are associated with an increased incidence of opportunistic infection, yet studies evaluating the impact of empiric azoles on the number and characteristics of future infections are lacking.
Hypothesis: We hypothesized that empiric azole exposure would not significantly alter the rates of future infectious episodes or associated outcomes.
Methods: We reviewed a prospectively collected and maintained surgical infection database from a tertiary hospital. All initial infectious episodes per patient per admission between Jan. 1, 2000 and Dec. 31, 2011 were identified and grouped according to the presence of a fungal isolate on initial culture and receipt of an empiric azole. Propensity score matching was performed using potential confounders (excluding initial culture results). The number and characteristics of subsequent infections, as well as mortality and length of stay were analyzed. Wilcoxon rank sum, chi-square, and fisher’s exact test were used as appropriate. Infection-free survival was evaluated using a Kaplan-Meier curve.
Results: We identified 6,530 patients (9.6% with fungal infection, 11.6% with empiric azole exposure) as part of the initial cohort. Propensity matching identified 410 pairs of patients based upon empiric azole exposure (133 pairs with initial fungal infection). Peritoneal infection was the most common site in both groups (56.8% of fungal vs. 72.7% of non-fungal; 24.5 vs. 17.7% respectively from upper GI source). There were no differences in mortality (12.8 vs. 10.5% for fungal, p=0.6; 11.9 vs. 8.7% for non-fungal, p = 0.2) or rate of subsequent infection with resistant pathogens. Empiric azole exposure was associated with a longer length of stay (median 11 vs. 9 days; p=0.003) and lower rates of subsequent CRBSI (3.7 vs. 11.5%; p = 0.001) for those patients without an initial fungal infection. There were no differences in infection-free survival based on azole exposure regardless of fungal culture results.
Conclusions: Our study did not identify a difference in the outcomes following initial infection or the characteristics of subsequent infectious episodes based upon receipt of empiric azole therapy. Empiric azole therapy appears to offer no benefit to surgical patients and should be avoided without culture-based evidence of fungal infection.