106 - Impact and Evaluation of BioFire® FilmArray® Respiratory Panel on Clinical Decision Making and Antibiotic Prescribing

Background: The BioFire® FilmArray® respiratory panel (RFA) has been proposed as a tool for timely diagnosis and treatment of respiratory tract infections. However, the impact of the RFA on clinical decision making, most notably antibiotic prescribing, de-escalation and duration has been varied.

Methods: We aimed to determine the impact of RFA results on antibiotic days of therapy (DOT) depending on patient disposition. We conducted a retrospective chart review of adults who had an RFA performed within 48 hours of admission or presentation to the emergency departments (ED) of 3 hospitals in Des Moines, Iowa, between March 3 and March 16, 2019. Patients were excluded if they had a non-respiratory infection with defined indication for antibiotics. RFA results were categorized as influenza, non-influenza virus or negative. Negative binomial regression models were used to calculate rate ratios (RR) for the association between RFA result and DOT.

Results: A total of 486 total patients were included. Patients were divided according to disposition status, with 243 patients admitted and 243 discharged from the ED. Among inpatients, the median DOT was 2 (IQR 0-7). The results of the adjusted analysis for inpatient are shown on Table 1. In this group, RFA result was not associated with DOT (p=0.598 for non-influenza viruses and 0.706 for negative RFA), while having a urine culture done was independently associated with higher rate ratio of DOT (RR 1.85, 95% CI 1.32-2.59; p< 0.001). Among patients discharged from the ED, the median DOT was 0 (0-8). The results of the adjusted analysis for this group are shown on Table 2. Compared to patients with influenza, those with non-influenza viruses had a RR for DOT of 4.18 (95% CI 1.16-14.9; p=0.028) and those with a negative RFA had an RR for DOT of 5.24 (95% CI 1.99-13.8; p= 0.028).Adjusted analysis for the association between Respiratory Film Array results and Days of Therapy among hospitalized patients
Adjusted analysis for the association between Respiratory Film Array Results and Days of Therapy among patients discharged from the ED


Conclusion: Among inpatients, RFA results did not impact DOT, and in this group, antibiotic use was driven by urine cultures. In contrast, among patients discharged from the ED, a non-influenza virus or a negative RFA was associated with much higher rates of DOT. Our results suggest that different strategies need deployment in the ED compared to inpatient services in order to guide utilization of rapid molecular tests and antibiotic use.