112 - Impact of Respiratory Viral PCR Panels (RVP) and Serum Procalcitonin (PCT) on Antibiotic Days of Therapy (DOT) in Patients Admitted with Lower Respiratory Tract Infections (LRTI)

Background: IDSA advocates for the use of RVP and PCT to reduce inappropriate antibiotic use. These assays were implemented in our health system without formal antimicrobial stewardship intervention. Herein, we evaluated assay utilization and impact on antibiotic DOT in patients admitted with LRTI.

Methods: Records of patients admitted to our health system in January 2019 with a diagnosis of LRTI (ICD 10 codes: J13-22, J44, or J85) were reviewed. Patients < 18 years old, receiving active treatment at time of admission for a concurrent infection, or had a RVP or initial PCT ordered > 48 hours from admission were excluded. Patients were cohorted based on at least one test ordered (VPPC) vs neither (CTRL). The primary endpoint was total antibiotic DOT, including inpatient and outpatient. Secondary endpoints were hospital length of stay (LOS), 30 day readmission (30DR), and all cause mortality (ACM). Multivariate linear regression was used to determine variables associated with DOT.

Results: Of 294 patients included, 15 (5.1%), 84 (28.6%), and 43 (14.6%) had RVP alone, PCT alone, or both ordered, respectively, resulting in 142 (48.3%) patients in the VPPC group. Providers modified therapy based on PCT and RVP results in 39.4% (50/127) and 33.3% (7/21) of patients, respectively. Median (IQR) DOT was similar between VPPC and CTRL groups (7 [5-9] vs 7 [3-8] days; p=0.159), respectively. Inpatient DOT (4 [2-5] vs 3 [2-4] days; p=0.001) and LOS (99.5 vs 81.7 hours; p=0.001) were longer in the VPPC group. VPPC patients were more likely to receive anti-pseudomonal B-lactams (anti-PSA) (26.8 vs 16.4%; p=0.044) and anti-MRSA antibiotics (45.1 vs 34.9%; p=0.096). No difference in 30DR (13.4 vs 15.1%; p=0.793) or ACM (2.1 vs 3.3%; p=0.794) was observed. Variables significantly associated with increased DOT were non-ICU admission, positive chest X-ray, LOS, younger age, and receipt of anti-MRSA or anti-PSA antibiotics.

Conclusion: Over one month, RVP or PCT was ordered in nearly half of admitted LRTI patients in our health system, but modification of therapy based on results was infrequent. The unrestricted use of these tests without stewardship intervention did not impact overall antibiotic DOT, LOS, 30DR, or ACM. These data emphasize the need for additional intervention to enhance the clinical utility of these tests.