Inappropriate Empiric Therapy Impacts Complications and Hospital Resource Utilization Differentially Among Different Types of Bacterial Nosocomial Pneumonia: A Cohort Study, United States, 2014–2019

Nosocomial pneumonia (NP) remains a costly complication of hospitalization fraught with subsequent complications and augmented resource utilization. Consisting of ventilated hospital-acquired bacterial pneumonia (vHABP), nonventilated hospital-acquired bacterial pneumonia (nvHABP), and ventilator-associated bacterial pneumonia (VABP), each may respond differently to inappropriate empiric treatment (IET). We explored whether IET affects the three pneumonia types differently. DESIGN: A multicenter, retrospective cohort study within the Premier Research database. SETTING: Acute care hospitals in the United States. PATIENTS: Patients with three types of NP were identified based on a previously published International Classification of Diseases, 9th Edition/International Classification of Diseases, 10th Edition Clinical Modification algorithm. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We compared the impact of IET on hospital costs, length of stay (LOS), and development of Clostridium difficile infection (CDI), extubation failure (EF), and reintubation (RT). Marginal effects were derived from multivariable regression analyses. IET was present if no drug covering the organism recovered from the index culture was administered within 2 days of the culture date. Among 17,819 patients who met the enrollment criteria, 26.5% had nvHABP, 25.6% vHABP, and 47.9% VABP. Compared with non-IET, IET was associated with increased mean unadjusted hospital LOS across all NP types: nvHABP 12.5 versus 21.1, vHABP 16.7 versus 19.2, and VABP 18.6 versus 21.4 days. The adjusted marginal hospital LOS (4.9 d) and costs ($13,147) with IET were the highest in nvHABP. Incident CDI was rare and similar across NP types (2.4% nvHABP to 3.6% VABP). Both EF and RT were more common with IET in VABP (EF, 15.4% vs 19.2%; RT, 6.2% vs 10.4%), but not vHABP (EF, 15.1% vs 17.7%; RT, 8.1% vs 9.1%). CONCLUSIONS: Although IET is relatively uncommon, it affects resource utilization and the risk of complications differently across NP types. The impact of IET is greatest on both LOS and costs in nvHABP and is greater on VABP than vHABP in terms of EF and RT.