Patient Outcomes on Day 4 of Intravenous Antibiotic Therapy in Non–Intensive Care Unit Hospitalized Adults With Community-Acquired Bacterial Pneumonia

BACKGROUND: Community-acquired bacterial pneumonia (CABP) is a leading cause of morbidity and mortality especially in hospitalized patients. In place of clinical end points traditionally used to evaluate antimicrobial efficacy for its treatment, Food and Drug Administration guidelines now require all registration trials to assess clinical response at day 4. The primary objective of this study was to assess health outcomes (length of stay [LOS] and hospital charges) between responders and nonresponders at this time point. METHODS: The Premier database was used to identify adult patients from 4 participating hospitals with a principal diagnosis of CABP (International Classification of Diseases, Ninth Revision, Clinical Modification, codes 481, 482.0, 483.8, 484.3, 484.5, 485, 486, or 487.0) hospitalized between July 1, 2010, and June 30, 2011. Only non–intensive care unit patients with hospital stays exceeding 2 days and receiving intravenous antibiotic agents within 24 hours of admission were included. After institutional review board approvals, a retrospective chart review extracted data for patient demographics, clinical efficacy variables at day 4, LOS, and total hospital charges. Data analysis included multivariable gamma regression models to control for patient demographics and clinical differences between responders and nonresponders. RESULTS: A total of 666 patients met study the criteria. Mean (SD) age was 70.7 (17.9) years, and 42.5% were males. Among these patients, 277 (41.6%) achieved clinical response by day 4 of initial antibiotic therapy. The unadjusted mean (SD) LOS was 6.3 (2.8) days for responders and 7.4 (5.6) days for nonresponders (P = 0.0009). Respective unadjusted total hospital charges were $22,827 (SD, $17,724) and $26,403 ($36,882) (P = 0.0031). Adjusted for demographics and clinical factors, nonresponders compared with responders had an increased LOS of 0.9 days (8.4 vs 7.5 days; P = 0.0008), resulting in associated charges of approximately $2500 ($34,139 vs $36,629; P = 0.0768). CONCLUSIONS: In this real-world chart study, less than half of hospitalized patients with CABP achieved clinical response at day 4 of initial intravenous antibiotic therapy. The observed clinical response was associated with a significantly shorter hospital stay and trended toward lower total hospital charges. These findings corroborate the Food and Drug Administration guidance for assessing antimicrobial therapy at day 4 because responder is associated with improved health outcomes.