Antibiotic Use and Outcomes After Implementation of the Drug Resistance in Pneumonia Score in ED Patients With Community-Onset Pneumonia

Background To guide rational antibiotic selection in community-onset pneumonia, we previously derived and validated a novel prediction tool, the Drug-Resistance in Pneumonia (DRIP) score. In 2015, the DRIP score was integrated into an existing electronic pneumonia clinical decision support tool (ePNa). Methods We conducted a quasi-experimental, pre-post implementation study of ePNa with DRIP score (2015) vs ePNa with health-care-associated pneumonia (HCAP) logic (2012) in ED patients admitted with community-onset pneumonia to four US hospitals. Using generalized linear models, we used the difference-in-differences method to estimate the average treatment effect on the treated with respect to ePNa with DRIP score on broad-spectrum antibiotic use, mortality, hospital stay, and cost, adjusting for available patient-level confounders. Results We analyzed 2,169 adult admissions: 1,122 in 2012 and 1,047 in 2015. A drug-resistant pathogen was recovered in 3.2% of patients in 2012 and 2.8% in 2015; inadequate initial empirical antibiotics were prescribed in 1.1% and 0.5%, respectively ( P  = .12). A broad-spectrum antibiotic was administered in 40.1% of admissions in 2012 and 33.0% in 2015 ( P P P  = .039). However, the average effects for ePNa with DRIP on mortality, length of stay, and cost were not statistically significant. Conclusions Electronic calculation of the DRIP score was more effective than HCAP criteria for guiding appropriate broad-spectrum antibiotic use in community-onset pneumonia.