Usefulness of β-lactam and Macrolide Combination Therapy for Treating Community-acquired Pneumonia Patients Hospitalized in the Intensive Care Unit: Propensity Score Analysis of a Prospective Cohort Study

Abstract Introduction Whether β-lactam and macrolide combination therapy reduces mortality in severe community-acquired pneumonia (SCAP) patients hospitalized in the intensive care unit (ICU) is controversial. The aim of the present study was to evaluate the usefulness of β-lactam and macrolide combination therapy for SCAP patients hospitalized in the ICU. Methods A prospective, observational, cohort study of hospitalized pneumonia patients was performed. Hospitalized SCAP patients admitted to the ICU within 24 h between October 2010 and October 2017 were included for analysis. The primary outcome was 30-day mortality, and secondary outcomes were 14-day mortality and ICU mortality. Inverse probability of treatment weighting (IPTW) analysis as a propensity score analysis was used to reduce biases, including six covariates: age, sex, C-reactive protein, albumin, Pneumonia Severity Index score, and APACHE II score. Results A total of 78 patients were included, with 48 patients in the non-macrolide-containing β-lactam therapy group and 30 patients in the macrolide combination therapy group. β-lactam and macrolide combination therapy significantly decreased 30-day mortality (16.7% vs. 43.8%; P = 0.015) and 14-day mortality (6.7% vs. 31.3%; P = 0.020), but not ICU mortality (10% vs 27.1%, P = 0.08) compared with non-macrolide-containing β-lactam therapy. After adjusting by IPTW, macrolide combination therapy also decreased 30-day mortality (odds ratio, 0.29; 95%CI, 0.09–0.96; P = 0.04) and 14-day mortality (odds ratio, 0.19; 95%CI, 0.04–0.92; P = 0.04), but not ICU mortality (odds ratio, 0.34; 95%CI, 0.08–1.36; P = 0.13). Conclusions Combination therapy with β-lactam and macrolides significantly improved the prognosis of SCAP patients hospitalized in the ICU compared with a non-macrolide-containing β-lactam regimen.