Guideline-Based Antibiotics and Mortality in Healthcare-Associated Pneumonia

Background

Guidelines recommend administration of antibiotics with activity against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa for treatment of healthcare-associated pneumonia (HCAP). It is unclear if this therapy improves outcomes for patients with HCAP.

Objective

To determine if administration of guideline-similar therapy (GST) was associated with a reduction in 30-day mortality for HCAP.

Design

Multi-center retrospective study.

Participants

Thirteen hundred and eleven admissions for HCAP in six Veterans Affairs Medical Centers.

Interventions

Each admission was classified as receiving GST, anti-MRSA or anti-pseudomonal components of GST, or other non-HCAP therapy initiated within 48 hours of hospitalization. Association between 30-day mortality and GST was estimated with a logistic regression model that included GST, propensity to receive GST, probability of recovering an organism from culture resistant to antibiotics traditionally used to treat community-acquired pneumonia (CAP-resistance), and a GST by CAP-resistance probability interaction.

Main Measures

Odds ratios and 95% confidence intervals OR (95% CI)] of 30-day mortality for patients treated with GST and predicted probability of recovering a CAP-resistant organism, and ratio of odds ratios ROR (95% CI)] for treatment by CAP-resistance probability interaction.

Key Results

Receipt of GST was associated with increased odds of 30-day mortality OR?=?2.11 (1.11, 4.04), P?=?0.02)] as was the predicted probability of recovering a CAP-resistant organism OR?=?1.67 (1.26, 2.20), P?P?=?0.05].

Conclusions

For HCAP patients with high probability of CAP-resistant organisms, GST was associated with lower mortality. Consideration of the magnitude of patient-specific risk for CAP-resistant organisms should be considered when selecting HCAP therapy.