Chest
Volume 131, Issue 2, February 2007, Pages 466-473
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Original Research: Lung Infection
Antibiotics for Bacteremic Pneumonia: Improved Outcomes With Macrolides but Not Fluoroquinolones

https://doi.org/10.1378/chest.06-1426Get rights and content

Abstract

Background:The questions of whether the use of antibiotics that are active against atypical organisms is beneficial in the treatment of community-acquired pneumonia and of the potential mechanisms of any beneficial effects remain unresolved. Proposed mechanisms include activity against atypical organisms vs the immunomodulatory effects of these antibiotics. The study of outcomes of a large cohort of patients with bacteremic pneumonia provides a unique opportunity to address these questions by excluding patients with primary atypical infection.

Methods:We reviewed data from the charts of 2,209 Medicare patients who were admitted to hospitals across the United States from either home or a nursing facility with bacteremic pneumonia between 1998 and 2001. Patients were stratified according to the type of antibiotic treatment. Multivariate modeling was performed to assess the relationship between the class of antibiotic used and several outcome variables.

Results:The initial use of any antibiotic active against atypical organisms was independently associated with a decreased risk of 30-day mortality (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.59 to 0.98; p = 0.03) and hospital admission within 30 days of discharge (OR, 0.67; 95% CI, 0.51 to 0.89; p = 0.02). Further analysis revealed that the benefits of atypical treatment were associated with the use of macrolides, but not the use of fluoroquinolones or tetracyclines, with macrolides conferring lower risks of in-hospital mortality (OR, 0.59; 95% CI, 0.40 to 0.88; p = 0.01), 30-day mortality (OR, 0.61; 95% CI, 0.43 to 0.87; p = 0.007), and hospital readmission within 30 days of discharge (OR, 0.59; 95% CI, 0.42 to 0.85; p = 0.004).

Conclusions:Initial antibiotic treatment including a macrolide agent is associated with improved outcomes in Medicare patients hospitalized with bacteremic pneumonia. These results have implications regarding the mechanism by which the use of a macrolide for treatment of pneumonia is associated with improved outcomes.

Section snippets

Materials and Methods

The data analyzed were part of the Medicare National Pneumonia Project, which is a component of the Medicare Quality Improvement Program. Therefore, neither informed consent nor institutional review board approval were required. Eligible patients were fee-for-service Medicare beneficiaries who had been discharged from the hospital between 1998 and 2001 with a principal diagnosis of pneumonia, and those with a principal diagnosis of septicemia or respiratory failure and a secondary diagnosis of

Results

A total of 2,349 episodes of bacteremic pneumonia from two sampling periods (1998 to 1999 and 2000 to 2001) were considered for inclusion in the study. Fifty-three episodes were excluded because of missing data elements, 26 because either an atypical pathogen or fungemia was identified, and 61 because antibiotic therapy was not started within 24 h of admission to the hospital. This left 2,209 cases, 1,140 from the 1998-to-1999 sampling period and 1,069 from the 2000-to-2001 sampling period.

Discussion

We have demonstrated that several factors are independently associated with improved outcomes in Medicare patients with bacteremic pneumonia. Severity of illness and concordant initial antibiotic therapy were predictive of outcomes. More noteworthy was the finding that treatment with a macrolide, but not with a fluoroquinolone, was independently associated with lower mortality rates and a lower 30-day hospital readmission rate. In contrast to some studies,17, 23but not all prior studies,7, 24

Acknowledgments

The authors wish to thank David Dorsky, MD, and Thomas Meehan, MD, MPH, for kindly reviewing the manuscript.

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  • Cited by (0)

    The analyses on which this publication is based were performed under contract No. 500–02-OK-03, funded by the Centers for Medicare & Medicaid Services, an agency of the US Department of Health and Human Services. The content of this publication does not necessarily reflect the views of the policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government. The authors assume full responsibility for the accuracy and completeness of the ideas presented.

    Dr. Metersky has served on an advisory board/speaker's bureau for the following pharmaceutical companies: Aventis; Bayer; Ortho; Oscient; and Pfizer. The other authors of the article have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/misc/reprints.shtml).

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