Hostname: page-component-7bb8b95d7b-fmk2r Total loading time: 0 Render date: 2024-10-06T11:19:55.275Z Has data issue: false hasContentIssue false

Comparison of Mortality Risk Associated With Bacteremia Due to Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus

Published online by Cambridge University Press:  02 January 2015

Simone Shurland*
Affiliation:
Veterans Affairs Maryland Health Care System, University of Maryland, School of Medicine, Baltimore Department of Epidemiology and Preventative Medicine, Division of Health Outcomes Research, University of Maryland, School of Medicine, Baltimore
Min Zhan
Affiliation:
Department of Epidemiology and Preventative Medicine, Division of Health Outcomes Research, University of Maryland, School of Medicine, Baltimore
Douglas D. Bradham
Affiliation:
Veterans Affairs Maryland Health Care System, University of Maryland, School of Medicine, Baltimore Department of Epidemiology and Preventative Medicine, Division of Health Outcomes Research, University of Maryland, School of Medicine, Baltimore
Mary-Claire Roghmann
Affiliation:
Veterans Affairs Maryland Health Care System, University of Maryland, School of Medicine, Baltimore Department of Epidemiology and Preventative Medicine, Division of Health Outcomes Research, University of Maryland, School of Medicine, Baltimore
*
Department of Epidemiology and Preventive Medicine, Division of Health Outcomes Research, University of Maryland, School of Medicine, 100 North Greene Street, Lower Level, Baltimore, MD 21201 (sshurlan@epi.umaryland.edu)

Abstract

Objective.

To quantify the clinical impact of methicillin-resistance in Staphylococcus aureus causing infection complicated by bacteremia in adult patients, while controlling for the severity of patients' underlying illnesses.

Design.

Retrospective cohort study from October 1, 1995, through December 31, 2003.

Patients and Setting.

A total of 438 patients with S. aureus infection complicated by bacteremia from a single Veterans Affairs healthcare system.

Results.

We found that 193 (44%) of the 438 patients had methicillin-resistant S. aureus (MRSA) infection and 114 (26%) died of causes attributable to S. aureus infection within 90 days after the infection was identified. Patients with MRSA infection had a higher mortality risk, compared with patients with methicillin-susceptible S. aureus (MSSA) infections (relative risk, 1.7 [95% confidence interval, 1.3-2.4]; P < .01), except for patients with pneumonia (relative risk, 0.7 [95% confidence interval, 0.4-1.3]). Patients with MRSA infections were significantly older (P < .01), had more underlying diseases (P = .02), and were more likely to have severe sepsis in response to their infection (P < .01) compared with patients with MSSA bacteremia. Patients who died within 90 days after S. aureus infection was identified were significantly older (P < .01) and more likely to have severe sepsis (P < .01) and pneumonia (P = .01), compared with patients who survived. After adjusting for age as a confounder, comorbidities, and pneumonia as an effect modifier, S. aureus infection-related mortality remained significantly higher in patients with MRSA infection than in those with MSSA infection, among those without pneumonia (hazard ratio, 1.8 [95% confidence interval, 1.2-3.0]); P < .01.

Conclusions.

The results of this study suggest that patients with MRSA infections other than pneumonia have a higher mortality risk than patients with MSSA infections other than pneumonia, independent of the severity of patients' underlying illnesses.

Type
Original Articles
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.National Nosocomial Infections Surveillance (NNIS) system report, data summary from January 1992-April 2000, issued June 2000. Am J Infect Control 2000;28:429448.CrossRefGoogle Scholar
2.Lewis, E, Saravolatz, LD. Comparison of methicillin-resistant and meth-icillin-sensitive Staphylococcus aureus bacteremia. Am J Infect Control 1985;13:109114.CrossRefGoogle ScholarPubMed
3.National Nosocomial Infections Surveillance (NNIS) System report, data summary from January 1990-May 1999, issued June 1999. Am J Infect Control 1999;27:520532.CrossRefGoogle Scholar
4.Selvey, LA, Whitby, M, Johnson, B. Nosocomial methicillin-resistant Staphylococcus aureus bacteremia: is it any worse than nosocomial meth-icillin-sensitive Staphylococcus aureus bacteremia? Infect Control Hosp Epidemiol 2000;21:645648.CrossRefGoogle ScholarPubMed
5.Lodise, TP, McKinnon, PS. Clinical and economic impact of methicillin resistance in patients with Staphylococcus aureus bacteremia. Diagn Microbiol Infect Dis 2005;52:113122.CrossRefGoogle ScholarPubMed
6.Cosgrove, SE, Sakoulas, G, Perencevich, EN, et al. Comparison of mortality associated with methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteremia: a meta-analysis. Clin Infect Dis 2003;36:5359.Google Scholar
7.Hurley, JC. Comparison of mortality associated with methicillin-susceptible and methicillin-resistant Staphylococcus aureus bacteremia: an ecological analysis. Clin Infect Dis 2003;37:866868; author reply 868-869.Google Scholar
8.Charlson, ME, Pompei, P, Ales, KL, et al. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987;40:373383.Google Scholar
9.Lesens, O, Methlin, C, Hansmann, Y, et al. Role of comorbidity in mortality related to Staphylococcus aureus bacteremia: a prospective study using the Charlson weighted index of comorbidity. Infect Control Hosp Epidemiol 2003;24:890896.CrossRefGoogle ScholarPubMed
10.Bone, RC, Balk, RA, Cerra, FB, et al; The ACCP/SCCM Consensus Conference Committee, American College of Chest Physicians/Society of Critical Care Medicine. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. Chest 1992;101:16441655.CrossRefGoogle ScholarPubMed
11.Garner, JS, Jarvis, WR, Emori, TG, et al. CDC definitions for nosocomial infections, 1988. Am J Infect Control 1988;16:128140.CrossRefGoogle ScholarPubMed
12.Durack, DT, Lukes, AS, Bright, DK. New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings: Duke Endocarditis Service. Am J Med 1994;96:200209.Google Scholar
13.Breslow, NE, Day, NE. Statistical Methods in Cancer Research, Volume I: The Analysis of Case-Control Studies. New York, NY: Oxford University Press Inc.; 1993. IARC Scientific Publication 32.Google Scholar
14.Concato, I, Feinstein, AR, Holford, TR. The risk of determining risk with multivariable models. Ann Intern Med 1993;118:201210.CrossRefGoogle ScholarPubMed
15.Fowler, VG Jr, Olsen, MK, Corey, GR, et al. Clinical identifiers of complicated Staphylococcus aureus bacteremia. Arch Intern Med 2003;163:20662072.CrossRefGoogle ScholarPubMed
16.Kim, SH, Park, WB, Lee, KD, et al. Outcome of Staphylococcus aureus bacteremia in patients with eradicable foci versus noneradicable foci. Clin Infect Dis 2003;37:794799.CrossRefGoogle ScholarPubMed
17.Romero-Vivas, J, Rubio, M, Fernandez, C, et al. Mortality associated with nosocomial bacteremia due to methicillin-resistant Staphylococcus aureus. Clin Infect Dis 1995;21:14171423.CrossRefGoogle ScholarPubMed
18.McClelland, RS, Fowler, VG Jr, Sanders, LL, et al. Staphylococcus aureus bacteremia among elderly vs younger adult patients: comparison of clinical features and mortality. Arch Intern Med 1999;159:12441247.Google Scholar
19.Blot, SI, Vandewoude, KH, Hoste, EA, et al. Outcome and attributable mortality in critically 111 patients with bacteremia involving methicillin-susceptible and methicillin-resistant Staphylococcus aureus. Arch Intern Med 2002;162:22292235.Google Scholar
20.Conterno, LO, Wey, SB, Castelo, A. Risk factors for mortality in Staphylococcus aureus bacteremia. Infect Control Hosp Epidemiol 1998;19:3237.CrossRefGoogle ScholarPubMed
21.Gastmeier, P, Sohr, D, Geffers, C, et al. Mortality risk factors with nosocomial Staphylococcus aureus infections in intensive care units: results from the German Nosocomial Infection Surveillance System (KISS). Infection 2005;33:5055.CrossRefGoogle ScholarPubMed
22.Zahar, JR, Clec'h, C, Tafflet, M, Garrouste-Orgeas, M. Is methicillin resistance associated with a worse prognosis in Staphylococcus aureus ventilator-associated pneumonia? Clin Infect Dis 2005;41:12241231.CrossRefGoogle ScholarPubMed
23.Gonzalez, C, Rubio, M, Romero-Vivas, J, et al. Bacteremic pneumonia due to Staphylococcus aureus: a comparison of disease caused by methicillin-resistant and methicillin-susceptible organisms. Clin Infect Dis 1999;29:11711177.Google Scholar
24.Combes, A, Luyt, CE, Fagon, JY, et al. Impact of methicillin resistance on outcome of Staphylococcus aureus ventilator-associated pneumonia. Am J Respir Crit Care Med 2004;170:786792.CrossRefGoogle ScholarPubMed
25.Lodise, TP, McKinnon, PS, Swiderski, L, et al. Outcomes analysis of delayed antibiotic treatment for hospital-acquired Staphylococcus aureus bacteremia. Clin Infect Dis 2003;36:14181423.Google Scholar
26.Levine, DP, Fromm, BS, Reddy, BR. Slow response to vancomycin or vancomycin plus rifampin in methicillin-resistant Staphylococcus aureus endocarditis. Ann Intern Med 1991;115:674680.CrossRefGoogle ScholarPubMed
27.Korzeniowski, O, Sande, MA. Combination antimicrobial therapy for Staphylococcus aureus endocarditis in patients addicted to parenteral drugs and in nonaddicts: a prospective study. Ann Intern Med 1982;97:496503.Google Scholar
28.Chambers, HF, Korzeniowski, OM, Sande, MA. Staphylococcus aureus endocarditis: clinical manifestations in addicts and nonaddicts. Medicine (Baltimore) 1983;62:170177.Google Scholar
29.Cosgrove, SE, Qi, Y, Kaye, KS, et al. The impact of methicillin resistance in Staphylococcus aureus bacteremia on patient outcomes: mortality, length of stay, and hospital charges. Infect Control Hosp Epidemiol 2005;26:166174.Google Scholar
30.Schneeweiss, S, Maclure, M. Use of comorbidity scores for control of confounding in studies using administrative databases. Int J Epidemiol 2000;29:891898.Google Scholar
31.Laupland, KB, Church, DL, Mucenski, M, et al. Population-based study of the epidemiology of and the risk factors for invasive Staphylococcus aureus infections. J Infect Dis 2003;187:14521459.Google Scholar