Skip to main content Accessibility help
Hostname: page-component-7ccbd9845f-mpxzb Total loading time: 0.383 Render date: 2023-01-28T17:59:35.945Z Has data issue: true Feature Flags: { "useRatesEcommerce": false } hasContentIssue true

Comparative Epidemiology of Bacteremia due to Methicillin-Resistant Staphylococcus aureus between Older and Younger Adults A Propensity Score Analysis

Published online by Cambridge University Press:  02 January 2015

Ravina Kullar*
College of Pharmacy, Oregon State University/Oregon Health and Science University, Portland, Oregon
Michael J. Rybak
Anti-Infective Research Laboratory, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan
Keith S. Kaye
Detroit Medical Center/Wayne State University, Detroit, Michigan
Oregon State University/Oregon Health and Science University, 3303 Southwest Bond Avenue, CH12C, Portland, OR 97239 (



We evaluated the clinical and molecular epidemiology of bloodstream infections (BSIs) due to methicillin-resistant Staphylococcus aureus (MRSA) in older versus younger patients treated with vancomycin, determining the independent effect of increased age on outcomes.


Observational retrospective cohort study.


Detroit Medical Center, level I trauma center.


Adult older (65 years and older) and younger (younger than 65 years) patients with documented BSIs due to MRSA treated with vancomycin (2005–2010).


Collected demographics, comorbidities, microbiology, treatment, outcomes. Multivariable model used to generate propensity score for each patient on the basis of the probability of being 65 years of age or older.


Three hundred twenty patients were eligible (69 patients 65 years and older; 251 patients younger than 65 years). Catheter-related infections and endocarditis were the most common sites of infection for older (20.3%) and younger (19.1%) adults, respectively. Median first total 24-hour vancomycin dose (1,000 vs 2,000 mg; P< .001) and initial trough (13.1 vs 15.0 mg/L; P = .043) was significantly lower in older versus younger patients. Vancomycin treatment failure rates were similar among older and younger patients (49.3% vs 53.4%; P = .545). In multivariable analysis of outcomes, after controlling for predictors of older age, there was no difference in clinical outcomes between older and younger adults.


After accounting for confounders associated with increased age, failure rate of patients with BSIs due to MRSA treated with vancomycin was similar between older and younger patients. Older adults were less likely to have optimal vancomycin dosing and initial trough levels than younger patients. Efforts should be made to optimize dosing of medications such as vancomycin in older adults.

Original Article
Copyright © The Society for Healthcare Epidemiology of America 2013

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.)


1.Fowler, VG JrMiro, JM, Hoen, B, et al.Staphylococcus aureus endocarditis: a consequence of medical progress. JAMA 2005;293:30123021.CrossRefGoogle ScholarPubMed
2.Hill, EE, Herijgers, P, Herregods, MC, et al.Evolving trends in infective endocarditis. Clin Microbiol Infect 2006;12:512.CrossRefGoogle ScholarPubMed
3.National Nosocomial Infections Surveillance (NNIS) System Report, data summary from January 1992 through June 2004, issued October 2004. Am J Infect Control 2004;32:470485.CrossRefGoogle Scholar
4.Engemann, JJ, Carmeli, Y, Cosgrove, SE, et al.Adverse clinical and economic outcomes attributable to methicillin resistance among patients with Staphylococcus aureus surgical site infection. Clin Infect Dis 2003;36:592598.CrossRefGoogle ScholarPubMed
5.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.CrossRefGoogle ScholarPubMed
6.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
7.McClelland, RS, Fowler, VG JrSanders, LL, et al.Staphylococcus aureus bacteremia among elderly vs younger adult patients: comparison of clinical features and mortality. Arch Intern Med 1999;159:12441247.CrossRefGoogle ScholarPubMed
8.Lee, CC, Chen, SY, Chang, IJ, et al.Comparison of clinical manifestations and outcome of community-acquired bloodstream infections among the oldest old, elderly, and adult patients. Medicine 2007;86:138144.Google Scholar
9.Bradley, SF. Staphylococcus aureus infections and antibiotic resistance in older adults. Clin Infect Dis 2002;34:211216.CrossRefGoogle ScholarPubMed
10.Bader, MS. Staphylococcus aureus bacteremia in older adults: predictors of 7-day mortality and infection with a methicillin-resistant strain. Infect Control Hosp Epidemiol 2006;27:12191225.CrossRefGoogle ScholarPubMed
11.Kaye, KS, Marchaim, D, Chen, TY, et al.Predictors of nosocomial bloodstream infections in older adults. J Am Geriatr Soc 2011;59:622627.CrossRefGoogle ScholarPubMed
12.Forsblom, E, Ruotsalainen, E, Molkanen, T, et al.Predisposing factors, disease progression and outcome in 430 prospectively followed patients of healthcare- and community-associated Staphylococcus aureus bacteraemia. J Hosp Infect 2011;78:102107.CrossRefGoogle ScholarPubMed
13.Nolan, CM, Beaty, HN. Staphylococcus aureus bacteremia: current clinical patterns. Am J Med 1976;60:495500.CrossRefGoogle ScholarPubMed
14.Levine, DP. Vancomycin: understanding its past and preserving its future. South Med J 2008;101:284291.CrossRefGoogle ScholarPubMed
15.Kullar, R, Davis, SL, Levine, DP, et al.Impact of vancomycin exposure on outcomes in patients with methicillin-resistant Staphylococcus aureus bacteremia: support for consensus guide-lines suggested targets. Clin Infect Dis 2011;52:975981.CrossRefGoogle Scholar
16.Sakoulas, G, Moise-Broder, PA, Schentag, J, et al.Relationship of MIC and bactericidal activity to efficacy of vancomycin for treatment of methicillin-resistant Staphylococcus aureus bacteremia. J Clin Microbiol 2004;42:23982402.CrossRefGoogle Scholar
17.Rybak, MJ. The pharmacokinetic and pharmacodynamic properties of vancomycin. Clin Infect Dis 2006;42(suppl 1):S35S39.CrossRefGoogle ScholarPubMed
18.Jones, RN. Microbiological features of vancomycin in the 21st century: minimum inhibitory concentration creep, bactericidal/static activity, and applied breakpoints to predict clinical outcomes or detect resistant strains. Clin Infect Dis 2006;42(suppl 1):S13S24.CrossRefGoogle Scholar
19.Kollef, MH. Limitations of vancomycin in the management of resistant staphylococcal infections. Clin Infect Dis 2007;45(suppl 3):S191S195.CrossRefGoogle ScholarPubMed
20.Soriano, A, Marco, F, Martinez, JA, et al.Influence of vancomycin minimum inhibitory concentration on the treatment of methicillin-resistant Staphylococcus aureus bacteremia. Clin Infect Dis 2008;46:193200.CrossRefGoogle Scholar
21.Khatib, R, Johnson, LB, Fakih, MG, et al.Persistence in Staphylococcus aureus bacteremia: incidence, characteristics of patients and outcome. Scand J Infect Dis 2006;38:714.CrossRefGoogle ScholarPubMed
22.Lodise, TP, Lomaestro, B, Graves, J, et al.Larger vancomycin doses (at least four grams per day) are associated with an increased incidence of nephrotoxicity. Antimicrob Agents Chemother 2008;52:13301336.CrossRefGoogle ScholarPubMed
23.Fowler, VG JrSakoulas, G, McIntyre, LM, et al.Persistent bacteremia due to methicillin-resistant Staphylococcus aureus infection is associated with agr dysfunction and low-level in vitro resistance to thrombin-induced platelet microbicidal protein. J Infect Dis 2004;190:11401149.CrossRefGoogle Scholar
24.Hawkins, C, Huang, J, Jin, N, et al.Persistent Staphylococcus aureus bacteremia: an analysis of risk factors and outcomes. Arch Intern Med 2007;167:18611867.CrossRefGoogle ScholarPubMed
25.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
26.Garner, JS, Jarvis, WR, Emori, TG, et al.CDC definitions for nosocomial infections, 1988. Am J Infect Control 1988;16:128140.CrossRefGoogle ScholarPubMed
27.Clinical and Laboratory Standards Institute (CLSI). Methods for Dilution Antimicrobial Susceptibility Test for Bacteria That Grow Aerobically; Approved Standard. 8th ed. Wayne, PA: CLSI, 2009. CLSI document M7-A8.Google Scholar
28.Rybak, MJ, Leonard, SN, Rossi, KL, et al.Characterization of vancomycin-heteroresistant Staphylococcus aureus from the metropolitan area of Detroit, Michigan, over a 22-year period (1986 to 2007). J Clin Microbiol 2008;46:29502954.CrossRefGoogle Scholar
29.Wootton, M, MacGowan, AP, Walsh, TR, et al.A multicenter study evaluating the current strategies for isolating Staphylococcus aureus strains with reduced susceptibility to glycopeptides. J Clin Microbiol 2007;45:329332.CrossRefGoogle ScholarPubMed
30.Zhang, K, McClure, JA, Elsayed, S, et al.Novel multiplex PCR assay for characterization and concomitant subtyping of staphylococcal cassette chromosome mec types I to V in methicillin-resistant Staphylococcus aureus. J Clin Microbiol 2005;43:50265033.CrossRefGoogle Scholar
31.Lina, G, Piemont, Y, Godail-Gamot, F, et al.Involvement of Panton-Valentine leukocidin-producing Staphylococcus aureus in primary skin infections and pneumonia. Clin Infect Dis 1999;29:11281132.CrossRefGoogle ScholarPubMed
32.Freeborne, N, Lynn, J, Desbiens, NA. Insights about dying from the SUPPORT project: the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments. J Am Geriatr Soc 2000;48:S199S205.CrossRefGoogle Scholar
33.Levinsky, NG, Yu, W, Ash, A, et al.Influence of age on Medicare expenditures and medical care in the last year of life. JAMA 2001;286:13491355.CrossRefGoogle ScholarPubMed
34.Hiramatsu, K, Cui, L, Kuroda, M, et al.The emergence and evolution of methicillin-resistant Staphylococcus aureus. Trends Microbiol 2001;9:486493.CrossRefGoogle ScholarPubMed
35.Herold, BC, Immergluck, LC, Maranan, MC, et al.Community-acquired methicillin-resistant Staphylococcus aureus in children with no identified predisposing risk. JAMA 1998;279:593598.CrossRefGoogle ScholarPubMed
36.Naimi, TS, LeDell, KH, Como-Sabetti, K, et al.Comparison of community- and health care-associated methicillin-resistant Staphylococcus aureus infection. JAMA 2003;290:29762984.CrossRefGoogle ScholarPubMed
Cited by

Save article to Kindle

To save this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the or variations. ‘’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Comparative Epidemiology of Bacteremia due to Methicillin-Resistant Staphylococcus aureus between Older and Younger Adults A Propensity Score Analysis
Available formats

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Comparative Epidemiology of Bacteremia due to Methicillin-Resistant Staphylococcus aureus between Older and Younger Adults A Propensity Score Analysis
Available formats

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Comparative Epidemiology of Bacteremia due to Methicillin-Resistant Staphylococcus aureus between Older and Younger Adults A Propensity Score Analysis
Available formats

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *