Clinical impact of methicillin-resistant Staphylococcus aureus bacteremia based on propensity scores
- 201 Downloads
Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen not only in nosocomial infections, but also in community-associated infections. The aim of this study was to evaluate the impacts of methicillin resistance on mortality, length of hospitalization, and hospital costs via propensity score matching in S. aureus bacteremia.
Patients and methods
A propensity-matched case–control study was conducted in a tertiary hospital in Korea from 2003 to 2008.
A total of 266 patients who had clinically significant S. aureus bloodstream infections were investigated. Fifty-three propensity-matched case–control pairs with MRSA bacteremia were likely to have stayed in the hospital longer before developing bacteremia (mean 25.0 vs. 6.1 days; P = 0.01). However, after developing bacteremia, the differences in the mean duration of hospital stay was not significant (mean 35.0 vs. 28.7 days; P = 0.33). Similar numbers of MRSA and methicillin-susceptible S. aureus (MSSA) patients died (P = 0.48). The mean total hospital costs after S. aureus bacteremia increased more for MRSA patients compared to MSSA patients. However, this difference was not statistically significant ($9,369.6 vs. $8,355.8; P = 0.62).
This study indicates that MRSA bacteremia is not associated with higher risks of mortality or hospital costs. It is, however, associated with a substantial increase in the length of hospital stay as compared to MSSA bacteremia. This information may help clinicians and policymakers derive methods to control the impacts of MRSA infection.
KeywordsMethicillin-resistant Staphylococcus aureus Propensity scores Mortality Hospital costs Korea
Conflict of interest
All authors report no conflicts of interest relevant to this article.
- 1.Fridkin SK, Hageman JC, Morrison M, Sanza LT, Como-Sabetti K, Jernigan JA, Harriman K, Harrison LH, Lynfield R, Farley MM; Active Bacterial Core Surveillance Program of the Emerging Infections Program Network. Methicillin-resistant Staphylococcus aureus disease in three communities. N Engl J Med. 2005;352:1436–44.PubMedCrossRefGoogle Scholar
- 3.Klevens RM, Morrison MA, Nadle J, Petit S, Gershman K, Ray S, Harrison LH, Lynfield R, Dumyati G, Townes JM, Craig AS, Zell ER, Fosheim GE, McDougal LK, Carey RB, Fridkin SK; Active Bacterial Core surveillance (ABCs) MRSA Investigators. Invasive methicillin-resistant Staphylococcus aureus infections in the United States. JAMA. 2007;298:1763–71.PubMedCrossRefGoogle Scholar
- 5.Kim KM, Yoo JH, Choi JH, Park ES, Kim KS. The nationwide surveillance results of nosocomial infections along with antimicrobial resistance in intensive care units of sixteen university hospitals in Korea, 2004. Korean J Nosocomial Infect Control. 2006;11:79–86.Google Scholar
- 11.Mermel LA, Allon M, Bouza E, Craven DE, Flynn P, O’Grady NP, Raad II, Rijnders BJ, Sherertz RJ, Warren DK. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 Update by the Infectious Diseases Society of America. Clin Infect Dis. 2009;49:1–45.PubMedCrossRefGoogle Scholar
- 12.National Committee for Clinical Laboratory Standards (NCCLS). Performance standards for antimicrobial susceptibility testing. Wayne: NCCLS; 2002.Google Scholar
- 13.McCabe WR, Jackson GG. Gram-negative bacteremia. Arch Intern Med. 1962;110:847–55.Google Scholar
- 14.Park YJ, Jeong JS, Park ES, Shin ES, Kim SH, Lee YS. Survey on the infection control of multidrug-resistant microorganisms in general hospitals in Korea. Korean J Nosocomial Infect Control. 2007;12:112–21.Google Scholar
- 15.Bone RC, Balk RA, Cerra FB, Dellinger RP, Fein AM, Knaus WA, Schein RM, Sibbald WJ. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. The ACCP/SCCM Consensus Conference Committee. American College of Chest Physicians/Society of Critical Care Medicine. Chest. 1992;101:1644–55.PubMedCrossRefGoogle Scholar
- 16.Parsons LS. Reducing bias in a propensity score matched-pair sample using Greedy matching techniques. In: Proceedings of the 26th Annual SAS Users Group International Conference, Long Beach, California, 22–25 April 2001. Cary: SAS Institute; 2001Google Scholar
- 19.Reed SD, Friedman JY, Engemann JJ, Griffiths RI, Anstrom KJ, Kaye KS, Stryjewski ME, Szczech LA, Reller LB, Corey GR, Schulman KA, Fowler VG Jr. Costs and outcomes among hemodialysis-dependent patients with methicillin-resistant or methicillin-susceptible Staphylococcus aureus bacteremia. Infect Control Hosp Epidemiol. 2005;26:175–83.PubMedCrossRefGoogle Scholar
- 28.Rojas EG, Liu LZ. Annual cost for the treatment of patients hospitalized with methicillin-resistant Staphylococcus aureus in the United States. Value Health. 2005;8:308.Google Scholar
- 29.Hansen S, Schwab F, Asensio A, Carsauw H, Heczko P, Klavs I, Lyytikäinen O, Palomar M, Riesenfeld-Orn I, Savey A, Szilagyi E, Valinteliene R, Fabry J, Gastmeier P. Methicillin-resistant Staphylococcus aureus (MRSA) in Europe: which infection control measures are taken? Infection. 2010;38:159–64.PubMedCrossRefGoogle Scholar