title: Center-level variation in infection rates after coronary artery bypass grafting.
abstract: BACKGROUND
  Health-care-acquired infections (HAIs) are a leading cause of morbidity and mortality after cardiac surgery. Prior work has identified several patient-related risk factors associated with HAIs. We hypothesized that rates of HAIs would differ across institutions, in part attributed to differences in case mix.
  
  
  RESULTS
  We analyzed 20 896 patients undergoing isolated coronary artery bypass grafting surgery at 33 medical centers in Michigan between January 1, 2009, and June 30, 2012. Overall HAIs included pneumonia, sepsis/septicemia, and surgical site infections, including deep sternal wound, thoracotomy, and harvest/cannulation site infections. We excluded patients presenting with endocarditis. Predicted rates of HAIs were estimated using multivariable logistic regression. Overall rate of HAI was 5.1% (1071 of 20 896; isolated pneumonia, 3.1% [n=644]; isolated sepsis/septicemia, 0.5% [n=99]; isolated deep sternal wound infection, 0.5% [n=96]; isolated harvest/cannulation site, 0.5% [n=97]; isolated thoracotomy, 0.02% [n=5]; multiple infections, 0.6% [n=130]). HAI subtypes differed across strata of center-level HAI rates. Although predicted risk of HAI differed in absolute terms by 2.8% across centers (3.9-6.7%; min:max), observed rates varied by 18.2% (0.9-19.1%).
  
  
  CONCLUSIONS
  There was a 18.2% difference in observed HAI rates across medical centers among patients undergoing isolated coronary artery bypass grafting surgery. This variability could not be explained by patient case mix. Future work should focus on the impact of other factors (eg, organizational and systems of clinical care) on risk of HAIs.
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Terry
authors.initials: T
authors.lastname: Shih
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Mallika
authors.initials: M
authors.lastname: Kommareddi
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Boeve
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Steven D
authors.initials: SD
authors.lastname: Harrington
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Holmes
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Gary
authors.initials: G
authors.lastname: Roth
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Patricia F
authors.initials: PF
authors.lastname: Theurer
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.).
authors.forename: Richard L
authors.initials: RL
authors.lastname: Prager
authors.affiliation: From the Departments of Surgery (T.S.), Biostatistics (M.Z.), and Cardiac Surgery (M.K., R.L.P., D.S.L.), University of Michigan, Ann Arbor; Department of Cardiac Surgery, Meijer Heart and Vascular Institute at Spectrum Health, Grand Rapids, MI (T.J.B.); Heart and Vascular Institute, Henry Ford Macomb Hospitals, Clinton Township, MI (S.D.H.); Department of Cardiac Surgery, McLaren Bay Region, Bay City, MI (R.J.H.); Department of Cardiothoracic and Vascular Surgery, McLaren Greater Lansing, MI (G.R.); and Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative, Ann Arbor (P.F.T., R.L.P., D.S.L.). likosky@umich.edu.
authors.forename: Donald S
authors.initials: DS
authors.lastname: Likosky
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology*
keywords: cardiopulmonary bypass; infection; surgery