title: Increased mortality, postoperative morbidity, and cost after red blood cell transfusion in patients having cardiac surgery.
abstract: BACKGROUND
  Red blood cell transfusion can both benefit and harm. To inform decisions about transfusion, we aimed to quantify associations of transfusion with clinical outcomes and cost in patients having cardiac surgery.
  
  
  RESULTS
  Clinical, hematology, and blood transfusion databases were linked with the UK population register. Additional hematocrit information was obtained from intensive care unit charts. Composite infection (respiratory or wound infection or septicemia) and ischemic outcomes (myocardial infarction, stroke, renal impairment, or failure) were prespecified as coprimary end points. Secondary outcomes were resource use, cost, and survival. Associations were estimated by regression modeling with adjustment for potential confounding. All adult patients having cardiac surgery between April 1, 1996, and December 31, 2003, with key exposure and outcome data were included (98%). Adjusted odds ratios for composite infection (737 of 8516) and ischemic outcomes (832 of 8518) for transfused versus nontransfused patients were 3.38 (95% confidence interval [CI], 2.60 to 4.40) and 3.35 (95% CI, 2.68 to 4.35), respectively. Transfusion was associated with increased relative cost of admission (any transfusion, 1.42 times [95% CI, 1.37 to 1.46], varying from 1.11 for 1 U to 3.35 for >9 U). At any time after their operations, transfused patients were less likely to have been discharged from hospital (hazard ratio [HR], 0.63; 95% CI, 0.60 to 0.67) and were more likely to have died (0 to 30 days: HR, 6.69; 95% CI, 3.66 to 15.1; 31 days to 1 year: HR, 2.59; 95% CI, 1.68 to 4.17; >1 year: HR, 1.32; 95% CI, 1.08 to 1.64).
  
  
  CONCLUSIONS
  Red blood cell transfusion in patients having cardiac surgery is strongly associated with both infection and ischemic postoperative morbidity, hospital stay, increased early and late mortality, and hospital costs.
authors.affiliation: Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Bristol, BS2 8HW, UK.
authors.forename: Gavin J
authors.initials: GJ
authors.lastname: Murphy
authors.forename: Barnaby C
authors.initials: BC
authors.lastname: Reeves
authors.forename: Chris A
authors.initials: CA
authors.lastname: Rogers
authors.forename: Syed I A
authors.initials: SI
authors.lastname: Rizvi
authors.forename: Lucy
authors.initials: L
authors.lastname: Culliford
authors.forename: Gianni D
authors.initials: GD
authors.lastname: Angelini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000379:methods / Q000401:mortality; D015331:Cohort Studies; D017281:Cost of Illness; D016208:Databases, Factual; D017707:Erythrocyte Transfusion / Q000009:adverse effects* / Q000191:economics / Q000401:mortality; D005260:Female; D006801:Humans; D007239:Infections / Q000209:etiology; D007511:Ischemia / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D011184:Postoperative Period; D012189:Retrospective Studies; D015996:Survival Rate; D006113:United Kingdom