title: Association of age and packed red blood cell transfusion to 1-year survival--an observational study of ICU patients.
abstract: OBJECTIVE
  To compare the 1-year survival for different age strata of intensive care unit (ICU) patients after receipt of packed red blood cell (PRBC) transfusions.
  
  
  BACKGROUND
  Despite guidelines documenting risks of PRBC transfusion and data showing that increasing age is associated with ICU mortality, little data exist on whether age alters the transfusion-related risk of decreased survival.
  
  
  METHODS
  We retrospectively examined data on 2393 consecutive male ICU patients admitted to a tertiary-care hospital from 2003 to 2009 in age strata: 21-50, 51-60, 61-70, 71-80 and >80 years. We calculated Cox regression models to determine the modifying effect of age on the impact of PRBC transfusion on 1-year survival by using interaction terms between receipt of transfusion and age strata, controlling for type of admission and Charlson co-morbidity indices. We also examined the distribution of admission haematocrit and whether transfusion rates differed by age strata.
  
  
  RESULTS
  All age strata experienced statistically similar risks of decreased 1-year survival after receipt of PRBC transfusions. However, patients age >80 were more likely than younger cohorts to have haematocrits of 25-30% at admission and were transfused at approximately twice the rate of each of the younger age strata.
  
  
  CONCLUSIONS
  We found no significant interaction between receipt of red cell transfusion and age, as variables, and survival at 1 year as an outcome.
authors.affiliation: Anesthesiology and Perioperative Care Service; Center for Health Care Evaluation, VA Palo Alto Health Care System, Palo Alto, CA 94304, USA. mudumbai@stanford.edu
authors.forename: S C
authors.initials: SC
authors.lastname: Mudumbai
authors.forename: R
authors.initials: R
authors.lastname: Cronkite
authors.forename: K Unger
authors.initials: KU
authors.lastname: Hu
authors.forename: P A
authors.initials: PA
authors.lastname: Heidenreich
authors.forename: C
authors.initials: C
authors.lastname: Gonzalez
authors.forename: E
authors.initials: E
authors.lastname: Bertaccini
authors.forename: R S
authors.initials: RS
authors.lastname: Stafford
authors.forename: B A
authors.initials: BA
authors.lastname: Cason
authors.forename: E R
authors.initials: ER
authors.lastname: Mariano
authors.forename: T
authors.initials: T
authors.lastname: Wagner
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D017707:Erythrocyte Transfusion / Q000401:mortality*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015996:Survival Rate; D062606:Tertiary Care Centers
keywords: elderly; intensive care unit; survival; transfusion