title: Cost-effectiveness of prospective red blood cell antigen matching to prevent alloimmunization among sickle cell patients.
abstract: BACKGROUND
  Sickle cell disease is associated with extensive health care utilization; estimated lifetime costs exceed $460,000 per patient. Approximately 30% of chronically transfused sickle cell patients become alloimmunized to red blood cell antigens, but these patients cannot be identified a priori. Prospective antigen matching can prevent alloimmunization, but is costly and may not benefit most patients.
  
  
  METHODS
  A Markov-based model was constructed to compare the health and financial implications of four alternative antigen-matching strategies for chronically transfused sickle cell patients. The strategies varied by the group of patients receiving matched blood (all patients prophylactically or only patients with a history of alloimmunization [history-based]), and by the extent of antigen matching (limited to C, E, and K, or extended to 11 antigens). Direct medical costs and alloimmunization events were assessed over 10- and 20-year periods, for a hypothetical cohort of initially transfusion-naive patients and for a dynamic population.
  
  
  RESULTS
  Within a hypothetical cohort of initially transfusion-naive patients, implementing prophylactic limited matching for all chronically transfused patients instead of history-based limited matching is expected to cost an additional $765.56 million over 10 years, but result in 2072 fewer alloimmunization events. Within the same cohort, implementing prospective extensive matching is expected to cost $1.86 billion more than history-based extensive matching, but result in 2424 fewer alloimmunization events. Averting a single alloimmunization event using prospective matching would cost $369,482 to $769,284. Among a dynamic population over 10 years, prospective limited matching is expected to cost $358.34 million more than history-based limited matching.
  
  
  CONCLUSIONS
  While prospective matching for all transfused patients would reduce alloimmunization, this strategy requires considerable expenditure.
authors.affiliation: Department of Pathology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland; Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland; Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Seema
authors.initials: S
authors.lastname: Kacker
authors.forename: Paul M
authors.initials: PM
authors.lastname: Ness
authors.forename: William J
authors.initials: WJ
authors.lastname: Savage
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Frick
authors.forename: R Sue
authors.initials: RS
authors.lastname: Shirey
authors.forename: Karen E
authors.initials: KE
authors.lastname: King
authors.forename: Aaron A R
authors.initials: AA
authors.lastname: Tobian
mesh_terms: D000743:Anemia, Hemolytic / Q000191:economics / Q000209:etiology / Q000276:immunology / Q000517:prevention & control; D000755:Anemia, Sickle Cell / Q000191:economics / Q000276:immunology* / Q000628:therapy*; D001787:Blood Group Incompatibility / Q000191:economics / Q000517:prevention & control*; D001788:Blood Grouping and Crossmatching / Q000191:economics* / Q000379:methods; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D017707:Erythrocyte Transfusion / Q000009:adverse effects* / Q000191:economics / Q000379:methods; D004912:Erythrocytes / Q000276:immunology*; D017048:Health Care Costs; D006801:Humans; D008390:Markov Chains