title: Do reactions after whole blood donation predict syncope on return donation?
abstract: BACKGROUND
  Adverse reactions after whole blood donation reduce the likelihood of a subsequent donation. Still, many donors return to give blood even after experiencing a reaction. Consequently, we evaluated the risk of recurrent syncope among returning donors.
  
  
  METHODS
  Allogeneic whole blood donors in 2009 who had vasovagal-type reactions including syncope were evaluated for return donation within 12 months and subsequent reactions, based on donation status (novice [first-time] or active [repeat]) or age at index donation.
  
  
  RESULTS
  Syncope after a first whole blood donation significantly reduced the frequency of return donation (18%), compared to either presyncopal symptoms (27%; p < 0.0001) or no reaction (35%; p < 0.0001). Among novice donors who returned to donate, syncope was more likely among donors who had any reaction (0.8%) or syncope (3.5%) at their first donation, compared to donors who had no reaction (0.3%; p < 0.0001). Syncope at a first donation identified only 2% (19 of 1062) of syncopal reactions among returning donors. For active, repeat donors who experienced syncope in 2009, a history of prior reactions had no effect on the likelihood of return donation or recurrent syncope.
  
  
  CONCLUSIONS
  Donation experience strongly influences the likelihood of return donation and the risk of subsequent reactions, but a prior reaction after whole blood donation does not reliably predict recurrent syncope among returning donors.
authors.affiliation: American Red Cross, Rockville, Maryland 20855, USA. Anne.Eder@redcross.org
authors.forename: Anne F
authors.initials: AF
authors.lastname: Eder
authors.forename: Edward P
authors.initials: EP
authors.lastname: Notari
authors.forename: Roger Y
authors.initials: RY
authors.lastname: Dodd
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D001771:Blood Banks / Q000706:statistics & numerical data*; D001782:Blood Donors / Q000523:psychology / Q000706:statistics & numerical data* / Q000600:supply & distribution; D002755:Choice Behavior; D003256:Community Participation / Q000523:psychology / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013575:Syncope / Q000175:diagnosis* / Q000453:epidemiology*; D055815:Young Adult