title: Effectiveness of confidential unit exclusion in screening blood donors of the regional blood bank in Londrina, Paraná State.
abstract: BACKGROUND
  For transfusion purposes, blood donors must be accepted both in clinical and serological evaluations and must not have excluded their own donation using the confidential unit exclusion.
  
  
  OBJECTIVE
  The objective of this study was to verify whether blood donors who choose self exclusion are more likely to be positive in serological tests than donors who do not.
  
  
  METHODS
  A cross-sectional analysis was carried out of 51,861 consecutive whole blood donations from January 2004 to December 2008 at a public blood bank in Londrina, Southern Brazil.
  
  
  RESULTS
  Self exclusion was chosen in 1672 (3.2%) donations, most frequently by first-time blood donors (p-value < 0.0001), by blood donors from external collections (p-value < 0.0001), by men (p value < 0.0001) and by under 30-year-old donors (p-value < 0.0001). The frequency of positive serology was 5.3% in the group that chose self exclusion and 3.5% in the group that did not choose self exclusion (p-value < 0.0001).
  
  
  CONCLUSIONS
  These results show that confidential unit exclusion used in this blood bank is effective and is inexpensive. However, the diagnostic power to detect blood-borne infections was low and resulted in the discard of a high number of blood bags without any direct or indirect serologic markers of pathogens. The use of confidential unit exclusion could be replaced with molecular tests to screen blood donors.
authors.affiliation: Laboratory of Clinical Analysis, Universidade Estadual de Londrina, PR, Brazil.
authors.forename: Ingridt Hildegard
authors.initials: IH
authors.lastname: Vogler
authors.forename: Mariza
authors.initials: M
authors.lastname: Saito
authors.forename: Adriana Aparecida
authors.initials: AA
authors.lastname: Spinosa
authors.forename: Marilza Celina
authors.initials: MC
authors.lastname: da Silva
authors.forename: Egberto
authors.initials: E
authors.lastname: Munhoz
authors.forename: Edna Maria Vissoci
authors.initials: EM
authors.lastname: Reiche