Effectiveness of confidential unit exclusion in screening blood donors of the regional blood bank in Londrina, Paraná State.

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.

Aim: 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.