Confidential unit exclusion (CUE): Double edged sword for blood transfusion center: A ten-year study on volunteer blood donors in Kohgiluyeh and Boyer Ahmad province, Iran.

Background: Confidential unit exclusion (CUE) is a mechanism developed in the1980s to increase blood safety by allowing donors to indicate confidentially if they think their blood is not safe for transfusion. While it has been used widely around the world, the efficacy of this strategy is still unclear. The present study evaluated the efficacy of the CUE system at the Blood Transfusion Center of Kohgiluyeh and Boyer Ahmad Province (KBTC), Iran by comparing the prevalence of transfusion-transmitted infectious (TTIs) in CUE and non-CUE groups.

Methods: This descriptive study used data from all volunteer blood donors over a ten-year period. Donors were classified in two groups: CUE and non-CUE. Screening tests were performed for hepatitis B surface antigens (HBs-Ag), hepatitis C virus antibody (HCV-Ab), and Human immunodeficiency virus antibody (HIV-Ab) and any repeatedly reactive results were confirmed by standard methods. Significant differences were determined by Chi test. The sensitivity, specificity and PPV of the CUE system were also calculated.

Results: In the present study, the non-CUE and CUE groups consisted of 98.94% and 1.06% of volunteer blood donors, respectively. First-time donors selected the CUE option more often than repeated and regular donors. The prevalence of TTIs was significantly higher in the CUE group and CUE sensitivity, specificity, and PPV were 5.5%, 98.95%, and 0.96%, respectively.

Conclusion: We recommend the CUE system be pursued for further enhancement of blood safety. However, further studies are needed to establish the overall usefulness of this procedure throughout the whole country.