The importance of practical evaluations in the context of external quality assessment in serology for brazilian hemotherapy

Introduction: External Quality Assessment (EQA) in Serology, managed by the Ministry of Health, is a quality tool that evaluates the proficiency of hemotherapy services (HS) in Brazil through practical and theoretical assessments.Practical Assessments (PA) are essential as they verify the accuracy of HS results by comparing them with an external sample.Given this, monitoring results over the years is crucial to track the performance of the blood network, ensuring the safety of laboratory screening for blood donors and transfusions. Objectives:To analyze the performance of HS in the PA of EQA-Sorology from 2019 to 2024. Methodology:The results of the PA from 2019 to 2024 were analyzed, totaling 11 assessments (EQA-51 to 61).In this analysis, the adhesion of HS and the concordant and discordant results, such as false positive (FP), false negative (FN), and indeterminate (IND), were considered by serological marker and EQA. Results:The average adherence of the HS was 98%, with three EQAs (54, 56, and 59) achieving 100% adherence, while EQA 57 recorded 95%.All services showed a higher number of concordant results, with rates ranging from 66% (EQA 61) to 98% (EQA 56).A total of 127 discordant results were recorded, including 61 FP, 55 FN, and 11 IND.EQAs 51 and 61 exhibited the highest discordance rates (27 errors each).EQA 61 had the highest number of FN results, concentrated in 34% of the HS, while EQA 51 had the highest number of FP results, concentrated in 18% of the HS.Regarding serological markers, the highest frequency of discordance was observed in syphilis (40 in 10 PAs), followed by HBsAg (21 in 8 PAs) and anti-HCV (18 in 5 PAs).Despite this, the overall accuracy rate per sample was higher than 97% in all PAs. Conclusion:Finally, in only 3 PAs, the HS obtained more than 2% discordant results, with non-treponemal tests for syphilis being the most affected, raising concerns about the quality of the tests.Discordant results may compromise the safety of serological screening, as FN results may lead to the release of contaminated blood bags.Despite this, the excellent performance of the HS can be confirmed, with high adherence to PAs and an average concordance rate of 88%, demonstrating the quality of the laboratory screening of blood donors and transfusions.