This report summarizes the 2021 survey results of the external quality assessment (EQA) scheme for the transfusion medicine program (TMP) in Korea. Proficiency testing materials were prepared at the Asan Medical Center for biannual distribution to participating laboratories. The accuracy rates and number of participating laboratories for the 14 survey items were as follows: ABO typing, 99.6%–100.0%; RhD typing, 99.8%–100.0%; crossmatching, 94.2%–99.0%; ABO subgroup typing, 100.0% in trial 1 and unagreed results in trial 2; Rh CcEe antigen test, 98.3%–100.0%; weak D test, 81.9%–91.6%; Duffy antigen test, 95.8%–100.0%, Lewis antigen test, 95.5%–100.0%; Kidd antigen test, both 100.0%; antibody screening, 99.4%–100.0%; direct antiglobulin test (DAT) using a polyspecific reagent, 99.3%–100.0%; DAT using anti-immunoglobulin-G monospecific reagent, both 100.0%; DAT using anti-C3d monospecific reagent, both 100.0%; antibody identification, 86.9%–100.0%; and ABO antibody titration, 87.5%–100.0%. Although the overall results were excellent, only 67.2% of the participating laboratories precisely determined samples within the ABO subgroup in the EQA conducted in the last half of 2021. The 2021 EQA scheme for TMP has contributed to the program’s improvement and maintenance of the participating laboratories.

Keywords: Transfusion medicine, Quality improvement, Laboratory proficiency testing