ABSTRACT
We report here the results of surveys for external quality assessment of blood bank tests performed in 2002. Response rates for the 1st, 2nd and 3rd trial were 91.0%, 91.6%, and 91.8%, respectively. Test items for the surveys were ABO grouping, Rh(D) typing, crossmatching, direct antiglobulin test, antibody screening and identification test. The average accuracy rates of ABO grouping and Rh typing were in the range of 99.4-100% and 97.4-100%, respectively. In crossmatching test, the accuracy rates were 92.5-98.3% for the compatible samples, 73.7-99.7% for the incompatible samples, 88.0% for the samples which were incompatible in albumin phase, and 73.7% for the samples which could be detected as incompatible only by antiglobulin method. The accuracy rates of direct antiglobulin test were 96.3-98.4% for negative samples and 95.9-97.0% for positive samples. The correct results were reported by 98.6-100% of the surveyed institutions for antibody screening test and 100% for identification test. Forty six institutions gave repeatedly incorrect answers for crossmatching. Nine institutions out of them gave incorrect answers for all the test specimens sent out 3 times last year.