Two trials involving proficiency tests for complete blood counts (CBCs) and blood cell morphology were conducted as part of the 2019 Routine Hematology Program of the Korean Association of External Quality Assessment Service. Three different control samples were subjected to CBC testing, and two blood cell morphology images were posted on the laboratory’s website during each trial. The mean response rates of the 1,791 participating laboratories were 97.2% and 34.9% for CBC and blood cell morphology, respectively. The distribution of equipment for CBC testing was comparable to that in 2018. The coefficient of variation (CV) ranges were 2.9%–4.1%, 1.6%–2.4%, 1.4%–2.8%, 4.7%–5.3%, and 4.8%–7.3% for white blood cell counts, red blood cell counts, hemoglobin, hematocrit, and platelet counts, respectively. The concordance rate ranged from 83.5% to 99.7% in the blood cell morphology tests. In 2019, the number of participating laboratories was higher than that in 2018, and the CVs of CBC results were similar to those in 2018.

Keywords: Laboratory proficiency testing, Blood cell count, Blood cell morphology