The general chemistry proficiency testing (PT) program (2021) of the Korean Association of External Quality Assessment Service consisted of routine chemistry and urine chemistry programs, including 29 and 13 tests, respectively. Liquid and lyophilized products based on human serum were used as the PT materials. The routine chemistry program was conducted 4 times a year, whereas the urine chemistry program was conducted twice a year. The statistical data for the test methods and reagent companies were reported based on the information and results of the test items provided by each laboratory. The computed statistical parameters included the mean, median, standard deviation, coefficient of variation (CV), and minimum and maximum values for each group. In each report, data for each test item were represented using tables, histograms, Levey–Jennings charts, and standard deviation indices. In the routine chemistry program, more than 1,000 participating laboratories performed 17 tests, and the number is still increasing. Alkaline phosphatase, lactate dehydrogenase, and triglyceride demonstrated relatively high CVs owing to the variations in results among the test methods; however, the CVs for the other test items were within 20%. Most laboratories participating in the urine chemistry program performed a qualitative urine human chorionic gonadotropin test. The statistical analysis of the data for urinary albumin revealed relatively high CVs.

Keywords: Proficiency testing, General chemistry, Korean Association of External Quality Assessment Service