In 2023, the Korean Association of External Quality Assessment Service conducted its general chemistry proficiency testing (PT) program, which included the routine chemistry and urine chemistry programs, with 29 and 13 test items, respectively. These PT materials comprised both lyophilized and liquid products based on human serum. The routine chemistry program was conducted 4 times annually, while the urine chemistry program was conducted biannually. Statistical analysis of the data for each test method and reagent company was based on the information and results supplied by participating institutions. This analysis included the number of participating institutes, the mean, standard deviation, coefficient of variation (CV), median, minimum, and maximum values for each group. Reports featured tables, histograms, Levey-Jennings charts, and the standard deviation index for each test item. In the routine chemistry program, over 1,000 institutions conducted the 17 test items, and this number continues to grow. Alkaline phosphatase displayed relatively high CVs due to variability in test results across different methods, although the CVs for other tests remained below 20%. In the urine chemistry program, the majority of laboratories participated in the qualitative test for urine human chorionic gonadotropin, and albumin demonstrated notably high CVs.

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