In 2022, the Korean Association of External Quality Assessment Service administered a general chemistry proficiency testing (PT) program that comprised routine chemistry and urine chemistry segments. The routine chemistry and urine chemistry programs included 29 and 13 test items, respectively. Lyophilized products derived from human serum served as the PT materials. The routine chemistry program was scheduled four times annually, whereas the urine chemistry program occurred twice a year. Statistical analyses were conducted on data pertaining to test methods and reagent companies. These analyses were based on information and results supplied by participating institutions and covered metrics such as the number of participants, mean, standard deviation, coefficient of variation (CV), median, and minimum and maximum values for each group. Reports featured tables, histograms, Levey–Jennings charts, and standard deviation indices to illustrate the statistics of each test item. In the routine chemistry segment, over 1,000 institutions participated in 17 of the test items, with participation steadily increasing. Alkaline phosphatase displayed relatively high CVs due to variances in test method outcomes. However, other metrics were within 20%. In the urine chemistry program, majority of laboratories participated in qualitative tests for urine human chorionic gonadotropin, and albumin exhibited relatively high CVs.

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