Annual Report of the Korean Association of External Quality Assessment Service on General Chemistry (2025)

The 2025 general chemistry proficiency testing program, administered by the Korean Association of External Quality Assessment Service, comprised both routine and urine chemistry surveys covering 29 and 13 analytes, respectively.In 2025, glucose was removed from the general chemistry program, following its inclusion in an accuracy-based proficiency testing program, while ethanol was added as a pilot analyte.Furthermore, result similarity testing was implemented to prevent the prior sharing of results among participating laboratories, while the outlier detection method was revised.The routine chemistry program was carried out quarterly, while the urine chemistry program was conducted twice during the year.Statistical evaluations were conducted depending on the test methods and reagent manufacturers.The statistical report provided the number of participating laboratories, arithmetic mean, standard deviation, coefficient of variation, median, and range for each peer group.Each institution received a report comprising summary tables, histograms, Levey-Jennings plots, and standard deviation indices for each analyte.Over 1,000 laboratories participated for 17 routine chemistry analytes, showing a continued upward trend.Alkaline phosphatase and lactate dehydrogenase demonstrated relatively high CVs, attributed to significant variability across the different testing methods, while the majority of other analytes maintained CVs below 20%.In the urine chemistry program, qualitative urinary human chorionic gonadotropin testing had the largest number of participants.Urine albumin showed a substantially greater interlaboratory variation than the other urine chemistry analytes.(Lab Med Qual Assur 2026;48:77-89)