In 2016, the clinical chemistry proficiency-testing program consisted of 21 programs, including the general chemistry program of the Korean Association of External Quality Assessment Service. The general chemistry program consisted of 28 test items and was conducted using two level control materials four times per year. Based on the information and results for each test item entered by each institution, statistical analysis data according to test method, instrument, and reagent were reported.

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... e report comprised a general statistics report showing the characteristics of all participating institutions and a separate institutional report showing the evaluation data of individual institutions. The statistics included the number of participating institutions and the mean, standard deviation, coefficient of variation, median, minimum, and maximum values for each group. Each report was composed of a table, histogram, and Levey-Jennings chart showing the statistics for each test item. The results of each institution and the statistics for each classification are presented in the table showing the statistics, and a standard deviation index is presented together with a method classification and a classification by reagent companies. A total of 14 items, including albumin, were evaluated by more than 1,000 institutions. There was no significant difference in the distribution of the measurement methods compared with those used in the previous year. The coefficient of variation showed a tendency to increase as the concentration of the level control material decreased and as the number of participating institutions decreased for each test item. Most of them showed a coefficient of variation within 10%. These statistical data will be useful when interpreting the survey results from the institutions and selecting a test method. (J Lab Med Qual Assur 2017;39:61-75)