OBJECTIVE: To evaluate the capacity of laboratories participated in the proficiency testing (PT) of determination potassium in serum and improve the quality of testing, and put forward technical suggestions for unsatisfied laboratories. METHODS: According to the requirements of CNAS related documents, the homogeneity and stability of the real PT sample were evaluated by one-way ANOVA and t test, respectively. The values of real PT samples were assigned by reference method which was used in PT results assay. It is required that the deviation of value of real PT samples (code:2, 3, 5) between the measured value and the assigned value shall be within ±15.0%. The precision of values for all samples should not be greater than 3.0%. RESULTS: All the laboratories submitted valid data according to the requirements. Only one laboratory did not meet the requirements, and the satisfaction rate was 90.9%. CONCLUSIONS The ability of most of laboratories are accurate and reliable.
Drinking Water/analysis* ; Laboratories ; Laboratory Proficiency Testing ; Potassium

BACKGROUND: Currently there is no external proficiency testing program for allergen-specific immunoglobulin E assays (sIgE) in Korea. The aim of this study was to evaluate the accuracy of sIgE performed in different laboratories in Korea using Polycheck Allergy Diagnostic (Biocheck GmbH, Germany) or simply ‘Polycheck’ and to further perform an inter-laboratory comparison of sIgE. METHODS: Three inter-laboratory trials were undertaken from June 2016 to December 2017 at nine institutions. Serum samples obtained from three patients who had a history of positive Polycheck results were used in each trial. A total of 59 allergens were evaluated from the standard panel, inhalation panel, and food panel. The acceptable rates (%) of classes 0–6 of the results were calculated using three different criteria, including the consensus of 80% participants of the College of American Pathologists (CAP), the most frequent value (MFV), and the Overall Misclassification Index Score (OMIS). RESULTS: The proportion of laboratories that showed acceptable results for CAP criteria, MFV, and OMIS were around 93.0%–97.7%, 66.3%–76.0%, and 0.1–1.3, respectively, in each trial. Under-performing institutes showed consistently higher (49/68, 72.1%) or lower (19/68, 27.9%) than acceptable results for all criteria. CONCLUSIONS: This is the first study evaluating the inter-laboratory variation of sIgE in Korea using various criteria. It was found that the acceptable rate could be altered based on changes in these criteria. These findings might be useful for the inter-laboratory comparison of sIgE in Korea in the future as well.
Academies and Institutes ; Allergens ; Consensus ; Humans ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulins ; Inhalation ; Korea ; Laboratory Proficiency Testing ; Mass Screening ; Quality Control

Two trials were conducted with proficiency tests for complete blood cell count (CBC) and blood cell morphology as part of the 2018 Routine Hematology Program of the Korean Association of External Quality Assessment Service. Three different control samples were sent for CBC testing and two blood cell morphology pictures were posted on the laboratory website during each trial. The mean response rates of the 1,719 participating laboratories were 97.4% and 37.2% for CBC and blood cell morphology, respectively. The distribution of equipment for CBC testing was comparable to that of the previous year. The coefficient of variation (CV) ranges were determined as 3.5%–4.1%, 1.9%–2.7%, 1.4%–2.8%, 4.5%–5.3%, and 5.4%–6.9% for white blood cell counts, red blood cell counts, hemoglobin, hematocrit, and platelet counts, respectively. The concordance rate ranged from 83.0% to 97.5% in blood cell morphology tests. We observed a continuous increase in the number of participating laboratories and a trend towards a decrease in the CVs of platelet counts compared to those in 2016. Values of the other assessed parameters were similar to those of the previous year.
Blood Cell Count ; Blood Cells ; Erythrocyte Count ; Hematocrit ; Hematology ; Laboratory Proficiency Testing ; Leukocyte Count ; Platelet Count

This study aims to explore the evaluation model for the proficiency testing of heavy metal and harmful element residues in pharmaceuticals,and to provide reference for the proficiency testing program and proficiency testing result in the field of residue analysis. The proficiency test result of cadmium determination in honeysuckle as an example. The algorithm A,NIQR,and Horwitz function are used to calculate the assigned value and the standard deviation. Z was obtained at the same time. If | Z | ≤2,the result is satisfactory. If 2< | Z | <3,the result is questionable. If | Z | ≥3,the result is unsatisfactory. In addition,the median value is the assigned value,and deviation(D%) is used. If D% is not more than 16%,the result is satisfactory; if D% is more than 16%,the result is unsatisfactory. After analysis,in the results of questionable or dissatisfied laboratories calculated by algorithm A and NIQR,the deviation error of some data is within the scope of the standard. In the results of the satisfactory laboratory evaluated by the Horwitz function,some data deviation errors far exceed the standard range. The evaluation result of the D% meets the requirements. According to heavy metal and harmful element trace analysis methods,this study is the first to apply D% to the evaluation of the detection ability of heavy metals and harmful elements in pharmaceuticals. This method makes the evaluation result more reasonable,and has important reference significance for the evaluation of other proficiency test results.
Cadmium ; analysis ; Laboratories ; Laboratory Proficiency Testing ; Lonicera ; chemistry ; Pharmaceutical Preparations ; standards ; Plant Preparations ; standards ; Trace Elements ; analysis

Herein, we report the results of the 2018 survey on the external quality assessment (EQA) scheme for the Transfusion Medicine Program (TMP) in Korea. The proficiency testing specimens were prepared at Ajou University Hospital and were sent to the participants biannually. The average accuracy rates for ten different test items on the regular survey were as follows: ABO typing, 99.5%–99.8% (N=841); RhD typing, 99.8%–100.0% (N=827); crossmatching, 89.4%–99.6% (N=708); ABO subtyping, 94.2% and 94.4% (N=53); Rh CcEe antigen testing, all 100.0% (N=51); weak D test, 80.9% (N=207) for the first trial and not graded for the second trial; antibody screening, 99.7%–100.0% (N=304); direct antiglobulin test (DAT) using a polyspecific reagent, 98.9%–100.0% (N=264); DAT using an immunoglobulin-G monospecific reagent, all 100.0% (N=66); DAT using a C3d monospecific reagent, 97.0%–100.0% (N=67); antibody identification, 98.4%–100.0% (N=127); and ABO antibody titration, 84.6%–100.0% (N=73). There were approximately 10.5% more participants in the 2018 EQA scheme than that in 2017. Excellent survey results were obtained in the 2018 EQA scheme compared with those in 2017, except for the weak D test. The 2018 EQA scheme for the TMP should be helpful for improving the quality of the participating laboratories.
Coombs Test ; Korea ; Laboratory Proficiency Testing ; Mass Screening ; Quality Improvement ; Thymidine Monophosphate ; Transfusion Medicine

The accuracy-based lipid (ABL) proficiency testing (PT) program was started in 2016 by the Korean External Quality Assessment Service to minimize the matrix effect. We analyzed 3 years of the program. We made or purchased six kinds of commutable frozen sera based on the Clinical and Laboratory Standards Institute 37A guideline and distributed it in two rounds per year from 2016 to 2018. We obtained reference values for levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), total glycerides, and triglycerides in each fresh frozen pool at the reference-measurement laboratories. We evaluated the average percent bias of the participating laboratories based on the National Cholesterol Education Program (NCEP) bias limit. The number of participating laboratories evaluating TC, HDLC, LDLC, total glycerides, and triglycerides increased from 164 to 223, 163 to 223, 158 to 214, 98 to 139, and 61 to 82, respectively. The average percent bias of all participating laboratories for TC, HDLC, LDLC, total glycerides, and triglycerides was +0.14%, −0.54%, +2.9%, −1.08%, and −1.32%, respectively. The average percent bias exceeded the NCEP bias limit only once or twice for TC, HDLC, and total glycerides but frequently for LDLC (eight out of 18 pools). The manufacturer-specific bias estimation report seemed useful for traceability. Although the average percent bias of participating laboratories for TC, HDLC, LDLC, total glycerides, and triglycerides was mostly within the bias limit provided by NCEP, cases of bias limit exceeding the NCEP bias limit occurred occasionally, especially for LDLC during the 3 years of the ABL PT program in Korea, suggesting that ABL PT can be used to keep maintaining traceability.
Bias (Epidemiology) ; Cholesterol ; Education ; Glycerides ; Korea ; Laboratory Proficiency Testing ; Lipoproteins ; Reference Values ; Triglycerides

Here, we have reported results of the surveys on the external quality assessment scheme (EQA) of the Transfusion Medicine Program (TMP) in Korea that were carried out in 2017. The proficiency testing specimens were prepared at Ajou University Hospital, and sent to the participants biannually. The average accuracy rates (N=the number of participants) for ten different test items on the regular survey were as follows: ABO typing, 99.1%–99.9% (N=714); RhD typing, 99.3%–100.0% (N=695); crossmatching, 88.9%–98.5% (N=618); ABO subtyping, 80.7% and 96.0% (N=51); Rh CcEe antigen testing, 98.8%–100.0% (N=51); weak D test, 99.3% and 100.0 (N=150); antibody screening, 98.6%–100.0% (N=295); direct antiglobulin test (DAT) using a poly-specific reagent, 99.2%–100.0 (N=256); DAT using an immunoglobulin-G monospecific reagent, all 100.0% (N=68); DAT using a C3d-monospecific reagent, 83.6%–100.0% (N=72); antibody identification, 88.7%–99.2% (N=123); and ABO Ab titration, 84.6%–100.0% (N=73). The number of participants for the EQA for TMP in 2017 was much higher than that in 2016. Except for the case of ABO subtyping, excellent survey results for the 2017 EQA for TMP were obtained, compared to those in 2016. Thus, the EQA for TMP in 2017 should be helpful for improving the quality of the participating laboratories.
Coombs Test ; Korea* ; Laboratory Proficiency Testing ; Mass Screening ; Quality Improvement ; Thymidine Monophosphate ; Transfusion Medicine*

Under the Routine Hematology Program of the Korean Association of External Quality Assessment Service, complete blood count (CBC) and blood cell morphology proficiency tests were performed during 2017. We conducted two trials, sent three control materials for CBC testing, and posted two cell morphology pictures on the website for each trial. Of 1,646 laboratories, the mean response rates for CBC and blood cell morphology were 96.7% and 42.0%, respectively. The distribution of equipment for CBC testing was similar to that of the previous year. The coefficient of variations for white blood cell counts, red blood cell counts, hemoglobin, hematocrit, and platelet counts were 3.7%–4.7%, 2.2%–2.4%, 1.5%–3.0%, 5.4%–6.0%, and 7.2%–10.2%, respectively. More than 80% of the blood cell morphology tests were concordant among all of the trials, except for the HHI-17-03 trial. In 2017, the number of participating laboratories increased, and the performance was similar to that of the previous year.
Blood Cell Count ; Blood Cells ; Erythrocyte Count ; Hematocrit ; Hematology* ; Korea* ; Laboratory Proficiency Testing ; Leukocyte Count ; Platelet Count

As part of the immunoserology program of the Korean Association of External Quality Assessment Service, we organized two trials on the external quality assessment of hepatitis viral markers in 2016 and 2017. The hepatitis viral antigens and antibodies program consisted of 10 test items. We delivered two and three types of pooled sera specimens to 965 and 965 institutions for the first and second trials of external proficiency testing in 2016, respectively. The number of participating laboratories was 915 (94.8%) and 913 (95.0%) in the first and second trials in 2016, respectively. We also delivered three kinds of pooled sera specimens to 936 and 1,015 institutions for the first and second trials of external proficiency testing in 2017, respectively. The number of participating laboratories was 920 (98.3%) and 996 (98.1%) in the first and second trials in 2017, respectively. The most commonly tested items were hepatitis B surface antigen, followed by the antibodies to hepatitis B surface antigen, anti-hepatitis C virus, hepatitis B envelope antigen, antibodies to hepatitis B envelope antigen, anti-hepatitis A virus and antibodies to hepatitis B core antigen. The most frequently used methods for detecting viral markers were the chemiluminescence immunoassay and the electrochemiluminescence immunoassay, but they yielded a few-false positive results due to the matrix effect. The immunochromatographic assay yielded false-negative results for anti-hepatitis A virus due to low sensitivity. Continuous improvement in the quality of viral hepatitis testing through participation in the survey seems necessary.
Antibodies ; Antigens, Viral ; Biomarkers* ; Hepatitis A ; Hepatitis B ; Hepatitis B Core Antigens ; Hepatitis B Surface Antigens ; Hepatitis B virus ; Hepatitis C ; Hepatitis* ; Immunoassay ; Immunochromatography ; Korea* ; Laboratory Proficiency Testing ; Luminescence

In 2017, the Korean Association of External Quality Assessment Service developed a special protein proficiency testing program that consisted of nine quantitative test items. This program was conducted twice a year using three-level control materials. Data and results of each test item were analyzed by respective institutions according to the test instruments. The report was prepared by dividing it into a common report that showed the characteristics of all the participating institutions and an organization-specific report that showed the assessment data of individual institutions. The following statistical data were presented: the number of participating institutions per group, mean, standard deviation, coefficient of variation, median, minimum value, and maximum value. The individual report was composed of a table, histogram, and Levey-Jennings chart showing the statistics for each test item. The results of the assessment of each institution and the statistical data for each classification are presented in a table, and a standard deviation index for both the company classification and classification by instruments was provided. Overall, no significant difference was observed between the number of participating institutions and the distribution of test equipment. The coefficient of variation tended to be relatively high for each test item because the concentration of quality control materials was low and the number of participating institutions was small. I believe that these statistical analysis data are useful for analyzing external quality control results of the institutions and selecting an immunoassay test instrument for special protein.
Classification ; Immunoassay ; Korea* ; Laboratory Proficiency Testing ; Quality Control