Analysis of the results of an international proficiency testing program for veterinary drug residue determination in food / 上海预防医学

ObjectiveTo evaluate the proficiency and consistency of domestic and foreign testing institutions in the field of veterinary drug residue detection in food， and to promote international cooperation and mutual recognition of testing results among these institutions. MethodsA robust statistical analysis was conducted on the testing results of 20 laboratories in eight countries and regions across North America， Europe， and Asia. The laboratories’ testing capabilities were evaluated using Z-score comparison. ResultsAmong the 20 participating laboratories， 18 achieved satisfactory results， resulting in a satisfaction rate of 90%， while 2 laboratories （10%） failed to meet the requirements. The satisfaction rate of domestic laboratories （100%） was higher than that of foreign laboratories （81.8%）. ConclusionDomestic laboratories perform better than overseas laboratories in determining veterinary drug residues in food. To enhance testing capabilities， these overseas laboratories with unsatisfactory evaluation results should strengthen their daily quality control and ensure traceability of original records.

Inter-laboratory testing as a strategy for external quality assessment for qualitative detection of SARS-CoV-2 by real-time RT-PCR testing in India

To implement the strategy of test, track and treat to tackle the ongoing COVID-19 pandemic, the number of real-time RT-PCR–based testing laboratories was increased for diagnosis of SARS-CoV-2 in the country. To ensure reliability of the laboratory results, the Indian Council of Medical Research initiated external quality assessment (EQA) by deploying inter-laboratory quality control (ILQC) activity for these laboratories by nominating 34 quality control (QC) laboratories. This report presents the results of this activity for a period of September 2020 till November 2020. A total of 597 laboratories participated in this activity and 86 per cent of these scored ?90 per cent concordance with QC laboratories. This ILQC activity showcased India’s preparedness in quality diagnosis of SARS-CoV-2.

Preparation and application of proficiency testing sample of myclobutanil and procymidone in apple powder / 上海预防医学

ObjectiveTo prepare pesticide residues in fruit matrix samples that meet the requirements of homogeneity and stability for the proficiency test. MethodsThe pollution-free apple was selected as the main raw material to prepare the pesticide residue proficiency test samples of myclobutanil and procymidone， and to evaluate the homogeneity and stability. The results of the proficiency test were assessed using robust analysis and Ζ value. ResultsThe homogeneity and stability of the reference materials met the relevant requirements. Among 109 laboratories participated in the proficiency testing， 107 （98.2%） laboratories had satisfactory results. Suspicious test results were reported only in two laboratories， one laboratory for each of the two assessment items. ConclusionAn apple powder matrix sample with pesticide residues is successfully prepared for proficiency test， and could provide an evaluation tool for pesticide residue testing laboratories.

Construction and improvement of lab automation system in emergency lab / 中华检验医学杂志

Objective:By exploring a construction and improvement system for total lab automation in emergency lab, this work aims to improve the success rates of project implementation and the effective utilization of medical resources.Methods:Firstly, clarify the short board of current solution and determine the configuration of the TLA solution which include the number of pre-analytic, post-analytic modules and analyzers by workflow and data analysis which based on the data from 16th to 22nd September 2019. Secondly, define the basic principles and design the optional solutions. Thirdly, determine the final solution based on the simulation results. Fourthly, evaluate the effectiveness of the solution by comparing the turnaroud time (TAT) before and after implementation.Result:We upgrade the system to improve the automation level of the track by add 1 online centrifuge module and upgrade the capacity of online storage module from 9 000 samples to 15 000 samples, and increase the throughput of the clinical chemistry analyzers form 2 500 tests/h to 5 400 tests/h and immunoassay analyzers from 668 tests/h to 1 320 tests/h with no more space. The 95th percentile TAT (from sample check in to validation) have 33% reduction on the premise of 9% increase on the workload of clinical chemistry and immunoassay, and it is highly consistent with the results obtained by data simulation whose 95th percentile TAT is 67 min.Conclusion:Good uasge of workflow and data analysis in the stage of solution design can help to ensure that the result can meet the expectations of the clinicians and effective utilization of medical resources.

Effectiveness of the National Quality Control Program in Mycology of Argentina and performance evaluation of participating laboratorios / Efectividad del Programa Nacional de Control de Calidad en Micología de Argentina y evaluación del desempeño de los laboratorios participantes

Abstract The National Quality Control Program in Mycology (PNCCM) of Argentina was establishedin 1996 to improve the quality of the mycological diagnosis, to help establish and to setup standardized procedures and continuous training of laboratory staff. The aim of this studywas to assess the effectiveness of the PNCCM in the 1996---2018 period. Data from the NationalMycology Laboratory Network (NMLN) and PNCCM database was used to estimate the increasein the number of controlled laboratories and jurisdictions, the percentage of participation, theimprovement in the quality of results and the adherence to the program. Satisfaction surveyswere performed to assess user satisfaction. The number of controlled laboratories increasedfrom 29 to 146; participation increased from 49% to 93% and general adherence was 72% inthe evaluated period (1996---2018). Improvement in the quality of the results was 15% for lowcomplexity samples; 7% for intermediate complexity samples and 14% for the identification ofhigh complexity strains. Up to 84% of the users consider the PNCCM to be ''very good'' and 16%''satisfactory''. These results show the importance of the PNCCM, which is widely accepted bymycological diagnostic laboratories from Argentina.

Resumen En 1996 se creó el Programa Nacional de Control de Calidad en Micología (PNCCM)de Argentina con el objetivo de mejorar la calidad del diagnóstico micológico, colaborar enel establecimiento de procedimientos estandarizados en aquellos laboratorios que carecen deellos y contribuir a la capacitación continua del personal.El objetivo de este estudio fue evaluar la efectividad del PNCCM en el período 1996-2018.Se utilizaron los datos de la base de la Red Nacional de Laboratorios de Micología (RNLM) ydel PNCCM para estimar el aumento en el número de laboratorios controlados y el porcentajede participación, la mejora de la calidad de los resultados y la adhesión al programa. Paraevaluar el grado de satisfacción de los usuarios, se analizaron las encuestas de satisfacción delos participantes. En el período evaluado, el número de laboratorios controlados aumentó de 29a 146, la participación aumentó de 49% a 93% y la adherencia general de los participantes fue del72%. La mejora de la calidad de los resultados de los laboratorios fue del 15% para muestras debaja complejidad, 7% para muestras de complejidad intermedia y 14% para la identificación decepas de alta complejidad. El 84% de los usuarios considera que el PNCCM es muy bueno y el 16%que es satisfactorio. Estos resultados evidencian la importancia del PNCCM, que es ampliamenteaceptado por los laboratorios que realizan diagnóstico micológico en nuestro país.

Study on Proficiency Testing of Determination Potassium in Serum / 中国医疗器械杂志

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.

Discussion on evaluation mode of proficiency testing for heavy metal and harmful element detection in medicines / 中国中药杂志

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.

Diphtheria diagnostic capacity in the Western Pacific Region

@#Diphtheria is an acute infectious disease affecting the upper respiratory tract and occasionally the skin and is caused by the action of diphtheria toxin produced by Corynebacterium diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis. Corynebacterium infections are usually difficult to control due to their epidemic patterns, the emergence of new strains, novel reservoirs and their dissemination to susceptible human and animal populations.1 Although C. diphtheriae is largely controlled through mass immunization programmes, diphtheria escalated to epidemic proportions within the Russian Federation and the former Soviet Republics in the 1990s, highlighting the potential for this disease to cause morbidity and mortality when immunization programmes are disrupted.2 A recent review of global diphtheria epidemiology, which included an analysis of cases and information about age, showed age distribu­tion shifts and found that the majority of cases occur in adoles­cents and adults.3 Shifts in age distribution, from children to adolescents and adults, were observed from countries in the Western Pacific Region such as the Lao People’s Democratic Republic,4 the Philippines3 and Viet Nam.5

Report of Korean Association of External Quality Assessment Service on the Accuracy-Based Lipid Proficiency Testing (2016–2018) / 임상검사와정도관리

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.

Annual Report of Korean Association of External Quality Assessment Service on Histocompatibility Testing (2018) / 임상검사와정도관리

Here, we report the results of the first histocompatibility proficiency testing (PT) performed by the Korean Association of External Quality Assessment Service in 2018. The directly prepared PT specimens of whole blood, sera, and mononuclear cell suspensions were distributed to participants biannually. The number of participants was comparable to that in the previous external PT program, and the response rate was 88%–100%. The accuracy rates for human leukocyte antigen (HLA) A, B, C, DR, and DQ low and high resolution typing were 100%/100%, 100%/98%, 100%/99%, and 99%/98%, respectively; HLA-B27 typing, 99.1%; T cell and B cell crossmatching, 3.1% and 6.0%, respectively; and HLA antibody screening and identification, 100% and 100%, respectively. The results of HLA crossmatching were not reported from four participants due to poor cell viability. Further improvements of the specimen delivery process, grading criteria for crossmatching, and format of participant summary are warranted.

Annual Report of the Korean Association of External Quality Assessment Service on General Chemistry (2018) / 임상검사와정도관리

In 2018, the general chemistry proficiency testing program of the Korean Association of External Quality Assessment Service consisted of the routine chemistry and urine chemistry programs including 32 and 13 test items, respectively. The test method classification system was revised in the routine chemistry program, and a qualitative test of human chorionic gonadotropin was added in the urine chemistry program. The routine chemistry program was conducted 4 times a year, while the urine chemistry program was conducted twice a year. Statistical analysis data for the test method and reagent companies were reported based on the information and results of the test items provided by each institution. Statistics included the number of participating institutes, mean, standard deviation, coefficient of variation (CV), median, and minimum and maximum values for each group. Each report included tables, histograms, Levey-Jennings charts, and the standard deviation index showing the statistics of each test item. In the routine chemistry program, more than 1,000 institutions performed the 17 test items, and the number is continuously increasing. CV for each test item showed a tendency to increase with decreasing concentration of the proficiency material but was within 10% in most cases. Alkaline phosphatase and lactate dehydrogenase were found to have relatively high CVs because of the differences in results among test methods. In the urine chemistry program, albumin and protein showed high CVs, and the distribution of the test method was different from that of the routine chemistry program.

Annual Report of the Korean Association of External Quality Assessment Service on Transfusion Medicine (2018) / 임상검사와정도관리

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.

Analyses of the Proficiency Testing Program and the Performance of Qualitative Reagents for Rheumatoid Factor / 임상검사와정도관리

BACKGROUND: Rheumatoid factor (RF) is used as one of the diagnostic criteria for rheumatoid arthritis. The purpose of this study was to evaluate qualitative RF reagents used in clinical laboratories in Korea, and to provide basic data that can be used as a reference to improve the quality of RF testing. METHODS: We reviewed the proficiency testing results for RF from the Korean Association of External Quality Assessment Service (KEQAS) and College of American Pathologists. Moreover, we evaluated five commercially available RF qualitative reagents, including LabSlide RF (IVD Lab Co., Korea), ASAN RA Latex Reagents (Asan Pharmaceuticals Co., Korea), RaPET RF (Stanbio Laboratory, USA), RF Latex Test (Pulse Scientific Inc., Canada), and RF-100 (Teco Diagnostics, USA). Commercially available quality control materials, calibrators, and pooled sera were used in this study. The consistency of qualitative reagents and Kappa statistics were calculated based on the quantitative values of the quality control materials and the mixed sera. RESULTS: Up to 51.5% of high concentration samples were reported as negative in KEQAS. RF qualitative reagent test results were not consistent among reagent types. The consistency of the qualitative and quantitative test results was between 51% and 100%, and the kappa statistics varied depending on the reagent manufacturer. CONCLUSIONS: Measurement of RF qualitative reagents used in domestic clinical laboratories was not consistent with the quantitative values, and hence it is necessary to improve the consistency and verify the adequacy of the cut-off value.

Annual Report of the Korean Association of External Quality Assessment Service on Routine Hematology (2018) / 임상검사와정도관리

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.

Accuracy-Based Proficiency Testing of Creatinine Measurement: 7 Years' Experience in Korea / 임상검사와정도관리

BACKGROUND: Standardization of creatinine assay is consistently performed and much effort has been put into improving the accuracy of the results. We aimed to analyze the results of accuracy-based proficiency testing of creatinine assays performed by the Korea Association of External Quality Assessment Service from 2011 to 2017 to assess the current state of creatinine assays in Korea. METHODS: From 2011 to 2017, the accuracy-based proficiency testing of creatinine was performed twice a year. We analyzed the results obtained from the participating laboratories and calculated the year-wise bias. The acceptable limit of bias was as follows: ±11.4% for creatinine concentration >1.0 mg/dL, and 0.114 mg/dL for creatinine concentration ≤1.0 mg/dL. The trend of bias with the major instruments and reagent manufacturers were analyzed. RESULTS: The number of participating laboratories was 54 in 2011, which gradually increased to 146–178 after 2015. For each of the three samples used in the survey, the percentage of laboratories whose biases in the results were within the acceptable limits was 33.3% for the first time in 2011, which gradually increased to 74.7%–85.0% after 2014. The mean biases in all the results of the participating laboratories were 11.1% in 2011 (1st trial) and 2.4% in 2017 (2nd trial). The biases in the results with the major instruments and reagents differed according to the manufacturers. CONCLUSIONS: The mean bias in the results obtained from the participating laboratories in the accuracy-based proficiency testing of creatinine surveys showed a decreasing trend.

Inter-Laboratory Comparison of Multi-Allergen-Specific Immunoglobulin E Screening Assay Using Polycheck Allergy Diagnostic / 임상검사와정도관리

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.

Report on the External Quality Assessment Scheme for Blood Gas (Central Laboratory and Point-of-Care Testing) and Glucose (Point-of-Care Testing) Analysis in Korea (2016–2017)

In the 2016 and 2017 programs for blood gas analysis (BGA) in central laboratory and by point-of-care testing (POCT), and glucose analysis by POCT, external quality assessment of 9, 3, and 1 analytes, respectively, was performed each year. The materials used were commercially available quality control materials, and three levels were used per trial. Based on the information and results from each participating laboratory, statistical analysis was carried out. Results were provided to each laboratory through individual and comprehensive reports. The mean response rates were 96.6%, 96.5%, and 95.6% for BGA in central laboratory, BGA (POCT), and glucose (POCT), respectively. The number of participating laboratories in BGA (central laboratory and POCT) in 2017 was not significantly different from that in 2016. However, in the glucose (POCT) program, the number of registered instruments sharply increased in 2017 as the allowable number of registered instruments was increased from 5 to 30. The coefficient of variation (CV) did not show any significant differences in pH, sodium, chloride, and ionized calcium of BGA. However, the differences of CV were found to be relative large between instruments in other analytes of BGA and glucose POCT.

Report on the External Quality Assessment Scheme for Hemoglobin A1c in Korea (2016–2017)

As part of the clinical chemistry programs of the Korean Association of External Quality Assessment Service, we organized trials to conduct external quality assessment of hemoglobin A1c (HbA1c) in 2016 and 2017. We delivered three commutable whole blood specimens for each trial. The overall response rates were 96.4% in 2016 and 98.4% and 99.6% in the first and second trials in 2017, respectively. Two types of reports were generated: a common report including the mean, standard deviation, coefficient of variation, median, minimum value, and maximum value according to manufacturer and instrument, as well as a summary report of the results from each participating laboratory, including a histogram for each specimen, Levey-Jennings chart for serial percent deviations, and table showing the target value, upper and lower limits, percent deviation, and grade. From 2016, the acceptance criterion was changed from ±8.0% to ±6.7%. The overall acceptable rates for the survey were 91.5%, 91.4%, 94.9%, and 89.0% for the first trial in 2016 through the second trial in 2017, respectively. The requisite continual improvement in the quality of HbA1c testing can be achieved through participation in similar accuracy-based proficiency testing programs.

Report on the External Quality Assessment Scheme of Serologic Tests for Syphilis in Korea (2016–2017)

The 2016–2017 surveys on the external quality assessment scheme for serologic tests for syphilis in Korea were conducted by the Korean Association of External Quality Assessment Service. Proficiency testing (PT) panels consisting of three pooled serum samples were shipped to 430 and 432 laboratories participating in the program in the 1st and 2nd trials of 2016 and 465 and 503 laboratories in the 1st and 2nd trials of 2017, respectively. The rates of returning results were 94.2% and 50.2% for non-treponemal and treponemal tests, respectively, in the 1st trial of 2016; 94.7% and 49.5% in the 2nd trial of 2016; 94.2% and 49.5% in the 1st trial of 2017; and 92.8% and 48.7% in the 2nd trial of 2017, respectively. The most commonly used methods for non-treponemal tests were rapid plasma reagin (RPR) card test, followed by RPR turbidoimmunoassay and venereal disease research laboratory tests. The most commonly used methods for treponemal tests were Treponema pallidum particle agglutination, followed by immunochromatographic assay, Treponema pallidum latex agglutination, chemiluminescence immunoassay, and fluorescent treponemal antibody-absorption. The accuracy rates of the 2017 PT for non-treponemal and treponemal tests were 92.5%–99.8% and 93.3%–100.0%, respectively, which were significantly lower compared to the 98.4%–100.0% and 97.0%–100.0% in 2016. A possible explanation for the lower accuracy rates in the 2017 PT survey is the matrix effect caused by pooling multiple individual serum samples. These data suggest that pooling of serum samples obtained from a small number of donors may help avoid the matrix effect affecting standard materials used for syphilis serology PT.

Report on the External Quality Assessment Scheme for Cytogenetics and Molecular Cytogenetics in Korea (2016–2017)

In both 2016 and 2017, the cytogenetic and molecular cytogenetic programs conducted three assessments for the Korean Association of External Quality Assessment Service. A total of six cases with chromosomal aberrations were distributed in 2016, and nine cases were examined in 2017 in the chromosome surveys. For the fluorescence in situ hybridization surveys, six cases and nine cases were assessed in 2016 and 2017, respectively. A total of 38 laboratories in 2016 and 39 laboratories in 2017 participated in the cytogenetics program. In the molecular cytogenetics program, a total of 32 laboratories participated in 2016, and 31 laboratories participated in 2017. Most of the participating laboratories showed acceptable results for the cytogenetics and molecular cytogenetics programs. For the unacceptable results, there were various annotation errors, suggesting the need for continuous education and quality control.