Grounding impedance measurement is a traditional proficiency testing programs, 2014 proficiency testing program on the basis of original ability to verify, combined with actual detection need, innovation introduced two verification point of the power input socket and metal plane testing. This paper analyzes and discusses the results of the ability verification in 2014, and puts forward the points of attention and the recommended method of metal plane test.
Laboratories ; standards ; Laboratory Proficiency Testing

BACKGROUND: External quality assessment (EQA) uses a standard deviation index (SDI), based on a peer group, to evaluate laboratory performance. However, evaluations using peer group SDIs often have limited applicability, because they are not statistically valid unless the number of institutions in the same peer group is large. The present study proposes a statistical model for simultaneously evaluating the performance of all participating institutions, as well as the performance of instruments on the market. METHODS: By assuming that proficiency test results were affected by the manufacturer, the instrument, and the institution, the effects of those factors were estimated using a linear mixed model. We used these effect estimates to calculate manufacturer, instrument, and institution SDIs. Using simulation, we evaluated the false positive rates and efficiencies of the proposed linear mixed model. RESULTS: Simulations showed that the linear mixed model empirical type I error rates preserved the nominal significance level. This model was also more statistically efficient than the peer group SDI. Rates of unacceptability were lower when using institution SDI than they were when using peer group SDI. Additional outliers that could not be evaluated using the current system were detected by the institution SDI statistic. The instrument SDI statistic detected outliers among different instrument groups. CONCLUSIONS: Institution and instrument SDIs are robust and efficient tools for EQA, and they can replace the currently used system of peer group SDI.
Laboratory Proficiency Testing ; Models, Statistical ; Peer Group

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.
Chemistry, Clinical ; Korea* ; Laboratory Proficiency Testing ; Research Report

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

In 2017, the Korean Association of External Quality Assessment Service developed a hormone proficiency testing program that comprised 11 test items for hormone I and four test items for hormone II. This program was conducted twice a year using three-level control materials. Data and results of each test item were analyzed by the respective institutions according to the test instruments. The report was prepared by dividing it into a common report that showed the characteristics of the overall 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 was provided for both the company classification and classification by instruments. Although the total number of participating institutions and distribution of test instruments were not significantly different from the previous year, the number of participating institutions varied by test item. 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 hormones.
Classification ; Immunoassay ; Korea* ; Laboratory Proficiency Testing ; Quality Control

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

We performed two trials on the external quality assessment for therapeutic drug monitoring (TDM) and testing for drugs of abuse (DOA) organized by the Therapeutic Drug Monitoring (TDM) subcommittee of the Korean Association of Quality Assurance for Clinical Laboratories (KAQACL) in 2013. In each trial, two levels of control material for TDM, and positive and negative control material for DOA testing, were requested from candidate institutions. The number of participating laboratories was 106 and 105 for the first and second trials, respectively. The average number of drug items was 5.6 per institution. The most commonly tested substances were valproic acid, followed by digoxin, phenytoin, carbamazepine, and tacrolimus, in descending order. The mean inter-laboratory coefficients of variation for low- and high-level control materials were 9.3% and 6.7%, respectively. The most widely used TDM analysers were Architect i System (Abbott Diagnostics, USA), followed by Cobas Integra (Roche Diagnostics, Switzerland) and Cobas c501 analyser (Roche Diagnostics). The number of participating laboratories for DOA testing increased by 30% compared with that in 2012. We received 100% and 98.2% correct answers from the participating DOA laboratories in each trial, respectively. In the external quality assessment for TDM by the TDM subcommittee of KAQACL in 2013, the overall performance of TDM was similar to previous years and the inter-laboratory precision was improved compared with that in 2012. Continuous quality improvement for TDM testing is needed through participation in a proficiency-testing program.
Carbamazepine ; Digoxin ; Drug Monitoring* ; Korea ; Laboratory Proficiency Testing ; Phenytoin ; Quality Improvement ; Street Drugs* ; Tacrolimus ; Valproic Acid

This proficiency testing program is established to evaluate the pharmaceutical preparation analysis capacity of laboratories recommended by 18 countries and economies. It was authorized by Asia Pacific Laboratory Accreditation Cooperation (APLAC), and organized by Shanghai Institute for Food and Drug Control (SIFDC) and China National Accreditation Service for Conformity Assessment (CNAS). The 0.3sigma test is used to evaluate the homogeneity and stability of the proficiency testing sample. The results of the laboratories were assessed by Z-score. The robust average and the robust standard deviation of the participants' results were calculated as assigned value and standard deviation for performance assessment of hydrochlorothiazide and captopril using robust statistics. Thirty-three of 38 laboratories recommended by 18 countries and economies sent their results back. Twenty-four laboratories' results were observed as satisfactory. Five laboratories were identified as having reported at least one questionable result. Four laboratories were identified as having reported at least one unsatisfactory result.
Accreditation ; Captopril ; analysis ; Drug Combinations ; Drug Stability ; Hydrochlorothiazide ; analysis ; Laboratory Proficiency Testing ; Pharmaceutical Preparations ; chemistry

As the Therapeutic Drug Monitoring Subcommittee (TDMS) of the Korean Association of Quality Assurance for Clinical Laboratories (KAQACL), we organised two trials as an external quality assessment of therapeutic drug monitoring (TDM) and testing for drugs of abuse (DOA) in 2014. In each trial, low and high level control materials for TDM testing, and positive and negative control materials for DOA testing, were requested from institutions. The number of participating laboratories was 107 for the first trial and 106 for the second. The average number of drug items provided was 5.7 per institution. The most commonly tested substances were, in descending order, valproic acid, digoxin, tacrolimus, phenytoin, and vancomycin. The mean inter-laboratory coefficients of variation for low- and high-level TDM control materials were 8.5% and 7.2%, respectively. The most widely used TDM analysers were the Architect i System (Abbott Diagnostics, USA), followed by the Cobas Integra (Roche Diagnostics, Switzerland) and the Cobas c501 analyser (Roche Diagnostics). The number of participating laboratories for DOA testing was 23% higher that than in 2013. In 96.9% of cases, our analysis confirmed the suitability of the tests at participating DOA laboratories in both trials. In the external quality assessment of TDM by the TDMS of KAQACL in 2014, the overall performance of TDM testing was found to be similar to that observed in the previous years, and inter-laboratory precision was higher than that in 2013. Continuous quality improvement of TDM testing by participation in a proficiency-testing program is necessary.
Digoxin ; Drug Monitoring* ; Korea ; Laboratory Proficiency Testing ; Phenytoin ; Quality Improvement ; Street Drugs* ; Tacrolimus ; Valproic Acid ; Vancomycin

We report here the results of surveys on external quality assessment (EQA) of blood bank tests in Korea carried out in 2014. The proficiency testing specimens were prepared at Ajou University Hospital and the response rates for the 1st and 2nd trials were 94.3% (537/549) and 96.0% (545/554), respectively. No answers were considered incorrect, and the average accuracy rates of six different test items on the regular survey were as follows: ABO grouping, 98.5% to 100.0%; RhD typing, 98.1% to 99.4%; crossmatching, 91.2% to 99.6%; direct antiglobulin test (DAT) using a polyspecific reagent, 96.7% to 98.4%; DAT using an immunoglobulin-G monospecific reagent, 93.8% to 98.7%; DAT using a C3d monospecific reagent, 89.5% to 98.7%; unexpected antibody screening test, 96.2% to 100.0%; and antibody identification test, 69.8% to 100.0%. Test items for the pilot survey were reactivities to anti-A1 and anti-H, Rh subgrouping, and ABO antibody titration. Except for the result of the antibody identification test for specimens with multiple antibodies, we obtained excellent survey results for the EQA of blood bank tests carried out in 2014. In addition, the number of participating institutes was higher in 2014 than in 2013. The EQA of blood bank tests in 2014 should be helpful for improving the quality of the participating laboratories.
Academies and Institutes ; Antibodies ; Blood Banks ; Coombs Test ; Korea ; Laboratory Proficiency Testing ; Mass Screening