• Sitemap
  • Contact us

pISSN 2950-9114 eISSN 2950-9122
Article View

Report On Proficiency Testing

Lab Med Qual Assur 2022; 44(3): 121-135

Published online September 30, 2022

https://doi.org/10.15263/jlmqa.2022.44.3.121

Copyright © Korean Association of External Quality Assessment Service.

Annual Report of the Korean Association of External Quality Assessment Service on General Chemistry (2021)

Yong-Wha Lee

Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea

Correspondence to:Yong-Wha Lee
Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, 170 Jomaru-ro, Wonmi-gu, Bucheon 14584, Korea
Tel +82-32-621-5943
E-mail lywmd@schmc.ac.kr

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

The general chemistry proficiency testing (PT) program (2021) of the Korean Association of External Quality Assessment Service consisted of routine chemistry and urine chemistry programs, including 29 and 13 tests, respectively. Liquid and lyophilized products based on human serum were used as the PT materials. The routine chemistry program was conducted 4 times a year, whereas the urine chemistry program was conducted twice a year. The statistical data for the test methods and reagent companies were reported based on the information and results of the test items provided by each laboratory. The computed statistical parameters included the mean, median, standard deviation, coefficient of variation (CV), and minimum and maximum values for each group. In each report, data for each test item were represented using tables, histograms, Levey–Jennings charts, and standard deviation indices. In the routine chemistry program, more than 1,000 participating laboratories performed 17 tests, and the number is still increasing. Alkaline phosphatase, lactate dehydrogenase, and triglyceride demonstrated relatively high CVs owing to the variations in results among the test methods; however, the CVs for the other test items were within 20%. Most laboratories participating in the urine chemistry program performed a qualitative urine human chorionic gonadotropin test. The statistical analysis of the data for urinary albumin revealed relatively high CVs.

Keywords: Proficiency testing, General chemistry, Korean Association of External Quality Assessment Service

대한임상검사정도관리협회 신빙도조사사업은 2021년 현재 6개 대분류하에 76개의 프로그램이 운영되고 있으며, 프로그램 단위별 검사종목도 457종목으로 증가하였다[1-5]. 임상화학 분야는 6개의 대분류 중 하나로, 일반화학검사 등 10개의 중분류 분야로 구성되어 있고, 이들은 일반화학검사와 요화학검사 등 27개의 세부 프로그램으로 나뉘어 있다. 일반화학검사와 요화학검사 프로그램에는 각각 29종과 13종의 검사항목이 포함되어 있다.

2021년 대한임상검사정도관리협회의 신빙도조사사업으로 시행되었던 일반화학검사와 요화학검사에 대한 신빙도조사사업 결과를 분석하여 보고하고자 한다.

1. 대상

일반화학검사 프로그램은 연 4회에 걸쳐, 회차별로 3개의 정도관리물질이 이용되어 시행되었다. 물질은 냉장상태가 유지될 수 있도록 아이스팩이 내장된 특수 제작박스에 넣어 참여 등록기관을 대상으로 각 회차별로 2월, 4월, 8월과 10월에 발송되었다. 요화학검사 프로그램은 연 2회에 걸쳐, 회차별로 3개의 정도관리물질이 이용되었고 1회차와 2회차를 각각 3월과 8월에 발송하였다.

2. 정도관리물질과 검사항목

일반화학검사의 정도관리물질로 액상 형태의 MAS chem TRAK H General Chemistry Controls (Thermo Fisher Scientific, Waltham, MA, USA)와 동결건조형태의 Lyphochek Assayed & Unassayed Chemistry Control (Bio-Rad Laboratories, Hercules, CA, USA)을 사용하였다(Table 1). 요화학검사의 정도관리물질로 Bio-Rad사의 Lyphochek Quantitative Urine Control (Bio-Rad Laboratories)을 사용하였다(Table 2).

Table 1 . Control materials provided for analysis and their release dates for conducting trials in the general chemistry program (2021).

TrialMaterial no.ManufacturerProduct nameLot no.Release date
1stCC-21-01Thermo Fisher*MAS chemTRAK H General Chemistry ControlsCHA21111A22 February
CC-21-02Thermo FisherMAS chemTRAK H General Chemistry ControlsCHA21112A
CC-21-03Thermo FisherMAS chemTRAK H General Chemistry ControlsCHA21113A
2ndCC-21-04Bio-RadLyphochek Assayed & Unassayed Chemistry control2647126 April
CC-21-05Bio-RadLyphochek Assayed & Unassayed Chemistry control26472
CC-21-06Bio-RadLyphochek Assayed & Unassayed Chemistry control28841
3rdCC-21-07Bio-RadLyphochek Assayed & Unassayed Chemistry control2648130 August
CC-21-08Bio-RadLyphochek Assayed & Unassayed Chemistry control26482
CC-21-09Bio-RadLyphochek Assayed & Unassayed Chemistry control28871
4thCC-21-10Thermo FisherMAS chemTRAK H General Chemistry ControlsCHA22101A25 October
CC-21-11Thermo FisherMAS chemTRAK H General Chemistry ControlsCHA22102A
CC-21-12Thermo FisherMAS chemTRAK H General Chemistry ControlsCHA22103A

*Thermo Fisher Scientific (Waltham, MA, USA). Bio-Rad Laboratories (Hercules, CA, USA)..



Table 2 . Control materials provided for analysis and their release dates for conducting trials in the urine chemistry program (2021).

TrialMaterial no.ManufacturerProduct nameLot no.Release date
1stCUC-21-01Bio-Rad*Lyphochek Quantitative Urine control6346115 March
CUC-21-02Bio-RadLyphochek Quantitative Urine control63441
CUC-21-03Bio-RadLyphochek Quantitative Urine control63462
2ndCUC-21-04Bio-RadLyphochek Quantitative Urine control6347130 August
CUC-21-05Bio-RadLyphochek Quantitative Urine control63472
CUC-21-06Bio-RadLyphochek Quantitative Urine control63452

*Bio-Rad Laboratories (Hercules, CA, USA)..



참여기관에서는 수령한 물질에 대해 검사 시행 후 회신 마감일 이내에 대한임상검사정도관리협회 신빙도조사사업 홈페이지(http://eqas.keqas.org)에 결과를 입력하였다. 협회에서는 기기회사와 시약회사로부터 제공된 검사항목별 검사방법, 기기와 시약에 대한 데이터베이스를 지속적으로 업데이트하고 있고, 참여기관이 홈페이지상에서 해당 검사항목에 대한 검사정보 선택과 결과 입력이 가능하도록 하였다.

3. 결과 판정 및 분석

각 기관에서 입력한 각 검사항목에 대한 정보와 결과를 기반으로 검사방법, 기기, 시약에 따라 통계분석을 시행하였다. 결과보고서는 전체 참여기관의 특성을 보여주는 공통보고서와 개별 기관에 대한 평가결과를 보여주는 기관별 보고서로 구성되어 있다. 공통보고서에는 전체 참여기관에 해당하는 통계, 검사방법을 기준분류로 한 통계결과와 시약 회사를 세분류로 한 통계결과를 각각 제시하였다.

제시된 통계결과에는 각 그룹별 참여기관 수, 평균, 표준편차, 변동계수, 중앙값, 최소값과 최대값이 포함되도록 하였고, 참여기관 수, 중앙값, 최소값과 최대값은 이상치를 제거하지 않은 상태에서 산출된 결과를 제시하였고, 평균, 표준편차와 변동계수는 각 군별로 이상치를 제거한 후 산출된 수치를 나타냈다. 해당 분류에서 이상치를 제거한 후 기관 수가 8개 미만인 경우 평균, 표준편차와 변동계수를 제시하지 않았고 기관 수가 3개 미만인 경우 중앙값도 제시하지 않았다. 이상치는 각 해당 분류에서 75 퍼센타일 값(Q3)과 25 퍼센타일 값(Q1)의 차(Q3–Q1; interquartile range, IQR)의 1.5배를 초과하여 Q1보다 낮거나 Q3보다 높은 결과값(<Q1–1.5×IQR 또는 >Q3+1.5×IQR)으로 설정하였다.

개별 보고서는 각 검사항목별로 통계결과를 보여주는 표, 히스토그램과 레비-제닝스 차트로 구성하였다. 통계치를 제시한 표에는 각 기관의 결과값과 각 분류별로 분석된 통계결과를 제시하였고 기준분류와 세분류에서는 standard deviation index (SDI)를 함께 제시하였다. 전체 결과에 대해서는 SDI를 제시하지 않았고 각 그룹에서 이상치 제거 후 기관 수가 8개 미만일 경우 SDI를 제시하지 않았다. 표준편차가 0이지만 기관의 결과값이 평균과 다를 경우에도 SDI를 제시하지 않았다.

히스토그램에서는 전체 기관의 분포와 기준분류별 분포를 제시하였고 각 기관의 위치를 표시하였다. 레비-제닝스 차트에는 기준분류별 최근 1년간의 SDI를 나타냈다.

일반화학검사 프로그램에서는 1,000개 이상의 기관이 참여하는 검사항목은 alanine aminotransferase, albumin, alkaline phosphatase (ALP), aspartate aminotransferase (AST), total bilirubin, chloride, total cholesterol, gamma-glutamyl transferase, glucose, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), potassium, total protein, sodium, triglyceride, urea nitrogen과 uric acid 등 17개 종목이었고, 회차를 거듭할수록 참가기관 수가 증가하였다(Table 3).

Table 3 . Number of participating laboratories for each test in the general chemistry program (2021).

TestTrials

1st2nd3rd4th
Alanine aminotransferase1,7731,7791,7841,786
Albumin1,6421,6421,6441,649
Alkaline phosphatase1,5611,5621,5671,572
Amylase854854861868
Aspartate aminotransferase1,7721,7781,7831,785
Bilirubin, direct811807820824
Bilirubin, total1,6441,6441,6511,653
Calcium784793793794
Chloride1,1361,1421,1451,154
Cholesterol, total1,7581,7631,7671,768
Creatine kinase715715719723
Gamma-glutamyl transpeptidase1,7161,7211,7261,725
Glucose1,7521,7591,7631,763
High-density lipoprotein cholesterol1,6281,6331,6381,641
Iron436438440444
Lactate dehydrogenase919917924926
Lipase468469476478
Low-density lipoprotein cholesterol9829861,0001,001
Magnesium323324330331
Osmolality176176179181
Phosphorus720728733739
Potassium1,1471,1541,1561,166
Protein, total1,6201,6221,6251,629
Sodium1,1471,1541,1561,166
Total CO2235240242243
Total iron-binding capacity400403405408
Triglyceride1,7101,7151,7211,723
Urea nitrogen1,7031,7061,7111,716
Uric acid1,3191,3161,3201,325


요화학검사 프로그램에서는 요 human chorionic gonadotropin 정성검사에 참여하는 기관이 265기관으로 가장 많았고, 이 외에도 200기관 이상 참여하는 검사항목은 albumin, chloride, creatinine, potassium, protein과 sodium 등 6개 종목이었다(Table 4).

Table 4 . Number of participating laboratories for each test in the urine chemistry program (2021).

TestTrials

1st2nd
Albumin202201
Calcium176174
Chloride209209
Creatinine246246
Glucose150150
Magnesium116116
Phosphorus151150
Potassium211211
Protein209209
Sodium213213
Urea nitrogen174174
Uric acid161161
urine hCG (qualitative)267265

Abbreviation: hCG, human chorionic gonadotropin..



일반화학검사 프로그램에서 변동계수는 상대적으로 정도관리물질의 농도가 낮을수록 높은 경향을 보였다(Table 5). 대부분 10% 이내의 변동계수를 보였지만 ALP, amylase, direct bilirubin, HDL-C, lactate dehydrogenase (LDH)와 lipase는 평균적으로 10% 이상의 높은 변동계수를 보였다. 동일한 검사법을 사용하는 군에서는 비교적 작은 변동계수를 보였으나, ALP는 검사법 간에 결과의 차이가 유의하게 큼으로써 변동계수도 상대적으로 큰 것으로 관찰되었다(Table 5). LDH도 검사법에 따라 결과의 차이가 매우 크므로 검사법이 혼재되어 있는 전체 기관으로부터 산출된 변동계수도 크다. 그러나 30% 이상의 변동계수를 보인 1, 2회차에 비해 3, 4회차의 변동계수는 6% 이하로 매우 낮은 현상을 보였다. 이는 주로 ‘pyruvate to lactate’ 검사법을 사용하는 기관들의 결과가 전체 기관 통계에서 아웃라이어로 제거되면서 주로 ‘lactate to pyruvate’ 검사법 사용 기관들의 결과를 중심으로 통계가 이루어진 결과로 해석되었다.

Table 5 . Peer group coefficients of variation (%) based on the tests and trials in the general chemistry program (2021).

TestTrials

CC-21-01CC-21-02CC-21-03CC-21-04CC-21-05CC-21-06CC-21-07CC-21-08CC-21-09CC-21-10CC-21-11CC-21-12
Alanine aminotransferase8.48.28.77.36.07.67.76.17.27.97.69.1
Albumin5.25.25.54.75.04.74.84.84.95.35.55.8
Alkaline phosphatase57.138.235.641.232.841.643.534.440.534.937.257.9
Amylase14.218.220.112.219.312.212.018.912.020.619.413.3
Aspartate aminotransferase6.85.55.46.05.36.46.25.36.25.65.86.2
Bilirubin, direct26.217.49.118.812.018.819.116.417.69.716.525.6
Bilirubin, total9.39.78.29.75.812.210.15.511.88.710.39.9
Calcium4.62.82.34.02.64.03.92.84.32.33.04.6
Chloride2.53.34.82.52.92.62.32.82.44.93.92.9
Cholesterol, total3.13.76.42.33.92.52.44.02.46.73.42.5
Creatine kinase4.15.25.73.54.43.23.54.32.85.74.93.8
Gamma-glutamyl transpeptidase6.86.56.27.06.46.46.25.76.55.96.16.7
Glucose3.63.13.23.42.83.53.52.83.53.03.03.2
High-density lipoprotein cholesterol20.318.613.913.011.815.615.912.317.113.615.717.5
Iron2.83.04.43.13.93.33.13.83.34.32.72.7
Lactate dehydrogenase36.643.244.539.244.338.25.15.24.65.55.75.6
Lipase6.114.820.17.414.16.77.313.47.718.913.86.3
Low-density lipoprotein cholesterol16.412.910.78.15.78.19.56.38.59.014.420.0
Magnesium6.12.92.23.52.53.33.52.00.02.14.06.5
Osmolality0.90.80.71.11.01.41.21.01.10.70.80.9
Phosphorus4.53.13.02.42.83.43.42.72.32.43.13.1
Potassium2.71.72.22.01.62.01.91.62.02.31.72.7
Protein, total2.92.73.23.03.43.13.23.53.33.02.72.8
Sodium1.41.72.81.21.41.41.31.21.32.91.71.1
Total CO26.86.76.77.06.06.97.25.87.77.16.15.9
Total iron-binding capacity2.42.44.03.43.63.53.13.33.73.11.91.5
Triglyceride43.642.742.23.55.13.73.95.63.650.148.948.0
Urea nitrogen3.93.43.54.94.04.74.94.05.03.43.13.9
Uric acid4.93.43.13.33.23.33.33.12.02.93.64.3


Triglyceride에 대한 물질별 변동계수를 살펴보면, Thermo Fisher 물질에 대한 변동계수가 40% 이상을 보인 반면, Bio-Rad 물질에 대한 변동계수는 6% 이하로 관찰되었다. 검체 내 글리세롤이 존재할 경우 triglyceride 측정 전 글리세롤 소거 여부에 따라 triglyceride 측정값이 영향을 받게 된다. Thermo Fisher 물질에 대한 triglyceride 측정값이 글리세롤 소거법에서 비소거법에 비해 매우 낮았고, 이는 본 물질에 글리세롤이 포함되어 있음을 시사한다. 글리세롤 소거법과 비소거법의 결과가 혼재함으로 인해 Thermo Fisher 물질에 대한 변동계수가 큰 것으로 관찰되었다(Tables 5, 6).

Table 6 . Distribution of analytical methods (principle) participated and coefficients of variation (%) according to principle of general chemistry in 2021.

TestMethodTrials

1st2nd3rd4th




Lab*CC-21-01CC-21-02CC-21-03LabCC-21-04CC-21-05CC-21-06LabCC-21-07CC-21-08CC-21-09LabCC-21-10CC-21-11CC-21-12
Alanine aminotransferaseTotal1,7738.48.28.71,7797.36.07.61,7847.76.17.21,7867.97.69.1
Dry chemistry103.53.33.4105.44.55.8109.15.58.7113.23.13.2
LDH with P5P2517.415.215.72512.07.512.12513.88.510.0254.34.18.8
LDH without P5P1,7188.28.18.61,7247.36.07.51,7327.66.17.21,7357.97.59.1
Other method2011.711.711.5209.16.98.31711.47.06.0157.97.25.8
AlbuminTotal1,6425.25.25.51,6424.75.04.71,6444.84.84.91,6495.35.55.8
Dye binding-BCG1,6135.25.25.41,6154.74.94.71,6174.84.84.91,6215.35.55.8
Dye binding-BCP84.84.57.363.65.21.271.45.23.286.76.04.0
Other method214.82.35.6204.44.95.0172.73.12.2165.65.36.2
Alkaline phosphataseTotal1,56157.138.235.61,56241.232.841.61,56743.534.440.51,57234.937.257.9
Other method1662.533.013.81510.810.79.31233.214.631.51038.340.556.4
PNPP, AMP buffer92711.411.712.993210.312.610.29529.410.99.895611.510.513.9
PNPP, DEA buffer16711.88.710.31619.39.68.91559.09.69.71567.27.116.3
PNPP, EAE buffer4518.73.84.04544.23.74.64486.13.44.54504.94.49.7
AmylaseTotal85414.218.220.185412.219.312.286112.018.912.086820.619.413.3
Dry chemistry108.25.43.2104.55.81.995.83.14.990.54.63.8
Hydrolysis of 2-chloro-4-nitrophenyl-azido-deoxy-maltopentaoside50.51.70.651.21.22.452.12.12.550.60.10.8
Hydrolysis of 2-chloro-4-nitrophenyl-galactopyranosylmaltoside1411.91.61.51411.71.21.71442.11.51.71441.51.51.6
Hydrolysis of 2-chloro-4-nitrophenyl-α-D-maltotrioside2082.42.92.42084.43.24.92074.72.94.42112.22.74.9
Hydrolysis of 4,6-ethylidene-4-nitrophenyl-maltoheptaose3524.65.35.83532.85.34.03614.05.93.93656.75.83.8
Hydrolysis of 4-nitrophenylbenzyl-α-maltopentaose13311.317.819.213610.418.810.613211.118.911.513223.518.912.6
Aspartate AminotransferaseTotal1,7726.85.55.41,7786.05.36.41,7836.25.36.21,7855.65.86.2
Dry chemistry109.34.72.8106.03.25.6107.53.47.5113.54.47.7
MDH with P5P218.53.73.9213.32.63.3214.44.34.4214.15.14.3
MDH without P5P1,7216.85.55.41,7276.05.36.41,7356.25.36.21,7385.55.86.2
Other method204.34.45.1204.64.33.8175.95.05.2154.84.96.7
Bilirubin, directTotal81126.217.49.180718.812.018.882019.116.417.68249.716.525.6
Copper ion oxidation4417.617.413.24315.611.817.44213.312.013.34210.29.710.8
Diazonium salt with blank35016.56.42.935023.25.720.835721.36.217.83583.43.28.4
Diazo-sulfanilic acid with blank3838.227.733.33830.923.533.13937.125.044.03924.924.240.7
Diazo-sulfanilic acid without blank2623.225.219.82513.219.27.22715.320.318.82713.316.521.4
Enzymatic oxidation414.013.915.9413.618.619.2427.717.322.9315.613.617.2
Other method726.124.120.0440.011.828.650.014.50.0522.97.824.8
Vanadate oxidation3425.78.04.534313.313.35.034612.313.45.53503.95.611.7
Bilirubin, totalTotal1,6449.39.78.21,6449.75.812.21,65110.15.511.81,6538.710.39.9
Copper ion oxidation1068.47.16.71079.87.08.01027.15.97.61047.18.69.0
Diazo-caffeine, sodium benzoate with blank53.72.80.856.43.54.041.82.42.445.86.38.2
Diazo-dimethyl sulfoxide with blank13711.26.76.11368.46.87.81357.55.59.61316.46.613.0
Diazo-dimethyl sulfoxide without blank11315.56.87.71127.94.912.511610.04.311.61174.15.013.9
Diazo-dyphylline with blank915.49.95.399.35.57.596.25.57.7106.78.615.2
Diazonium salt-dyphylline without blank911.87.68.21012.55.415.81217.410.717.5116.67.512.8
Diazonium salt-Surfactant with blank52020.712.19.552010.76.712.953111.26.612.353410.413.122.6
Diazonium salt-Surfactant without blank339.29.610.03110.67.67.7307.58.510.5308.98.59.7
Enzymatic oxidation1614.810.96.31612.48.013.9167.86.110.4152.94.45.3
Other method2712.88.58.4257.76.913.32111.55.712.7216.87.112.9
Vanadate oxidation6692.94.23.06735.23.06.36753.62.86.16763.03.84.8
CalciumTotal7844.62.82.37934.02.64.07933.92.84.37942.33.04.6
Colorimetry arsenazo III1664.53.33.61683.22.83.11713.73.33.31742.93.23.6
Colorimetry_methylxylenol blue642.00.91.4672.21.81.6691.51.71.8711.21.61.5
Colorimetry_OCPC3763.52.72.33753.13.02.73653.32.93.23612.42.73.6
NM-BAPTA1661.31.41.51721.61.31.51751.11.41.61751.41.01.8
Other method114.32.93.691.01.00.8123.13.23.7122.84.05.5
ChlorideTotal1,1362.53.34.81,1422.52.92.61,1452.32.82.41,1544.93.92.9
ISE, diluted6341.31.41.76362.51.92.56352.61.82.96421.70.90.8
ISE, undiluted4931.92.33.44981.72.52.25031.72.61.75053.52.42.0
Other method92.42.93.884.45.05.773.86.63.172.43.82.6
Cholesterol, totalTotal1,7583.13.76.41,7632.33.92.51,7672.44.02.41,7686.73.42.5
Cholesterol esterase1,7383.13.76.41,7442.33.92.51,7522.44.02.41,7546.73.42.5
Other method204.86.96.7194.96.74.0151.52.71.8146.13.33.7
Creatine kinaseTotal7154.15.25.77153.54.43.27193.54.32.87235.74.93.8
Creatine phosphate to creatine2672.62.82.92712.82.12.62712.61.82.22742.12.02.4
Creatine phosphate to creatine with activator4373.46.06.54333.65.43.34383.65.32.94396.25.42.3
Dry chemistry68.112.310.866.15.97.460.82.53.265.81.97.6
Other method50.63.51.8515.915.39.947.47.65.3458.011.110.0
Gamma-glutamyl transpeptidaseTotal1,7166.86.56.21,7217.06.46.41,7266.25.76.51,7255.96.16.7
Gamma-glutamyl-carboxy-nitroanilide1,6706.86.56.21,6756.96.46.41,6856.25.86.01,6855.96.16.6
Gamma-glutamyl-p-nitroanilide198.96.67.31910.98.210.2185.75.16.8186.36.06.4
G-glutamyl-p-nitroanilide (dry chemistry)96.86.13.595.33.33.396.90.912.0103.67.610.5
Other method185.84.33.8185.51.63.8142.83.54.7123.93.68.1
GlucoseTotal1,7523.63.13.21,7593.42.83.51,7633.52.83.51,7633.03.03.2
Glucose oxidase4795.13.83.44753.73.23.74663.52.72.94673.13.44.6
Hexokinase1,2533.23.03.11,2642.62.72.71,2823.12.82.71,2823.12.92.7
Other method2010.33.41.7204.62.76.3155.62.74.6142.42.84.4
High-density lipoprotein cholesterolTotal1,62820.318.613.91,63313.011.815.61,63815.912.317.11,64113.615.717.5
Enzymatic with detergent7397.36.18.77468.310.18.77487.510.78.17475.27.28.1
Enzymatic with electrostatic114.85.86.5141.40.01.9172.70.03.5170.05.23.2
Enzymatic with immunoinhibition2205.25.46.12184.05.55.21964.43.35.21896.05.98.1
Enzymatic with others24226.327.127.424615.311.014.524216.613.315.124430.931.430.9
Enzymatic with polyanion precipitation12814.517.921.61185.110.510.51178.510.710.011810.29.18.3
Enzymatic with polyethylene glycol2673.24.65.32733.13.32.92783.33.33.02795.04.83.0
Other method2117.617.321.9188.27.99.64011.28.110.5474.66.74.3
IronTotal4362.83.04.44383.13.93.34403.13.83.34444.32.72.7
Bathophenanthroline without deproteinization1321.71.82.51341.42.61.61251.42.11.31272.21.61.4
Ferrozine without deproteinization1641.31.52.51651.72.42.01701.72.31.81712.71.81.7
Nitroso-PSAP without deproteinization510.91.21.3471.41.31.4531.02.01.2541.30.50.7
Pyridyl AZO dye ascorbate without deproteinization33.54.318.630.917.15.931.813.17.1310.05.05.3
Tripyridyltriazine without deproteinization831.31.72.7860.92.41.0871.62.11.5872.31.30.9
Lactate dehydrogenaseTotal91936.643.244.591739.244.338.29245.15.24.69265.55.75.6
Lactate to pyruvate6484.74.74.56584.04.24.06754.14.14.16784.95.05.0
Pyruvate to lactate2629.78.27.62518.77.68.42419.18.09.22397.88.49.3
Pyruvate to lactate (dry chemistry)73.82.02.776.62.28.278.61.84.371.91.57.7
LipaseTotal4686.114.820.14697.414.16.74767.313.47.747818.913.86.3
Hydrolysis of 1,2-diglyceride with quinone dye844.63.73.6843.22.93.2863.22.61.8862.42.84.5
Hydrolysis of 1,2-O-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester3734.715.922.03754.715.64.73816.514.77.538420.715.16.2
Hydrolysis of 1-oleoyl-2,3-diacetyl glycerol93.42.90.092.61.33.283.00.03.580.03.43.9
Low-density lipoprotein cholesterolTotal98216.412.910.79868.15.78.11,0009.56.38.51,0019.014.420.0
Enzymatic with detergent73718.014.311.17387.94.87.47568.85.36.67537.515.221.4
Enzymatic with others2174.86.59.22227.49.58.72049.910.211.020312.08.96.8
Enzymatic with polyethylene glycol203.88.210.62010.28.010.71810.111.010.1198.612.517.9
Other method811.18.110.5618.513.815.7222.84.91.4261.32.02.3
MagnesiumTotal3236.12.92.23243.52.53.33303.52.00.03312.14.06.5
Colorimetry_Xylidyl blue3216.02.92.23213.42.53.23273.52.00.03282.12.96.4
OsmolalityTotal1760.90.80.71761.11.01.41791.21.01.11810.70.80.9
Freezing point depression osmometer1690.90.80.71691.11.01.41731.21.01.11750.70.70.8
Other method722.029.937.672.11.41.1631.326.032.1637.227.917.7
PhosphorusTotal7204.53.13.07282.42.83.47333.42.72.37392.43.13.1
Molybden blue colorimetry1873.01.82.61912.11.92.11922.11.92.01942.02.42.7
Phosphomolybdate5303.53.83.15333.72.42.55373.62.72.35412.83.32.9
PotassiumTotal1,1472.71.72.21,1542.01.62.01,1561.91.62.01,1662.31.72.7
ISE, diluted6352.60.01.76381.81.41.86361.81.41.86441.51.52.7
ISE, undiluted5032.91.72.15082.02.32.15131.91.52.15152.21.82.8
Other method96.01.74.681.34.42.873.44.32.570.71.84.0
Protein, totalTotal1,6202.92.73.21,6223.03.43.11,6253.23.53.31,6293.02.72.8
Biuret method1,6022.92.72.31,6053.03.43.11,6113.23.53.31,6163.02.62.7
Other method183.04.34.6173.82.95.1143.75.14.2133.33.23.3
SodiumTotal1,1471.41.72.81,1541.21.41.41,1561.31.21.31,1662.91.71.1
ISE, diluted6181.11.11.26221.10.81.06211.11.11.16281.20.90.9
ISE, undiluted5201.11.41.95241.21.61.45281.11.41.25312.21.51.1
Other method92.00.62.481.30.92.071.91.00.970.90.81.4
Total CO2Total2356.86.76.72407.06.06.92427.25.87.72437.16.15.9
Phosphoenolpyruvate carboxylase2336.86.76.82397.05.96.92407.15.97.62437.16.15.9
Total iron-binding capacityTotal4002.42.44.04033.43.63.54053.13.33.74083.11.91.5
Bathophenanthroline1191.92.33.01211.52.71.81111.53.41.21142.81.91.7
Chromazural B251.52.64.6263.62.52.8275.33.04.1274.92.43.0
Ferrozine1252.02.23.31282.33.82.31342.53.12.51333.12.11.8
Nitroso-PSAP1281.71.52.01262.72.42.81322.91.93.11332.11.21.1
TriglycerideTotal1,71043.642.742.21,7153.55.13.71,7213.95.63.61,72350.148.948.0
Enzymatic with free glycerol elimination5674.16.18.25702.93.22.75722.93.32.657210.27.24.7
Enzymatic without free glycerol elimination1,1245.55.77.01,1264.45.94.31,1344.56.84.11,1376.45.55.3
Other method198.97.98.9193.58.02.8154.44.54.3144.94.95.1
Urea nitrogenTotal1,7033.93.43.51,7064.94.04.71,7114.94.05.01,7163.43.13.9
Other method195.75.25.4194.53.85.0156.15.67.4144.84.66.9
Urease with colorimetry162.86.08.4164.29.73.5104.63.63.2112.33.22.8
Urease with GLDH1,6673.93.43.41,6704.84.04.71,6864.94.05.01,6913.43.03.8
Uric acidTotal1,3194.93.43.11,3163.33.23.31,3203.33.12.01,3252.93.64.3
Other method118.44.45.684.54.54.674.85.85.878.06.07.3
Uricase1,3014.93.43.11,3013.33.23.31,3063.33.12.01,3112.73.64.3
Uricase (dry chemistry)72.52.31.472.42.80.072.22.21.972.92.80.0

Abbreviations: LDH, lactate dehydrogenase; P5P, pyridoxal-5-phosphate; BCG, bromocresol green; BCP, bromocresol purple; PNPP, para nitrophenylphosphate; AMP, 2-amino- 2-methyl-1-propanol; DEA, diethanolamine; EAE, 2-ethylaminoethanol; MDH, malate dehydrogenase; OCPC, o-creolphthalein complexone; NM-BAPTA, 5-nitro-5’-methyl-BAPTA; ISE, ion-selective electrodes; Nitroso-PSAP, 2-nitroso-5-(N-propyl-N-sulfopropylamino)-phenol; GLDH, glutamate dehydrogenase..

*Number of Laboratories participated in Korean External Quality Assessment Service 2021..



일부 검사에서 일부 물질에 대해 변동계수가 0%인 경우는 변동계수 산출을 위한 아웃라이어 제거 후 남은 결과치가 단일 숫자일 경우에 해당한다.

변동계수는 각 기관의 상대적 정확도를 나타내는 지표인 SDI 산출에 영향을 준다. 변동계수가 큰 경우 SDI는 상대적으로 작아질 수 있으므로 결과 해석 시 유의하여야 한다.

요화학검사 프로그램에서 각 검사항목별 변동계수는 대부분 10% 이내의 값을 보였으나 albumin은 13.0%–40.6%로 가장 큰 변동계수를 보였다(Table 7). 특히 6개 중 3개의 정도관리물질에 대해서 37% 이상의 변동계수를 보였는데, 이는 정도관리물질의 농도가 매우 낮은 것에 기인하는 것으로 생각되었다.

Table 7 . Peer group coefficients of variation (%) based on the tests and trials in the urine chemistry program (2021).

TestTrials

CUC-21-01CUC-21-02CUC-21-03CUC-21-04CUC-21-05CUC-21-06
Albumin40.613.740.513.037.014.4
Calcium4.52.83.32.33.92.8
Chloride7.02.26.01.98.32.1
Creatinine4.13.93.83.13.72.9
Glucose3.32.20.02.13.12.3
Magnesium2.82.52.73.22.93.0
Phosphorus2.02.22.32.52.22.1
Potassium1.62.91.64.21.94.5
Protein6.37.16.67.85.77.4
Sodium3.31.22.71.22.70.9
Urea nitrogen3.73.43.52.93.22.7
Uric acid4.63.35.42.54.22.5


일반화학검사 프로그램에서 각 검사항목의 회차별 결과에서 검사방법(대분류)에 따른 기관 수와 변동계수의 분포는 Table 6과 같았다. 한 가지 검사방법이 전체의 80%를 넘는 검사로는, ALT의 LDH without pyridoxal-5-phosphate (P5P)법, albumin의 dye binding bromocresol green법, AST의 malate dehydrogenase without P5P법, total cholesterol의 cholesterol esterase법, gamma-glutamyl transpeptidase의 gamma-glutamyl-carboxy-nitroanilide법, magnesium의 colorimetry-xylidyl blue법, osmolality의 freezing point depression osmometer법, total protein의 Biuret법, total CO2의 phosphoenolpyruvate carboxylase법, urea nitrogen의 urease with glutamate dehydrogenase법과 uric acid의 uricase법이 있었으며, 예년과 비슷한 경향을 보였다(Table 6).

요화학검사에서 albumin의 측정법으로는 immunoturbidimetry법이 주로 이용되었고, protein의 측정법으로 dye binding using pyrogallol red법과 turbidimetry using benzethonium chloride법이 주로 이용되었다(Table 8). Sodium, potassium과 chloride 등의 전해질검사에는 대부분의 검사기관이 희석 이온선택전극법을 이용하였다.

Table 8 . Distribution of analytical methods (principle) and coefficients of variation (%) according to the principle of the urine chemistry program in 2021.

TestMethodTrials

1st2nd


Lab*CUC-21-01CUC-21-02CUC-21-03LabCUC-21-04CUC-21-05CUC-21-06
AlbuminTotal20240.613.740.520113.037.014.4
Immunoturbidimetry19638.913.439.119412.035.213.5
CalciumTotal1764.52.83.31742.33.92.8
Colorimetry_Arsenazo III293.12.12.2312.31.81.6
Colorimetry_Methylxylenol blue215.92.64.8231.94.02.2
Colorimetry_OCPC594.22.83.1552.54.72.9
NM-BAPTA653.31.71.9641.42.51.7
ChlorideTotal2097.02.26.02091.98.32.1
ISE, diluted2047.02.26.02021.98.32.1
ISE, undiluted417.72.514.161.17.62.1
CreatinineTotal2464.13.93.82463.13.72.9
Enzymatic method163.15.63.3155.22.95.0
Kinetic Jaffe with compensation93.72.83.682.83.32.5
Kinetic Jaffe without compensation1973.53.43.11972.73.42.5
Rate blanked compensated kinetic Jaffe method232.42.53.3252.42.62.6
GlucoseTotal1503.32.20.01502.13.12.3
Hexokinase1503.32.20.01502.13.12.3
MagnesiumTotal1162.82.52.71163.22.93.0
Colorimetry_Xylidyl blue1152.82.52.71143.22.93.0
PhosphorusTotal1512.02.22.31502.52.22.1
Molybden blue colorimetry222.01.02.0211.11.91.3
Phosphomolybdate1292.02.02.21292.52.22.3
PotassiumTotal2111.62.91.62114.21.94.5
ISE, diluted2061.62.91.62044.21.94.5
ISE, undiluted43.26.31.767.23.15.2
ProteinTotal2096.37.16.62097.85.77.4
Biuret method123.81.94.4111.02.31.4
Dye binding using pyrogallol red1147.16.28.41137.56.16.3
Turbidimetry using benzethonium chloride833.62.54.0842.54.72.8
SodiumTotal2133.31.22.72131.22.70.9
ISE, diluted2083.31.22.72061.22.70.9
ISE, undiluted41.17.27.863.94.62.4
Urea nitrogenTotal1743.73.43.51742.93.22.7
Urease with GLDH1743.73.43.51742.93.22.7
Uric acidTotal1614.63.35.41612.54.22.5
Uricase1614.63.35.41612.54.22.5

Abbreviations: OCPC, o-creolphthalein complexone; NM-BAPTA, 5-nitro-5'-methyl-BAPTA; ISE, ion-selective electrodes; GLDH, glutamate dehydrogenase..

*Number of Laboratories participated in Korean External Quality Assessment Service 2021..



2021년 일반화학검사 프로그램과 요화학검사 프로그램의 신빙도조사 결과에 대해 보다 자세한 통계분석 결과는 대한임상검사정도관리협회 신빙도조사사업 홈페이지(http://eqas.keqas.org)에서 조회가 가능하다.

  1. Lee YW. Annual report of the Korean Association of External Quality Assessment Service on general chemistry (2020). Lab Med Qual Assur 2021;43:107-21.
    CrossRef
  2. Lee YW. Annual report of the Korean Association of External Quality Assessment Service on general chemistry (2019). Lab Med Qual Assur 2020;42:97-111.
    CrossRef
  3. Lee YW. Annual report of the Korean Association of External Quality Assessment Service on general chemistry (2018). J Lab Med Qual Assur 2019;41:51-64.
    CrossRef
  4. Lee YW. Annual report on the external quality assessment scheme for general chemistry in Korea (2017). J Lab Med Qual Assur 2018;40:113-27.
    CrossRef
  5. L Lee YW, Jeon BR, Kim JG, Jun SH, Yun YM, Chun S, et al. Annual report on the external quality assessment scheme for routine clinical chemistry in Korea (2016). J Lab Med Qual Assur 2017;39:61-75.
    CrossRef

Supplementary File


Share this article on :

Stats or metrics