Ann Lab Med.  2021 Jul;41(4):366-371. 10.3343/alm.2021.41.4.366.

Standardization Status of Total Cholesterol Concentration Measurement: Analysis of Korean External Quality Assessment Data

• Yoon YA
• Lee YW
• Kim S
• Lee K
• Park HD
• Chun S
• Min WK

• KMID: 2512715
• DOI: http://doi.org/10.3343/alm.2021.41.4.366

Abstract

Background
Total cholesterol concentration measurement is important in the diagnosis of dyslipidemia and evaluation of cardiovascular disease risk factors. Measurement reliability for obtaining an accurate total cholesterol concentration requires procedure standardization. We evaluated the standardization status for total cholesterol concentration measurement through Korean external quality assessment (EQA) data analysis.
Methods
This study involved 1,670 laboratories that participated in the EQA of total cholesterol concentration measurements in 2019 for 32 products from different manufacturers. The target concentrations of three quality control (QC) materials (samples A, B, and C) were measured using the reference method and compared with EQA data. The performance criteria for total cholesterol concentration measurement were based on the National Cholesterol Education Program guidelines, with ± 3% inaccuracy.
Results
The target values and inaccuracies of the QC material based on the reference method measurements were 254.65 ± 7.64, 108.30 ± 3.25, and 256.29 ± 7.69 mg/dL (6.59 ± 0.20, 2.80 ± 0.08, and 6.63 ± 0.20 mmol/L) for samples A, B, and C, respectively. The performance criteria were not met in 42.7% laboratories for sample A, 68.4% of laboratories for sample B, and 38.0% laboratories for sample C.
Conclusions
Despite significant efforts to accurately measure total cholesterol concentrations, further actions are needed for measurement standardization. Manufacturers reporting values that differ from target values should check calibrator traceability; additional efforts to accurately measure total cholesterol concentrations are required for laboratories that use products from these manufacturers.

Keyword

Inaccuracy; Total cholesterol; External quality assessment; Standardization

Figure

• 

  Fig. 1 Distribution of total cholesterol concentrations according to manufacturers, and target values and performance criteria of quality control materials (samples A, B, and C). The peer group mean is the average value of all laboratories in the same manufacturer group. Numbers from 1 to 24 were given to each manufacturer group in ascending order of peer group mean. (A) Data obtained using sample A. (B) Data obtained using sample B. (C) Data obtained using sample C. Abbreviation: SD, standard deviation.

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