Toward High-Quality Real-World Laboratory Data in the Era of Healthcare Big Data.

With Industry 4.0, big data and artificial intelligence have become paramount in the field of medicine. Electronic health records, the primary source of medical data, are not collected for research purposes but represent real-world data; therefore, they have various constraints.

Quantitative Evaluation of the Real-World Harmonization Status of Laboratory Test Items Using External Quality Assessment Data.

Background: In recent decades, the analytical quality of clinical laboratory results has substantially increased because of collaborative efforts. To effectively utilize laboratory results in applications, such as machine learning through big data, understanding the level of harmonization for each test would be beneficial. We aimed to develop a quantitative harmonization index that reflects the harmonization status of real-world laboratory tests.

Impact of Academia-Government Collaboration on Laboratory Medicine Standardization in South Korea: analysis of eight years creatinine proficiency testing experience.

Objectives: To evaluate the performance of the Academia-Government Collaboration for Laboratory Medicine Standardization in Korea (KR-STDZN) based on data from KR-STDZN proficiency testing (KR-STDZN-PT) for creatinine over eight years (2015-2022).

Methods: We used KR-STDZN-PT data of creatinine tests from 2015 to 2022. Acceptance of the participating institutions' test results was assessed by calculating the acceptance performance as absolute bias (absBias%), total coefficient of variance (tCV%), and total error (TE%) for each sample using six measurements from each institution and true values of each reference material.

Usefulness and performance evaluation of serum KL-6 and SP-A assays in healthy individuals and patients with interstitial lung disease.

Background: Interstitial lung abnormalities (ILAs) are associated with the risk of progression to interstitial lung diseases (ILDs). Krebs von den Lungen 6 (KL-6) and surfactant protein (SP)-A have been used as biomarkers of ILDs. In this study, we evaluated the levels of these biomarkers and identified their clinical correlations in healthy individuals to assess their usefulness in the diagnosis of ILAs.

A New Strategy for Evaluating the Quality of Laboratory Results for Big Data Research: Using External Quality Assessment Survey Data (2010-2020).

Background: To ensure valid results of big data research in the medical field, the input laboratory results need to be of high quality. We aimed to establish a strategy for evaluating the quality of laboratory results suitable for big data research.

Methods: We used Korean Association of External Quality Assessment Service (KEQAS) data to retrospectively review multicenter data.

Total PSA Test Performance Evaluation on Cobas Pure and Measurement System Comparison with Different Calibrators.

Background: This study investigated the performance evaluation of total prostate specific antigen (tPSA) testing using Cobas Pure integrated solutions system (calibrated against WHO IS 96/670) and the comparison with established measurement systems with different traceability.

Methods: The evaluation was performed in terms of imprecision, linearity, detection limit, and correlation with Alinity i (calibrated against WHO IS 96/670) and Unicel DxI 800 (calibrated against the manufacturer's working calibrators).

Results: Within-laboratory reproducibility and repeatability were observed less than 1.

Accuracy of the New Creatinine-based Equations for Estimating Glomerular Filtration Rate in Koreans.

Background: New creatinine-based estimated glomerular filtration rate (eGFR) equations, including the 2021 Chronic Kidney Disease Epidemiology Collaboration (2021 CKD-EPI) and European Kidney Function Consortium (EKFC) equations, have been introduced recently. We assessed the performance of the 2021 CKD-EPI and EKFC equations in the Korean population.

Methods: We analyzed 1,654 Korean patients aged ≥18 years who underwent chromium-51-ethylenediamine tetraacetic acid GFR measurements (mGFR).

Association between measured or calculated small dense low-density lipoprotein cholesterol and oxidized low-density lipoprotein in subjects with or without type 2 diabetes mellitus.

Background: Small dense low-density lipoprotein (sdLDL) possesses atherogenic potential and is predicted to be susceptible to atherogenic modifications, which further increases its atherogenicity. However, studies on the association between measured or estimated sdLDL cholesterol (sdLDL-C) levels and atherogenic modification in diverse population groups are lacking.

Methods: Surplus serum samples were collected from male subjects with type 2 diabetes mellitus (DM) under treatment (n = 300) and without DM (non-DM; n = 150).

Intuitive Modification of the Friedewald Formula for Calculation of LDL-Cholesterol.

Background: High LDL-cholesterol (LDL-C) is an established risk factor for cardiovascular disease and is considered an important therapeutic target. It can be measured directly or calculated from the results of other lipid tests. The Friedewald formula is the most widely used formula for calculating LDL-C.

Strategies to shorten turnaround time in outpatient laboratory.

Background: Turnaround time (TAT) is one of the most important indicators of laboratory quality. For the outpatient routine chemistry tests whose results are checked by clinicians on the same day, we set a quality goal that >90% of these samples should be reported within 60 min. As more than 20% of the samples failed to achieve this goal in 2020, we introduced an additional autoanalyzer and a real-time monitoring system to improve this rate.

Practical Considerations for Clinical Laboratories in Top-down Approach for Assessing the Measurement Uncertainty of Clinical Chemistry Analytes.

Background: The top-down (TD) approach using internal quality control (IQC) data is regarded a practical method for estimating measurement uncertainty (MU) in clinical laboratories. We estimated the MU of 14 clinical chemistry analytes using the TD approach and evaluated the effect of lot changes on the MU.

Methods: MU values were estimated using subgrouping by reagent lot changes or using the data as a whole, and both methods were compared.

Age Group-specific Reference Intervals for the Elecsys Anti-Müllerian Hormone Assay in Healthy Korean Women: a Nationwide Population-based Study.

Background: Anti-Müllerian hormone (AMH) is one of the most reliable markers of ovarian reserve. Automated AMH assays are widely used in clinical laboratories, but reference intervals for the Elecsys AMH assay for Asian populations have not yet been determined. We aimed to determine reference intervals in healthy Korean women.

A New Trial to Measure ABO Antibodies Using Complement-Dependent Cytotoxicity.

Background and objectives: The ABO antibody (Ab) titration tests are used in monitoring in ABO-incompatible (ABOi) solid organ transplantation (SOT). However, currently developed ABO Ab tests show Ab binding reactions. This study attempted to measure ABO Ab level using complement-dependent cytotoxicity (CDC).

Evaluation of Intra- and Interlaboratory Variations in SARS-CoV-2 Real-Time RT-PCR Through Nationwide Proficiency Testing.

Objective: This study aimed to examine the intra- and interlaboratory variations of cycle threshold (Ct) values using the nationwide proficiency testing for SARS-CoV-2.

Methods: Triplicated strong-positive contrived samples duplicated weak-positive contrived samples, and 2 negative samples were transported to participating laboratories in October 2021.

Results: A total of 232 laboratories responded.

Effect of Outlier Elimination on the 99th Percentile Upper Reference Limits of High-Sensitivity Cardiac Troponin I Assays Based on a Strictly Selected Healthy Reference Population.

Background: We established high-sensitivity cardiac troponin I (hsTnI) 99th percentile upper reference limits (URLs) for the Centaur XPT High-Sensitivity Troponin I assay (Centaur hsTnI; Siemens, Erlangen, Germany) and Atellica IM High-Sensitivity Troponin I assay (Atellica hsTnI; Siemens) and assessed the effect of outlier elimination.

Methods: The reference population comprised 380 men and 387 women, satisfying the strict systematic reference population criteria. After reference population verification by the N-terminal pro-B-type natriuretic peptide (NT-proBNP) assay, 99th percentile URLs for Centaur hsTnI and Atellica hsTnI were calculated before and after outlier elimination.

Semiquantitative Analysis of the Results of an Image-Based Urine Sediment Analyzer Considering the Preanalytical Factors.

Background: Automated microscopic platforms are increasingly used in clinical laboratories for rapid analysis of samples. However, it is important to present the results quantitatively or semiquantitatively because automated platforms use various technologies for analysis as well as different sediment preparation methods. The results of cell counting using an on screen image review program for the cobas u 701 analyzer (Roche Diagnostics Interna-tional, Rotkreuz, Switzerland) differed from those obtained by manual microscopic examination (MME).

Status of Four Trace Elements in Elderly Patients with Online Hemodiafiltration.

Background: Essential trace elements play key roles in multiple biological systems, and hemodialysis patients are at risk for deficiency of essential trace elements. The aim of the study was to assess the essential element status in end stage renal disease patients undergoing online hemodiafiltration (online HDF) in outpatient dialysis clinic.

Methods: A total of 28 Korean patients with regular online HDF were included.

Identification of a Splice Variant (c.5074+3A>C) of by RNA Sequencing and TOPO Cloning.

Grading the pathogenicity of 1/2 variants has great clinical importance in patient treatment as well as in the prevention and screening of hereditary breast and ovarian cancer (HBOC). For accurate evaluation, confirming the splicing effect of a possible splice site variant is crucial. We report a significant splicing variant (c.

Recent Trends in Creatinine Assays in Korea: Long-Term Accuracy-Based Proficiency Testing Survey Data by the Korean Association of External Quality Assessment Service (2011-2019).

Background: Accurate serum creatinine (Cr) concentration measurement is essential for evaluating kidney function. In 2011, the Korean Association of External Quality Assessment Service (KEQAS) launched an accuracy-based Cr proficiency testing (ABCr PT) survey. We analyzed long-term data of the KEQAS ABCr PT survey collected between 2011 and 2019 to assess recent trends in Cr assays in Korea.

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

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.