Effect of usual source of care on receiving smoking cessation advice: Korean National Health Panel data analysis

Background: Despite various anti-smoking policies, the smoking rate in adults is still high in Korea. Doctors' advice is known to increase the smoking cessation success rate. However, few studies have reported the effect of having a usual source of care (USC) on receiving smoking cessation advice. Objective: To determine the effect of USC on receiving smoking cessation advice. Methods: We performed multiple panel logistic regression analyses to identify the effect of having a USC on the rate of receiving a doctor's smoking cessation advice using 2009, 2012 and 2013 datasets from the Korea Health Panel database. Only people who responded to questions regarding a USC and smoking cessation advice were analysed. Eventually, 5243 observations were included in the final analysis. Results: A higher percentage of people with a USC received smoking cessation advice from doctors (58.4% in 2009, 64.0% in 2012 and 59.6% in 2013) than those not having a USC (28.6% in 2009, 37.5% in 2012 and 34.8% in 2013). The odds ratios (ORs) of receiving smoking cessation advice in people with a USC were higher than those of people without a USC after performing multiple panel logistic regression analysis with random effects (OR: 2.24; 95% confidence interval: 1.90-2.63). Conclusions: Having a USC increased the odds of receiving a doctor's smoking cessation advice in Koreans. The results of this study suggest that a health care policy that encourages having a USC is useful in receiving more smoking cessation advice in a Korean population

Survey on the Implementation of Delta Checks and Panic Values in Immunoassays in Korea

배경: 본 연구에서는 온라인 설문 조사를 통해 국내 임상 실험실에서 자동면역분석검사의 델타, 패닉 점검의 적용 현황을 파악하고자 하였다. 방법: 암 표지자 AFP, CA125, CA19-9, CEA, PSA 및 갑상선기능 검사 T3, free T4, TSH를 시행하고 있는 검사실에 근무하는 진단검사의학과 전문의를 대상으로 설문조사를 시행하였다. 각 검사별 델타 점검의 적용 여부, 델타 점검 유형, 델타 점검 시 사용하는 이전 검사와의 기간 등과, 패닉 점검의 적용여부와 기준을 조사하였다. 결과: 총 87기관 검사실에서 설문에 회신하였고, 75기관(86.2%)에서 8개의 검사를 모두 시행하고 있었다. 델타 점검을 시행하는 빈도는 PSA가 38.8% (33/85)로 가장 높았고, CA19-9가 34.1% (28/82)로 가장 낮았다. 가장 많이 사용하는 델타 점검 공식은 delta percent change (DPC)로, 델타 점검의 65.6–92.6%가 DPC로 시행하고 있었다. DPC를 활용하는 검사실의 약 50%는 델타 점검의 기간제한이 없었고, 일부 검사실에서 1개월, 3개월, 6개월 또는 12개월로 기간제한을 설정하고 있었다. DPC의 기준은 4.5%에서 200%까지 다양했는데, 50% 기준을 가장 많이 사용하고 있었고, 그다음은 20%였다. 패닉 점검을 시행하는 빈도는 CA19-9가 51.2% (42/82)로 가장 높았고 free T4가 36.0% (31/86)로 가장 낮았다. 패닉 점검의 사용 빈도는 CA19-9에서 가장 높았고(51.2%, 42/82), free T4에서 가장 낮았다(36.0%, 31/86). 패닉 점검의 시행 기준은 주로 자체검사실 자료 또는 시약회사가 제공한 자료를 바탕으로 설정되었다. 결론: 우리는 많은 실험실에서 호르몬 및 종양표지자 분석에서 델타 또는 패닉 점검을 적용하지 않는다는 것을 확인했다. 효율적인 델타 점검 기준과 패닉 점검에 대한 추가적인 조사 연구가 필요함을 확인하였다. Background: This study aimed to inquire about the implementation of delta checks and panic values for immunoassays in clinical laboratories through an online survey. Methods: A questionnaire survey was conducted on laboratory medicine specialists working in laboratories that perform five tumor markers, including alpha-fetoprotein, cancer antigen 125, cancer antigen 19-9 (CA19-9), carcinoembryonic antigen, and prostate-specific antigen (PSA), and thyroid function tests, including triiodothyronine, free thyroxine (T4), and thyroid-stimulating hormone. Results: A total of 87 institutions responded to the questionnaire, and 75 laboratories (86.2%) were performing all 8 tests. The delta check was most used in the PSA test (38.8%, 33/85) and less used in CA19-9 (34.1%, 28/82). The delta percent change (DPC) formula was the most commonly used (65.6–92.6%). The criteria of DPC varied from 4.5 to 200%, and the most common was 50%, followed by 20%. Approximately 50% of laboratories using DPC did not use time intervals, and some laboratories used time limits as 1, 3, 6, or 12 months. The panic checks were most performed in CA19-9 test (51.2%, 42/82) and less performed in free T4 (36.0%, 31/86). The criteria for the panic value were mainly established based on the in-house laboratory data or data provided by reagent companies. Conclusions: Many laboratories do not apply delta or panic checks in immunoassays. Further research on the suitable delta check criteria and panic values for the assay and patient characteristics is needed

Evaluation of Two Safety Syringes for Arterial Blood Gas Analysis

배경: 동맥혈가스분석은 생명이 위급한 환자에게 혈액가스 및 산-염기 평형, 전해질 수치를 제공하는 매우 중요한 검사이며 정확한 결과가 요구된다. 동맥혈가스분석용 주사기의 여러 요인이 결과에 영향을 미칠 수 있지만 주사기를 도입하기 전에 이를 평가하는 임상 검사실은 거의 없다. 우리는 임상 검사실에서 널리 사용되고 있는 동맥혈가스분석용 안전주사기인 Greenmedi 헤파린안전주사기(GRS; SANG-A FRONTEC, Korea) 및 Portex 동맥혈용안전주사기(POS; Smiths Medical, USA)에 대해 성능을 평가하였다. 방법: 서울아산병원 진단검사의학과 중앙검사실로 접수된 검체를 대상으로 응괴 발생률, 용혈 발생률을 평가하였고, 3가지 농도의 정도관리물질을 사용하여 가스투과도, 검체량에 의한 영향, 정밀도, 일치도를 평가하였다. 정도관리물질을 실온 보관 후 pO2, pCO2, pH를 측정하여 가스 투과도를 평가하였고. 여러 용량의 정도관리물질로 검체량에 의한 영향을 평가하였다. 검사를 반복하여 정밀도를 평가하였고, 두 주사기의 결과값의 일치도를 분석하였다. 결과: 응괴 발생률은 호흡기내과 일반병동에서 GRS로 채취했을 때 1.07% (51/4,769)로 허용범위를 넘었고, 중환자실에서 POS로 채혈했을 때 0% (0/387)였다. 용혈 발생률은 GRS 14.9% (14/94), POS 10.0% (8/80)로 둘 다 허용범위보다 높았다. GRS, POS 주사기 둘 다 최대허용보관시간은 10분 미만이며, 최소허용검체량은 0.6 mL 초과였다. 정밀도는 모두 우수한 결과를 보였으나 pO2는 두 주사기 간 비교적 낮은 일치도를 보였다. 결론: 두 제품 모두 정밀도는 우수하였으나, 용혈 발생률이 높았다. 또한 결과값의 낮은 상관관계 및 보관시간 및 채취용량에 의한 영향도 확인되었으므로 사용 시 유의해야 한다. 각 검사실에서는 주사기를 도입 전에 주사기의 품질 평가를 선행할 것을 제안한다. Background: Arterial blood gas (ABG) analysis is a crucial test providing vital information for patients who are critically ill. Accurate results are essential; however, pre-implementation evaluation of ABG syringes is uncommon. We evaluated the performance of the Greenmedi heparin syringe (GRS; SANG-A FRONTEC, Korea) and the Portex arterial blood sampling kit (POS; Smiths Medical, USA), which are widely used in clinical laboratories. Methods: Samples from Asan Medical Center were assessed for clotting rate and hemolysis rate. Gas permeability, sample volume impact, precision, and concordance were evaluated using quality control materials. Gas permeability was assessed by measuring pO2, pCO2, and pH after storing the materials for different time periods. The influence of sample volume was tested at various quantities. Precision was evaluated through repeated tests, and concordance between the two syringes’ results was analyzed. Results: GRS had a clotting rate of 1.07% (51/4,769), exceeding the acceptable range, whereas POS had no clotted samples (0/387). Hemolysis rates were 14.9% (14/94) for GRS and 10.0% (8/80) for POS, both higher than the acceptable rate. Both syringes had a storage time of less than 10 minutes and required a minimum sample volume above 0.6 mL. Precision was noteworthy, but there was a relatively weak concordance between pO2 values obtained with the two syringes. Conclusions: Both syringes demonstrated notable precision but had high hemolysis rates. Results showed low concordance and were influenced by storage time and sample volume. Caution should be exercised when using these syringes, and it is recommended to assess their quality before implementation in each laboratory

국내 임상검사실의 검사전단계 품질관리 현황

배경: 진단검사의학에서 검사전단계(preanalytical phase)에서 발생하는 오류는 전체 검사 오류의 반 이상을 차지하나, 국내에서는 검사전단계 관련 연구 및 관리가 부족한 상황이다. 저자들은 국내 진단검사의학 검사실을 대상으로 검사전단계 관리 현황을 파악하였다. 방법: 병원급 이상 의료기관에 근무하는 진단검사의학과 전문의를 대상으로 2021년 6월 14일부터 8월 16일까지 온라인 설문플랫폼을 이용하여 검사전단계 주요 요소에 대해 관리 현황을 설문조사 하였다. 결과: 채혈 전 환자 확인 시 의식이 없는 환자에서 한 가지 요소만 확인하는 기관이 12.5%였다. 대부분의 검사실에서 금식 관련 규정을 가지고 있었으나, 내용에는 차이를 보였다. 검체 라벨은 되도록 환자 앞에서 붙이는 것이 원칙이나, 병동 또는 응급실에서는 잘 지켜지지 않았다. 채혈부터 검사실 접수까지 걸리는 시간을 모니터링 하는 기관은 45.7%, 채혈이 규정대로 수행되는지 평가하는 기관은 75.3%에 불과했다. 대부분의 검사실에서 육안확인 방식으로 검체 용혈을 확인하였고, 용혈지수를 사용하는 기관은 40% 미만이었다. 용혈지수 보고방식은 다양하였으며, 대부분의 기관에서 용혈지수에 대한 내부정도관리를 시행하지 않고 있었다. 결론: 이번 연구를 통해 우리나라 의료기관의 검사전단계 현황을 파악하였으며, 금식 규정, 검체 라벨링 및 운반, 채혈 후 접수까지의 소요시간, 검체 내 용혈 등 중요한 요소들이 적절하게 관리되지 않음을 확인하였다. 이 연구 결과는 검사전단계 품질향상 활동을 위한 중요한 기초 자료로 활용될 수 있을 것이다. Background: In laboratory medicine, preanalytical errors account for more than half of laboratory errors; however, in Korea, research on pre-analytical phase management is lacking. This study revealed the status of preanalytical phase management in Korean clinical laboratories. Methods: Clinical pathologists in Korean hospitals, from secondary to tertiary hospital levels, were surveyed on the major preanalytical factors using an online platform from June 14, 2021, to August 16, 2021. Results: For patient identification before blood collection, 12.5% of the laboratories checked only one factor in unconscious patients. Most laboratories had fasting policies; however, the specifics varied. Specimens are supposed to be labeled in front of the patient; however, this was not always followed in the wards or emergency departments. Only 45.7% of the laboratories checked the time from blood collection to laboratory reception. Moreover, only 75.3% of the organizations evaluated whether blood collection was being performed according to protocol. Most laboratories were found to employ visual confirmation to detect in vitro hemolysis, with less than 40% laboratories using the hemolysis index. The reporting of the hemolysis index was inconsistent, as most organizations did not conduct internal quality control for this parameter. Conclusions: The study established the preanalytical phase status in Korean medical institutions and found that crucial factors, such as fasting regulations, specimen labeling and transportation, time from blood collection to reception, and in vitro hemolysis, were not being managed properly. These results can serve as an essential basis for quality improvement activities in the preanalytical phase

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. 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

Application of the Analytical Performance Specification for Quality Management of Clinical Chemistry Tests

임상 검사실에서 품질관리 시스템의 구현은 환자 진료를 위한 다양한 검사결과의 품질관리에 필수적이다. 분석수행사양(analytical performance speci cation)은 임상적 요구사항이 충족되었는지를 평가하는 중요한 기준이 되며, 품질관리 결과를 효과적으로 평가하기 위해서 적절한 근거에 기반한 판정기준을 설정하는 것이 중요하다. 본 종설에서는 각 평가 지침에 대한 일련의 판정기준으로 분석수행사양의 목표를 제공하여 검사실에서 이를 보다 쉽게 활용할 수 있도록 하고자 하였다. 이를 위해 정밀도, 직선성 검정, 측정 방법 또는 검체 간의 비교, 시약 로트 간 비교, 변화치검색, 검사방법의 바이어스 평가를 포함하여 임상 검사실의 품질관리에 사용되는 CLSI (임상 및 검사실 표준 연구소) 평가 지침을 조사하였다. ‘대한임상학회 검사표준화및질향상위원회’의 토의를 거쳐 각 지침에서 제시하는 평가기준의 정의와 각 지침과 관련된 비정밀도, 바이어스, 총허용오차 등 분석수행사양의 종류를 제안하였다. 또한, 각 임상화학검사에 대하여 다양한 근거를 기반으로 한 복수의 분석수행사양 목표를 제시함으로써 임상 검사실이 목표로 설정해야 할 검사 성능 수준에 대한 일반적인 범위를 제공하고자 하였다. 본 종설에서 제안된 자료를 통하여 다양한 임상화학검사에 대한 효과적인 품질관리를 촉진하고 각 검사실의 고유한 상황에 맞는 분석수행사양 목표 선택 및 적용 과정을 용이하게 할 것으로 기대된다. In the realm of clinical laboratories, the implementation of a quality management system is vital for the quality management of various test results for patient treatment. Analytical performance specifications (APS) serve as the critical criteria for assessing whether clinical requirements have been fulfilled, and ensuring that these standards are based on appropriate evidence is crucial to effectively estimate the processes and outcomes of the quality management system. Our aim was to define practical APS goals as acceptability criteria for evaluating test quality. This would make it straightforward for laboratories to apply these guidelines. To this end, we examined relevant Clinical and Laboratory Standards Institute guidelines employed in the quality management of clinical laboratories, such as encompassing precision, linearity, comparison between measurement procedures or samples, comparison between reagent lots, delta check of patients’ results, bias evaluation of test methods, among others. Furthermore, after discussion with the Committee on Standardization and Quality Improvement of Korean Society of Clinical Chemistry, we proposed definitions on the evaluation criteria provided in each guideline and the types of APS such as imprecision, bias, and the total allowable error corresponding to them. Setting multiple evidence-based APS goals for each clinical chemistry test would assist in establishing a range of performance levels that clinical laboratories should aim for. We expect the data suggested in this review to facilitate effective quality management for various clinical chemistry tests and simplify the selection and application of APS for the unique circumstances of each laboratory

Performance of Tacrolimus Electrochemiluminescence Immunoassay on Cobas Pure Integrated Solutions

Background: Cobas pure integrated solutions (Roche Diagnostics International AG, Switzerland) is a newly launched automatic analyzer combining clinical chemistry, immunoassay, and ion-selective electrode diagnostic testing. We evaluated the analytical performance of tacrolimus electrochemiluminescence immunoassay (ECLIA) on cobas pure and compared it with that of affinity chrome-mediated immunoassay (ACMIA) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Methods: Quality control materials and residual whole blood samples from patients receiving tacrolimus were used in evaluating the performance metrics, including the precision, linearity, comparison, and carryover, of tacrolimus ECLIA (Roche Diagnostics GmbH, Germany) on cobas pure. The precision, linearity, and comparison were assessed in accordance with Clinical and Laboratory Standards Institute guidelines EP5-A3, EP6-A, and EP9-A3, respectively, and the carryover was calculated. Results of tacrolimus ECLIA on cobas pure were compared with those of tacrolimus ACMIA (Siemens Healthineers, USA) and LC-MS/MS (Waters Corporation, USA) on other platforms. Results: The within-laboratory precisions of tacrolimus ECLIA on cobas pure were 4.0%, 3.1%, and 3.2% at low, medium, and high concentrations of quality control materials. The linearity of the assay was acceptable (0.91-27.43 ng/mL). Correlation analysis indicated that the results of tacrolimus ECLIA on cobas pure were comparable to those of Dimension TAC and LC-MS/MS (r=0.977 and 0.994, respectively) with slight difference. Moreover, the carryover effect was 0.03%. Conclusions: Tacrolimus ECLIA on cobas pure showed acceptable precision, linearity, and correlation with ACMIA and LC-MS/MS except for a slight difference. The overall performance of tacrolimus ECLIA on cobas pure is suitable for the therapeutic drug monitoring of tacrolimus in clinical laboratories

Schemes and Performance Evaluation Criteria of Korean Association of External Quality Assessment (KEQAS) for Improving Laboratory Testing

External quality assessment (EQA) is important for evaluating clinical laboratories and enhancing their testing quality. EQA schemes are variable; thus, it is crucial that the EQA organizers share their experiences to continuously improve the EQA scheme. The Korean Association of External Quality Assessment Service (KEQAS) has been the leading, authorized EQA institute for the standardization and quality management of laboratory testing in Korean medical institutions since 1976. The EQA scheme underwent a major change in 2016, and the number of EQA programs increased significantly since then. The key changes implemented in EQA scheme include a fully computerized assessment to accelerate feedback and unification of the testing and reporting methods. We provide an overview of the EQA schemes and performance evaluation criteria of the KEQAS and suggest directions for achieving the global harmonization of EQA