Wadhwa Nishtha, Bhat Kiran, Kalsi Mansi, Sadhu Tushita
Biochemistry, Himalayan Institute of Medical Sciences, Dehradun, IND.
Biochemistry, Shri Guru Ram Rai Institute of Medical and Health Science, Dehradun, IND.
Cureus. 2025 Feb 15;17(2):e79043. doi: 10.7759/cureus.79043. eCollection 2025 Feb.
Introduction To evaluate the variability in values reported by a clinical laboratory, it is important to assess the measurement uncertainty (MU). Furthermore, verifying that the estimated MU aligns with relevant analytical performance specifications (APS) is essential. Previous research has indicated variability in how laboratories estimate and apply MU, with some failing to meet APS, potentially affecting clinical decision-making. Additionally, factors such as differences in instrumentation, reagent quality, and calibration protocols may contribute to regional variations in MU, emphasizing the need for a systematic evaluation. This study aimed to determine the MU of 31 measurands and compare it with the APS available in the literature to assess whether our measuring systems can meet these APS. Methods The study was conducted in the Clinical Biochemistry Laboratory of the Himalayan Institute of Medical Sciences, Dehradun, India. The measuring systems in our laboratory are Beckman Coulter DxC 700 AU (Beckman Coulter, Inc., Brea, California, United States), Beckman Coulter UniCel DxI 800 (Beckman Coulter, Inc.,), and bioMérieux VIDAS (bioMérieux SA, Marcy-l'Étoile, France). The 'top-down' approach which uses internal quality control data and calibrator information was used for the estimation of MU. The formula used was: =√( + + ). Objectively derived APS available in the literature were utilized to determine the allowable MU. Results A total of 24 measurands exhibited uncertainty estimates below the minimum APS limits. However, serum lactate dehydrogenase (LD), creatine kinase (CK), alkaline phosphatase (ALP), sodium, chloride, glucose, and ferritin showed MU higher than the minimum APS. The calibrator uncertainties (u) for ALP (4.7), LD (5.45), CK (11.06), and Ferritin (23.2) were significantly high, contributing to their elevated MU estimates. Additionally, the minimum APS for serum chloride (0.74) and sodium (0.40) were particularly stringent and could not be met. Conclusion The evaluation of MU provides objective insights into the quality of measurement systems and, its comparison, against set APS, supports the applicability of laboratory results in clinical decision-making. Failing to meet APS can lead to misdiagnosis, treatment errors, and patient safety risks. It may also hinder ISO 15189 accreditation and increase retesting costs.
引言
为评估临床实验室报告值的变异性，评估测量不确定度（MU）很重要。此外，验证估计的MU是否符合相关分析性能规范（APS）至关重要。先前的研究表明，实验室在估计和应用MU方面存在变异性，一些实验室未能达到APS，这可能会影响临床决策。此外，仪器差异、试剂质量和校准方案等因素可能导致MU的区域差异，这凸显了进行系统评估的必要性。本研究旨在确定31个被测量的MU，并将其与文献中可用的APS进行比较，以评估我们的测量系统是否能够满足这些APS。
方法
该研究在印度德拉敦喜马拉雅医学科学研究所的临床生物化学实验室进行。我们实验室的测量系统有贝克曼库尔特DxC 700 AU（美国加利福尼亚州布雷亚的贝克曼库尔特公司）、贝克曼库尔特UniCel DxI 800（贝克曼库尔特公司）和生物梅里埃VIDAS（法国马西 - 埃图瓦勒的生物梅里埃公司）。使用内部质量控制数据和校准品信息的“自上而下”方法来估计MU。使用的公式为： =√( + + )。利用文献中客观推导的APS来确定允许的MU。
结果
共有24个被测量的不确定度估计值低于最低APS限值。然而，血清乳酸脱氢酶（LD）、肌酸激酶（CK）、碱性磷酸酶（ALP）、钠、氯、葡萄糖和铁蛋白的MU高于最低APS。碱性磷酸酶（4.7）、乳酸脱氢酶（5.45）、肌酸激酶（11.06）和铁蛋白（23.2）的校准品不确定度（u）显著较高，导致它们的MU估计值升高。此外，血清氯（0.74）和钠（0.40）的最低APS特别严格，无法满足。
结论
对MU的评估为测量系统的质量提供了客观见解，并且将其与设定的APS进行比较，支持实验室结果在临床决策中的适用性。未能达到APS可能导致误诊、治疗错误和患者安全风险。它还可能阻碍ISO 15189认可并增加重新检测成本。
