Gruenberg Jessica M, Stein Tracy A, Karger Amy B
Department of Laboratory Medicine and Pathology, University of Minnesota, 420 Delaware St SE, MMC 609, Minneapolis, MN 55455, United States.
Clin Biochem. 2018 Mar;53:139-142. doi: 10.1016/j.clinbiochem.2018.01.023. Epub 2018 Feb 1.
Delta checks are a long-standing practice for identifying errors in the laboratory. However, with the decrease in errors due to laboratory automation, their utility is unclear. The objective of this retrospective analysis was to determine whether establishment of a creatinine delta check would be an effective means for capturing true laboratory error.
All patients with a minimum of two creatinine results during March of 2015 were selected for review (n = 23,410 creatinine results). The lowest % change for a previously confirmed creatinine error in our laboratory was approximately 60%; therefore only results that changed by at least ±60% (n = 254) were reviewed. The etiology of creatinine value change was categorized as laboratory error, pathologic change, or non-pathologic change, based upon chart review.
1.2% (3/254) of reviewed delta checks were determined to reflect 2 instances of true laboratory error that went unrecognized by laboratory staff. 91.3% (232/254) of the delta checks were determined to reflect a pathologic or dialysis-related change in creatinine levels. The remaining 7.5% of delta checks (19/234) were deemed to be non-pathologic changes in creatinine.
This study identified two instances of laboratory error reflected by 3 delta checks (1.2%); the vast majority (91.3%) of creatinine results that changed by ±60% were pathologic or dialysis-related. Thus, establishment of a ±60% delta check for creatinine would overwhelmingly flag true biological change and would not be an efficient means for identifying rare laboratory errors. Clinical laboratories should perform similar retrospective analyses prior to enacting delta checks to determine whether they will effectively capture laboratory error.
差异检查是实验室识别错误的一项长期做法。然而，随着实验室自动化导致的错误减少，其效用尚不清楚。这项回顾性分析的目的是确定建立肌酐差异检查是否是捕捉真正实验室错误的有效手段。
选择2015年3月期间至少有两次肌酐检测结果的所有患者进行回顾（共23410次肌酐检测结果）。我们实验室之前确认的肌酐错误的最低百分比变化约为60%；因此，仅对变化至少±60%的结果（n = 254）进行回顾。根据病历审查，将肌酐值变化的病因分为实验室错误、病理变化或非病理变化。
在审查的差异检查中，1.2%（3/254）被确定反映了2例实验室工作人员未识别出的真正实验室错误。91.3%（232/254）的差异检查被确定反映了肌酐水平的病理或与透析相关的变化。其余7.5%的差异检查（19/234）被认为是肌酐的非病理变化。
本研究通过3次差异检查（1.2%）识别出2例实验室错误；绝大多数（91.3%）变化±60%的肌酐检测结果是病理性的或与透析相关的。因此，建立±60%的肌酐差异检查将绝大多数标记真正的生物学变化，而不是识别罕见实验室错误的有效手段。临床实验室在实施差异检查之前应进行类似的回顾性分析，以确定它们是否能有效捕捉实验室错误。
