Estimation of change limits (deltacheck) in clinical laboratory

Abstract

Objectives Change limits, more commonly called delta check, are those in which a change in a patient’s measured result in relation to their corresponding preceding measurement is suspected of being erroneous and should be considered as a doubtful result. The aim of this study was to provide change limits for some biochemical and haematological quantities to detect doubtful measured results and to assess its effectiveness to detect erroneous results for their application in and the standardization of the plausibility control. Methods Change limits have been estimated for 13 biochemical and 6 haematological quantities. For each quantity, relative differences (D), expressed as a percentage between the two consecutive measured results from the same patient (from scheduled laboratory requests), were calculated. From these differences (D), the p5 and p95 percentiles of the data distribution were calculated. To assess the effectiveness of the change limits to detect laboratory errors, 43 erroneous laboratory reports, containing different biochemical and haematological quantities, were obtained from the standard laboratory plausibility control procedure. Results From the 43 erroneous laboratory reports, 31 (72%) were due to endovenous administration errors and 12 (28%) were due to mislabeling errors. All erroneous laboratory reports were detected when the change limits of the quantities were combined and applied together. Conclusions The best combination of quantities, which detect all the erroneous reports in the same specimen were: potassium, albumin, creatinine, glucose and haemoglobin.

The Role and Limitations of the Reference Interval Within Clinical Chemistry and Its Reliability for Disease Detection

“…Computer algorithms can be set up in LIMS that withhold results and prevent their release to requestors. A common rule is the “delta check” which is a limit on the difference between two measurements for the same analyte [ 24 ]. A change in result outside of these set parameters will cause a result failure and lead to it being held for review.…”

Relationship between Cystatin C levels and the severity of kidney damage in patients with kidney failure

“…(34) • Post análisis: en esta etapa se lleva a cabo la revisión, reporte y liberación de los resultados obtenidos, el almacenamiento, retención, y desecho de las muestras analizadas. (41) • Deltacheck: permite evaluar el porcentaje máximo de la variación que existe entre un resultado actual y uno ya obtenido según el analito analizado en este caso la cistatina C, el laboratorio clínico es el encargado de obtener estos coeficientes de variación delta a partir de un cv de control interno (42) . • Estrategia: estos límites de cambio en el laboratorio se pueden determinar a partir de percentiles de distribución poblacional o datos de la variabilidad biológica intraindividual.…”