Quality indicators and specifications for key analytical-extranalytical processes in the clinical laboratory. Five years’ experience using the Six Sigma concept

Abstract

The results for indicators related with sample collection indicate that the process is stable and well controlled. However, based on the results for Hemolyzed serum sample, the group saw the need for installing centrifuges in all phlebotomy centers and established a recommendation to unify the system for measuring hemolysis. The indicator External control exceeds acceptance limit clearly highlighted the need to rigorously monitor the analytic phase of the clinical laboratory. The values obtained for the indicator Reports from referred tests exceed delivery time show that there is considerable deviation regarding the expected report delivery time, whereas for in-house laboratory reports, delivery time is satisfactory.

Harmonization in hemolysis detection and prevention. A working group of the Catalonian Health Institute (ICS) experience

“…Since 2004, the group of clinical laboratories of the Institut Català de la Salut, (Catalonian Health Institute) have been evaluating the results obtained from different quality indicators, with the aim of obtaining firm quality specifications for all the processes, including the preanalytical phase processes [7][8][9][10]. To define the quality specifications of these indicators, results were chosen among the laboratory comparison results (state of the art) [11].…”

“…However, there was a great interlaboratory variability, ranging from 0.01% to 1.9% [10], mainly due to the following facts: the lack of standardization in hemolysis detection methods, the existence of non-homogeneous interference limits and the different characteristic of the samples collection centers.…”

Utilidad del análisis modal de fallos y efectos para la detección de errores en el transporte de muestras al laboratorio clínico

“…Aunque diversos grupos de trabajo 14 • N.º muestras con tiempos de llegada > 3h/Total muestras transportadas y controladas (%)…”

Quality Assurance in the Preanalytical Phase

“…The advent of computerized test requesting has reduced some of the errors that occurred when requests were paper-based, as noted in a study that evaluated the evolution of quality indicators of key laboratory processes over a 5-year period; in that study, the error rate for test requests fell from 4.1% to 3.3% (Alsina et al, 2007;Llopis et al, 2010). However, due to the ease of access (i.e.…”

“…Therefore, we can deduce that the quality specifications proposed by Alsina (Alsina et al, 2007) reflect current state of the art and support the recommended acceptability limits. The same group of laboratories carried out a follow-up study (LLopis et al , 2010) in which quality specifications for the preanalytical indicators were assessed annually over a 5-year period following their initial implementation in order to evaluate changes (Alsina et al, 2007) The authors proposed converting the specification value to the six-sigma scale in order to establish the degree of control over the process, with processes having a sigma greater than or equal to 4 considered well-controlled (Westgard, 2006). Most of the indicator values remained stable over the 5-year study period and so the mean of the inter-laboratory medians-which proved to be a robust value over the course of the study period-was recommended as a desirable specification.…”