Assesment of Analytical Performance of HbA1C Test by Six Sigma Methodology

Abstract

Background and Objective: The HbA1 c test is a biomarker used to evaluate the long-term outcomes of diabetes, and therefore its role in diabetes management is important Analytical reliability of clinical laboratories may be obtained by Internal Quality Control (IQC), External Quality Control (EQC) etc. by analyzing the data with statistical methods. In six sigma methodology, which is one of these methods, the analytical performance can be evaluated with a single number named "process sigma value". This study aimed to compare the six sigma levels in line with the results of IQC and EQC of HbA1c tests which is one of the most commonly used tests in our laboratory.

Material and Methods: IQC and EQC data between May 2015-August 2015 were collected. Monthly process sigma levels were calculated by using formula "(TEa% - Bias%)/CV%. For Bias; values that the firm provided from IQC results and the standard deviation index (SDI) values in EQC reports were used. 6% were basis for the allowed total error values (NGSP).

Results: Process sigma level were determined according to IQC1, IQC2 and EQC results by month as May (3.4-8.4-9.6), June (3.9-5.2-4.5), July (5.9-8.4-4.7), August (8.7-8.4-8.2), respectively in 2015.

Conclusions: In our study it was observed that HbA1C test is in conformity with the process sigma levels according to IQC and EQC data. HbA1 c test was found to be compatible with internal quality control and external quality control results in accordance with process sigma levels and it was also evaluated as favorable considering our laboratory performance.