http://localhost:8080/xmlui/handle/123456789/8100 1 - 75 Wed, 08 Apr 2026 22:58:55 GMT 2026-04-08T22:58:55Z http://localhost:8080/xmlui/handle/123456789/8129 Title: Tools for evaluating the performance of HbA1c analyzer: Sigma Metric and Quality Goal Index Ratio Authors: Doventas, Yasemin Erdogan; Erdogan, Hatice Abstract: improvement. This model provides three features that improve the results: low inaccuracy, less deviation, and correct performance of the analytical method. Internal quality control and external quality assessment programs are routinely carried out in all clinical laboratories to evaluate and continually improve the analytical quality. The Six Sigma model is a global quality management system that can also be applied in the determination of glycated hemoglobin (HbA1c). In recent years, this model has been supported by Quality Goal Index (QGI). In this study, we aimed to evaluate the analytical performances of Arkray HA8180V HbA1c analyzer according to internal and external quality Sigma metrics and QGI. Methods: The data have been evaluated according to two internal control materials (Bio-DPC and KBUDEK External Quality Program) to calculate Sigma levels [Sigma=(TEa%-bias%)/CV%] and quality target indexes (QGI=bias/1.5×CV), where TEa is the total analytical error and CV is the coefficient of variation. QGI is a metric that can distinguish between techniques to deal with sensitivity and accuracy issues as well as calibrator lot changes. Results: The mean Sigma levels for low and high quality control materials were found to be 5.17 and 2.51, respectively. QGI was found to be 0.8-1.2 for both levels. Conclusion: The performance of HA8180V HbA1c analyzers was found to be acceptable compared to Sigma metrics. The values of OGI between 0.8 and 1.2 indicate inaccurate and inconsistent result. However, when evaluated as a whole with Sigma values, the results of the devices were found reliable. Sat, 01 Jan 2022 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/8129 2022-01-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/8128 Title: Estimation of measurement uncertainty of glycated hemoglobin at Atellica Solutions Authors: Eren, Funda; Oguz, Esra Firat Abstract: Objectives: Glycated hemoglobin (HbA1c) is a commonly used laboratory test for screening, monitoring, and diagnosing diabetes mellitus (DM). Uncertainty is a statistical expression that shows the effects of factors arising during measurement processes and affecting the reported results. It is important to give reliable laboratory results. This study aims to estimate the measurement uncertainty (MU) of HbA1c at Siemens Atellica Solutions. Methods: Internal and external quality control results of 6 months data were used to calculate the MU according to the Clinical & Laboratory Standards Institute (CLSI) document EP29-A. The coefficient of variation (CV%) of the two levels of internal quality control materials was calculated. The external quality control results of 6 months data obtained from the EQAS program of Bio-Rad were used to calculate the bias. Results: The precision results of the assay were within the current National Glycohemoglobin Standardization Program requirement of ≤4%. The HbA1c level above 6.5% is one of the diagnostic criteria of DM. We estimated the expanded uncertainty as 6.40% for HbA1c at the level of 6.5%. It is presented as 6.5±0.4%. Conclusion: It is important that laboratorians report accurate and reliable test results as clinicians make their decisions based on laboratory data. Laboratories should add measurement uncertainty results as a part of quality control programs. The laboratory tests with clinical decision limits should be presented with measurement uncertainty results. Sat, 01 Jan 2022 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/8128 2022-01-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/8127 Title: Total analytical error assessment of Yerköy State Hospital biochemistry laboratory Authors: Yardim, Meltem Abstract: were specified by the Ministry of Health of Turkey and put into practice. Our study aimed to assess the analytical performance of 15 test parameters studied in our laboratory in terms of the TEa-TR criteria and demonstrate the effect of the method of CV% use in the TAE formula on the performance of tests when two-level internal quality control (IQC) was employed. Methods: Total analytical error (TAE) was calculated using the formula TAE%=(CV%×1.65)+bias%. Two different procedures were followed for TAE calculation. TAE1 and TAE2 were separately calculated for each control level using the CV% values obtained from the data of IQC at two different levels used for each test. In addition, TAE3 values were found for each test parameter in line with the total CV% value (Total CV%=√(CV12+CV22) obtained using the IQC data from two different levels. Results: When CV% values were separately taken for each control level, the maximum allowable CV% value was exceeded in two tests at IQC Level 2, whereas the TEa-TR limit was exceeded in two tests at IQC Level 1 and in 2 tests at IQC Level 2 during the 6-month period. According to the TEa-TR formula, the allowable CV% was exceeded 19 times in 13 out of 15 tests, and TEa limits were exceeded 15 times in 10 tests during the 6-month period. Conclusion: When the total CV% was calculated from Level 1 and Level 2 according to the TEa-TR formula, both the maximum allowable CV% and allowable TEa% limits were exceeded many times. However, when the CV% and TAE values were calculated separately for different levels of IQC samples, the analytical performance of the tests were found better. We think that calculating the TAE and CV% values separately is more useful in showing the analytical performance of the test at different levels. Sat, 01 Jan 2022 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/8127 2022-01-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/8122 Title: Evaluation of total antioxidant capacity in human seminal plasma Authors: Demir, Meltem; Ozdem, Sebahat Abstract: Objectives: Male factor infertility accounts for up to half of all cases of infertility. Oxidative stress (OS) is a condition associated with an increased rate of cellular damage induced by oxygen and oxygen-derived oxidants, commonly known as reactive oxygen species (ROS). Methods: Semen samples were obtained from 65 males aged 23-36 years who were a partner in an infertile couple and presented at the urology clinic of Antalya Medicalpark hospital. Routine spermiogram parameters were analyzed according to World Health Organization guidelines. The study was conducted using a normozoospermic group (n=18) with normal semen parameters, and 47 men with abnormal semen parameters; azoospermic (n=16), teratozoospermic (n=16) and oligoasthenoteratozoospermic (n=15). The total oxidant status (TOS), total antioxidant capacity (TAC), activity, and advanced oxidation protein products (AOPPs) levels in semen were determined using spectrophotometric method. The oxidative stress index (OSI) value of the seminal plasma was calculated. The results were analyzed statistically. Results: The AOPPs level, TOS activity and OSI index value in seminal plasma was significantly higher in the oligoasthenozoospermic, teratozoospermic and azospermic groups compared with the normozoospermic group. In contrast, the TAC activity was higher in normozoospermic group than infertile group. Conclusion: This study investigated whether the antioxidant status and the extent of protein oxidation in seminal plasma could be a valuable predictor of sperm function. The results suggest that TAC assay and OSI index may be useful markers for male infertility. Sat, 01 Jan 2022 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/8122 2022-01-01T00:00:00Z