A Comparative Study on Determination of Erythrocyte Sedimentation Rate by Two Automated Erythrocyte Sedimentation Rate Analysis Techniques-Ves Matic Cube 30 and Mixrate X20 in Comparison to Modified Manual Westergren Method

Abstract

BACKGROUND: Erythrocyte sedimentation rate (ESR) is a widely used simple and cost-efficient lab test for the diagnosis and follow-up of many diseases. Even though the Westergren method is considered as gold standard, it has many drawbacks such as long test time duration, infection risk to technician, and need of citrated blood sample and to overcome these limitations, automated ESR analysis techniques have been introduced. This study aimed to compare and assess the agreement as well as to analyze the correlation between the ESR values obtained by two automated ESR analysis techniques– Ves Matic Cube 30 and Mixrate-X20 against the gold standard–Modified Manual Westergren method. MATERIALS AND METHODS: Four milliliter blood samples were collected from 1174 patients who came to the Central laboratory with complete blood count and ESR test request forms, after taking informed consent. Each of these samples was subjected to ESR test in both Mixrate X20 and Ves Matic Cube 30, followed by ESR analysis through the modified manual Westergren method. All values obtained were recorded and analyzed using SPSS software. Mean, standard deviation, Bland–Altman agreement analysis, Linear regression, and Pearson's correlation coefficient analysis was done. RESULTS: Of 1174 study samples, 588 were male and 586 were female and major proportion of the study sample was in the age group of 50–59 years. Bland–Altman agreement analysis of manual ESR Vs Ves Matic cube 30, showed a mean difference of −2.44 ± 13.01 with 95% limit of agreement (LOA) between −27.93 and 23.05 whereas it was 0.05 ± 1.68 with 95% LOA between −3.24 and 3.34 for manual ESR vs Mixrate X20. Pearson's correlation coefficient for manual ESR Vs Ves Matic Cube 30 was r = 0.891 whereas r = 0.998 for manual ESR Vs Mixrate X20, indicating a strong positive correlation between ESR values obtained through manual method and both automated ESR analyzers. CONCLUSION: ESR results from both automated analyzers are agreeable to the reference method with no proportional bias statistically. However, the results from Mixrate X20 ESR analyzer correlate very well with the manual ESR, with close readings that do not affect the clinical interpretation and so can be used in clinical laboratories to optimize workflow and use of human resources.