Maria Dolores Sofia
Azienda Ospedaliero University,Italy
Title: Erythrocyte sedimentation rate (ESR): comparison between VES-Matic Cube 80 and the manual method
Biography
Biography: Maria Dolores Sofia
Abstract
Erythrocyte sedimentation rate (ESR), though simple and nonspecific, is still the most widely used laboratory test for monitoring the course of infection, inflammatory diseases and some types of cancer. The aim of this study was to compare the performance of VES-Matic Cube 80, automated analyzer (DIESSE Diagnostica Senese, Siena, Italy) with the traditional manual method with sodium citrate as anticoagulant.
Methods: Both methods were applied to 357 randomly selected samples from inpatients and outpatients admitted between February and April 2011. Correlation coefficient, linear regression, paired Student’s t test and Bland-Altman method were examined to compare the accuracy between automated and manual method. Precision was evaluated in randomly selected subsamples for the following ESR ranges (10 samples each): low (≤20 mm), intermediate (21 to 40 mm) and high (>40 mm). In the latter case, five replications for each sample were performed with one-hour interval between measurements.Means, SD, 95% CI,CV and Bland-Altman analysis were taken into account.
Results: Results with both methods were significantly correlated (r = 0.91; P < 0.001 ). Bland-Altman analysis showed a systematic bias (-5.89 mm) with 95% CI of 17.2 to –29.05 . Results were highly replicable up to the 5th measurement with VES-Matic but not with the manual method .
Conclusions: Accuracy and precision with VES-Matic were significantly better than with manual method. Ascolta Trascrizione fonetica Bland-Altman analysis revealed a wide degree of scattering between results obtained with the two ESR techniques, which was not clearly demonstrated using the linear regression analysis. Repeatability of results over time was significantly better with VES-Matic.