Evaluation of Ves-Matic Cube 200 for erythrocyte sedimentation rate determination

International Council for Standardization in Haematology suggested Westergren method as the reference method to analyze erythrocyte sedimentation rate (ESR). However, in recent years closed automated systems that measure ESR directly from a capped EDTA blood sample tube have been developed. We evaluated the analytic performance of one of these new methods, the Ves-Matic Cube 200.

K(2) EDTA and citrated blood samples were taken from 101 randomly selected outpatients in Ankara Numune Education and Research Hospital. The ESR results using Ves-Matic Cube 200 and Westergren as reference method from 101 patients were compared and interference studies were performed.

We found the mean difference between the two methods as 0.19 ± 15.85 mm/hr (-3.317 to 2.940 mm/hr, 95% confidence interval). Regression analysis yielded the equation "y = -2.59 + 1.15x" between the two methods (r = 0.82).

Ves-Matic Cube 200 should be monitored carefully for good quality control. Temperature correction should be applied to study control material as recommended by the manufacturer. Ves-Matic Cube 200 device should be monitored carefully, performance studies should be performed, and the results should be checked in order to eliminate the random errors during the routine studies.