An evaluation of the Abaxis VSPro for the measurement of equine plasma fibrinogen concentrations

Reasons for performing study: Accurate measurement of plasma fibrinogen concentrations is an important tool for assessment of horses with inflammatory diseases. Objectives: To determine the precision and accuracy of a benchtop instrument using both fresh and frozen equine plasma by comparing the plasma fibrinogen concentration measured by a benchtop instrument to 2 separate laboratory standard methods (ACL 100 and STA Compact) for fibrinogen measurement. Methods: Accuracy and precision of the VSPro was evaluated using both human fibrinogen standards and samples from horses. Fifty frozen samples from horses with gastrointestinal disease had the fibrinogen concentration measured using the ACL 1000 and the VSPro. Fifty fresh samples were collected from hospitalised horses and fibrinogen concentration was measured using the STA Compact coagulation machine and the VSPro. Correlations for measurements were performed, as well as Bland‐Altman analysis. Results: Coefficients of variability for the VSPro ranged from 7% to 15%. The VSPro fibrinogen values were well correlated to both the ACL 1000 (r = 0.94, P<0.001) and the STA Compact measurements (r = 0.926, P<0.001). Bland‐Altman analysis showed a mean bias of ‐0.83 g/l (95% confidence interval ‐2.03–0.324 g/l) for the ACL 1000 and a mean bias of ‐0.024 g/l (95% confidence interval ‐1.434–1.386 g/l) for the STA Compact. Conclusions: The VSPro appears to have adequate accuracy and precision for clinical measurement of plasma fibrinogen concentrations. Potential relevance: The VSPro provides a measurement of equine plasma fibrinogen concentration using a benchtop instrument with a rapid test time that has comparable accuracy to the fibrinogen concentration obtained from reference laboratories.