Evaluation of Freestyle Optium Neo H and TaiDoc-TD4235 point-of-care meters for measuring blood β-hydroxybutyrate concentration in sheep

Abstract

Background: Accurate and rapid measurement of blood β-hydroxybutyrate (β-OHB) concentrations is critical to identify hyperketonemia in sheep. Objective: The objective of this study was to test the performance of Freestyle Optium Neo H and TaiDoc-TD4235 point-of-care (POC) devices for measuring blood β-OHB concentrations in sheep. Methods: Venous blood samples from 105 sheep were evaluated with Freestyle Optium Neo H and TaiDoc-TD4235 meters. A reference approach was the laboratory measurement of serum BHB concentrations using the Randox D-3 Hydroxybutyrate reagent kit. Data were analyzed using Passing- Bablok regression and Bland–Altman analysis. The diagnostic accuracy was assessed using serum β-OHB concentration at a cut-off value of 0.8 mmol/L. Results: Passing-Bablok regression analysis revealed an intercept of 0.066 (CI95: 0.018–0.125) and slope of 1.242 (CI95: 1.136–1.342) for Freestyle Optium Neo H. Intercept and slope values for the TaiDoc-TD4235 meter were 0.625 (CI95: 0.539–0.724) and 1.265 (CI95: 1.044–1.497), respectively. The Bland–Altman plot revealed a bias of 0.224 mmol/L and 0.737 mmol/L for Freestyle Optium Neo H and TaiDoc-TD4235 meters, respectively, compared with the reference method. Observed Total Error (TEobs) was 56.7% for the Freestyle Optium Neo H and 168.7% for the Taidoc-TD4235. The sensitivity and specificity for the Freestyle Optium Neo H were 100% and 80.9%, respectively, at the threshold of 0.8 mmol/L. The Taidoc-TD4235 demonstrated a sensitivity of 93.3% and specificity of 8.9% at the threshold of 0.8 mmol/L. Conclusions: Because of the large TEobs, the Freestyle Optium Neo H and TaiDoc-TD4235 meters should not be used to quantify blood β-OHB concentrations in sheep.