Analytical validation and diagnostic accuracy of a portable hemoglobin/hematocrit meter in cats

Abstract

Anemia is a common clinical condition in cats, and accurate measurement of hematocrit (HCT) and hemoglobin (Hb) is essential for diagnosis and monitoring. Conventional laboratory methods are reliable but may not be practical for critically ill patients. Point-of-care (POC) devices offer rapid results using minimal blood volume, however studies evaluating their accuracy in cats remain limited. This prospective study evaluated the analytical and diagnostic performance of the Mission Ultra Hemoglobin/Hematocrit Testing System in 118 client-owned cats. HCT and Hb values obtained with Mission Ultra were compared with reference methods. The microcentrifuge method and the desktop autoanalyzer served as the reference methods for HCT and Hb measurements, respectively. Bland-Altman plots, Passing-Bablok regression, and Receiver Operating Characteristic (ROC) analysis were used to assess agreement and diagnostic accuracy. Mission Ultra showed a negative bias for HCT (-1.8 %, LoA: -5.4 % to 9 %, p < 0.001) and Hb (-0.6 g/dL, LoA: -2 g/dL to 3.2 g/dL, p < 0.001). Passing-Bablok regression revealed constant and proportional bias for HCT and constant bias for Hb. ROC analysis identified optimized thresholds of <29 % for HCT and < 9.6 g/dL for Hb, yielding sensitivities of 92.3 % and 100 %, and specificities of 94.6 % and 94.7 %, respectively. Although Mission Ultra demonstrated good sensitivity and specificity at the established thresholds for HCT and Hb, the observed biases and relatively wide limits of agreement in comparison with the reference methods may limit its reliability in clinical decision-making.