METHODS: In this cross-sectional, non-randomized clinical performance study, participants aged ≥8 years were prospectively recruited. Hemoglobin was measured non-invasively using the Vivaray Hb pro and compared with venous blood samples analyzed on a calibrated Coulter counter. Agreement between methods was assessed using Bland-Altman analysis, including regression-based evaluation for proportional bias. Mean difference, mean absolute error (MAE) and proportions of measurements within tolerance limits were also calculated. Complete paired measurements were available for 763 individuals.
RESULTS: Bland-Altman analysis returned a mean difference of -0.40 g/dL. The bias was hemoglobin-dependent, being higher than the true value at low hemoglobin levels and underestimation at higher levels. Regression-based analysis showed proportional bias (β1 = -0.178), indicating decreasing difference with increasing hemoglobin concentration. The MAE was 1.5 g/dL but was lower (1.2) in the clinically predominant ranges of 8.1-13 g/dL.
CONCLUSION: The Vivaray Hb pro can function as a useful non-invsive screening and point-of-care assessment device for measuring hemoglobin, particularly in settings where rapid, painless and repeatable measurements are desirable.