The Validation of a New Visual Anaemia Evaluation Tool HemoHue HH1 in Patients with End-Stage Renal Disease

In chronic haemodialysis patients, anaemia is a frequent finding associated with high therapeutic costs and further expenses resulting from serial laboratory measurements. HemoHue HH1, HemoHue Ltd, is a novel tool consisting of a visual scale for the noninvasive assessment of anaemia by matching the coloration of the conjunctiva with a calibrated hue scale. The aim of the study was to investigate the usefulness of HemoHue in estimating individual haemoglobin concentrations and binary treatment outcomes in haemodialysis patients. A prospective blinded study with 80 hemodialysis patients comparing the visual haemoglobin assessment with the standard laboratory measurement was performed. Each patient’s haemoglobin concentration was estimated by seven different medical and nonmedical observers with variable degrees of clinical experience on two different occasions. The estimated population mean was close to the measured one (11.06？±？1.67 versus 11.32？±？1.23？g/dL, ). A learning effect could be detected. Relative errors in individual estimates reached, however, up to 50%. Insufficient performance in predicting binary outcomes (ROC AUC: 0.72 to 0.78) and poor interrater reliability (Kappa < 0.6) further characterised this method. 1. Introduction Anaemia is a feature commonly encountered in daily medical practice especially in well-defined clinical subpopulations such as nephrologic, oncologic, or pediatric patients. Diagnosis and therapeutic monitoring of anaemia are based on blood sampling and laboratory measurements, both necessitating the presence of qualified personnel, logistic, and technical resources and generate high costs especially if repetitive measurements are required. This is particularly striking when considering end-stage renal disease patients treated with recombinant human erythropoietin (rHuEPO) [1]. The imperative to reach and stay within a narrow haemoglobin concentration target range [2, 3], the peculiar pharmacokinetic and pharmacodynamic properties of rHuEPO [4–8], making its use difficult even in hands of experienced nephrologists, has led to the general acceptance of systematic and frequent monitoring of the haemoglobin concentration levels during therapy with rHuEPO. Although in developed countries laboratory facilities are easily accessible, the availability of a simple, cheap, noninvasive, and reproducible bedside method to assess the degree of anaemia in patients necessitating serial measurements would be very suitable [9, 10]. Severe anaemia may be detected by the naked-eye in the presence of significant skin pallor, pale nail