Recently HemoCue® portable hemoglobin photometer using venous or capillary blood samples has been widely used for quick assessment of hemoglobin concentrations; especially in poor settings where skills and resources are limited.
The accuracy of HemoCue® for measuring hemoglobin in clinical settings is still a matter of controversy. The results of this study have shown that the hemoglobin concentration of HemoCue® using either venous or capillary blood samples have lower level of precision and was not comparable with that of automated hematology analyzer; the limits of agreement were larger than the predefined clinically acceptable limits of ±1 g/dl. This is goes with the previous findings of the studies conducted among pregnant women at high altitude  and adult patients hospitalized in surgical intensive care unit . The difference between the readings has been explained by the use of only one microcuvette with HemoCue® especially when using capillary blood samples and laboratory values, and advised loading multiple microcuvettes and averaging the hemoglobin values obtained has been proposed .
However, other studies showed that the results obtained by using HemoCue® for hemoglobin assessment among pregnant women were comparable to that of automated hematology analyzer as a standard . Bernard et al., found that the results of hemoglobin concentration among pregnant and non-pregnant populations using HemoCue® were comparable to that of automated hematology analyzer and Cyanmethemoglobin methods . Other studies which were conducted in different settings and populations such as patients with gastrointestinal bleeding, surgical patients repeated measurement of one sample, urban general practice, neonates, patients undergoing aortic surgery in the theatre and blood donors recommended HemoCue® for the hemoglobin estimation [8, 24–31]. Paiva et al. found that HemoCue® was more appropriate for capillary compared to venous blood samples . However, there was within-subject variability of capillary blood hemoglobin values that might explain the unreliability of the method, and it has been shown that two capillary samples taken from different fingers of the same subjects had hemoglobin concentrations differing by/ more than two g/dL using the HemoCue® .
In spite of the non-acceptable agreement of HemoCue® with automated hematology analyzer in this study, the HemoCue® is however simple to use, need minimum training, cheap, and gives an immediate result. Furthermore, it is useful in clinical and epidemiological settings where finger puncture allows capillary blood sampling as an easy technique which is less resource-intensive than vein puncture, and is more acceptable to patients and the community.