Fig. 3

Accuracy of rapid hemoglobin tests. Panel a illustrates a very strong positive correlation between the AnemoCheck-LRS and the gold standard method (r = 0.93, p < 0.0001) for samples within the detection limit of the assay (Hb 2–8 g/dL); panel b illustrates that the WHO Haemoglobin Colour Scale (WHO HCS) consistently overestimated hemoglobin concentration compared to the gold standard method with a moderate correlation (r = 0.57, p < 0.0001) for samples within the detection limit of the assay (Hb 4–14 g/dL); panel c illustrates the very strong correlation of the HemoCue Hb 201⁺ test to the gold standard method (r = 0.99, p < 0.0001) which was included as a POC method for the study to evaluate its future utility in the field as a portable, replacement gold standard. For each panel, the solid line represents a perfect agreement and the dotted line represents a best fit line