In this study of almost 1500 young children, mean capillary Hb concentrations by HemoCue Hb301 were significantly higher compared with mean venous Hb concentrations determined by two automated haematology analysers (Sysmex XT-1800i and Mindray BC-3000Plus), resulting in a significantly lower anaemia prevalence by Hemocue (53.7% vs 73.9%). Here, GSTM1 is linked to anemia (phenotype).