Assessing agreement of hemoglobin and three- fold conversion of hematocrit as methods for detecting anemia in children living in malaria-endemic areas of Calabar, Nigeria

BACKGROUND: One of the major causes of anemia, defined as the reduction in the level of hemoglobin or red blood cells (RBCs) in the blood, in children in sub-Saharan Africa is malaria. Anemia is diagnosed by using either the hematocrit method or by measuring the hemoglobin concentration. AIMS: To evaluate the relationship and agreement between hemoglobin and three-fold conversion of hematocrit results of participants in a clinical trial. MATERIALS AND METHODS: This is a cross-sectional study that obtained data from a multi-center clinical trial that took place from 2007 to 2008 in public health facilities in Calabar, Nigeria. The hemoglobin and hematocrit results of 494 children who had ≥2000 parasite density recruited were pooled to evaluate the relationship and agreement between the two methods. The difference between the measures against the mean of the two measures was plotted according to the theory of Bland and Altman. RESULTS: The mean age of the children was 34 months, with approximately equal number of boys and girls. The measured hemoglobin was lower than the calculated hemoglobin in 84.5% of the children. The result showed that lower the hemoglobin concentration, the higher the chances that the three-fold hematocrit conversion overestimates hemoglobin levels in the participants. CONCLUSIONS: The three-fold hematocrit conversion of hemoglobin estimation is a less reliable method than the measured hemoglobin in anemic children in the study setting.