Agreement assessment between hemoglobin and hematocrit to detect anemia prevalence in children less than 5 years old

Abstract This study aimed to assess the extent of agreement between hemoglobin (Hb) and hematocrit (Ht), while also verifying whether anemia prevalence can be determined by hematocrit cut-off points. A hundred pairs of capillary Hb and Ht of children less than 5 years old were analyzed. The Hb and Ht concentrations were measured using HemoCue and microhematocrit centrifuge, respectively. The Bland and Altman’s method was used to assess the agreement between ‘observed Hb’ and ‘Hb estimated through Ht’ (Hb = Ht/3). The ROC curve was constructed based on the reference to anemia classification according to Hb. The subjects were classified according to the status of anemia obtained through the Ht, also evaluating the agreement regarding Hb. The area under the ROC curve identified that Ht <35% correctly classified 85% of subjects with Hb <11.0 g/dL. However, the cut-off point of <33% showed higher kappa (k = 0.49 against 0.41) and higher relative agreement (82% vs. 74%) compared to Ht