Objectives
Hemoglobin (Hb) assessment by Hemocue® is used widely for anemia screening in both adults and children. However, few studies have compared the diagnostic accuracy of Hemocue® versus an automated hematology analyzer, particularly in young children. The study objective was to compare hemoglobin concentrations by Hemocue® and automated hematology analyzers in young children in rural communities of Lao PDR.
Methods
Data were drawn from the Lao Zinc Study, a randomized controlled intervention trial. At enrollment, capillary blood was collected from 6-23 mo old children for assessment of Hb by Hemocue® Hb301 to assess eligibility. In a sub-group (n=1210), venous blood was collected on the same day for complete blood count using one of two hematology analyzers (XT-1800, Sysmex and BC-3000Plus, Mindray Medical International Ltd.). Pearsons correlation coefficient (r) was calculated, sensitivity (Se) and specificity (Sp) analyses were performed, and agreement between the two methods was estimated using Bland-Altman plots.
Results
There was a high correlation between the 2 methods (r=0.7). However, mean Hb was higher by Hemocue® than by hematology analyzers combined (109±10 g/L vs 104±13 g/L), resulting in an anemia prevalence (Hb <110 g/L) of 51.9% vs 69.7%, respectively. The Se and Sp for detection of anemia by Hemocue® were 68.1% and 85.2%, respectively. The Bland-Altman plot indicated a bias of 5.1 g/L and limits of agreement were -12.6 g/L to 22.9 g/L.
Conclusions
Capillary Hb assessed using Hemocue® showed weak agreement compared with venous blood Hb assessed by automated hematology analyzers resulting in significantly different anemia prevalences.Funded by the Micronutrient Initiative, the Mathile Institute for the Advancement of Human Nutrition and the Bill & Melinda Gates Foundation
