Background: Current strategy to identify iron deficiency anemia relies on markers involving high costs. Reports have suggested red cell distribution width (RDW) as a potential screening test for identifying iron deficiency anemia (IDA) but studies in pediatric populations are lacking. Our study elucidates the discriminative ability of RDW for detecting IDA among young children.
Methods: 2091 blood reports of children aged 1-3 years from an urban low socio-economic population of Delhi were analyzed to evaluate the sensitivity of RDW in discriminating IDA using receiver's operating characteristic curve. Hemoglobin and RDW were estimated using coulter, zinc protoporphyrin with AVIV fluorometer and serum ferritin by enzyme linked immunosorbent assay.
Results: A total of 1026 samples were classified as iron deficient anemia using gold standard. As a marker of overall efficiency, area under the curve for RDW was 0.83 (95% CI, 0.81- 0.84; p < 0.001). Sensitivity of RDW at cut-off of 18% to detect iron deficiency anemia was 76.5% and specificity 73.1% yielding a positive predictive value of 73% and negative predictive value of 76%. At a cut-off of RDW 16.4%, the sensitivity was 94% and at a cut-off of 21%, the specificity was 95%. Combination of hemoglobin ≤ 10 g/dL and RDW >15%, yielded a sensitivity of 99% and specificity of 90%. These data suggest that simple coulter analysis estimating hemoglobin and RDW can be used for identification of children in need for iron therapy.
Conclusions: In India and similar settings, RDW >15% with hemoglobin ≤ 10.0 g/dL identifies iron deficient anemic children without need for iron status markers which could help reduce cost of management especially in poor settings.
Trial registration: Clinicaltrials.gov NCT00255385.