Evaluation of five discriminating indexes to distinguish Beta-Thalassemia trait from iron Deficiency Anaemia

Objective: to assess the reliability of different red blood cell indices-based formulae in the indexes formula in differential diagnosis of beta thalassemia trait and iron deficiency anaemia. methods: this cross-sectional study was conducted between january and october 2015 in dera ismail khan in the khyber pakhtunkhwa province of pakistan. patients of beta thalassemia trait and iron deficiency anaemia were registered irrespective of age and gender. about 5 ml of blood was taken from each patient to analyse different red cell parameters like red blood cell count,haemoglobin,mean cell volume,mean cell haemoglobin,mean cell haemoglobin concentration,and red cell distribution width. five formulae were used to discriminate between the two conditions. these were red cell distribution width index,shine and lal index,mentzer index,srivastava index,and the green and king index. sensitivity,specificity,positive and negative predictive values and youden's index of all the indices were calculated. results: of the 800 patients,230(29%) had beta thalassemia trait and 570(71%) had iron deficiency anaemia. the red cell distribution width index appeared be a reliable index in discriminating between beta thalassemia trait and iron deficiency anaemia with sensitivity and specificity of 100% and 93% respectively. conclusion: the red cell distribution width index was the most consistent index for differentiating between beta thalassemia trait and iron deficiency anaemia. iit could be used as a screening index for beta thalassemia trait in areas where haemoglobin electrophoresis facility is unavailable. © 2016,pakistan medical association. all rights reserved.