Abstract
Iron deficiency anaemia (IDA) is the most common nutritional disorder worldwide and disproportionately affects women of reproductive age. In Pakistan, the prevalence of anaemia among females exceeds 40%. However, confirmatory tests such as serum ferritin and total iron-binding capacity are often inaccessible due to financial and logistical constraints. As a result, a complete blood count (CBC) is a universally available and cost-effective alternative for the early detection of IDA. This cross-sectional study evaluated the diagnostic effectiveness of routine haematological indices, including haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and red cell distribution width (RDW), in 50 females aged 18 to 45 years with clinically suspected IDA and haemoglobin levels below 12 g/dL. Venous blood samples were collected in EDTA tubes and analysed using an automated haematology analyser. Participants with haemoglobinopathies, anaemia of chronic disease, pregnancy, or those receiving current haematinic therapy were excluded from the study, which was conducted over 8 months at the Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan. Among the participants, 62% were anaemic, with a mean haemoglobin level of 10.01 g/dL. Elevated RDW was observed in 82% of cases, indicating anisocytosis, while MCV and MCH remained within normal reference ranges, which is consistent with early-stage normocytic IDA. The mean platelet count was 387.5×10³/µL, approaching thrombocytosis and further supporting the diagnosis of iron deficiency. A weak correlation was noted between haemoglobin and MCV, reinforcing the predominance of a normocytic pattern. These findings indicate that elevated RDW, combined with reduced haemoglobin in the absence of microcytosis or hypochromia, is a sensitive indicator of early iron deficiency anaemia. Routine CBC parameters, particularly RDW, provide an accessible, reliable, and clinically valuable screening tool for IDA, especially in resource-limited settings where advanced iron studies are not routinely available.