Red Blood Cell Indices beyond Haemoglobin Show Limited Utility for Iron Deficiency Detection in Bangladeshi Adult Women: A Tertiary Care Hospital Study

Background: Anaemia in women remains a major health concern in lowincome countries like Bangladesh. It puts at risk the well-being of women of childbearing age and hinders progress toward achieving the United Nations Sustainable Development Goals (SDGs) by 2030. For treating anemia, injectable iron supplements are inexpensive, efficient, and have a quicker onset of action. However, administering it without confirming iron status may result in iron overload. Although red blood cell (RBC) indices are often used as surrogate markers for iron status, their diagnostic accuracy remains controversial. Objective: The goal of our study is to assess whether RBC indices alone can reliably predict iron deficiency, with the aim of reducing the cost of iron profiling and guiding safe parenteral iron supplementation, so that anaemia can be prevented at the root level at an affordable cost. Methods: The study included Bangladeshi adult women attending the outpatient department of a tertiary care hospital. After evaluating inclusion and exclusion criteria, patients with clinical anaemia (evidenced by pallor or glossitis) were enrolled. Results: Among 130 women, 83 (63.8%) had transferrin saturation or TSAT < 20 %. Haemoglobin (Hb), out of all the complete‑blood‑count (CBC) indices, showed the strongest correlation with TSAT (ρ = 0.55, p < 0.001). Although RBC count and MCV differed modestly between groups, adding these and other indices to Hb did not improve discrimination. Cross-validated AUC fell from 0.714 (Hb only) to 0.644 (Hb + four indices). Sensitivity increased marginally, but specificity declined, resulting in more false positives. Conclusion: Hb may be adequate for correctly determining iron deficiency in Bangladeshi women. The low price of CBC (about 400 BDT) compared with TSAT assessments (about 1,000-2,200 BDT) makes it a cost-effective initial screening tool. However, biochemical testing (TSAT or ferritin) is still required for diagnostic certainty, especially when iron overload is suspected.