The Correlation of Red Cell Distribution Width With Peripheral Blood Smear: A Study From a Tertiary Care Hospital in Peshawar

Objective: Anemia is a condition characterized by a shortage of red blood cells (RBCs) and hemoglobin (Hb). A peripheral blood smear (PBS) test involves examining a blood sample to identify important abnormalities in the red blood cells, white blood cells (WBC), and platelets. The aim of this study was to correlate the red cell distribution width (RDW) with peripheral blood smear findings in anemic patients presenting to a tertiary care hospital in Peshawar.

Methodology: This cross-sectional study was conducted at Hayatabad Medical Complex, Peshawar, from January 15, 2023, to July 14, 2023. A total of 450 patients aged 18 years and above with confirmed or suspected anemia (Hb of <13 g/dL in men and <12 g/dL in women), hemolytic disorders, or conditions affecting RBC morphology were included. Peripheral blood smear analysis was performed by two independent hematologists to minimize observer bias. Spearman's rank correlation coefficient was applied to determine the correlation between red cell distribution width and the morphological findings on the peripheral blood smear.

Results: Among 450 anemic patients, 232 (51.6%) were women, and 218 (48.4%) were men. The mean age was 25.72 ± 23.23 years. RBC indices showed microcytic RBCs in 270 (60.0%) patients, normocytic RBCs in 157 (34.9%), and macrocytic RBCs in 23 (5.1%). Hypochromic RBCs were found in 301 (66.9%) cases and normochromic in 109 (24.2%). Peripheral blood smear analysis revealed polychromasia in 37 (8.2%) patients and hypochromia in 247 (54.9%). Statistically significant correlations were observed between red cell distribution width and most PBS findings.

Conclusion: Microcytic hypochromic anemia was the most prevalent type on the peripheral blood smear, showing a significant correlation with red cell distribution width. The strong correlation between RDW and anisocytosis suggests the potential utility of RDW as a screening tool in clinical practice.