Comparison of peripheral blood smear examination with automated haematology analyzer for diagnosing different types of anemia.

Abstract

Objective: This study aims to determine diagnostic accuracy of peripheral blood smear and automated haematology analyzer and to determine frequency of different types of anemia diagnosed by peripheral blood smear and automated hematology analyzer. Study Design: Cross Sectional study. Setting: Department of Pathology, Rawal Institute of Health Sciences, Islamabad. Period: November 2015 to April 2016. Material & Methods: Sample size of 149 suspected anemia patients was calculated using WHO calculator with 95% confidence interval. Research approval was taken from hospital ethical board. Patients were approached through non probability consecutive sampling method. Both peripheral blood smear examination and automated haematology analysis of each sample was performed. Diagnostic accuracy and frequency of anemia types was measured. Data analysis was done with the help of SPSS version 25. Chi-square and fissure exact test and ROC curve analysis was applied and significant (p<0.05) results were reported. Results: Total 149 patients were included in study. There were 42(28.2%) male and 107(71.8%) female.  Mean age of patients was 35.1±2.1SD. Peripheral blood smear and automated haematology analyzer showed sensitivity (68% vs 92%), specificity (59% vs 88%), PPV (72% vs 92%), NPV (55% vs 88%) and diagnostic accuracy (64% vs 91) respectively. Most common type of anemia diagnosed with peripheral blood smear was microcytic hypochromic anemia with raised RDW 36.7% followed by normocytic normochromic anemia with raised RDW 13.3% and macrocytic anemia (p=0.001) while in automated haematology analyzer microc ytic hypochromic anemia with raised RDW54.4% followed by normochromic normocytic anemoia with normal RDW 11.1% (p=0.000). Conclusion: Automated haematyology analyzer had high diagnostic accuracy for diagnosis of anemia.  Microcytic hypochromic anemia and normocytic normochromic are most common anemias diagnosed by peripheral blood smear and automated hematology analyzer and peripheral blood smear cannot be completely replaced by automated haemolytic analyzer. However, if both methods are used simultaneously, more accurate results can be obtained.