Comparison of efficacy of filter paper cyanmethemoglobin method with automated hematology analyzer for estimation of hemoglobin

BACKGROUND: Screening of hemoglobin (Hb) before blood donation is one among the vital tests. It is performed to select a blood donor to prevent the collection of blood from an anemic person. However, no accurate, cost-effective, reliable, and standardized method is available to estimate Hb. OBJECTIVE: The aim is to evaluate the efficacy of filter paper cyanmethemoglobin (FPCH) method with the automated hematology analyzer in the estimation of Hb concentration for screening of a suitable donor. METHODOLOGY: This was a cross-sectional study in which the blood samples of 2000 patients visiting KLE's Dr. Prabhakar Kore Charitable Hospital, Belagavi, were collected in vials and directly estimated for Hb using automated hematology analyzer. To evaluate the efficacy of FPCH, 20 μL of blood sample was transferred onto Whatman filter paper and dried at room temperature. After drying, it was placed in 5 mL of Drabkin's solution for 30 min. Optical density was estimated by measuring the absorbance. Data were analyzed using SPSS version 20. The correlation coefficient, paired t-test, and difference between the means of both the methods were calculated. RESULTS: The mean Hb estimated by FPCH was 11.25 g/dL and automated hematology analyzer gave 11.35 g/dL. The difference in the means of both the methods was 0.1 g/dL. Paired t-test was done to test the level of significance and the result was 8.151 (95% confidence interval: 0.08–0.13 g/dL, P < 0.001). The correlation coefficient was found to be 0.976 (P < 0.001). CONCLUSION: FPCH is an efficient method, which is comparable to the automated hematology analyzers for Hb estimation. It could be used as an alternative screening tool for detection of Hb in a blood donation camp.