Minimizing the error in the hemoglobin estimation of blood donors as an articulate step toward donors' blood management.

Introduction: Hemoglobin (Hb) estimation in blood donors is conducted using capillary samples on portable hemoglobinometers, representing measurement methods in practice. The reference standard is conducted using a venous sample on a hematology analyzer, representing the mentor measurement method or the true value. The correction involves the calculation of the secondary adjustment factor (SAF) to mitigate the difference between the two values.

Material and methods: A cross-sectional study enrolled 187 blood donors after approval from the institute's ethics committee. On each donor, capillary Hb was performed on the first drop and the second drop of blood using the hemoglobinometer (HCC-1 & 2) and venous Hb using the hemoglobinometer (HC-V) and hematology analyzer (HA-V) consecutively. The secondary adjustment factor was derived from the slope of the regression equation by calculating the ratio of change in HA-V to the corresponding change in HCC -1 & 2.

Results: The Hb on HCC-1 & 2 was 15.02 ± 1.30 g/dL & 15.03 ± 1.34 g/dL, whereas the Hb on HC-V & HA-V was 15.00 ± 1.24 g/dL & 14.41 ± 1.19 g/dL respectively. No difference in means of Hb between HCC-1 & HCC-2 was observed. The equation to calculate SAF was HA-V = 3.25 + 0.74 × HCC-1 and HA-V= 3.58 + 0.72 × HCC-2 respectively.

Conclusion: The study highlights the need for Hb cut-off for blood donors specific for the type of sample, the drop of blood in case of capillary sample and use correction with secondary adjustment to strengthen quality assurance.