Evaluation of the Performance of Copper Sulphate and HaemaCue Methods for Haemoglobin Estimation Among Blood Donors in Dar es Salaam, Tanzania

Abstract

Background: The Tanzania National Blood Transfusion Service (NBTS) uses Copper Sulphate (CuSO4) method for Hemoglobin (Hb) measurement in blood donors. However, this method may potentially provide many false results; this is because CuSO4 is affected by the abnormal amount of serum protein since it precipitates Hb and other proteins in the blood. Currently, there is paucity of information in Tanzania on the proportion of false deferrals and false eligible blood donors through CuSO4 method when compared with other Hb estimation methods like HemoCue. Objective: This study aimed to evaluate the performance of CuSO4 and HemoCue methods for Hb estimation among blood donors in Dar es Salaam, Tanzania. Methodology: This was a cross-sectional study conducted from January to March 2019. It was conducted in Dar es Salaam at three (3) blood donation centers which are Muhimbili National Hospital (MNH), Eastern Zone Blood Transfusion Centre (EZBTC) and Temeke Regional Referral Hospital. A total of 204 blood donors were recruited. For each blood donor, capillary and venous blood was collected. Hb was estimated by CuSO4, HemoCue and automated hematology analyzer (as a gold standard). Data was analyzed by Epi info 7. P-value of < 0.05 was used as a cut-off for significance test, Correlation coefficient was applied in finding the relation between venous blood Hb and capillary blood Hb and kappa agreements measurements for CuSO4 and HemoCue was also established. Results: The median age of the study participants was 30 [IQR, 20-39] years and 53% of the participants were males. The study revealed that the proportion of false eligible donor was 19.6% and false deferral blood was 2.9% by CuSO4 method. The specificity for HemoCue was 62.5% and 92.9% in finger prick and in venous sample, respectively. In contrast, that of CuSO4 was 28.6% and 35.7% in finger prick and venous samples, respectively. The sensitivity was above 96% for both methods. Difference in mean of 0.53 g/dl was also observed by using HemoCue method between venous and capillary Hb levels. In addition, linear regression model indicated a positive correlation between venous Hb from a finger prick (r=0.913). Conclusion: This study found that the performance of CuSO4 in Dar es Salaam region was low compared to HemaCue. NBTS should review, improve and monitor the performance of CuSO4 before opting for another method