The Hemoglobin color scale yielded the overall best results with sensitivity of (97%), specificity (93%), PPV and NPV 96% and 95% , respectively at a discriminative Hb value of 12 g/dl.
It also had low rate of false passes (7%) and false failures (3%).
This method is cost effective [17] and can be implemented as primary screening technology for blood donation in our country if the Hb threshold for blood donation can be lowered to 12 g/dl.