Validity of the haemoglobin colour scale in blood donor screening

Background and Objectives The haemoglobin colour scale (HCS) has been devel oped as a simple, reliable and inexpensive clinical device for diagnosing a naemia and estimating its severity when laboratory-based haemoglobinometry is not available. The purpose of this study was to assess its validity for screening blood donors for anaemia. Material and Methods The HCS was tested at five blood transfusion centres o n a total of 2801 donors. Blood was obtained by skin puncture as part of th e routine procedure at the donor sessions. HCS readings were compared with screening by the copper sulphate method, which was in routine use in the ce ntres, and with haemoglobin (Hb) measurements by means of calibrated HemoCu e haemoglobinometers. HCS readings were considered as normal when the readi ngs were greater than or equal to 12 g/dl. Results Analysis of the paired results showed that the HCS had an accuracy of 97.5% in distinguishing subjects with normal Hb from those below the acc eptable limit, when checked against the HemoCue. The HCS was more reliable than the copper-sulphate specific-gravity method, yielding 3.7% false readi ngs compared with 6.1% false readings, respectively. When discrimination wa s set at 12 g/dl with the HemoCue, the HCS gave an incorrect reading in 2.4 % of donors. The majority of these false results (44 donors; 1.58%) were ca used by the HCS indicating rejection of the donor (i.e, Hb < 12 g/dl) when the correct Hb was higher, whilst in 23 donors (0.82%) the HCS incorrectly indicated a normal Hb; however, in all but four of these donors the correct Hb values were 11.0-11.9 g/dl, and none were below 10 g/dl. Conclusion The operators were able to master the HCS technique after a few minutes of practice, and all found the test to be user friendly and easy to read. The HCS is proposed as a replacement for the copper sulphate method for blood transfusion donor selection.