Evaluation of three methods for hemoglobin measurement in a blood donor setting.

CONTEXT The hemoglobin (Hb) level is the most-used parameter for screening blood donors for the presence of anemia, one of the most-used methods for measuring Hb levels is based on photometric detection of cyanmetahemoglobin, as an alternative to this technology, HemoCue has developed a photometric method based on the determination of azide metahemoglobin. OBJECTIVE To evaluate the performance of three methods for hemoglobin (Hb) determination in a blood bank setting. DESIGN Prospective study utilizing blood samples to compare methods for Hb determination. SETTING Hemotherapy Service of the Hospital Israelita Albert Einstein, a private institution in the tertiary health care system. SAMPLE Serial blood samples were collected from 259 individuals during the period from March to June 1996. MAIN MEASUREMENTS Test performances and their comparisons were assessed by the analysis of coefficients of variation (CV), linear regression and mean differences. RESULTS The CV for the three methods were: Coulter 0.68%, Cobas 0.82% and HemoCue 0.69%. There was no difference between the mean Hb determination for the three methods (p>0.05). The Coulter and Cobas methods showed the best agreement and the HemoCue method gave a lower Hb determination when compared to both the Coulter and Cobas methods. However, pairs of methods involving the HemoCue seem to have narrower limits of agreement (+/- 0.78 and +/- 1.02) than the Coulter and Cobas combination (+/- 1.13). CONCLUSION The three methods provide good agreement for hemoglobin determination.