Historical review and assessment of clinical hemoglobinometry in the United States.

An historical review of clinical hemoglobinometry has been presented. Investigators who have made important contributions to our knowledge of hemoglobin have been cited. A questionnaire was distributed to 750 clinical laboratories in the United States to ascertain (a) the type of instrumentation used routinely to measure hemoglobin; (b) the methods that are now being used for clinical hemoglobinometry; (c) reference material that is used for daily quality control; and (d) the methods used for primary standardization. The results of the 263 responses to the questionnaire are reported. It is noteworthy that at the present time, 78 percent of the responding laboratories use the same instrumentation system. An assessment has been made of the precision of hemoglobin measurements undertaken in clinical laboratories in the United States over the past four decades. The data indicate that hemoglobin measurements during the past four years have become significantly more precise. There is probably no single factor responsible for this timely improvement; however, it may be inferred that the shift from manual to automated methodology in recent years is an important contributing factor.