Context.—The Coulter DxH 800 hematology analyzer can determine conventional hematologic parameters. It also provides many new hematologic parameters, some of which show potential clinical utility.
Objectives.—To study, for the first time, the biological variations of new hematologic parameters and reinvestigate the biological variations of conventional hematologic parameters using the newest Coulter hematology analyzer.
Design.—Forty adult volunteers (21 women and 19 men) were included. All participants maintained their normal lifestyles. Blood samples were drawn in duplicate by a single experienced phlebotomist and analyzed within 2 hours using a single analyzer. Before each batch analysis, the instrument quality controls were performed using the same lots of reagents.
Results.—Within-subject and between-subject biological variations for the conventional hematologic parameters were compatible with published data. The analytic variation of the DxH 800 for these parameters appeared smaller. Index of individuality (ratio of within-subject to between-subject biological variation) for all parameters was low. In addition, intraday and interday biological variations of most parameters studied are fairly constant among the population examined.
Conclusions.—These observations are clinically valuable. Data on within-subject biological variation and analytic precision may be used to generate objective delta-check values for use in quality management. Comparing within-subject and between-subject biological variation on new parameters may allow us to decide the utility of traditional population-based reference ranges. Furthermore, documentation of biological variations of new parameters is an essential prerequisite in the development of any clinical application in the future.