Objective: to determine the frequency and reasons for rejection of specimens submitted to the laboratory for complete blood count studies.
Design and setting: College of American Pathologists' Q-Probes laboratory quality improvement study prospective recording of rejected complete blood count specimens and associated factors in 703 laboratories.
Main outcome measure: Percentage of submitted specimens rejected for testing.
Results: Of 7,894,882 complete blood count specimens submitted for testing to the participating laboratories during the data collection period, 35,347 (0.45%) were rejected. The most frequent reason for rejection was a clotted specimen, which occurred about six times more frequently than the second most cited reason, insufficient specimen quantity. Compared with their respective frequency of use for specimen collection, significantly more rejected specimens were collected in microtubes than in other containers. Compared with the respective frequency with which they collect specimens, laboratory personnel had significantly fewer rejected specimens than the other personnel groups. The poorest performance was exhibited by other in-hospital nonlaboratory personnel. Hospital bedsize was also a significant performance factor; smaller hospitals demonstrated lower rejection percentages.
Conclusions: Specimen rejection should be monitored on a regular basis, identifying institution-specific factors that are associated with rejection. Monitoring of sufficient significant variables will help narrow the focus of corrective action. Action thresholds should be set sufficiently low to assure ongoing efforts toward improvement.