Clinical Pathology Abstracts, 1/16

Create PDF

Editor: Deborah Sesok-Pizzini, MD, MBA, professor, Department of Clinical Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, and chief, Division of Transfusion Medicine, Children’s Hospital of Philadelphia.

A logical delta check for identifying erroneous blood cell count results

Regulations require that hospitals have a quality management plan that benchmarks key indicators of quality performance. One such indicator is a delta check, which is a broad quality control for preanalytic and analytic errors that identifies significant variation in a patient’s present lab result when compared with the patient’s previous result for the same test. The author conducted a study that involved implementing an effective and practical complete blood cell count (CBC) delta check by optimizing specificity and sensitivity using weighed deltas of multiple parameters. The mean red blood cell volume (MCV) delta (greater than 3.0 fL) check was retrospectively assessed on 110 days between November 2010 and March 2011. The composite CBC delta (CCD) test was then formulated using serial same-patient CBC data and random interpatient CBCs. This was followed by a logical delta check, which ignores CCD failures due to platelet change only. The author’s results showed that the MCV delta check test recognized only three of the six mislabeled specimens in the initial review period, whereas the CCD identified all of them. The logical delta check flagged two percent of eligible results, one-third as many as the MCV delta check. Furthermore, the CCD and logical delta checks revealed 20 presumed or confirmed mislabeling events, only half of which were identified by the MCV delta check. The study showed that the MCV delta check test was not as useful as the logical delta check for correcting errors in the laboratory due to low specificity and sensitivity. The logical delta check was demonstrated to be a more useful tool in identifying preanalytic and analytic specimen problems, including specimens labeled with the wrong name.

Miller I. Development and evaluation of a logical delta check for identifying erroneous blood count results in a tertiary care hospital. Arch Pathol Lab Med. 2015;139:1042–1047.

Correspondence: Dr. Ira Miller at ira_miller@rush.edu