The Delta Check in Action: Causes and Consequences of Discrepant Laboratory Results


Discrepant results are often identified by delta check alerts. Delta checks compare current laboratory results to previous results; if the difference between the two values exceeds predetermined biological limits (within a predetermined length of time), a technologist is alerted and the discrepancy can be investigated further. Causes of discrepant laboratory results include both preanalytical and analytical issues, as well as true biological changes occurring within the patient.

Many preanalytical issues cannot be detected by traditional QC methods, leading to the possible reporting of erroneous laboratory results. The wrong result compromises patient care by leading to inappropriate diagnoses or treatment. Delta check alerts provide an additional means to identify these types of problems, in addition to alerting health care providers to true changes in their patient’s condition.

Originally presented on February 12, 2015, in Salt Lake City, Utah.

Lecture Presenter

Joely A. Straseski, PhD, MS, MT(ASCP), DABCC

Joely A. Straseski, PhD, MS, MT(ASCP), DABCC

Medical Director, Endocrinology Laboratory
ARUP Laboratories
Medical Director, Automated Core Laboratory
ARUP Laboratories
Associate Professor of Pathology
University of Utah School of Medicine

Dr. Straseski is an associate professor of pathology at the University of Utah School of Medicine. She received her PhD in pathology and laboratory medicine and a master of science in bacteriology from the University of Wisconsin-Madison, where she also served as a postdoctoral associate in the Department of Pathology. Dr. Straseski completed a postdoctoral fellowship in clinical chemistry at the Johns Hopkins Medical Institutions in Baltimore, Maryland. She is an active member of the American Association for Clinical Chemistry and American Society for Clinical Pathology, a fellow of the AACC Academy and the chair of the Board of Editors for Clinical Laboratory News. Dr. Straseski is board certified in clinical chemistry by the American Board of Clinical Chemistry.


After this presentation, participants will be able to:

  • Define a delta check error or limit.
  • Recognize sources of pre-analytical, analytical, and biological variation and how they may affect laboratory tests.
  • Perform calculations that may be used to determine delta check limits.
  • Outline important questions to ask when investigating a discrepant laboratory result.

Sponsored by:

University of Utah School of Medicine, Department of Pathology, and ARUP Laboratories