Patient Safety Focus: Mislabeled Specimens


Ask The Expert

Mislabeled Specimen
When Should Relabeling of Mislabeled Specimens be Allowed?
Should Relabeling be Noted in the Medical Record?

Michael Astion, MD, PhD

Professor and Director of Reference Laboratory Services
University of Washington, Department of Laboratory Medicine

Question 1: We have managerial staff, pathologists, and pathologists-in-training who often ask a similar question related to replaceable specimens that are mislabeled, unlabeled, or under labeled: “Why can’t we allow the care provider to authorize relabeling of the specimen? The care provider assures us that he or she knows the identity of the specimen in the container.”

The Joint Commission’s first National Patient Safety Goal is “improve the accuracy of patient identification,” which includes ensuring that two identifiers are used throughout the administration of any lab service (1). This goal is not met if there is a loss of two matching identifiers anywhere in the testing process. Matching identifiers are commonly lost during specimen collection and during lab processing of specimens when primary or aliquot tubes are labeled. In addition, there are a variety of “under” labeling scenarios in lab services, including specimens with one or no identifiers.

Early in their training, pathology residents commonly ask about relabeling specimens. Although care providers are almost always correct regarding the actual identity of a mislabeled (Figure 1) or under labeled (Figure 2) specimen, it is important not to permit relabeling even when the specimen is replaceable. This includes nearly all blood and urine specimens from ambulatory settings, as well as those from routine, non-emergency hospital settings.

Figure 1
Mislabeled Specimen

The identification on the tube and the requisition do not match. This is a fictitious case created for teaching purposes.

Courtesy of

Figure 2
Under Labeled Specimen

The patient name is not on the blood tube, although it is on the test order. This is a fictitious case created for teaching purposes.

Courtesy of

Why must labs reject specimens when the care provider is probably correct regarding the identity of the specimen? The implication of the two-identifier rule is clear: many patients and care providers have to be inconvenienced and sometimes mildly harmed, so that a few patients are not seriously injured or do not die as the result of an error.

Underlying the two-identifier rule is also the assumption that the cost of the many inconveniences and small harms is less than the benefit of avoiding rare cases of serious injury and death. The inconveniences of rejecting a mislabeled or under-labeled specimen affects both patients and care providers and includes the various aspects of specimen recollection, such as physicians filling out test orders for a second time, patients coming back to a collection location, and phlebotomists returning to hospital rooms to redraw hospitalized patients. Among the mild harms to patients from recollection are increased blood loss, occasional injury due to phlebotomy, and delays in diagnosis and treatment. Veteran laboratory directors, however, know all too well the rare, deeper harm caused by misidentification of lab specimens. Mislabeling at any phase of testing can cause misdiagnosis and a variety of treatment errors ranging from medication overdoses and transfusion mismatches that can lead to serious injury and even death of the patient.

The two-identifier rule has another positive effect besides blocking harm caused by mislabeling and under labeling. The presence of two identifiers is a surrogate marker for all aspects of quality related to specimen collection. Quality managers know that in comparison to specimens and accompanying test requisitions that are properly labeled, specimens without two matching identifiers are more likely to have other quality problems including clotting, contamination, hemolysis, insufficient quantity, and collection in the wrong container. These problems are not always detected by visually observing the specimen container; therefore, enforcing the two-identifier rule has the hidden benefit of rejecting specimens before they end up with problems in the analytic phase of testing.

An effective way of instituting a restrictive relabeling policy is to limit the number of medical personnel allowed to authorize relabeling. Higher relabeling rates are typically associated with allowing more people to authorize relabeling. In one institution I am familiar with, a strict relabeling policy was implemented in which care providers were required to obtain permission for relabeling from the medical director of the institution. Only a few other associate medical directors were also authorized to allow relabeling. The relabeling rate quickly dropped from about 25% to near-zero for replaceable specimens as care providers chose not to engage in a conversation with the medical director when there were clear violations of the two-identifier rule.

Question 2: When relabeling of mislabeled or under labeled specimens is allowed by the medical director of our hospital, should the result that goes to the clinician have a statement about the relabeling, or is the result reported just like any routine result?

Even with a restrictive relabeling policy, relabeling will sometimes be indicated for irreplaceable specimens. Some specimens are irreplaceable because specimen recollection is impossible, while others are irreplaceable because the conditions of the original collection cannot be duplicated or the lack of a result poses a significant risk to the patient.

However, the most common irreplaceable specimen is one in which the risk of recollection is greater than the risk of mislabeling. Examples include cerebrospinal fluid, bone marrow aspirates, and surgically collected specimens. Blood and urine rarely will be candidates for relabeling.

Even for cases where recollection might harm the patient, the medical director authorized to approve relabeling must be confident of the specimen’s identity. A prudent approach to assessing the risk of relabeling is to weigh the following factors: 1.) the risk of reporting a result on a relabeled specimen; 2.) the risk of recollection, and 3.) the risk of having no result at all.

If relabeling is allowed and testing takes place, a free text remark should accompany the result on the lab report. Table 1 provides three typical free text remarks used in my healthcare system. These remarks should be added to the patient’s result because medical records need to be an honest accounting of the lab testing event. Moreover, mislabeled, unlabeled, and under labeled specimens should be differentiated in the medical record from properly labeled specimens because the results of problematic specimens are not as reliable as those from properly labeled specimens.

Table 1
Examples of text remarks on lab reports from specimens in which relabeling of an irreplaceable specimen was permitted.

  • Specimen received mislabeled and run at the request of the care provider.
  • Specimen received unlabeled and run at the request of the care provider.
  • Specimen received with one identifier and run at the request of the care provider.

In conclusion, pathologists and other lab workers face a predicament when confronted by angry care providers who want relabeling of a mislabeled, unlabeled, or under labeled specimen. The care provider is probably right about the identity of the specimen, but the request for relabeling still must be denied for replaceable specimens. In the rare instance that a specimen is irreplaceable and relabeling is allowed by a high-ranking medical director, a free text remark describing the problem with the specimen should be added to the result.


  • National Patient Safety Goals. Website accessed November 6, 2009.
  • Wagar EA, Stankovic AK, Raab S, Nakhleh RE, et. al. Specimen labeling errors: a Q-probes analysis of 147 clinical laboratories. Arch Pathol Lab Med 2008;132:1617–22.
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Patient Safety Focus Editorial Board

Michael Astion, MD, PhD
Department of Laboratory Medicine
University of Washington, Seattle

Peggy A. Ahlin, BS, MT(ASCP)
ARUP Laboratories
Salt Lake City, Utah 
James S. Hernandez, MD, MS 
  Mayo Clinic Arizona
Scottsdale and Phoenix

Devery Howerton, PhD

Centers for Disease Control and Prevention
Atlanta, Ga.

Sponsored by ARUP Laboratories, Inc.