Thursday, April 28, 2005

Relative Frequency of Mislabeled Laboratory Samples from the Emergency Department (ED) Compared to Other Hospital Areas

Linda M. Sandhaus, Kennan J. Sauder, and Edward Michelson.

The receipt of mislabeled samples is a pre-analytical error experienced by many hospital laboratories. Error rates from the ED may be higher than from other clinical areas.

We compared the rate of mislabeled laboratory samples from the ED with that from other hospital locations. A secondary objective was to determine if laboratory personnel consistently followed laboratory policies for handling mislabeled samples.

The study took place in a metropolitan medical center with 77,000 ED patient visits yearly. Total laboratory orders received from July1 to August 31, 2004 were obtained from the laboratory information system. An order consists of all samples from a patient submitted with one requisition. Laboratory initiated incident reports are used to document mislabeled samples.

There were 51/13,855 (0.36%) documented mislabeled orders from the ED compared to 37/99,166 (0.037%) documented labeling errors from all other hospital locations. For ED patients, these included blood (29), urine (14), urine and blood (4), culture swabs (3) and cerebral spinal fluid (1). Twenty-eight orders were re-labeled and 14 were rejected, in accordance with laboratory policies. Nine (9) samples were re-labeled that should have been rejected. Results were reported on the wrong patient in one instance due to a mislabeled order.

Laboratory samples drawn in the ED are about 10 times more likely to be mislabeled than samples from elsewhere in the hospital. Laboratory personnel do not consistently follow policies for sample rejection. Mislabeled samples pose a threat to patient safety due to delays in sample processing, re-draws, and the possibility that results may be reported on the wrong patients. Further study is needed to determine the root causes of these errors and to design effective interventions. A limitation of this study is that not all mislabeling incidents may have been recognized or documented.

See more of Poster Session
See more of The 2005 Institute for Quality in Laboratory Medicine Conference