Mislabeling of cases, specimens, blocks, and slides: a college of american pathologists study of 136 institutions.

CONTEXT: Accurate specimen labeling is a major patient-safety initiative by the Joint Commission and the College of American Pathologists. Inadequate specimen labels have led to patient injury from wrong patient diagnosis, wrong side treatment, and delay in diagnosis.

OBJECTIVES: To quantify the rates of mislabeled cases, specimens, blocks, and slides and to identify the sources of error and the ways in which errors are detected.

DESIGN: In this voluntary-subscription Q-Probes study, participants prospectively reviewed surgical pathology cases for 8 weeks or until 30 errors (mislabeled cases, specimens, blocks, and slides) were identified. Information collected on each labeling error included the work location where the defect occurred, what was mislabeled, the number of items affected, the point of detection, and the consequences of the mislabeling error, along with institutional demographics and practice. The rates of mislabeled cases, specimens, blocks, and slides were tested for association with institutional demographics and practice variables.

RESULTS: Of the 136 institutions providing information on a total of 1811 mislabeling occurrences, the overall mislabeling rates per 1000 were 1.1 cases, 1.0 specimen, 1.7 blocks, and 1.1 slides. Of all mislabeling events, 27.1% were cases, 19.8% specimens, 25.5% blocks, and 27.7% slides. The work locations at which the errors occurred were 20.9% before accessioning, 12.4% at accessioning, 21.7% at block labeling, 10.2% during gross pathology, and 30.4% at tissue cutting. Errors were typically detected in the first or second steps immediately following the error. Lower mislabeled slide rates were associated with continuous individual case accessioning and use of formal checks at accessioning. Routinely including a statement in the gross description that the specimen is labeled with the patient's name and is properly identified was also associated with lower rates of specimen mislabeling. The errors were corrected before reports were issued 96.7% of the time; for 3.2% of errors, a corrected report was issued. In 1.3% of error occurrences, participants gauged that patient care was affected.

CONCLUSIONS: This study quantified mislabeling rates across 136 institutions of cases (0.11%), specimens (0.1%), blocks (0.17%), and slides (0.11%). Errors in labeling appear nearly equally throughout the system of accessioning, gross pathology processing, and tissue cutting. Errors are typically detected in the immediate steps after the errors occurred, reinforcing the need for quality checks throughout the system.