Surgical specimen identification errors: a new measure of quality in surgical care

Communication errors are the primary factor contributing to all types of sentinel events including those involving surgical patients. One type of communication error is mislabeled specimens. The extent to which these errors occur is poorly quantified. We designed a study to measure the incidence and type of specimen identification errors in the surgical patient population.

We performed a prospective cohort study that included all patients who underwent surgery in an outpatient clinic or hospital operating room and for whom a pathology specimen was sent to the laboratory. The study took place during a 6-month period (October 2004 to April 2005) at an urban, academic medical center. The study's main end-points were the incidence and type of specimen labeling errors in the hospital operating room and the outpatient clinic. The specimen was the unit of analysis. All specimens were screened for "identification errors," which, for the purposes of this study, were defined as any discrepancy between information on the specimen requisition form and the accompanying labeled specimen received in the laboratory. Errors were stratified by the type of identification error, source, location, and type of procedure.

A total of 21,351 surgical specimens were included in the analysis. There were 91 (4.3/1000) surgical specimen identification errors (18, specimen not labeled; 16, empty container; 16, laterality incorrect; 14, incorrect tissue site; 11, incorrect patient; 9, no patient name; and 7, no tissue site). Identification errors occurred in 0.512% of specimens originating from an outpatient clinic (53/10,354 specimens) and 0.346% of specimens originating from an operating room (38/10,997 specimens). Procedures involving the breast were the most common type to involve an identification error (breast = 11, skin = 10, colon = 8); in addition, 59.3% (54/91) of errors were associated with a biopsy procedure. Follow-up was complete in all cases found to have an identification error.

Surgical specimen identification errors are common and pose important risks to all patients. In our study, these events occurred in 4.3 per 1000 surgical specimens or an annualized rate of occurrence of 182 mislabeled specimens per year. Given the frequency with which these errors occur and their potential effect on patients, the rate of surgical specimen identification errors may be an important measure of patient safety. Strategies to reduce the rate of these errors should be a research priority.