Hypothesis: We hypothesized that wrong-site surgery is infrequent and that a substantial proportion of such incidents are not preventable by current site-verification protocols.
Design: Case series and survey of site-verification protocols.
Setting: Hospitals and a malpractice liability insurer.
Patients and other participants: All wrong-site surgery cases reported to a large malpractice insurer between 1985 and 2004.
Main outcome measures: Incidence, characteristics, and causes of wrong-site surgery and characteristics of site-verification protocols.
Results: Among 2,826,367 operations at insured institutions during the study period, 25 nonspine wrong-site operations were identified, producing an incidence of 1 in 112,994 operations (95% confidence interval, 1 in 76,336 to 1 in 174,825). Medical records were available for review in 13 cases. Among reviewed claims, patient injury was permanent-significant in 1, temporary-major in 2, and temporary-minor or temporary-insignificant in 10. Under optimal conditions, the Joint Commission on Accreditation of Healthcare Organizations Universal Protocol might have prevented 8 (62%) of 13 cases. Hospital protocol design varied significantly. The protocols mandated 2 to 4 personnel to perform 12 separate operative-site checks on average (range, 5-20). Five protocols required site marking in cases that involved nonmidline organs or structures; 6 required it in all cases.
Conclusions: Wrong-site surgery is unacceptable but exceedingly rare, and major injury from wrong-site surgery is even rarer. Current site-verification protocols could have prevented only two thirds of the examined cases. Many protocols involve considerable complexity without clear added benefit.