In August 1998, the Joint Commission issued a Sentinel Event Alert examining the problem of wrong site surgery, including a review of 15 cases that had been reported to JCAHO. Today, the sentinel event database includes 150 reported cases of wrong site, wrong person or wrong procedure surgery, of which 126 have root cause analysis information. Of the 126 cases, 41 percent relate to orthopedic/podiatric surgery; 20 percent relate to general surgery; 14 percent to neurosurgery; 11 percent to urologic surgery; and the remaining to dental/oral maxillofacial, cardiovascular-thoracic, ear-nose-throat, and ophthalmologic surgery. Fifty-eight percent of the cases occurred in either a hospital-based ambulatory surgery unit or freestanding ambulatory setting, with 29 percent occurring in the inpatient operating room and 13 percent in other inpatient sites such as the Emergency Department or ICU. Seventy-six percent involved surgery on the wrong body part or site; 13 percent involved surgery on the wrong patient; and 11 percent involved the wrong surgical procedure.