The incidence and nature of surgical adverse events in Colorado and Utah in 1992

Background. Despite more than three decades of research on iatrogenesis, su rgical adverse events have not been subjected to detailed study to identify their characteristics. This information could be invaluable, however, for guiding quality assurance and research efforts aimed at reducing the occurr ence of surgical adverse events. Thus we conducted a retrospective chart re view of 15,000 randomly selected admissions to Colorado and Utah hospitals during 1992 to identify and analyze these events. Methods. We selected a representative sample of hospitals from Utah and Col orado and then randomly sampled 15,000 nonpsychiatric discharges from 1992. With use of a 2-stage record-review process modeled on previous adverse ev ent studies, we estimated the incidence, morbidity, and preventability of s urgical adverse events that caused death, disability at the time of dischar ge, or prolonged hospital stay. We characterized their distribution by type Of injury and by physician specialty and determined incidence rates by pro cedure. Results. Adverse events were no more likely in surgical care than in nonsur gical care. Nonetheless, 66% of all adverse events were surgical, and the a nnual incidence among hospitalized patients who underwent an operation or c hild delivery was 3.0% (confidence interval 2.7% to 3.4%). Among surgical a dverse events 54% (confidence interval 48.9% to 58.9%) were preventable. We identified 12 common operations with significantly elevated adverse event incidence rates that ranged from 4.4% for hysterectomy (confidence interval 2.9% to 6.8%) to 18.9% for abdominal aortic aneurysms repair (confidence i nterval 8.3% to 37.5%). Eight operations also carried a significantly highe r risk of a preventable adverse went: lower extremity bypass graft (11.0%), abdominal aortic aneurysm repair (8.1%), colon resection (5.9%), coronary artery bypass graft/cardiac valve surgery (4.7%), transurethral resection o f the prostate or of a bladder tumor (3.9%), cholecystectomy (3.0%) hystere ctomy (2.8%), and appendectomy (1.5%). Among all surgical adverse events, 5 .6% (confidence interval 3.7% to 8.3%) resulted in death, accounting for 12 .2% (confidence interval 6.9% to 21.4%) of all hospital deaths in Utah and Colorado. Technique-related complications, wound infections, and postoperat ive bleeding produced nearly half of all surgical adverse events. Conclusion. These findings provide direction for research to identify the c auses of surgical adverse events and for targeted quality improvement effor ts.