Human error, not communication and systems, underlies surgical complications

This study prospectively assesses the underlying errors contributing to surgical complications over a 12-month period in a complex academic department of surgery using a validated scoring template.

Studies in "high reliability organizations" suggest that systems failures are responsible for errors. Reports from the aviation industry target communication failures in the cockpit. No prior studies have developed a validated classification system and have determined the types of errors responsible for surgical complications.

A classification system of medical error during operation was created, validated, and data collected on the frequency, type, and severity of medical errors in 9,830 surgical procedures. Statistical analysis of concordance, validity, and reliability were performed.

Reported major complications occurred in 332 patients (3.4%) with error in 78.3%: errors in surgical technique (63.5%), judgment errors (29.6%), inattention to detail (29.3%), and incomplete understanding (22.7%). Error contributed more than 50% to the complication in 75%. A total of 13.6% of cases had error but no injury, 34.4% prolongation of hospitalization, 25.1% temporary disability, 8.4% permanent disability, and 16.0% death. In 20%, the error was a "mistake" (the wrong thing), and in 58% a "slip" (the right thing incorrectly). System errors (2%) and communication errors (2%) were infrequently identified.

After surgical technique, most surgical error was caused by human factors: judgment, inattention to detail, and incomplete understanding, and not to organizational/system errors or breaks in communication. Training efforts to minimize error and enhance patient safety must address human factor causes of error.