Skip Navigation U.S. Department of Health and Human Services
Agency for Healthcare Research Quality
Archive print banner

Patient Safety and Quality

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to for current information.

Studies reveal factors contributing to technical errors in surgery and medical errors made by physician trainees

The majority of technical errors in surgery are made by experienced surgeons during routine operations on complex patients and/or in complex circumstances. In contrast, errors in judgment, teamwork breakdowns, and lack of technical competence contribute most to the medical errors that physician trainees make. Those are the conclusions of two studies that reviewed malpractice claims from several liability insurers. The studies were supported by the Agency for Healthcare Research and Quality (HS11886, HS11285, HS11544, and T32 HS00020), and are briefly described here.

Regenbogen, S.E., Greenberg, C.C., Studdert, D.M., and others (2007, November). "Patterns of technical errors among surgical malpractice claims: An analysis of strategies to prevent injury to surgical patients." Annals of Surgery 246(5), pp. 705-711.

Most technical errors in surgery (73 percent), such as nicking the bladder during a hysterectomy, are made by experienced surgeons during routine operations (84 percent) on complex patients and/or in complex circumstances. A review of 444 malpractice claims from 4 liability insurers revealed that 258 involved injuries due to surgical errors, and technical errors were a contributing factor in 52 percent of the cases. Nearly half (49 percent) of the technical errors caused permanent disability and an additional 16 percent resulted in death. Two-thirds (65 percent) of the technical errors were linked to manual errors (errors of execution with a direct physical act causing injury), 9 percent to errors in judgment (error of planning such as wrong timing or failure to diagnose), and 26 percent to both manual and judgment error.

The most common type of manual error involved incidental injury to one of the soft internal organs such as the lungs or digestive tract (34 percent), followed by breakdown of operative repair or failure to relieve the disease (16 percent), hemorrhage (16 percent), and peripheral nerve injury (14 percent). The most common type of judgment or knowledge error was delay or error in intraoperative diagnosis or management (16 percent), such as failure to recognize a complication during the surgery.

Other relatively frequent judgment or knowledge errors included incorrect choice of procedure or technique (9 percent) and wrong operative site (7 percent). Only a minority of technical errors involved advanced procedures requiring special training (16 percent), surgeons inexperienced with the task (14 percent), or poorly supervised residents (9 percent). However, patient-related complexities, such as difficult or unexpected anatomy, contributed to 61 percent, and technology or systems failures contributed to 21 percent of the technical surgical errors.

Singh, H., Thomas, E.J., Peterson, L.A., and Studdert, D.M. (2007, October). "Medical errors involving trainees: A study of closed malpractice claims from 5 insurers." Archives of Internal Medicine 167(19), pp. 2030-2036.

This study found that errors in judgment, teamwork breakdowns, and lack of technical competence contribute to most of the medical errors that physician trainees make. The researchers analyzed malpractice claims from 2002 to 2004 from the files of five liability insurers to identify patient injuries due to medical error. The errors occurred between 1979 and 2001. Among the 240 cases of harmful errors involving physician trainees, errors in judgment accounted for 72 percent, teamwork breakdowns 70 percent, and lack of technical competence 58 percent of the medical errors.

One-third of these medical errors resulted in significant physical injury, one-fifth in major physical injury, and one-third resulted in death. Lack of supervision and patient handoff problems were the most prevalent types of teamwork problems contributing to medical errors involving trainees versus nontrainees (54 vs. 7 percent and 20 vs. 12 percent, respectively). Judgment errors (72 percent) and failures of vigilance or memory (57 percent) were also involved in most trainee medical errors.

Monitoring and diagnostic decisionmaking were involved in many errors. For example, in one case, a surgical resident missed the diagnosis of a bile leak following abdominal surgery. Other significant factors contributing to trainee vs. nontrainee medical errors included: lack of technical competence (58 vs. 42 percent); lack of supervision (54 vs. 7 percent); handoff problems (19 vs. 13 percent); and excessive workload (19 vs. 5 percent).

The collective findings from these studies should help leaders of physician residency programs to orient training interventions to these problem areas.

Return to Contents
Proceed to Next Article


The information on this page is archived and provided for reference purposes only.


AHRQ Advancing Excellence in Health Care