Daniel M. Keller, PhD

May 01, 2012

May 1, 2012 (Miami, Florida) — Restrictions on how many hours neurosurgical residents are allowed to work are associated with an increase in the rate of complications, but there is no change in mortality rates at teaching hospitals, Brian Hoh, MD, associate professor of neurological surgery at the University of Florida in Gainesville reported here at the American Association of Neurological Surgeons (AANS) 80th Annual Scientific Meeting.

In July 2003, the Accreditation Council for Graduate Medical Education (ACGME) mandated a maximum of 24 continuous hours on duty for residents and, in general, a maximum of 80 hours/week, with 10 hours encouraged between each work period. One 24-hour day off was required each week.

Duty-hour restrictions were based on the supposition that long work hours led to resident fatigue, medical errors, and adverse patient outcomes. However, some authors stated concerns that duty-hour restrictions could lead to medical errors because of discontinuity of care, patient hand-offs, and reduced experience for residents. Many serious neurosurgical trauma admissions occur at off-hours or at night and involve a high degree of resident involvement.

The investigators drew data from the National Inpatient Sample database, which encompasses about 8 million hospital admissions in the United States each year. The database specifies hospitals as "teaching" or "nonteaching." They looked at data for admissions according to the International Classification of Disease, Ninth Revision (ICD-9), codes that defined head or spine trauma.

Complications Rose at Teaching Hospitals but Not Nonteaching Ones

By comparing outcomes in teaching hospitals for high-risk, critically ill neurosurgical trauma patients admitted to the intensive care unit (n = 39,337) in the years 1999-2002 (before duty-hour restrictions) with the years 2005-2008 (after the new regulations were in place; n = 67,669), Dr. Hoh and colleagues found a 23% greater rate of complications according to various ICD-9 codes during the latter period compared with the former (odds ratio [OR], 1.23; 95% confidence interval [CI], 1.00 - 1.50; P = .05). Mortality rates did not differ between the 2 periods (P = .32).

As a control, the authors analyzed 48,548 admissions to nonteaching hospitals for the period before duty-hour restrictions and 67,056 admissions after restrictions were put in place for residents. Presumably, nonteaching hospitals do not employ residents. Neither complications (OR, 0.98; 95% CI, 0.787 - 1.22; P = .86) nor mortality rates (OR, 0.91; 95% CI, 0.812 - 1.01; P < .08) differed between the 2 periods.

For teaching hospitals, there was no significant difference in the hospital length of stay between the 2 periods, but charges were higher with duty-hour restrictions (P < .001). However, charges were also higher (P < .001) with duty-hour restrictions in the nonteaching hospitals, suggesting that rising costs at both kinds of hospitals may have been independent of the restrictions and merely reflected rising costs overall as time went on. Regardless of the kind of hospital or the time period, complications were associated with longer length of stay and higher costs.

Dr. Hoh noted some limitations of the study, including that it was retrospective and relied on an administrative database, with a potential for coding errors. The study could demonstrate only associations and not causality. The classification as a teaching hospital did not mean that it necessarily had neurosurgery residents.

Transfers of Care Linked to Adverse Events

Dr. Hoh speculated on reasons that the reduced duty-hours have not translated into lower complication rates at teaching hospitals. First, he said, under the old system, even if a fatigued resident made an error, there are layers of supervision in the healthcare team to catch mistakes. "Also, duty-hour restrictions have resulted in increased transfers of care, and these transfers of care are the strongest predictor for potentially preventable adverse patient events," he said. "Duty-hour restrictions have also resulted in reduced resident experience."

Ralph Dacey Jr, MD, professor and chairman of neurological surgery at Washington University School of Medicine in St. Louis, Missouri, was the invited discussant of the presentation. He said, "This study suggests that patient outcomes in our nation's teaching hospitals would actually have been better without the 2003 ACGME duty-hour restrictions."

Dr. Dacey said the study "is consistent with the preponderance of reports in the literature which indicates that there is very little data supporting a link between duty-hour limitations and improved patient care." But he added that it is "extremely unlikely for a variety of political and administrative reasons" that duty-hour restrictions will be eliminated.

Nonetheless, he recommended that neurosurgeons continue to advocate for "common sense, practical enhancements to the current regulations" that can improve residents' availability for critical patient care episodes and can improve continuity of care and residents' experience.

Dr. Hoh and Dr. Dacey have disclosed no relevant financial relationships.

American Association of Neurological Surgeons 80th Annual Scientific Meeting of the: Abstract # 703. Presented April 17, 2012.