The long-running controversy over the working hours of physicians in training is heating up again, as educators and advocates debate what's best for new doctors and the patients they treat.

The council that accredits physician-education programs is considering loosening "duty hour" changes that it approved in 2011. The biggest change would increase the length of the shift that first-year residents are allowed to work from 16 hours straight to 28 hours within a maximum 80-hour work week.

The changes were recommended this month by a task force of the Accreditation Council for Graduate Medical Education (ACGME). The full council is to make a decision in February.

Proponents and opponents have been marshaling new surveys and analyses to try to sway the ACGME, which is accepting public comment through Dec. 19.

At issue are thorny questions about whether letting novice doctors work marathon hours is bad for their patients or themselves, or both.

The Philadelphia-based American Board of Surgeons contends that residents — who spend up to six years in training — need flexibility and autonomy to uphold their commitment to patients. The board cited a new survey of surgery residents that found most preferred the freedom to work longer hours when needed to care for patients.

"Two thousand years of medical ethics says the primary obligation of the doctor is to the patient," said Frank Lewis, executive director of the surgeons' board. "That obligation should outweigh financial and personal issues. But the work rules say the clock is the primary determinant."

The consumer group Public Citizen and the American Medical Student Association counter that extremely long shifts increase the chances that residents will make medical errors, suffer depression, and get in car accidents, among other harms.  A new survey commissioned by Public Citizen found Americans "overwhelmingly oppose" weakening shift limits.

Sammy Almashat, a physician in Public Citizen's health research group, said even the current  shift limits — 16 hours for first-year residents, 28 hours for other residents — are routinely flouted.

"There is vast under-reporting and outright lying about the hours residents work," he said. "I saw this as a resident myself. The real issue is an economic one. Residents have a fixed salary with no overtime. Hospitals don't want to pay for more staff if they can just work the residents longer."

Almashat was not surprised that the survey of surgery residents, published online this week by the Journal of the American College of Surgeons, found most say they want flexible work rules.

"Medical residency is a culture where pushing yourself to the limit is seen as a strength," Almashat said. "You're surveying residents in hospitals where they want to be seen as conforming to the prevailing culture."

Duty hours — terminology that the ACGME wants to replace with "clinical and educational work hours" —  have been the subject of controversy at least since 1984. That year, the death of an 18-year-old student under the care of New York Hospital residents led to national soul-searching and policy debates.

In 2003, the ACGME responded by restricting residents' work week to 80 hours. In 2011, it added the 16-hour shift limit for first-year residents.

However, the changes have not been clearly shown to improve patient safety and quality of care.

Earlier this year, a national study led by researchers in Chicago and Philadelphia found that surgical residents who worked up to 30 consecutive hours were more satisfied with their training and patient care than residents limited to 16-hour shifts. The two groups had no differences in rates of patient deaths or complications after a year. (The residents in this study participated in the newly published survey.)

The ACGME's proposed duty-hour revisions would preserve some restrictions, including the maximum 80-hour work week averaged over four weeks, 14 hours off between shifts, and one day in seven free of all duties.

But in addition to letting all residents work up to 28 hours straight, the revisions would let them stay even longer to care for a single patient "in unusual circumstances and of their own accord."

"This promotes professionalism, empathy and commitment," the ACGME said in a Nov. 4 letter to graduate medical educators, posted on the council's website.