Looking at data about more than 60,000 surgeries conducted in the United States between 2005 and 2007, researchers whose findings appeared in the Annals of Surgery said that when a resident was involved, just under 6 percent of patients had a major complication such as severe bleeding or a serious infection.

The rate was the same for surgeries in which no residents participated.

"This shows that resident participation is safe," said Ravi Kiran, the lead researcher on the new study and a colorectal surgeon at the Cleveland Clinic in Ohio.

Residents are medical school graduates receiving training in a specialty. Some studies have raised the possibility that having a resident on board increases patients' risk of complications.

The study did find that the odds of minor complications, mainly skin infection at the surgery site, were slightly higher when residents took part, though Kiran said the differences were very small and not likely to be clinically significant.

When residents were involved in the surgery, 3 percent of patients had a "superficial" infection at the surgery site, versus 2.2 percent of patients who had surgery with no resident on hand.

It was not fully clear why such infections were more common when residents took part, but on average those procedures took a little longer -- 122 minutes, versus 97 minutes when no residents were involved.

Other studies have found that longer surgery times tend to carry a higher risk of superficial infection, so that might help to explain the higher risk seen with operations involving residents, Kiran said.

As with serious complications, there was no significant difference in death rates between groups where residents were involved and those where they were not, Kiran's team found. Some 0.18 percent of patients in the resident group died, versus 0.2 percent in the non-resident group.

A number of studies have found that surgeons' level of experience is key in patients' outcomes and that patients at large, busy centers tend to fare better than those at smaller hospitals. Experienced surgeons at large medical centers are often the same ones with a resident on the team. SOURCE: bit.ly/Pi26rF

(Reporting from New York by Amy Norton at Reuters Health; editing by Elaine Lies)

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