Nurse anesthetists can safely provide care without doctors supervising them, according to a report released on Tuesday.

And a second report found that physicians trained in other countries provide care just as good as U.S. doctors.

Both reports, published in the journal Health Affairs, suggest ways to help provide care to more Americans at potentially lower cost, just as healthcare reform promises to extend health coverage to millions who do not have it.

"Nurse anesthetists get essentially the same training in anesthesia as anesthesiologists. So in this case, a nurse is just about a perfect substitute for the doctor," Jerry Cromwell, a health economist at the Research Triangle Institute in North Carolina who led one study, said in a statement.

"Eliminating physician supervision will not only allow nurses to do what they are trained and highly qualified to do, but it will encourage hospitals and surgeons to use a more cost-effective mix of anesthetists."

Nurse anesthetists typically earn less than anesthesiologists, who are medical doctors.

Cromwell and colleague Brian Dulisse analyzed 481,440 hospitalizations covered by Medicare, the federal health insurance plan for the elderly. While more nurse anesthetists cared for patients during surgery between 1999 and 2005, there was no increase in bad outcomes.

The second study looked at the care provided by foreign-trained doctors.

"Despite a rigorous U.S. certification process for international graduates, the quality of care provided by doctors educated abroad has been an ongoing concern," said John Norcini, president of the Foundation for Advancement of International Medical Education and Research, who led the study.

Norcini's team analyzed 244,153 hospitalizations of patients with congestive heart failure or acute heart attack in Pennsylvania who were treated by either a U.S.-trained or foreign-trained doctor.

Patients of foreign-born international medical graduates had the lowest death rates. Patients of U.S. citizens who attended medical school in other countries had the highest death rates. U.S.-born and trained doctors fell in the middle.

"These findings bring attention to foreign-trained doctors and the valuable role they have played in responding to the nation's physician shortage," Norcini said.

"It is reassuring to know that patients of these doctors receive the same quality of care that they would receive from a physician trained in the United States."

He said 25 percent of all doctors practicing in the United States are educated abroad.

The study also found that experience did not always mean the best care. The longer it had been since a doctor left medical school, the worse the rate of death and complications requiring patients to stay in the hospital longer.

"Ongoing training programs and periodic reassessment of doctors' knowledge and skills can help maintain the level of physician competence needed to deliver high quality health care," Norcini said.

About 46 million Americans, or 15 percent of the population, now have no health insurance. A new healthcare law signed in March is projected to extend coverage to 32 million more Americans, mainly by requiring them to buy it.

Many groups worry the already stretched medical system will be unable to accommodate so many more people seeking regular health care services.