Atheist and agnostic doctors are as likely to provide care for the poor as religious physicians, according to a new study by researchers at the University of Chicago and Yale New Haven Hospital.

Doctors who said they were "spiritual, but not religious," also ranked high in caring for the poor.

"We can say a lot of doctors are doing a lot of good, whether religious or not," said Dr. Farr Curlin, one of the authors of the study, published in the Annals of Family Medicine.

Most studies show religious people more likely than others to help the poor, according to Dr. Harold Koenig, director for the Center for the Study of Religion, Spirituality and Health at Duke University.

"But nobody has looked at this question in physicians," he said. "It's the largest and most systematic study of U.S. physicians. The fact that there weren't large differences is interesting."

He cautioned that the survey tool had limitations based on how religion was measured.

Doctors were asked to describe their "intrinsic religiosity," level of spirituality and frequency of attendance at religious services. Of the participating doctors, 110 said they had no religious affiliation.

"People who are not religious generally believe that you have to help other people because this is the only life you have," said Hemant Mehta of Orland Park, author of I Sold My Soul on eBay: Seeing Faith Through an Atheist's Eyes.

Curlin, who attends a nondenominational church, said the findings disappointed him.

"Caring for the poor is an expression of faithfulness and commitment," he said. "But many religious physicians don't make the connection."

"People who are not religious generally believe that you have to help other people because this is the only life you have.