These results were not anticipated. Religious belief tends to decrease as education and income levels increase, yet doctors are highly educated and, on average, well compensated. The finding also differs radically from 90 years of studies showing that only a minority of scientists (excluding physicians) believes in God or an afterlife.
"We did not think physicians were nearly this religious," said study author Farr Curlin, M.D., instructor in the department of medicine and a member of the MacLean Center for Clinical Medical Ethics at the University of Chicago. "We suspect that people who combine an aptitude for science with an interest in religion and an affinity for public service are particularly attracted to medicine. The responsibility to care for those who are suffering, and the rewards of helping those in need, resonate throughout most religious traditions."
Although physicians are nearly as religious as the general population, their specific beliefs often differ from those of their patients. While more than 80 percent of patients describe themselves at Protestant or Catholic, only 60 percent of physicians come from either group.
Physicians are 26 times more likely to be Hindu than the overall U.S. population (5.3% of doctors vs. 0.2% of non-physicians). Doctors are seven times more likely to be Jewish (14.1% vs. 1.9%), six times more likely to be Buddhist (1.2% vs. 0.2%) and five times more likely to be Muslim (2.7% vs. 0.5%).
Although doctors are more likely than the general population to attend religious services, they are less willing to "apply their religious beliefs to other areas of life," the researchers found. Sixty-one percent of doctors say they "try to make sense" of a difficult situation and "decide what to do without relying on God," versus only 29 percent of the general population.
"We have paid a good deal of attention to the religious beliefs of patients and how their faith influences medical decisions," Curlin said, "but until now no one has looked in the same way at physicians, the other half of every doctor-patient relationship. These findings lead us to further wonder how doctors' faiths shape their clinical encounters."
Inquiries into the religious beliefs, or the lack of them, among U.S. scientists date back to a landmark 1916 survey by psychologist James Leuba that documented widespread disbelief. Leuba found that only 40 percent of scientists believed in a personal God, 15 percent were uncertain and 45 percent disbelieved.
Surveys published in Nature in 1997 and 1998, showed little change since 1916, with only 39 percent of all scientists declaring a personal belief in God. Belief among "leading" scientists, however -- defined in this case as members of the National Academy of Sciences -- was far lower: only seven percent in 1998. Curiously, among scientists, mathematicians were the most likely to believe in God and biologists the least likely.
Although physicians have extensive training in biology, the study by Curlin and colleagues paints a very different picture, showing high levels of belief.
The survey revealed considerable variation between different medical specialties. Doctors in family practice and pediatrics were far more likely to carry their religious belief into "all my other dealings" and to look to God for "support and guidance." Psychiatrists and radiologists were the least likely.
Christian, Mormon and Buddhist doctors were the most likely to say "my religious beliefs influence my practice of medicine." Jewish and Hindu physicians were the least likely. Physicians from the South and Midwest were slightly more religious than those from the East and West.
The survey used a 12-page questionnaire mailed to a random sample of 2,000 U.S. practicing physicians; 63 percent responded to one of three mailings. The researchers did not find evidence that religious physicians were more likely to respond that those who are not religious. Results from this survey were compared with the 1998 General Social Survey, which examines demographic and opinion variables in a sampling of U.S. households.
The next step, said Curlin, who describes himself as an "orthodox Christian in the Protestant tradition," is to begin to look at how a doctors' religious (or secular) beliefs and values might influence the way they care for patients.
The Greenwall Foundation and the Robert Wood Johnson Clinical Scholars Program funded the study. Additional authors include John Lantos, M.D.; Chad Roach, B.S.; Sarah Sellergren, M.A.; and Marshall Chin, M.D., M.P.H., all from the University of Chicago.