Doctors are increasingly marrying other well-educated people with careers, and that may be exacerbating the shortage of doctors in already underserved rural areas of the U.S., suggests new research.

More than half of U.S. doctors are now married to other highly educated people, and those marriages are tied to a 38 percent reduced odds of the doctors working in rural underserved areas, researchers report in JAMA.

"It's making it increasingly difficult for rural areas to attract physicians," said lead author Douglas O. Staiger of Dartmouth College in Hanover, New Hampshire.

The researchers used Census and survey records to study one percent of all employed physicians age 25 to 70 working in the U.S. every decade from 1960 to 2000 - totaling almost 20,000 doctors, and every year from 2005 to 2011 - totaling more than 55,000 doctors.

From the data, the researchers determined if a doctor's spouse had six or more years of college before 1990 or a master's degree or higher from 1990 to 2011.

They sorted rural Census blocks into primary care Health Professional Shortage Areas.

Doctors with highly educated spouses increased from 9 percent in 1960 to 54 percent in 2010, and one third of highly educated spouses were also doctors consistently over time.

In 1960, 4 percent of married physicians were women, but that number rose to 31 percent in 2010. They were more likely than men to be married to a spouse with a graduate degree.

Between 2005 and 2011, about 11 percent of the U.S. population lived in Health Professional Shortage Areas, while only about 5 percent of doctors worked in these areas.

About 4 percent of married doctors with a highly educated spouse worked in underserved areas, compared to about 7 percent of married doctors without highly educated spouses.

Single, young, female, black and Hispanic doctors were also less likely to work in underserved areas, compared to married doctors without highly educated spouses.

"People have focused on lots of the other reasons for the physician shortage, and we were just trying to emphasize that an increasingly important barrier is this joint location issue for married couples who both have careers," Staiger said.

More on this...

Cities offer more general amenities, higher average incomes and more opportunities for professional development, he said.

"People who haven't grown up in rural areas are unlikely to locate there, and fewer and fewer people have grown up in rural areas," he said.

But rural areas still need doctors, particularly primary care and urgent care doctors, he said. These areas try to attract doctors by offering more money.

Other ways to address the problem may include training nurse practitioners or other health professionals to act as primary care providers, or to use telemedicine to connect urban doctors to rural patients, Staiger said.

"A lot of research for decades has shown that the two most powerful factors are having grown up in a rural area and being committed to particular specialties that fit in a rural area, like family practice," said Dr. Howard Rabinowitz of Thomas Jefferson University Hospital in Philadelphia.

"The first way people approach it is to try and preferentially admit to medical school students who are likely to go rural," said Rabinowitz, who was not part of the new study.

Some rural practices will pay off a doctor's student loans to attract them to the job, he told Reuters Health.

Identifying people who actually want to go rural and support them has been the most effective way to address the shortage so far, he said.