April 28 (Bloomberg) -- At an office in New York's midtown Manhattan, Edwidge Thomas and two colleagues see about two dozen patients daily. Thomas, who diagnoses illnesses, prescribes drugs and refers cases to specialists, isn't an M.D., nor is anybody else at the practice.

She and her coworkers are nurses with advanced training, including a doctorate for Thomas. These so-called nurse practitioners now number 110,000 in the U.S., twice as many as a decade ago and one for every eight doctors.

The nurses are filling a vacuum of providing primary care to patients as more medical doctors specialize in such fields as cardiology or surgery. The U.S. has about 885,000 physicians, and 34 percent deliver primary care services, down from 37 percent in 1980, according to the American Medical Association.

``The truth now is that nurses can have much more education than before and the ability to manage diseases across the board,'' says Thomas, 44, who has a doctorate in nursing practice from Columbia University in New York. ``Nurses always were subordinate to physicians -- it was the fluff-the-pillow thing.''

The spread of such practitioners is raising the pay and prestige of nurses -- and the hackles of doctors who have an interest in preserving their domain. Two in three of the advanced-degree nurses are providing primary care. While doctors avoid many smaller communities and often devote their big-city practices to specialties such as cancer care, some don't like the idea that nurses are taking up the slack.

``If folks want to practice medicine, they should go to medical school,'' says Rebecca Patchin, a pain-management doctor in Riverside, California, and a trustee of the AMA. Doctors get more training in pharmacology and physiology and are better able to diagnose disease, says Patchin, 56, who began her career as a basic nurse.

Doctor, Nurse Shortages

Along with physician assistants and certified nurse midwives, the nurses are helping to meet demand that's outstripping the supply of doctors as baby boomers age and need more care. While the average salary for nurse practitioners nationally is in the high $70,000's, about half of what doctors make, some advanced nurses are making six-figure salaries, according to a nursing association.

The new career choice may also contribute to a shortage of hospital nurses by attracting those with advanced degrees who might otherwise teach. Last year, nursing programs turned down 33,000 qualified applicants mostly because there weren't enough people to train them, according to the American Association of Colleges of Nursing in Washington. The U.S. will have a shortage of 800,000 registered nurses by 2020, the National Center for Health Workforce Analysis projects.

`Emotional Connection'

Rosemary Waters, a retired New York teacher who is one of Thomas's patients, says she prefers the practice run by advanced nurses. Thomas discovered her diabetes, which was confirmed by an endocrinologist. Under New York law, so-called nurse practitioners need licenses, are certified in specialties such as family health and gerontology, and must collaborate with doctors.

``Nurse Thomas takes all the time with me that I need,'' in contrast to many doctors who have been more rushed, 64-year-old Waters says. ``There's more of an emotional connection. You're not on an assembly line.''

Patient satisfaction is higher with nurses, according to a survey of 16 studies on the substitution of nurses for doctors in primary care, published this year by John Wiley & Sons Inc. in Hoboken, New Jersey. Compared with doctors, nurses tend to have longer consultations and to provide more information, researchers found.

Taking Manhattan

Proving what nurses could accomplish was part of the idea when Columbia in 1994 set up a clinic run by nurses in Manhattan's Washington Heights section, where neighborhood doctors were sparse. In a study in which 1,300 people were randomly assigned to receive care from nurses or from doctors, ``patients' outcomes were comparable,'' according to a January 2000 report in the Journal of the AMA.

``That was just huge,'' says Mary O'Neil Mundinger, 68, Columbia's nursing dean, who was an author of the study. ``All of a sudden, nurses seemed to be equivalent to physicians.'' Even before the results were in, the school in 1997 opened Columbia Advanced Practice Nurse Associates, or Capna, in midtown.

``We wanted to open a practice where there are lots of physicians nearby to show that people will choose nurses not just by default but because they want this style of care,'' Mundinger says.

Capna has attracted more than 3,000 patients, mostly by word of mouth. Mundinger, while declining to disclose billings, says the practice recoups its costs. The office just moved to new quarters on the East Side of Manhattan with 1,100 square feet, a 38 percent increase.

Filling Doctor Gap

The advanced nursing practitioners, the elite among the 3 million U.S. nurses, have spread since the first ones appeared in 1965. Schools produce about 5,000 annually. Most have master's degrees.

Doctors are too few ``at least in some regions and specialties,'' the Chicago-based AMA said last June. Medical schools need to increase annual enrollment 15 percent by 2015, says the Washington-based Association of American Medical Colleges, which may double the recommendation to 30 percent.

Smaller communities with nurse practitioners include State Center, Iowa; Mount Morris, Pennsylvania; Gretna, Florida; Portal, Georgia; and Canaan, Maine. The fees that the nurses charge for office visits are often lower than those of doctors, according to the American Academy of Nurse Practitioners, a professional group based in Austin, Texas.

While nurses handle more than 600 million patient visits a year, no annual total of their billings exists, according to the American Academy of Nurse Practitioners, a professional group based in Austin, Texas. At Capna, fees are ``exactly the same as M.D. fees for the same level of complexity of visit,'' Mundinger says.

`Anxiety About Turf'

Nurse practitioners are gaining broader acceptance by health insurers and medical regulators. In Iowa, Oregon and a dozen other states, nurse practitioners can operate without doctors' collaboration or supervision. Most states allow the nurses to prescribe the vast majority of drugs, with the exception of controlled substances such as narcotics.

Medicare, the U.S. insurance program for the elderly and disabled, reimburses nurse practitioners who bill independently at 85 percent of the amounts paid to doctors, a limitation set by Congress. In New York, Medicaid, the state-federal program for the poor, pays the nurses 100 percent of M.D. fees.

Nurse practitioners who bill independently of doctors submitted $1.4 billion in charges to the Medicare program in 2005, a 19 percent increase from 2004, according to government figures. The program allowed $635.4 million of the 2005 charges, 85 percent of the amount that doctors would have been allowed. The government's share of the tab was $468 million, up 11 percent from 2004.

Protocol Agreements

Doctors in some states still lobby against expansion of the nurses' franchise. In Georgia, a doctors' group got legislators to require much more specificity in so-called protocol agreements between advanced nurses and collaborating doctors. In return, the nurses will be able to sign prescriptions for drugs. Governor George Perdue, a Republican known as Sonny, has until May 9 to decide whether to sign the legislation.

``There's anxiety about turf,'' says Jan Towers, director of health policy in the Washington office of the American Academy of Nurse Practitioners. ``I don't know why that should be. There are plenty of patients to go around.''

To contact the reporter on this story: Jeffrey Tannenbaum in New York at jtannenbaum@bloomberg.net.

Last Updated: April 28, 2006 00:09 EDT