Are NPs and primary care doctors interchangeable

March 20, 2000

A recent report says they are, but at least one doctor calls the results "far from convincing."


The New Generation of Providers

Are NPs and primary care doctors interchangeable?

A recent report says they are, but at least one doctor calls the results "far from convincing."

BY Anita J. Slomski
Group Practice Editor

Mary O. Mundinger would answer a resounding Yes to the title question, based on her comparative study of doctors and NPs caring for a population of 1,300 patients. "NPs' and doctors' outcomes are indistinguishable in this study, so that would suggest that they indeed are interchangeable," says Mundinger, dean of Columbia University School of Nursing.

The patients, primarily Hispanics who sought health care through the emergency room or urgent care center at Columbia Presbyterian Medical Center in New York City, were randomly assigned to primary care doctors or to NPs in an independent practice with hospital privileges and prescribing authority. The NPs and physicians had identical productivity requirements. The study, published in the Jan. 5 issue of JAMA, was the first large-scale, randomized clinical trial of NPs and physicians in similar practices, according to Mundinger.

After six months, researchers evaluated the patients' health status and satisfaction with care. The results: No significant differences were found in outcomes for patients with diabetes and asthma, although hypertensive patients under the care of NPs had lower diastolic values. NPs and physicians hospitalized patients at the same rate and used the same amounts of services. On one of four aspects of patient satisfaction, scores were somewhat higher for the physicians, which Mundinger attributes to the NPs' being required to move their practice during the study.

"If NPs can care for a group of non-English-speaking, underserved patients and bring their health status up in six months, it's pretty easy to say that they can do a good job with any patients," says Mundinger.

Not necessarily, writes internist Harold C. Sox in an editorial accompanying Mundinger's study. Sox, of Dartmouth-Hitchcock Medical Center in Lebanon, NH, calls the study "a remarkable accomplishment" and "ambitious," but faults it for being too time-limited "to test a health professional's competence across the broad spectrum of primary health care" and for using patients not representative of the larger population.

The study, Sox says, did not prove that NPs are the equal of primary care doctors in such tasks as making accurate diagnoses, evaluating emergency patients, managing inpatients, and treating patients with complex problems. Therefore, using this study to claim that NPs' care is as good as that of doctors' is "far from convincing," writes Sox.

Mundinger shrugs off the criticism. "Yes, it would have been nice to follow these patients for a year, and it would have been better if we'd had all sorts of ethnic groups as patients," she says. "But the take-home message is that an individual who selects an NP as a primary care provider is making a safe, quality decision. And if that adds competition to the primary care workforce, then that is an outcome of this study."

Mundinger has now collected two years of data for a three-year follow-up study. "We proved the competency of NPs in the first study," she says. "The new one will examine what patients get from an NP that is different from a physician's care. Do they get more involved in their own care with an NP?"

Meanwhile, Mundinger's own independent practice, Columbia Advanced Practice Nurse Associates, is thriving. (See "What kind of patients would rather wee a nurse practitioner?" Feb. 8, 1999, also available at "We moved to a bigger site in midtown Manhattan—right on Madison and 57th. We are getting seven new patients a week, and 92 percent come back for a second visit."



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