Family nurse practitioner Myra Howard runs the Buellton Medical Center in Buellton, California. She’s also the majority shareholder in the clinic. But the law still requires that her practice is supervised by a physician.

“If my family practice physician decides to leave, I have to close my door and all my services and investment goes away,” Howard said. She and the five physicians she has hired serve an average of 30 patients a day ranging from celebrities to undocumented workers.

Finding family practice physicians to take on supervisory roles in this area is difficult she said. That makes it expensive and risky for her and other nurse practitioners (NPs) to run their own clinics in areas lacking health care services, especially in rural and semi-rural areas like Buellton.

California is one of 33 states requiring NPs to be supervised by a physician. That’s despite the fact they are advanced practice registered nurses, most of whom have masters or doctorate degrees and are trained and licensed in specific practice areas to evaluate patients, diagnose, order and interpret diagnostic tests, initiate and manage treatments and prescribe medicine.

Over the last 38 years 17 states and the District of Columbia have amended their laws to allow NPs “full practice authority,” enabling them to practice to the full extent of their training without physician supervision.

A bill by Senator Ed Hernandez (D-West Covina) would have added California to that list, but after passing the Senate, it failed in the Assembly Appropriations Committee in August. Hernandez’s chief of staff, Tim Valderrama, said there is a mountain of evidence demonstrating the safety of expanded practice for NPs and that Hernandez will absolutely introduce another bill.

“West of the continental divide we’re the only state that hasn’t modernized its scope of practice for nurse practitioners,” said Blanca Castro, advocacy manager for the California office of the AARP.

An aging U.S. population and millions of people gaining health insurance through the Affordable Care Act has compounded the shortage of primary care providers and added more urgency to debates over how much independence NPs should have.

Many poor and elderly patients have trouble finding providers who will take Medicare and Medicaid, especially in rural areas, said Mary Knudtson, a nurse practitioner with a doctorate in nursing science and executive director of the University of California Santa Cruz Student Health Services. The American Academy of Nurse Practitioners reports that 87 percent of NPs take Medicare, 84 percent take Medicaid and 88 percent have trained in primary care.

Meanwhile since 1998 the proportion of US medical students choosing primary care has dropped from about 60 percent to between 20 and 27 percent, according to a study published this year in the journal Health Affairs. The report states that between 1998 and 2010 the number of Medicare patients receiving care from NPs increased fifteen fold.

The California Medical Association (CMA) and the Coalition for Patient Access and Quality Care, made up largely of physician associations, say the legislation would have posed a threat to patient safety.

“Quality of care and safety of care have to be paramount,” said CMA President Dr. Paul Phinney. “I have worked with nurse practitioners for 30 years and really, really value their care.” But he added that they have significantly less training and when faced with medical situations outside the norm they tend to order more labs, more antibiotics and referrals, increasing costs and decreasing convenience.

One of CMA’s biggest concerns is giving NPs the authority to prescribe narcotic pain medications without supervision.

“We’re in the middle of an epidemic of opioid overdose deaths,” Phinney said.

But many NPs already have the training and certification to prescribe those drugs.

“I prescribe Demerol and morphine, if I feel it’s appropriate, without a physician’s approval,” Howard said. “Making nurse practitioners more independent isn’t going to increase the amount of meds out there.”

With more than 20 years of patient outcomes and more than 600 million office visits to NPs last year alone in the U.S., there doesn’t seem to be justification for the patient safety argument, said Tay Kopanos, vice president of health policy state government affairs for the American Association of Nurse Practitioners.

“If there was a problem with safety and quality, it would have been highlighted,” she said.

CMA keeps throwing out patient safety as a concern, Knudtson said. But it’s no different for NPs than physicians. If they have a diagnostic dilemma, or the patient’s condition is outside their scope of practice, they need to refer that patient to an appropriate provider, she said.

“The current law doesn’t improve patient safety, it increases the cost of care,” she said.

Kopanos and others point to dozens of studies over decades reporting the competency of NPs. “Research suggests that NPs can perform many primary care services as well as physicians do,” according to a 2012 paper by the National Governors Association, “and achieve equal or higher patient satisfaction rates among their patients.”

The biggest impact of limiting the scope of practice for NPs is that it prevents those nurses from practicing in rural or underserved communities, Kopanos said.

Phinney disagrees, stating that in states allowing independent practice, NPs tend to practice in the same areas as physicians.

American Association of Nurse Practitioners statistics show that there are NPs moving to rural areas in states like Wyoming, Iowa and Montana. In Wyoming 34.9 percent of the population lives in rural areas and 43 percent of the state’s nurse practitioners work there, Kopanos said.

She added that it’s a misconception that physicians are practicing regular supervision of NPs. In the majority of states with supervised NPs most physicians don’t know who is scheduled and they don’t review the charts, she said.

“Often times they’re not even in the same office or building,” said Castro of AARP.

Mark Dressner, president of the California Academy of Family Physicians and a primary care physician at the Children’s Clinic in Long Beach said it’s true that the nurse practitioners may go all day without talking to him, but they do go over charts together.

He said the main concern is the difference in training. For instance with high blood pressure patients, a patient may have something a bit out of the norm that could indicate an adrenal tumor rather than typical hardening of the arteries and an NP has not been trained to catch that, he said.

He said most of the NPs he talks to in his office cringe at the idea of practicing independently. “Our push is patient-based care, team care, led by a physician,” Dressner said.

“Independent practice just moves in the wrong direction” said Phinney. Clinically integrated, multidisciplinary teams will lead to improved care and expanded capacity, he said.

Kopanos agreed that a team approach makes sense in certain settings like the ICU, but in others it makes health-care less effective.

“Full practice authority doesn’t limit teams, it gives them more flexibility,” she said.