It's often taken as a key tenet in any discussion of health policy: The country has too few doctors, and the shortage will only get worse over time. As the population ages and the health law expands insurance, the argument goes, there are simply too few doctors to see the newly-insured and the newly-elderly.
There's just one small problem, says Linda Green, a mathematician who has spent two decades studying the health care system: It might not be true. In a new Health Affairs paper, Green argues that forecasting models have greatly overestimated the doctor shortage. Instead of getting worse, she says, access to health care might actually improve in coming years.
"Generally everybody has been screaming that the sky is falling and we have this shortage of something like 45,000 physicians in the next 15 years," says Green, a professor in the decision, risk and operations department of Columbia University's Graduate School of Business. "We're saying, no, it's not. You're basing your projections on the wrong model."
Most forecasts of doctor shortages assume that a primary care physician can handle a set amount of patients in a practice, usually about 2,500. And if that remains the case, Green agrees there would indeed be too few doctors to meet the nation's medical needs.
However, Green doesn't think the status quo is here to stay: She argues that the health care system is rapidly changing. First, doctors are increasingly joining up into big practices. They're able to share support staff and office space, which can make it easier to take on a bigger patient population. She refers to this as "physician pooling."
Second, the health care workforce is changing, as physician assistants and nurse practitioners take on larger roles. Having non-physicians take care of routine care, things like strep throats and ear infections, can again increase the size of a doctor's patient population.
Green and her co-authors model two situations, both taking into account the increased demand expected to come from insurance expansion and aging.
One scenario looks at the primary care physician landscape if it stays just as is. The other looks at what happens if doctors become more pooled (in this scenario, it assumes a three-doctor practice, where patients could be seen by any of three physicians). It also assumes that doctors divert about 20 percent of their patients to other health care providers, like nurses and physician assistants. That red line in the middle shows the expected demand for doctors.
In other words, make those two changes, and suddenly the doctor shortage disappears.
"All of these things, the growth in the supply of non-doctors, the team approach, they all add up to having physicians cover twice as many patients as they have in the past," Green says.
Not everyone, however, agrees - particularly those who have been forecasting a doctor shortage. That includes Atul Grover, chief public policy officer for the Association of American Medical Colleges. It publishes what are, perhaps, the most cited physician workforce shortage projections. It expects 29,800 too few doctors as soon as 2015.
Grover concedes that forecasting workforce shortages is tricky business; it's hard to know what the health care workforce will look like in a few years from now, let alone a full decade.
AAMC's model does factor in expected growth in the non-physician workforce - some of the demand diversion that Green mentions in her paper. But it does not expect that type of workforce to grow fast enough to wipe out the doctor shortage completely.
"You can see this idealized world where there are all these Patient-Centered Medical Homes, and everyone is working in teams," Grover says. "But that's just 1 percent of the health care system. There are so many scope of practice issues and so many reimbursement issues that can slow this."
Grover adds that, even if the primary care shortage is alleviated, there is still a specialist shortage. The AAMC projects a shortage of 46,000 specialty doctors within the next decade, and it's harder for these doctors to implement some of the work-saving techniques that might work in primary care.
"I have trouble seeing how you delegate work away from a neurosurgeon," he says. "I still want my surgeon to have all his years of medical school and fellowship."