One of the claims I have frequently heard in support of some sort of government intervention in providing health insurance above and beyond Medicare and Medicaid in the US, is that it will reduce the need for patients without insurance to use emergency rooms instead of primary care facilities and that will reduce the cost:
Majority Leader Harry Reid, a Democrat, accused Republicans seeking to repeal the health-care law of trying to “force millions of American families to once again rely on expensive emergency room care—or go without care at all.” (Source)
Emergency room usage (and its associated expense) has been an important argument when healthcare reform is discussed, as in the article Obamacare Has a New Problem: It Won’t Fix Emergency Rooms. Studies have been conducted to attempt to quantify how emergency room use correlates with being uninsured, like the study The Effect of Health Insurance Coverage on the Use of Medical Services.
In this article about an appearance by Mitt Romney on 60 Minutes, the interviewer says "That's the most expensive way to do it—in the emergency room." and the author writes:
This constitutes a dramatic reversal in position for Romney, who passed a universal health care law in Massachusetts, in part, to eliminate the costs incurred when the uninsured show up in emergency rooms for care.
Is the total cost in the US of providing universal health care insurance in addition to the existing Medicaid and Medicare programs much less expensive than the total cost of uninsured people using emergency rooms for care?
I am not asking specifically about the costs of a particular implementation (aka the Affordable Care Act) although data collected since Obamacare has been in effect should be helpful.
I suspect that maybe the costs of additional consumption of services by insured versus uninsured people and the bureaucratic overhead of administering insurance plans (among other factors) may make it more cost effective to subsidize building urgent care centers for the uninsured in areas where the cost of treating people in emergency rooms is high due to demand. I'm looking for evidence to either confirm my suspicion or show me that it's wishful thinking. A recent article on Bakersfield.com claims that
Emergency room visits are up 29 percent in Kern County since 2009 when the Affordable Care Act was passed, running counter to one of the key takeaways from the law: that they would decrease as consumers take advantage of preventive care.
which adds some evidence that increased consumption of healthcare services may not by offset by the "savings" that access to preventive care is claimed to provide.
There is an implicit assumption in the arguments about emergency room usage that treating the uninsured in emergency rooms when they need care is more costly than if we provided them with insurance, but I'm having trouble finding convincing evidence that is true for anything but the most simplistic calculation of cost.
Keep in mind that the "expensive emergency room care" claim has never been about the quality or comprehensiveness of care—just the expense. Access to preventative care is a factor, but access to care is still potentially an issue whether someone is insured or not.
An example of that type of concern is outlined in Health Insurance Coverage and Adverse Experiences With Physician Availability: United States, 2012:
Almost 90% of general physicians accept new patients with private insurance, but less than 75% accept new patients with public coverage (e.g., Medicare, Medicaid), and the proportion of specialists accepting new patients with Medicare or Medicaid is declining.
There may be a more recent study that shows that trend reversing. I wasn't able to find one in the limited time I have today. Regardless, whether the insurance provided by the government is accepted by care providers (including specialists like mental health professionals and oncologists) would be a factor in comparing the total cost.