(photo: Jimmy Wayne)

Given the incredible structural similarity between the Massachusetts health care reform law signed by Mitt Romney and the new national Affordable Care Act signed by President Obama, the release of the annual physician workforce survey (PDF) from the Massachusetts Medical Society has generated a lot of attention. But I would caution everyone involved that on issues like the impact ACA will have on ER use or physician availability, what has happened in Massachusetts might be a very poor guide to predict what will happen nationally.

Many conservative writers, like Philip Klein and the WSJ editorial board, are using the report’s finding of longer appointment wait times, increased ER usage, and doctors accepting few new patients as proof that Romneycare failed. and so Obamacare will fail.

In the law’s defense, Jonathan Cohn makes a very strong case that some of the bad news is just statistical noise or the continuing of trends that existed long before the reform and not really affected by it.

Elsewhere, it appears that primary care physicians (although not specialists) are becoming less likely to see new patients. And that’s certainly worrisome. But that decay was also underway before the Massachusetts reforms: It doesn’t appear to have accelerated starting in 2007. The Journal and others also point to a 2010 study on rising emergency room usage between 2004 and 2008. But, again, the rate of increase didn’t change after reform: It was going up before the coverage expansion took place. In fact, the most detailed study of ER usage in Massachusetts I’ve seen comes from Sarah Miller, a graduate student at the University of Illinois. It suggests that reform’s direct effect was to reduce utilization, albeit very slightly.

Massachusetts before reform isn’t like the rest of America now

Before its reform, Massachusetts had one of the highest insurance rates in the country. It also already had a relatively very generous health insurance safety net that covered many of the most in need. Many of the newly covered were the relatively healthy and young. Depending on your source, US Census or Mass. DHCFP (PDF), and the numbers used, reform only resulted in roughly five percent more of the population getting coverage over several years.

The conservative argument is that this at most five-percent (and probably much less based on who the new insured are) increase in demand spread over several years is the cause of some major problem in the medical care supply is very weak at best, as pointed out by Cohn.

On the other hand, what will happen nationally thanks to ACA will be significantly larger than the very small increase that happened in Massachusetts. The CMS (PDF) predicts ACA will result in 10 percent of the country gaining coverage, a 12-percent increase in the number of people with insurance. In some states, that increase will be significantly higher and those people gaining insurance will be sicker and poorer than the people who gained coverage in Massachusetts.

The impact on ER visits, costs and waiting times for appointment caused by a five percent more of fairly healthy people in Massachusetts getting insurance could be a really poor predictor of what happens when a similar program causes a 15-percent jump in those with insurance in a state like Mississippi.