Not too long ago, ACA opponents were claiming that Medicaid was bad for health. Some even claimed it killed people. So I was eager to see if an RCT would find that. The initial results were positive and statistically significant.
All by itself this finding is a worthwhile addition to the discussion; the meme that Medicaid coverage could lead to worse health outcomes was always a bit tricky to understand. Trying to illicit a causal mechanism where Medicaid was worse for health but private insurance/Medicare were not that led naturally to the policy of "end Medicaid" was always a bit dicey. If it was malice on the part of medical doctors due to low reimbursement rates then that rather changes the discussion in important ways.
So I think we should take this argument by Megan McArdle with a great deal of care:
And yet, we did find a significant improvement in catastrophic medical bills, which coincidentally also affect about 5% of the control group. Yet the folks saying Oregon's sample of diabetics is too small to tell us anything do not think it is too small to tell us anything about catastrophic medical bills.
I think that there are two points here. One, the point estimates of the changes for chronic medical conditions are well within the levels of clinical significance. So it is odd to suddenly interpret the data like an extreme frequentist and claim that the only interpretation is "no effect".
But the other piece that is more important is that this is actually a good result. If we take Megan's 5% rate, that would mean that 5% of poor Americans have a catastrophic medical bill within a two year period. How can trying to solve that problem not be a major priority? Isn't this great evidence that (given how expensive medicine has gotten) that this was a massively successful intervention?
I'd have more sympathy for the situation if we were making hard decisions to bring down costs. But that isn't a major priority right now. Medicaid is a very cost effective way to deliver care in a country where care is very pricey. Why isn't this a major and positive result?