There were no major detected differences between the uninsured and Medicaid recipients. There was more treatment for diabetes, though no difference between the two groups on a key indicator of the disease.
The only major health gain was psychological. Depression dropped from about 30 percent to 21 percent between the groups.
One reason may have been that Medicaid recipients don't fear huge medical bills. Their out-of-pocket health costs were $337.
For the uninsured, out-of-pocket costs were 64 percent higher. (Presumably, most non-out-of-pocket costs for the uninsured were covered by free clinics, charity care and uncollected debt.)
"Health insurance is a financial product that is aimed at providing financial security," says the study. On that ground, it succeeded.
By most clinical measures, it didn't.
Perhaps it is too early. The expanded Medicaid coverage was only two years old at the time of the study. Maybe greater health improvements will emerge.
But maybe they won't and - and not only because the uninsured already receive care.
Many uninsured are relatively healthy; insurance won't make them healthier. For others, modern medicine can't cure every health problem.
For still others, bad luck or bad habits are hard to change. About two-fifths of Oregon's uninsured were obese or smoked; Medicaid didn't alter that.
Much of this was known - or could have been surmised - during the debate over Obamacare.
The Congressional Budget Office reported that the uninsured typically received 50 percent to 70 percent of the care of the insured.
A study in 2007 of the 1965 creation of Medicare - insurance for the elderly - concluded that it had "no discernible impact on elderly mortality" in the first 10 years but improved recipients' financial security by limiting out-of-pocket expenses.
Obamacare's advocates ignored these ambiguities. They were too busy flaunting their own moral superiority.
Universal health insurance is a legitimate goal, but 2009 - in the midst of a major economic crisis - was the wrong time to pursue it.
Predictably, it polarized public opinion and subverted confidence for what seem, based on the available evidence, modest likely public health improvements.
The crusade for universal coverage has been as much about advocates' sense of self-worth as about benefits for the uninsured.