Oregon's 2008 Medicaid (Oregon Health Plan) expansion offered a gift to health researchers.
Since people either got Medicaid coverage or didn't by lottery, large numbers of people--thousands--would be available totest the resultsof health insurance coverage (or not) on previously uncovered populations.
Bottom line: the covered people are not a whole lot healthier, but they made more use of health care services and spent less of their own money.
We spend an hour getting a fuller picture of health outcomes from the study.