Oregon Medicaid Study

A couple of years ago, Oregon decided to add people to their Medicaid rolls.  However, the state didn’t have enough money to add everyone who was uninsured, but wanted to get Medicaid coverage.  So in the interest of fairness, Oregon held a lottery.  The winners of the lottery got access to Medicaid coverage.  The losers continued on without insurance coverage.

It turns out that this is a perfect experiment to test the theory that having insurance coverage leads to better health outcomes.  The idea is that with insurance, people will have better access to physicians.  This access will increase monitoring and counseling.  Also, there will be less emergency rooms visits, leading to lower cost healthcare overall.  To test this theory, you would need a randomized group trial that would control for all the possible factors that would differentiate a population that already had insurance from a population that did not.

The lottery is what makes this a perfect experiment.  It separated the participants into two randomly selected groups: a control group with no insurance, and a test group with Medicaid insurance.  A randomized trial is the gold standard of experimental design.

At the end of three years, a study was published tracking the health results of the two groups, insured and uninsured.  The primary findings of the study:

• Heath care utilization increased for the insured group.
• Rates of depression were 30% lower in the insured group.
• There were no statistically meaningful differences between groups in several measures of health: blood sugar, cholesterol, and blood pressure.
• Hospital admissions and emergency room visits were statistically similar for both groups.

Liberal commentators are focusing on the first two bullet points: “Isn’t it great!  We’ve found a way to make poor people happier!”  “At last poor people can get the health insurance that is their birthright.”

Conservative commentators have focused on the last two bullet points.  “If your use of primary care goes up (by over a $1000 per person on average), but you don’t cut hospital and emergency room visits, aren’t you just pissing away the money spent on primary care?”  “More medical care does not lead to improved outcomes?  Then why are we expanding Medicaid?”

One of the interesting points is that even though the use of diabetes drugs increased in the insured group, their blood sugar (actually, glycolimated hemoglobin) did not drop.  This would not surprise anyone who has ever seen someone swallow a blood sugar pill, and then wash it down with a Mountain Dew.

Ultimately, I think this study shoots down the theory that the key to good health is going to the doctor regularly, which is kind of a silly idea when you think about it.  Healthy people don’t go to the doctor regularly.