Much has already been written about the Oregon Medicaid study that just came out in the New England Journal of Medicine. Unfortunately, the vast majority is reflex, rather than reflection. The study seems to serve as a Rorschach test of sorts, confirming people’s biases about whether Medicaid is “good” or “bad”.
The proponents of Medicaid point to all the ways in which Medicaid seems to help those who were enrolled – and the critics point to all the ways in which it didn’t. But, if we take a step back to read the study carefully and think about what it teaches us, there is a lot to learn.
Here is a brief, and inadequate, summary (you should really read the study): In 2008, Oregon used a lottery system to give a set of uninsured people access to Medicaid. This essentially gave Kate Baicker and her colleagues a natural experiment to study the effects of being on Medicaid.
Those who won the lottery and gained access were compared to a control group who participated in the lottery but weren’t selected. Opportunities to conduct such an experiment are rare and represent the gold standard for studying the effect of anything (e.g. Medicaid) on anything (like health outcomes).
Two years after enrollment, Baicker and colleagues examined what happened to people who got Medicaid versus those who remained uninsured. There are six main findings from the study. Compared to people who did not receive Medicaid coverage:
- People with Medicaid used more healthcare services – more doctor visits, more medications and even a few more ER visits and hospitalizations, though these last two were not statistically significant.
- People with Medicaid were more likely to get lots of tests – some of them probably good (cholesterol screening, Pap smears, mammograms) and some of them, probably bad (PSA tests).
- People with Medicaid, therefore, not surprisingly, spent more money on healthcare overall.
