Oregon Health Study Update for Participants

Thank you again for taking part in the Oregon Health Study! The results below are for the mail survey that took place in 2008 and 2009. If you took part in the in-person interview and health screening, those results will be available in early 2012. We are also doing ongoing surveys of people who have been on the reservation list.

About the Study

In 2008, Oregon opened a reservation list to people interested in applying for the Oregon Health Plan – Oregon’s Medicaid program for adults. The program, which already insured over 300,000 people, had enough funds to provide health insurance to an additional 10,000 Oregonians. To be as fair as possible, the state decided to draw names at random from the list to decide who would receive an application to apply and who would not.

Many more people signed up for the list than Oregon could insure. This meant that some people on the list would – at random - have the chance to apply and some would not. Researchers from Oregon and across the United States realized that this would be a unique opportunity to measure the impact of health insurance.

Researchers surveyed people on the list one year after the state did the drawings. The results from that survey indicate that enrollment in Medicaid substantially increases health care use, reduces financial strain, and improves self-reported health and well-being.

Key Study Findings

The study finds that for uninsured low-income adults, enrollment in Medicaid has the following effects after about one year:

• Insurance increases the likelihood of using outpatient care by 35 percent, using prescription drugs by 15 percent, and being admitted to the hospital by 30 percent, but does not seem to have an effect on use of emergency departments.
• Insurance increases the use of recommended preventative care such as mammograms by 60 percent and cholesterol monitoring by 20 percent.
• Insurance increases the probability individuals report having a regular office or clinic for their primary care by 70 percent and the likelihood they report having a particular doctor that they usually see by 55 percent.
• Overall, the increased health care use from enrollment in Medicaid translates into about a 25 percent increase in annual health care expenditures.

• Insurance decreases the probability of having an unpaid medical bill sent to a collection agency by 25 percent – which also benefits health care providers since the vast majority of such debts are never paid.
• Insurance decreases the probability individuals report having any out of pocket medical expenses by 35 percent.
• Insurance decreases the likelihood individuals report having to borrow money or skip payment on other bills because of medical expenses by 40 percent.

• Insurance increases the probability that people report themselves in good to excellent health (compared with fair or poor health) by 25 percent.
• Insurance decreases the probability that people report a decline in their health over the last six months by 40 percent.
• Insurance increases the probability of not screening positive for depression by 10 percent.

• Those selected in the lottery were 25 percentage points more likely to be enrolled in Medicaid, but this public coverage did not crowd our private coverage: they were no less likely to be covered by private health insurance.

A Unique Opportunity in Oregon

The random drawing for health insurance in Oregon provided the unique research opportunity to measure the effects of health insurance using a randomized controlled trial (RCT).

• What is an RCT?
  An RCT is a type of scientific experiment where half of those in the study experience something different from the other half. This “different experience” must be randomly assigned so that it is the only difference between the two groups. This allows researchers to measure the impact of that “different experience” – in this case, health insurance.
• Why is an RCT important to this study?
  An RCT is the gold standard for medical evidence. It is uncommon that social policy researchers are able to use such a design.
  This study represents the first use of a randomized controlled design to evaluate the impact of insuring the uninsured in the United States.

Ongoing Research

These results are just the beginning. Over the next two years, we will continue to share our findings from other parts of the Oregon Health Study research program.

Stay connected to www.oregonhealthstudy.org for more results that include…

• Research findings that include measures of physical health including blood pressure, cholesterol, diabetic blood sugar control, and obesity.
• Outcomes will also be studied over a longer time frame than the current results, which examines only the first year of Medicaid coverage.