Under the Affordable Care Act (ACA), states can extend Medicaid eligibility to nearly all adults with income up to 138% of the federal poverty level (FPL) with full Federal financing from 2014 through 2016.  Information on the health care needs, health risks, and likely health care use of the uninsured adults who could gain coverage under the ACA could help Medicaid programs prepare for the expansion. This paper uses data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010 to analyze health conditions among uninsured adults aged 19-64 who have income no more than 138% FPL in comparison to adults currently on Medicaid.  We compared the prevalence of risk factors (e.g. self-reported smoking status, exercise, alcohol use, illegal drug use, and obesity) and measures of health status (some self-reported and some based on results from laboratory tests).  Health conditions based on lab tests were hypertension, diabetes, and hypercholesterolemia. For those with one of these three conditions, we evaluated the proportion whose condition was undiagnosed or uncontrolled.  Analyses used sample weights and standard errors accounted for the complex design of the survey. Wald F-tests were used for comparisons.  Statistical significance was assessed at p < 0.05.   

We find that the uninsured had some lower health risks relative to those who were already enrolled in Medicaid.  For example, they were less likely to be obese and more likely to exercise.  Still, one-third of the uninsured adults were obese, half currently smoked, one-quarter reported a functional limitation, and one-quarter reported their health as fair or poor, all factors that could contribute toward health care utilization and spending.   The uninsured were less likely than those on Medicaid to have one or more of the three chronic medical conditions we considered in more detail (diabetes, hypertension, hypercholesterolemia) (30.1%, CI 27.1-33.4 vs. 40.2%, CI 33.6-46.9).  However, conditional upon having a condition, they were more likely to have it undiagnosed or uncontrolled.  For instance, nearly one-third of uninsured adults with hypertension were undiagnosed (30.5%, CI 23.4- 37.6) as compared to 17.7% (CI 10.2-25.1) of Medicaid adults.  Nearly two-thirds (67.3%, CI 58.8-75.7) of the uninsured with hypertension had uncontrolled hypertension, compared to 40.2% (CI 29.9-50.5) of adults on Medicaid.

While uninsured with income less than 138 percent FPL have fewer health conditions on average than adults currently on Medicaid, there could be a need for care among those with undiagnosed health conditions in the early years following their enrollment in Medicaid.   This analysis suggests that if all of the uninsured enrolled, the uninsured who would gain Medicaid coverage would be healthier on average than adults currently enrolled in Medicaid.  However, we also found that about one-quarter of possible new Medicaid enrollees with diabetes, hypertension, or hypercholesterolemia did not have the problem diagnosed at the time of NHANES exam and over half did not have the problem properly controlled, suggesting need for care.