Are marketplace enrollees sicker than those with employer-sponsored insurance?

To date, little is known about the health status of the 7.3 million Americans who signed up for health insurance through either federal- or state-run exchanges created by the Affordable Care Act (ACA). One effective way to gain information is to examine their use of prescription drugs.

A new study, being released by Health Affairs as a Web First, compared prescription data from January to September of 2014 of more than one million Marketplace enrollees. The study reviewed the characteristics and medication use of early enrollees (October 1, 2013 through February 28, 2014) and those enrolling later (between March 1 and May 31, 2014), and compared those findings with a sample of some one million Americans enrolled in employer-sponsored health coverage.

There were three key findings, which have implications for understanding the impact of the ACA. According to the study, those who signed up earlier were on average four years older and used more medication than later enrollees. Additionally, the authors found that prescription drug spending among Marketplace enrollees as a whole was lower than in the comparison group: $72 versus $93 per month during the nine-month study period. Finally, Marketplace enrollees were nearly four times more likely to use HIV medications and had 36 percent higher out-of-pocket expenses for specialty medications than did the comparison group.

Data for the study were gathered from Express Scripts, Inc., the largest pharmacy benefit manager in the United States, to compare the characteristics and medication use of more than one million Marketplace enrollees with a matched sample in employer-sponsored insurance plans. "Our descriptive analysis, which showed lower medication use among Marketplace enrollees relative to a comparison group with employer-sponsored coverage, suggest that the ACA Marketplaces did not experience adverse selection in their first year," conclude the authors. "However, we cannot necessarily rule out adverse selection...[because] some of the differences in usage between Marketplace and comparison group enrollees may be attributable to the extended time it can take previously uninsured Marketplace enrollees to obtain care and have unrecognized conditions diagnosed and treated."