Low cognitive ability and poor skill with numbers prevent many Medicare beneficiaries, including those with multiple chronic illnesses, from enrolling in supplemental coverage, according to a study by researchers at the Robert F. Wagner Graduate School of Public Service.

The paper was written for the August edition of Health Affairs by professors Sewin Chan and Brian Elbel, who is also on the faculty of the NYU School of Medicine. It found that individuals in the lower third of cognitive ability (the general capacity to understand and use information) and numeracy (the ability to work with numbers) were 11 percent less likely than those in the upper third to enroll in a supplemental Medicare insurance plan.

“This result means that many Medicare beneficiaries are not getting the financial protections and other benefits that would be available to them if they were enrolled in a supplemental insurance plan,” Chan and Elbel write, adding that policymakers should consider enhanced education programs, simpler sets of choices, or even some type of automatic enrollment system.

In analyzing data between 1996-2008 from the National Health and Retirement Study, the authors found that the weaker these individuals’ cognitive abilities and numeracy—with such weaknesses tending to be most pronounced among the poor or those who have multiple chronic illnesses—the greater their chances of not enrolling in any gap-filling Medicare coverage.