Study authors J. Michael McWilliams, M.D., Ph.D.; Alan Zaslavsky, Ph.D.; and Haiden Huskamp, Ph.D., all of whom are affiliated
with Harvard Medical School's Department of Health Care Policy, used data from the University of Michigan's longitudinal Health
and Retirement Study and linked Medicare claims from 2004 to 2007 to evaluate the nondrug spending of 6,001 elderly Medicare
beneficiaries.