Will the Medicare Prescription Drug Benefit Eliminate Cost Barriers for Older Adults with Diabetes Mellitus?

Abstract

To determine the proportion of older people with diabetes mellitus (DM) eligible to enroll in the standard Medicare Part D drug benefit who will exceed the initial $2,250 coverage limit and to determine the effect of hypoglycemic choice on risk of exceeding the coverage limit. Cross-sectional survey. Nationally representative sample of adults living in United States households participating in the 2001 Medical Expenditure Panel Survey (MEPS). Individuals aged 65 and older with a diagnosis of DM eligible to enroll in the standard Medicare Part D drug benefit. Prescription medication use and expenditures adjusted to 2006 U.S. dollars as reported in the MEPS prescribed medicine file. Survey-weighted logistic regression models were used to estimate the odds of annual medication expenditures exceeding $2,250, controlling for hypoglycemic type, sociodemographic characteristics, chronic conditions, and health status. Of the estimated 3.2 million elderly people with DM eligible for the standard drug benefit filling a prescription in 2001, approximately 64% had medication expenditures in excess of $2,250 in 2006 adjusted dollars. The proportion exceeding the initial coverage limit varied by type of hypoglycemic drug used from 60% of those using traditional hypoglycemics to more than 75% of those using novel hypoglycemics. Patients with more comorbidities and poorer health status were at greater risk of exceeding the initial coverage limit. A large proportion of older adults with DM may exceed the initial coverage limit under the standard Medicare Part D drug benefit and incur significant out-of-pocket spending.