OIG study finds that 56% of Part D drugs are generics
US DEPARTMENT OF HEALTH AND HUMAN SERVICES, OFFICE OF THE INSPECTOR
GENERAL REPORT: “Generic Drug Utilization in the Medicare Part D
Program” (OEI-05-07-00130, November 2007, .pdf format, 30p.).
Abstract:
We found that Part D achieved a high level of generic drug use during the
first two quarters of 2006. Under Part D, generic drugs were dispensed 88
percent of the time when generic substitutes were available. However, 37
percent of prescriptions were for drugs that have no generic substitutes,
limiting opportunities to dispense generics. Overall, 56 percent of all
drugs dispensed were generic drugs.
Our findings indicate that variation in the rate of single-source drug
prescribing primarily accounted for variation in generic drug utilization.
Therefore, to achieve increases in generic drug utilization, Part D plans
may realize gains by encouraging the prescribing of multisource drugs,
which have generic equivalents. However, such efforts should be
undertaken with caution to ensure that beneficiaries maintain access to
appropriate treatment.
In response to our draft report, CMS generally concurred with our
findings. CMS noted differences between our and CMSs calculation of
generic drug utilization and suggested that this may be because of its
inclusion of multisource brand name drugs in its measure of generic drug
utilization. We did not include multisource brand name drug utilization
data in our measure of generic drug utilization because these data are
inconsistent with the definition of generic drugs under Part D.