The effect of transitioning to medicare part d drug coverage in seniors dually eligible for medicare and medicaid.
OBJECTIVE
To evaluate medication use, out-of-pocket spending, and medication switching during the transition period for patients dually eligible for Medicaid and Medicare (dual eligibles).


METHODS
Time-trend analysis, using segmented linear regression.


METHODS
Patient-level pharmacy dispensing data from January 2005 to December 2006 from a large pharmacy chain with stores in 34 states.


METHODS
Dual eligibles aged 65 and older.


METHODS
Changes in utilization, patient copayments, and medication switching were analyzed using interrupted time trend analyses. Utilization and spending were evaluated for five study drugs: clopidogrel, proton pump inhibitors (PPIs), warfarin, and statins (essential drugs covered by Part D plans) and benzodiazepines (not covered through Part D but potentially covered through Medicaid).


RESULTS
Drug use for 13,032 dual eligibles was evaluated. There was no significant effect of the transition to Medicare Part D on use of all study drugs, including the uncovered benzodiazepines. Cumulative reductions were seen in copayments for all covered drugs after implementation of Part D, ranging from 25% annually for PPIs to 53% for warfarin, but there was a larger increase in copayments, 91% annually, for benzodiazepines after the transition. The rate of switching medications was 3.0 times as great for the PPIs after implementation of Part D than before implementation, but there was no significant change in the other study drug classes.


CONCLUSIONS
These findings in a single, large pharmacy chain indicate that the transition plan for dual eligibles led to less medication discontinuation and switching than many had expected. The substantially greater cost sharing for benzodiazepines highlights the importance of implementing a thoughtful transition plan when executing such a national policy.
Shrank
William H
WH
Department of Medicine, Division of Pharmacoepidemiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02120, USA.
Patrick
Amanda R
AR
Pedan
Alex
A
Polinski
Jennifer M
JM
Varasteh
Laleh
L
Levin
Raisa
R
Liu
Nan
N
Schneeweiss
Sebastian
S
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008484:Medicaid / Q000706:statistics & numerical data*; D054524:Medicare Part D / Q000706:statistics & numerical data*; D014481:United States