Effects of Medicare Part D on drug affordability and use: Are seniors with prior high out-of-pocket drug spending affected more?
BACKGROUND
Medicare Part D was expected to have differential impacts on patient drug expenditures and use based on beneficiaries' levels of pre-Part D patient drug spending, but it is unknown whether these projections have borne out.


OBJECTIVE
We sought to evaluate whether and how the policy effect of Medicare Part D on drug expenditures and use was modified by levels of pre-Part D drug spending.


METHODS
A quasi-experimental, pretest-posttest, nonequivalent control group design was used. Data were obtained from a regional supermarket chain for all prescriptions dispensed between January 1, 2005, and December 31, 2007 (n=1,230,612) to patients aged 60 years and older as of January 1, 2005 (n=51,305) to construct 12-month pre-Part D and post-Part D periods. Annual medication use was measured as the total number of pill days acquired. Annual drug expenditures were measured as total expenditures, patient out-of-pocket expenditures, and the proportion of total expenditures paid out of pocket by the patient.


RESULTS
Part D resulted in significant reductions in out-of-pocket spending (17.6%) and significant increases in drug use (4.0%) for individuals in the highest pre-Part D drug-spending group relative to controls. The reduction in out-of-pocket spending for the highest pre-part D spending group was significantly greater compared with the moderate and lowest pre-Part D spending groups.


CONCLUSIONS
Our findings suggest that, as expected, Part D facilitated access to medications for patients who previously experienced the greatest costs without adversely increasing use and costs among those with the lowest prior cost.
Sonderegger Research Center, Division of Social and Administrative Sciences, University of Wisconsin School of Pharmacy, Madison, WI 53705, USA. damott@pharmacy.wisc.edu
David A
DA
Mott
Joshua M
JM
Thorpe
Carolyn T
CT
Thorpe
David H
DH
Kreling
Abhijit S
AS
Gadkari
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003157:Community Pharmacy Services / Q000191:economics*; D003363:Cost Control; D016527:Drug Costs; D011307:Drug Prescriptions / Q000191:economics; D004608:Eligibility Determination; D005260:Female; D005382:Financing, Personal; D018166:Health Care Reform; D006297:Health Services Accessibility / Q000191:economics*; D006302:Health Services Research; D006801:Humans; D007182:Income; D019458:Insurance Coverage / Q000191:economics*; D007356:Insurance, Pharmaceutical Services / Q000191:economics*; D008297:Male; D054524:Medicare Part D / Q000191:economics*; D055553:Prescription Drugs / Q000191:economics*; D013997:Time Factors; D014481:United States
D055553:Prescription Drugs