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.
Mott
David A
DA
Sonderegger Research Center, Division of Social and Administrative Sciences, University of Wisconsin School of Pharmacy, Madison, WI 53705, USA. damott@pharmacy.wisc.edu
Thorpe
Joshua M
JM
Thorpe
Carolyn T
CT
Kreling
David H
DH
Gadkari
Abhijit S
AS
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