The Effects of Medicare Part D on Health Outcomes of Newly Covered Medicare Beneficiaries

The effect of prescription drug insurance on the incidence of potentially inappropriate prescribing: Evidence from Medicare Part D

The Medicare Part D program has been documented to increase the affordability and accessibility of drugs and improve the quality of prescription drug use; however, less is known about the equity impact of the Part D program on potentially inappropriate prescribing-specifically, incidences of polypharmacy and potentially inappropriate medication (PIM) use based on different racial/ethnic groups. Using a difference in the regression discontinuity design, we found that among Whites, Part D was associated with increases in polypharmacy and "broadly defined" PIM use, while the use of "always avoid" PIM remained unchanged. Conversely, Blacks and Hispanics reported no changes in such drug utilization patterns.

Effect of Medicare Part D on Ethnoracial Disparities in Antidementia Medication Use

OBJECTIVES

To examine ethnoracial disparities in antidementia medication use, accounting for implementation of Part D, and to evaluate the role of prescription drug coverage as a cause of antidementia medication disparities.

DESIGN

Rotating panel of Medicare beneficiaries who participated in the Medicare Current Beneficiary Survey from 2003 to 2013.

SETTING

Nationally representative sample of Medicare fee-for-service (FFS) beneficiaries with dementia.

PARTICIPANTS

Community-dwelling FFS Medicare beneficiaries with dementia (N=4,304).

MEASUREMENTS

Antidementia medication use, defined as at least one prescription fill in a given year.

RESULTS

Unadjusted antidementia medication use was 10-percentage points lower for ethnoracial minority beneficiaries before Part D was implemented in 2006 (p=.01). This difference was attenuated after adjusting for demographic and socioeconomic factors (6-percentage points; p=.10). Part D was associated with a 6-percentage point increase in use (p<.01). The increase in use associated with Part D was higher although not statistically significantly so in ethnoracial minority beneficiaries (8-percentage points, p=.08). Analyses of each ethnoracial group found a significant effect of Part D only in Hispanic/Latino beneficiaries (18-percentage points; p<.01, adjusted).

CONCLUSION

Antidementia medication disparities were reduced with expanded prescription drug coverage through Medicare Part D. Increases in antidementia medication use for minority beneficiaries started after Part D was implemented, with the largest increases in use observed in Hispanic/Latino beneficiaries.

The Impact of Medicare Part D on Self-Employment

We explore the relationship between access to affordable health insurance and self-employment using exogenous variation from the introduction of Medicare Part D that reduced the out-of-pocket cost of prescription drugs and improved health outcomes in a difference-in-differences model using the American Community Survey. We find that our treatment group of individuals aged 65-69 were 0.5 percentage points (or 5%) more likely to be self-employed in relation to a control group aged 60-64.