Impact of Medicare Part D on income-related inequality in drug expenditure
In this project, we outline the use of inequality measures to evaluate the impact of extending health insurance on income-related inequality in drug expenditure using the example of Medicare Part D in the United States. The Medicare Part D program increased access to prescription medications for Medicare beneficiaries from 2006. We use pooled cross-sectional samples from the Medical Expenditure Panel Survey to estimate income-related inequality in drug expenditures using the concentration index and generalised concentration index. A difference-in-differences analysis is conducted on the inequality in drug expenditures between the elderly (over 65 years) and near-elderly (54-63 years) pre and post the implementation of Medicare Part D to evaluate the effect of the policy on the inequality in public drug expenditures.
This study demonstrates the usefulness of measuring the impact of health system changes on inequalities in health expenditure and provides a guide for future evaluations.
University of Melbourne