Impact of drug coverage on medical expenditures among the elderly.

Our study compares expenditures for Medicare covered medical services among enrollees in three State pharmacy assistance programs with spending among low-income residents eligible or near-eligible for, but not enrolled in such State-sponsored programs after controlling for between-group differences in demographic, socioeconomic, health status, and insurance status characteristics. We estimate a two-part model in total and by type of service (inpatient, outpatient, and professional) and chronic condition (hypertension, heart disease, and arthritis). We find that drug coverage has no discernible effect on the use and cost of inpatient services, but is associated with a statistically significant increase in Medicare spending for physician services.