Benzodiazepine use and expenditures for Medicare beneficiaries and the implications of Medicare Part D exclusions

Objectives: Benzodiazepines are excluded from prescription drug coverage under Medicare Part D. The objectives of this study were twofold: to provide national estimates of benzodiazepine utilization and expenditure patterns and to examine the impact of drug coverage and other factors associated with utilization of benzodiazepines and potential benzodiazepine substitute classes. Methods: The 2002 Medicare Current Beneficiary Survey provided national estimates of benzodiazepine use and expenditures among Medicare beneficiaries. Multivariate logistic regression was conducted to assess the relationships between independent variables and use of benzodiazepines and potential substitute classes. The independent variable of interest was drug coverage, assessed by payer source. Other covariates included in the models were chronic conditions associated with benzodiazepine use, age, sex, race, and income. Results: In 2002, 13.7% of Medicare beneficiaries received at least one benzodiazepine fill, with an average of 5.8 benzodiazepine prescriptions filled at an annual cost of $ 190. Specific sources of prescription drug coverage were not significantly associated with benzodiazepine use. Female gender, chronic mental illness, age under 65, and lower income were significantly positively associated with benzodiazepine use in the Medicare population, whereas black and other races were significantly negatively associated with benzodiazepine use in this population. Compared with Medicare beneficiaries without supplemental drug coverage, beneficiaries with supplemental drug coverage were more likely to use potential benzodiazepine substitute classes than benzodiazepines. Conclusions: Benzodiazepines were widely used by Medicare beneficiaries. Drug coverage influences access to benzodiazepines and potential substitute classes. These findings have important implications for identifying beneficiaries potentially affected by the exclusion of benzodiazepine coverage under Medicare Part D.