The introduction of generic risperidone in Medicare Part D

Area of Science:

• Pharmacoeconomics and Health Services Research
• Psychiatry and Mental Health
• Health Policy and Management

Background:

• The availability of generic second-generation antipsychotics (SGAs), beginning with risperidone in July 2008, presented an opportunity to decrease medication expenses and reduce barriers to access.
• Understanding the impact of generic SGA introduction on healthcare spending and patient adherence is crucial for optimizing treatment strategies.

Purpose of the Study:

• To evaluate the association between the uptake of generic risperidone and changes in antipsychotic spending and adherence among Medicare Advantage (MA) beneficiaries.
• To compare the effectiveness of different health plan types in encouraging the use of generic SGAs.

Main Methods:

• A historic cohort study design was employed, including MA beneficiaries undergoing SGA treatment before July 2008.
• Antipsychotic spending, adherence (proportion of days covered ≥ 80%), and nonpersistence were analyzed using linear, logistic, and Cox proportional hazard models, respectively.
• Comparisons were made between beneficiaries who used generic risperidone and those who did not, adjusting for individual and plan characteristics.

Main Results:

• Generic risperidone use was observed in 22.8% of beneficiaries between July 2008 and December 2009, primarily among those previously on branded risperidone.
• Beneficiaries in Health Maintenance Organization (HMO) plans showed higher rates of generic risperidone use compared to those in private fee-for-service (FFS) plans.
• Switching to generic risperidone was associated with significantly lower out-of-pocket spending, improved adherence, and reduced nonpersistence compared to continuing other SGAs.

Conclusions:

• Generic risperidone use was concentrated among patients who previously used the branded version.
• HMO plans demonstrated greater success in promoting generic SGA adoption than unmanaged private FFS plans.
• Opportunities exist to further encourage generic SGA utilization to reduce costs and enhance patient treatment adherence and outcomes.