How expensive is antipsychotic polypharmacy? Experience from five US state Medicaid programs

Area of Science:

• Health Economics
• Psychopharmacology
• Health Services Research

Background:

• Antipsychotic polypharmacy is a common practice in managing complex mental health conditions.
• Understanding the economic implications of antipsychotic polypharmacy is essential for healthcare resource allocation.

Purpose of the Study:

• To determine the healthcare costs linked to antipsychotic polypharmacy.
• To identify predictors associated with high-cost patients undergoing antipsychotic polypharmacy.

Main Methods:

• A retrospective cohort study analyzed Medicaid claims data from 55,383 patients across five states (1998-2002).
• Polypharmacy was defined as initiating multiple antipsychotics or concomitant use for over 60 days.
• Healthcare costs were calculated for 365 days post-index claim, with logistic regression identifying high-cost predictors.

Main Results:

• Antipsychotic polypharmacy affected 6% of patients annually and was linked to significantly higher drug expenditures ($1716-2079) versus monotherapy.
• Non-drug expenditures showed smaller, variable differences across states.
• In California, polypharmacy increased the likelihood of being a high-cost patient (OR=2.69) and even more so with concomitant psychotropics (OR=6.26).

Conclusions:

• Limiting antipsychotic polypharmacy presents a significant opportunity for cost savings in healthcare.
• Careful implementation is needed to prevent unintended consequences or shifts to more expensive treatments.
• Study findings should be interpreted considering limitations of claims data and state-specific Medicaid program variations.