antipsychotics, Medicare Part D, geographic variation


Purpose: To determine if there is a geographic variation in antipsychotic prescribing in Medicare recipients in 10 US divisions.

Methods: Data was collected in the Microsoft Excel format from the Medicare Provider Utilization and Payment Data: Part D Prescriber Public Use File for 2013 CMS data. Antipsychotics were sorted and downloaded into separate excel formats. The states were separated into the 10 geographic according to the US Census Bureau to identify prescribing trends. The primary endpoint was to determine the difference in the rates of CMS Medicare Part D utilizers who had antipsychotic prescriptions in each of the 10 geographic divisions. 
The rate of antipsychotic prescribing was calculated by determining the number of prescription claims for each antipsychotic for the division and dividing by the number of people utilizing Medicare Part D in each division. Data was converted to SPSS (version19, Armonk, NY) for further analysis. ANOVA was used to compare the differences.

Results: Approximately 35 million claims were included in the data set. Antipsychotics comprised 4.75% of the total spending on medications for Medicare Part D. New England was found to have the highest rate of claims at 0.83. No statistically significant differences in the rate of antipsychotic prescribing across geographic regions was observed; however, a statistically significant difference was observed for total claims (P<0.001) and total antipsychotic costs (P<0.017) across regions.

Conclusion: Additional studies need to be conducted to determine if there is a difference in antipsychotic prescribing in the United States.

Conflict of Interest

"We declare no conflicts of interest or financial interests that the authors or members of their immediate families have in any product or service discussed in the manuscript, including grants (pending or received), employment, gifts, stock holdings or options, honoraria, consultancies, expert testimony, patents and royalties".