Clinician contributions to central nervous system-active polypharmacy among older adults with dementia in the United States.

Background: Exposure to central nervous system (CNS)-active polypharmacy-overlapping exposure to three or more CNS-active medications-is potentially harmful yet common among persons living with dementia (PLWD). The extent to which these medications are prescribed to community-dwelling PLWD by individual clinicians versus distributed across multiple prescribers is unclear.

Methods: We identified community-dwelling Medicare beneficiaries with a dementia diagnosis and Medicare Parts A, B, and D coverage for at least one month in 2019. Using fill date and days' supply for prescriptions filled between January 1, 2019 and December 31, 2019, we identified beneficiaries exposed to CNS-active polypharmacy (i.e., >30 days of overlapping exposure to three or more antidepressant, antipsychotic, antiseizure, benzodiazepine, opioid, nonbenzodiazepine benzodiazepine receptor agonists, or skeletal muscle relaxant medications). We examined the number and type of clinicians who contributed to polypharmacy person-days among PLWD.

Results: The cohort included 955,074 PLWD who were primarily female (64.0%), were White (78.5%), and had a mean age of 83.4 years (standard deviation 8.0). Notably, 14.3% were exposed to CNS-active polypharmacy. At the person level, 24.6% of PLWD experienced polypharmacy prescribed by a single clinician. Considering total days of exposure, 45.3% of polypharmacy person-days were prescribed by a single clinician. Primary care physicians prescribed 63.0% of polypharmacy person-days and accounted for the plurality of days for all seven medication classes, followed by psychiatrists for antipsychotics and benzodiazepines and primary care advanced practice providers (APPs) for antidepressants and antiseizure medications.

Conclusion: In this cross-sectional analysis of Medicare claims data, primary care clinicians (both physicians and APPs) prescribed the majority of medications that contributed to CNS-active polypharmacy for PLWD. Future research is needed to identify strategies to support primary care clinicians in appropriate prescribing of CNS-active medications to PLWD.