Antipsychotics and benzodiazepines are considered PIMs in older adults with PD and dementia, respectively, and contribute to increased morbidity and mortality. 

This retrospective cohort study included Medicare Part D beneficiaries age 65 and older with PD who died between January 1, 2017 and December 31, 2017. Clinical characteristics were compared between community-dwelling and nursing home residents using descriptive statistics. Outpatient prescriptions for antipsychotics (chlorpromazine, fluphenazine, haloperidol, lurasidone, olanzapine, paliperidone, perphenazine, pimozide, risperidone, ziprasidone) and benzodiazepines (alprazolam, clonazepam, diazepam, flurazepam, lorazepam, oxazepam, temazepam) were defined using the 2015 Beers Criteria. The proportion of unique individuals receiving PIMs in the last 6 months of life were compared between groups using chi-square analyses. Inpatient and hospice prescriptions were excluded. 

There were 40,594 Medicare Part D decedents with PD in 2017, of which 35,009 (86.2%) were prescribed at least 1 medication in their last 6 months of life, resulting in 1,306,738 total prescriptions. Of 19,170 community-dwelling residents, 15,182 (79.2%) had dementia. Of 16,263 nursing home residents, 15,195 (93.4%) had dementia. When comparing outpatient PIM prescriptions, nursing home residents with PD were more likely than community-dwelling residents with PD to be prescribed at least 1 antipsychotic (14.3% vs. 6.5%, p<0.001) and 1 benzodiazepine (34.3% vs. 22.7%, p<0.001) in their last 6 months of life. 

Nursing home residents are more likely than community-dwelling residents with PD to be diagnosed with dementia and prescribed PIMs in the last 6 months of life. These data may reflect inappropriate prescribing practices in US nursing homes, and their association with 6-month mortality warrants further investigation.