Potentially Inappropriate Medication Use Among Patients With Dementia in Traditional Medicare and Medicare Advantage.

Background: Older adults with dementia are susceptible to receiving potentially inappropriate medications (PIMs), where the risks likely outweigh the benefits. Medicare advantage prescription drug plans (MA-PDs) cover both medical and prescription drug benefits, creating a financial incentive to reduce PIM use and unnecessary health care costs from adverse drug events, whereas standalone Medicare prescription drug plans (PDPs) used by traditional Medicare beneficiaries are only responsible for outpatient prescription drug costs.

Objective: The objective is to compare the use of PIMs between PDP and MA-PD enrollees with dementia.

Methods: Using 2016-2019 Medicare claims and encounter data, we estimated the associations between Medicare enrollment type and PIM use: (1) potentially harmful drug-disease interactions in older adults with dementia; (2) potentially harmful drug-disease interactions in older adults with dementia and a history of falls; and (3) high-risk medication use in older adults.

Results: MA-PD enrollees had significantly lower utilization of PIMs than standalone PDP enrollees: a 0.7 percentage-point [95% CI: 0.5, 0.8] lower prevalence of potentially harmful drug-disease interactions in older adults with dementia; a 3.1 percentage-point [2.6, 3.5] lower prevalence of potentially harmful drug-disease interactions in older adults with dementia and a history of falls; and a 0.5 percentage-point [0.4, 0.6] lower prevalence of high-risk medications in older adults.

Conclusions: MA-PD enrollees with dementia experienced consistently lower prevalence of PIM use than those in PDP. As Medicare advantage enrollment continues to grow, it will be increasingly important to identify and leverage the features of MA-PD plans that promote safe medication prescribing for Medicare beneficiaries with dementia.