Clinical outcomes and treatment patterns of older adults with dementia-related psychosis by dementia type in the United States.

Background: Little is known about the incidence of clinical events and treatment patterns among older adults with dementia-related psychosis. Given that dementia-related psychosis comprises various dementia types, this study describes the incidence of clinical events and treatment patterns by dementia type after patients with dementia are diagnosed with psychosis.

Methods: Adults aged ≥ 65 years with dementia and newly diagnosed with psychosis were identified in US Medicare claims during 2013-2018. Baseline characteristics were evaluated at the time of the psychosis diagnosis. After the initial psychosis diagnosis, incidence rates (IRs) of clinical events (e.g., falls/fractures, infections, healthcare utilization), mortality, and patterns of antipsychotic treatment were described for each dementia type (Alzheimer's disease [AD], Parkinson's disease dementia [PDD], dementia with Lewy bodies [DLB], frontotemporal dementia [FTD], vascular dementia [VD], and unspecified dementia). Daily mean cumulative counts were estimated to describe the incidence of recurrent events over time. Mortality was described using Kaplan-Meier survival curves.

Results: We identified 484,520 patients with dementia-related psychosis: mean age, 84 years (standard deviation, 7.8); female, 66%. At the time of psychosis diagnosis, the most prevalent type of dementia was unspecified dementia (56%), followed by AD (31%), VD (12%), PDD (10%), DLB (3%), and FTD (< 1%), and most patients had scores indicating severe illness on the Charlson Comorbidity Index (71%) and frailty index (62%). Across all dementia types, IRs (per 100 person-years) were high for emergency department visits, oral anti-infective use, and urinary tract infections after the initial psychosis diagnosis. Patients with DLB had the highest incidence of most clinical outcomes. After 1 year of follow-up, the cumulative probability of death was about 30% for all dementia types, and after 5 years, was about 80% among patients with DLB, VD, AD, or PDD and about 60%-65% among patients with FTD or unspecified dementia.

Conclusions: Patients with dementia-related psychosis had a high burden of comorbidities, frailty, emergency department visits, infections, and death. Specifically, after DRP diagnosis, patients with DLB and VD had the highest burden of clinical events of interest.