AIMS: To describe demographic and clinical characteristics of older adults with Alzheimer’s disease–related psychosis (ADP) and to estimate the incidence of specific clinical events by antipsychotic treatment status.
METHODS: This cohort study identified adults aged ≥ 65 years with Alzheimer’s disease and newly diagnosed psychosis in the US Medicare database (2013-2018) who were previously unexposed to antipsychotics before their psychosis diagnosis. Two nonmutually exclusive subcohorts of patients with ADP were identified: those who initiated treatment with antipsychotic medications (antipsychotic users) and those who remained untreated (antipsychotic nonusers). Baseline characteristics were evaluated before psychosis diagnosis in untreated patients and before antipsychotic initiation in treated patients. Incidence rates were estimated for falls and fractures (composite and separately), seizure or epilepsy (new onset and any), and mortality.
RESULTS: The study identified 145,333 ADP antipsychotic nonusers and 49,452 antipsychotic users. Baseline demographics were similar between both cohorts; however, antipsychotic users had higher baseline skilled nursing facility use (40.3% and 27.8%), mood (72.7% and 62.1%) and anxiety disorders (70.9% and 57.3%), falls/fractures (39.5% and 33.8%), urinary tract infections (55.1% and 47.0%), and frailty index scores (76.0% and 69.7%) than antipsychotic nonusers. The crude incidence rates (95% confidence interval) per 100 person-years in antipsychotic users and antipsychotic nonusers, respectively, were 70.0 (68.9-71.2) and 55.8 (55.4-56.1) for falls and fractures composite, 69.0 (67.9-70.1) and 54.9 (54.5-55.2) for falls, 38.6 (38.1-39.0) and 33.0 (32.7-33.2) for mortality, and 45.8 (44.9-46.7) and 54.2 (53.9-54.6) for any seizure or epilepsy.
CONCLUSIONS: In this descriptive study, patients with ADP who initiated treatment with antipsychotics had a higher burden of some baseline comorbidities; experienced higher incidence of falls, fractures, and mortality; and had lower incidence of seizure or epilepsy than antipsychotic nonusers.
