Incremental health care resource utilization and costs associated among patients with Parkinson's disease psychosis and incident dementia: An analysis of medicare beneficiaries.

Background: Real-world evidence examining the incremental health care resource use (HCRU) and cost burden of incident dementia among patients with Parkinson's disease psychosis (PDP) are needed within the United States (US).

Objectives: To compare HCRU and cost burden between PDP patients with incident dementia (PDP + D) versus without incident dementia (PDP).

Methods: A retrospective analysis of inpatient (Part A), outpatient (Part B), and prescription drug (Part D) claims from the 100% Medicare sample was conducted to compare PDP + D patients versus PDP patients between 01/01/14-12/31/18. Patients with a diagnosis of dementia, psychosis, secondary parkinsonism, or other psychotic disorders, during 12-month pre-index were excluded. Patients in both groups were matched using 1:1 propensity score matching (PSM) methodology using 31 variables (age, sex, race, region and 27 Elixhauser comorbidity characteristics). Differences in 12-month post-index HCRU rates and mean per patient per year (PPPY) costs for all-cause inpatient (IP) hospitalizations, and by type of IP stay (i.e., short-term [ST-stay], skilled nursing facility [SNF-stay] and long-term [LT-stay]) were analyzed via logistic and gamma log-link regression models.

Results: Of the 12,484 patients who met our study criteria, 1855 PSM-matched cohorts were identified. Mean age, gender, and comorbidities were similar in PSM groups. Approximately, 50.3% with PDP + D reported ≥1 all-cause IP hospitalizations versus 36.0% with PDP (p < 0.05) during 12-month follow-up. Specifically, all-cause ST-stay, SNF-stay, and LT-stay among PDP + D versus PDP patients were: 45.2% versus 35.7%, 28.3% versus 15.7%, and 8.5% versus 6.0% (p < 0.05), respectively. Psychiatric-related ST-stay, SNF-stay, and LT-stay among PDP + D versus PDP patients were: 12.3% versus 9.0%, 7.5% versus 3.4%, and 2.4% versus 1.2% (p < 0.05), respectively. Mean PPPY all-cause IP hospitalization costs for PDP + D patients versus PDP patients was $17,891 (±29,882) versus $11,599 (±$25,247) (p < 0.05).

Conclusions: Patients with PDP + D experience significantly higher all-cause and psychiatric-related IP hospitalizations, including ST-stays, LT stays, and SNF stays. They also had 54% greater mean PPPY IP hospitalization costs versus PDP patients.