Patients treated with pimavanserin or quetiapine for Parkinson’s disease psychosis: analysis of health resource utilization patterns among Medicare beneficiaries

BACKGROUND: Pimavanserin (PIM) is the only FDA approved atypical antipsychotic (AAP) for the treatment of Parkinson's Disease Psychosis (PDP) while other off-label AAPs like quetiapine (QUE) are also used. Real-world comparative effects of PIM and QUE on health resource utilization (HCRU) may provide insights about their relative benefits. OBJECTIVES: To examine annual HCRU among newly initiated PIM or QUE monotherapy among patients with PDP. METHODS: Retrospective analysis of 100% Medicare (Parts A, B, and D) claims of patients with PDP during 1 January 2013 to 31 December 2019 was conducted. Treatment-naive patients with first prescription for PIM or QUE from 1 January 2014 to 31 December 2018 were selected if they had ≥12-months continuous monotherapy and had no prior AAP use for ≥12-month pre-index. Post-index 12-month HCRU was compared between 1:1 propensity score matched (PSM) PIM or QUE cohorts. HCRU outcomes included: rates of all-cause and psychiatric-related inpatient hospitalizations by stay-type i.e., long-term stays (LT-stays), short-term stays (ST-stays), skilled nursing facility stays (SNF-stays), outpatient hospitalizations, emergency room (ER) visits, and office visits. Relative risk and 95% confidence intervals are reported RR (95% CI). RESULTS: A total of 842 and 7,116 were treated with PIM and QUE, respectively. Mean age and gender distribution were similar among both groups. After PSM, those on PIM (n=842) had significantly lower RR for all-cause: inpatient hospitalizations RR=0.78 (0.70-0.87), ST-stays RR=0.75 (0.66-0.84), SNF-stays RR=0.64 (0.54-0.76), and ER visits RR=0.91 (0.84-0.97) vs. QUE (n=842). PIM patients had slightly higher RR for all-cause office visits RR=1.03 (1.01-1.05) vs. QUE. Psychiatric-related inpatient hospitalizations were also lower for PIM vs. QUE: RR=0.63 (0.48-0.82) ST-stays RR=0.61 (0.43-0.86), SNF-stay RR=0.69 (0.47-1.02), and ER visits RR=0.53 (0.37-0.76). CONCLUSIONS: In this analysis of PDP patients, PIM monotherapy resulted in nearly 22% and 37% lower all-cause hospitalizations and psychiatric-related inpatient hospitalizations compared to QUE.