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.

Automated summary

Pimavanserin is the only FDA approved atypical antipsychotic for Parkinson's Disease Psychosis, while other off-label antipsychotics like quetiapine are also used. Comparative analysis shows that PIM monotherapy results in lower hospitalizations compared to QUE.