Risk of long-term care admissions among Medicare beneficiaries treated with pimavanserin or quetiapine for Parkinson's disease psychosis in USA: a retrospective administrative claims database analysis

Aim: Risk of long-term care (LTC) admission (LTCA) associated with atypical antipsychotic (AAP) use among patients with Parkinson's disease psychosis (PDP) is a major concern. However, no comparative studies have examined the differences in risk of LTC admissions between pimavanserin (PIM), the only FDA-approved AAP for PDP, and other off-label AAPs including quetiapine (QUE). Objective: To examine all-cause LTCA rates and risk among PDP patients treated with AAPs such as QUE or PIM. Methods: Analysis of Parts A, B and D claims (100% Medicare sample; 2013–2019) of Medicare beneficiaries with PDP that initiate ≥12-month continuous PIM or QUE monotherapy from 1 January 2014 to 31 December 2018 (i.e., index date) without any AAP use in the 12-month pre-index period was conducted. Outcome assessments among 1:1 propensity score-matched (31 variables – age, sex, race, region and 27 Elixhauser comorbidities) beneficiaries on PIM versus QUE included risk of all-cause skilled nursing facility stays (SNF-stays), LTC-stays, and overall LTCA (i.e., SNF-stays or LTC-stays). All-cause LTCA rates and LTCA risk were compared using logistic regression and cox proportional hazards models, respectively, controlling for demographics, comorbidities and co-existing-dementia or insomnia. Results: Of the matched sample (n = 842 for each group) from total sample (n = 9652), overall all-cause LTCA and SNF-stay rates were 23.2 and 20.2% for PIM versus 33.8 and 31.4% for QUE, respectively (p < 0.05, for each). Hazard ratio (95% CI) for risk of SNF-stay and overall LTCA was 0.78 (0.61, 0.98) and 0.80 (0.66, 0.97), respectively, for PIM versus QUE beneficiaries (p < 0.05, for each). Conclusion: The 20% lower risk of LTCA (i.e., greater delay) with PIM versus QUE in this analysis may suggest that PIM should be started early for the treatment of PDP.

This study compared patients aged greater than or equal to 65 years old residing in the community setting and diagnosed with Parkinson’s disease psychosis (PDP) who were initiated on pimavanserin (PIM) or other atypical antipsychotics (AAPs). Currently, PIM, is the only FDA-approved AAP, however, other AAPs, such as quetiapine (QUE) are used off-label for PDP. In this study, patients were evaluated for their risk of long-term care admissions while being on PIM versus (i) other AAPs, and (ii) QUE.

A 100% US Medicare sample with Medical claims data (Part A and B) and Pharmacy claims data (Part D) between 2013–2019 was used to compare long-term care admission rates. The annual risk of skilled nursing facilities stays (SNF-stays), long-term care stays (LTC-stays), and overall LTC admission (LTCA) between those who are treated with PIM only or QUE only for at least 12 months were compared during 12 months of follow-up. To make the PIM only and QUE only groups comparable, researchers matched individuals based on 31 different factors such as age, sex, race, region and 27 comorbid health conditions that resulted in a total of 842 matched patients in each group. PIM patients had lower rates of all-cause LTC admissions (23.2% vs 33.8% and SNF-stays (20.2% vs 31.4%) compared to QUE patients. The hazard ratios indicated a 22% lower risk of SNF-stays (hazard ratio = 0.78) and 20% lower risk for overall LTCA (hazard ratio = 0.80) for PIM compared to QUE, suggesting that starting PIM early may delay as well as reduce LTCA among Medicare beneficiaries with PDP compared to QUE. The results for PIM vs other AAPs were shown to be similar as PIM vs QUE in these outcomes.