OBJECTIVES: Antipsychotic (AP) treatment is used to reduce psychotic symptoms among Parkinson’s disease psychosis (PDP) patients. This study identified characteristics and factors associated with treatment disruption among US Medicare PDP patients.

METHODS: Parkinson’s disease (PD) patients were identified during 2012-2015 using ICD-9 diagnosis codes from the Medicare database. PDP patients were identified after PD diagnosis and required to have two AP prescription claims (1^st AP claim was index date). PDP patients were required to have 6 months of pre-index and 12 months of post-index data. During post-index, treatment disruption was defined as patients either discontinued (>30 days gap between AP fills) or were sporadic (>30 days gaps, on-off). Descriptive statistics and multivariate analysis was conducted to identify factors associated with the treatment disruptions.

RESULTS: Of 116,029 PD patients, 7,195 were identified as PDP patients. The PDP patients (mean age 80.3±7.5) had higher rates of dementia vs other PD patients (24.1% vs 60.4%) and depression (9.9% vs 18.8%), respectively. In the PDP group, 33.5% were continuers; 52.0% were discontinuers; and 14.5% were sporadic AP users during post-index. Gender, diabetes, malignancy, hypertension, prior skilled nursing facility, and use of aripiprazole, quetiapine and risperidone were found to be statistically different between continuers and discontinuers. There were similar findings between continuers and sporadic users; however, age, depression, and olanzapine use were additionally identified. Factors associated with AP discontinuation were; diabetes (OR 1.155, 95% CI 1.026, 1.301), any malignancy (OR 1.235, 95% CI 1.042, 1.465), and hypertension (OR 1.230, 95% CI 1.091, 1.386). In sporadic AP users, depression was also associated with discontinuation (OR 1.364, 95% CI 1.105, 1.683).

CONCLUSIONS: There is significant off-label use of AP treatment within the PDP population and a high percentage of treatment disruption was shown in this database review. This signifies an unmet need and suboptimal treatment since disruption is prevalent.