The effect of functional status impairment on nursing home admission risk among patients with advanced Parkinson's disease.

Aims: To estimate the relationship between functional status (FS) impairment and nursing home admission (NHA) risk in Parkinson's disease (PD) patients, and quantify the effect of advanced PD (APD) treatment on NHA risk relative to standard of care (SoC).Materials and methods: PD patients were identified in the Medicare Current Beneficiary Survey (MCBS) (1992-2010). A working definition based on the literature and clinical expert input determined APD status. A logit model estimated the relationship between FS impairment and NHA risk. The effect of levodopa-carbidopa intestinal gel (LCIG) on NHA risk relative to SoC was simulated using clinical trial data (control: optimized oral levodopa-carbidopa IR, ClinicalTrials.gov NCT00660387 and NCT0357994).Results: Non-advanced PD and APD significantly increased NHA risk when controlling for demographics (p < 0.01). APD status was no longer significant after controlling for FS limitations, implying that FS limitations explain the increased NHA risk in APD patients. Reduced impairment in FS in patients with APD treated with LCIG reduced risk of NHA by 13.5% relative to SoC.Limitations: This study applies clinical trial results to real-world data. LCIG treatment might have a different effect on NHA risk for the nationally representative population than the effect measured in the trial. Both data sources employ different instruments to measure FS, instrument wording and study follow-up differed, which might bias our estimates. Finally, there lacks consensus on a definition of APD. The prevalence of APD in this study is high, perhaps due to the specific definition used.Conclusions: Patients with APD experience a higher risk in NHA than those with non-advanced disease. This increased risk in NHA in patients with APD is explained by greater limitations in FS. The relative reduction in risk of NHA for the APD population treated with LCIG is quantitatively similar to doubling Medicaid home care services.