Severity of dysphagia is associated with hospitalizations and mortality in patients with Parkinson’s disease

Background: Aspiration pneumonia is the commonest cause of hospitalizations and death in patients with Parkinson's disease (PD). Among these patients, the relationships between severity of dysphagia, hospitalizations for related complications, and death are not robustly defined. Our aim was to characterize the relationship between PD-related oropharyngeal dysfunction and clinically relevant outcomes. Methods: Retrospective cohort study of 312 patients with PD at a tertiary center who underwent videofluoroscopic swallow studies conducted by expert therapists between 2010 and 2015. Level of swallowing function was represented using the 7-point Functional Oral Intake Scale (FOIS) (7 = normal function). Significance and relative risk calculations utilized Poisson regression. Time to composite outcome of first hospitalization or death was summarized using Kaplan-Meier curve with log-rank test. Key Results: One hundred thirty eight patients had a recorded FOIS score. The prevalence of oropharyngeal dysfunction was 76.1%. The median duration of follow-up was 26.8 months. In multivariate analyses, patients with FOIS 5 (RR = 2.01 [95% CI: 1.22, 3.32]), FOIS 3 (RR = 2.78 [95% CI: 1.75, 4.40]), and FOIS 1 (RR = 2.50 [95% CI: 1.49, 4.20]) were significantly associated with increased risk of hospitalization or death compared to FOIS 7 after co-variate adjustments. GERD was also associated with a significant increased risk of hospitalization or death (RR = 1.28 [95% CI: 1.01, 1.64]). Time to first hospitalization or death was shorter in patients with lower FOIS scores (p < 0.00005). Conclusions and Inferences: Severity of oropharyngeal dysphagia, as measured by the FOIS, is associated with poorer survival and shorter time to hospitalization for dysphagia-related complications, pneumonia, or death in PD.