Assessing the relationship between non-motor symptoms and health-related quality of life in Parkinson's disease: a retrospective observational cohort study

Abstract

Objectives: Non-motor symptoms (NMSs) negatively impact the health-related quality of life (HrQOL) of patients with Parkinson's disease (PD). The Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) is a comprehensive scale for evaluating PD. It remains unclear whether the NMSs evaluated with MDS-UPDRS are predictive of HrQOL. This study aimed to investigate whether NMSs, as evaluated with the MDS-UPDRS, could predict the HrQOL of patients with PD.

Materials and methods: We conducted a 2-year retrospective observational cohort study assessing 108 patients with PD who were recruited from a single tertiary center between January 2015 and December 2017. MDS-UPDRS was used to assess NMSs and motor symptoms and Parkinson's Disease Questionnaire-39 (PDQ-39) to measure patients' HrQOL.

Results: The median age of patients was 69 years, and 65.7% were female. The median MDS-UPDRS part I, part II, part III, and PDQ-39-summary index scores were 8, 10, 22, and 25, respectively. The final stepwise multiple linear regression model showed that female sex (standard partial regression coefficient β = 0.131, P < 0.05) and baseline MDS-UPDRS part I (β = 0.272, P < 0.01) and part II (β = 0.571, P < 0.01) scores significantly predicted the PDQ-39-SI scores at the 2-year follow-up.

Conclusions: In addition to motor symptoms, NMSs at the 2-year follow-up may be useful for predicting the HrQOL of patients with PD. In clinical practice, MDS-UPDRS-guided assessment and treatment of motor symptoms and NMSs may contribute to improving HrQOL in patients with PD.

Keywords: Health-related quality of life; Longitudinal study; MDS-UPDRS; Non-motor symptoms; Parkinson’s disease.