The impact of non-motor symptoms on health-related quality of life of patients with Parkinson's disease

Mov Disord. 2011 Feb 15;26(3):399-406. doi: 10.1002/mds.23462. Epub 2011 Jan 24.


Background: Non-motor symptoms are detrimental to health-related quality of life (HRQoL) of Parkinson's disease patients. In this study, the Non-Motor Symptoms Scale (NMSS) was used to assess the impact of the non-motor symptoms on HRQoL of Parkinson's disease patients.

Methods: In a multicenter, international, cross sectional study on 411 Parkinson's disease patients, the NMSS was applied along with clinical (Hoehn and Yahr staging and SCOPA-Motor) and HRQoL measures (PDQ-39, and EQ-5D). Prevalence of non-motor symptoms was determined also through the NMSS. The association of NMSS and SCOPA-Motor with HRQoL measures and the differences in HRQoL scores between patients with and without non-motor symptoms in each NMSS domain were estimated by non-parametric statistics. Predictors of HRQoL were sought through multiple linear regression analyses.

Results: Nocturia (68.4% of the sample), fatigue (65.9%), and dribbling saliva (56.7%), were the most frequent complaints. Total NMSS score: (1) showed a higher correlation coefficient (r(S) = 0.70) with the PDQ-39 Summary Index (SI) than SCOPA-Motor (r(S) = 0.58); (2) showed high-moderate correlation (r(S) = 0.60 - 0.38) with all PDQ-39 domains; and (3) was the best predictor of HRQoL as measured by the PDQ-39 SI. For each NMSS domain, patients with symptoms had significantly worse HRQoL scores than patients without symptoms.

Discussion: To our knowledge, this is the first study to determine in a holistic manner the impact of the non-motor symptoms on HRQoL of Parkinson's disease patients. The results show that non-motor symptoms have, as a whole, a greater impact on HRQoL than motor symptoms and non-motor symptoms progression contributes importantly to HRQoL decline in patients with Parkinson's disease.

Publication types

  • Multicenter Study

MeSH terms

  • Aged
  • Cross-Sectional Studies
  • Disability Evaluation
  • Disease Progression
  • Female
  • Gastrointestinal Diseases / etiology
  • Health Status*
  • Humans
  • International Cooperation
  • Linear Models
  • Male
  • Middle Aged
  • Mood Disorders / etiology
  • Parkinson Disease / complications*
  • Parkinson Disease / epidemiology
  • Parkinson Disease / psychology*
  • Psychometrics
  • Quality of Life / psychology*
  • Respiratory Tract Diseases / etiology
  • Severity of Illness Index
  • Sleep Wake Disorders / etiology
  • Urologic Diseases / etiology