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


CONCLUSIONS
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.
Area of Applied Epidemiology, National Centre of Epidemiology and CIBERNED, Carlos III Institute of Health, Madrid, Spain. pmartinez@isciii.es
Pablo
P
Martinez-Martin
Carmen
C
Rodriguez-Blazquez
Monica M
MM
Kurtis
K Ray
KR
Chaudhuri
D000368:Aged; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D005767:Gastrointestinal Diseases / Q000209:etiology; D006304:Health Status; D006801:Humans; D007391:International Cooperation; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000209:etiology; D010300:Parkinson Disease / Q000150:complications* / Q000453:epidemiology / Q000523:psychology*; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D012140:Respiratory Tract Diseases / Q000209:etiology; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000209:etiology; D014570:Urologic Diseases / Q000209:etiology