title: Pramipexole versus levodopa in patients with early Parkinson's disease: effect on generic and disease-specific quality of life.
abstract: OBJECTIVE
  Although health-related quality of life (HRQOL) has been included in multiple Parkinson's disease (PD) clinical trials, little is known about how HRQOL responds to treatments over time. Here we assess the effect of therapy on HRQOL and explore factors that influence the HRQOL profiles and subdomains.
  
  
  METHODS
  A total of 301 subjects with early PD were randomized to either initial pramipexole or initial levodopa and followed every 3 months over a 4-year period. To estimate health outcomes, we used EQ-5D and PDQUALIF. We calculated the incremental effectiveness as the accumulated difference in the total HRQOL over time between treatments. The subgroup analyses (by sex, race, age, baseline patient characteristics, and occurrence of adverse events) were conducted using the same approach. Sensitivity analysis was performed to test the effect of missing data imputation on the results.
  
  
  RESULTS
  All three HRQOL measures resulted in similar profiles over time characterized by initial improvement over the first 3 to 6 months and followed by a gradual decline in years 2, 3, and 4. The difference in HRQOL between the treatment arms widened in favor of pramipexole in years 3 and 4 for all HRQOL measures used (EQ-5D: Y3 0.048, P = 0.03; Y4 0.071, P = 0.04). Our analyses suggested that the effect of pramipexole on HRQOL was mediated through nonmotor functions, whereas levodopa improved primarily motor domains of HRQOL.
  
  
  CONCLUSIONS
  Our results suggest that pramipexole and levodopa affect patient HRQOL via improvement on different domains of well-being: nonmotor effect for pramipexole and mobility improvement for levodopa.
authors.affiliation: Department of Community and Preventive Medicine, University of Rochester School of Medicine, Rochester, NY 14620, USA. katia_noyes@urmc.rochester.edu
authors.forename: Katia
authors.initials: K
authors.lastname: Noyes
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Dick
authors.forename: Robert G
authors.initials: RG
authors.lastname: Holloway
mesh_terms: D000978:Antiparkinson Agents / Q000627:therapeutic use*; D052160:Benzothiazoles; D018491:Dopamine Agonists / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology; D010865:Pilot Projects; D000077487:Pramipexole; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D018434:Sickness Impact Profile; D013844:Thiazoles / Q000627:therapeutic use*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents; D052160:Benzothiazoles; D018491:Dopamine Agonists; D013844:Thiazoles; D007980:Levodopa; D000077487:Pramipexole