Disease progress and response to treatment as predictors of survival, disability, cognitive impairment and depression in Parkinson's disease

Thuy C. Vu, John G. Nutt, Nicholas H.G. Holford

Research output: Contribution to journalArticle

31 Scopus citations


AIM To describe the time to clinical events (death, disability, cognitive impairment and depression) in Parkinson's disease using the time course of disease status and treatment as explanatory variables. METHODS Disease status based on the Unified Parkinson's Disease Rating Scale (UPDRS) and the time to clinical outcome events were obtained from 800 patients who initially had early Parkinson's disease. Parametric hazard models were used to describe the time to the events of interest. RESULTS Time course of disease status (severity) was an important predictor of clinical outcome events. There was an increased hazard ratio for death 1.4 (95% CI 1.31, 149), disability 2.75 (95% CI 2.30, 3.28), cognitive impairment 4.35 (95% CI 1.94, 9.74), and depressive state 1.43 (95% CI 1.26, 1.63) with each 10 unit increase of UPDRS. Age at study entry increased the hazard with hazard ratios of 49.1 (95% CI 8.7, 278) for death, 4.76 (95% CI 1.10, 20.6) for disability and 90.0 (95% CI 63.3-128) for cognitive impairment at age 60 years. Selegiline treatment had independent effects as a predictor of death at 8 year follow-up with a hazard ratio of 2.54 (95% CI 1.51, 4.25) but had beneficial effects on disability with a hazard ratio of 0.363 (95% CI 0.132, 0.533) and depression with a hazard ratio of 0.372 (95% CI 0.12, 0.552). CONCLUSIONS Our findings show that the time course of disease status based on UPDRS is a much better predictor of future clinical events than any baseline disease characteristic. Continued selegiline treatment appears to increase the hazard of death.

Original languageEnglish (US)
Pages (from-to)284-295
Number of pages12
JournalBritish Journal of Clinical Pharmacology
Issue number2
StatePublished - Aug 1 2012



  • Disease progress
  • Levodopa
  • Parkinson's disease
  • Selegiline
  • Time to event
  • Time-dependent covariate

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)

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