Phenotypic characteristics of Parkinson’s disease cohort members at baseline exam (2001–2007) and follow-up (2008–2010).

Abbreviations: SD = standard deviation; PD = Parkinson’s disease; yrs = years; n.a. = not applicable; n.c. = not calculated; UPDRS = Unified Parkinson’s Disease Rating Scale; MMSE = Mini Mental State Exam; GDS = Geriatric Depression Score. *P-value for t-test of fast vs. slow progressors. §P-value for t-test of deceased participants vs. slow progressors. †P-value for t-test of lost participants vs. slow progressors. **PD subscores (bradykinesia, rigidity, tremor, gait/balance) calculated according to Louis (ref 3). §§Mini Mental State Exam score according to Folstein (ref 64). ††Geriatric Depression Score according to Yesavage (ref 65).