The Long Term Impact of Initiating Pramipexole Versus Levodopa in Early Parkinson's Disease (CALM-PD Cohort Study)

To determine the long-term consequences (8 years) of initiating patients with Parkinson's disease on either pramipexole or levodopa. We hypothesize that patients initiating therapy with pramipexole compared with levodopa will demonstrate less self-reported disability as measured by the Modified Schwab and England (S/E) scale 8 years after randomization.