Statistical Models of Parkinson's Disease Progression: Predictive Validity in a 3-Year Follow-up. - Mendes, Alexandre; Gonçalves, Alexandra; Nuno Vila-Chã; Calejo, Margarida; Moreira, Inês; Fernandes, Joana; Damásio, Joana; Teixeira-Pinto, Armando; Krack, Paul; Lima, António Bastos; Cavaco, Sara (Journal of Parkinson's Disease, 2016)