The REFINE-PD study is a controlled trial embedded within a larger cluster controlled study (the IMPACT study). The study aims to investigate the efficacy of a multifactorial falls prevention program for patients with Parkinson's Disease (PD). This program contains PD-specific elements (e.g., optimizing dopaminergic therapy), plus a generic falls prevention program. The intervention will be tailored to each individual's specific risk profile for falls, as identified during detailed baseline examination.