Developing consensus among movement disorder specialists on clinical indicators for identification and management of advanced Parkinson's disease: a multi-country Delphi-panel approach.

Background: Lack of a global consensus on the definition of advanced Parkinson's disease (APD) and considerations for timing of device-aided therapies may result in heterogeneity in care.

Objectives: To reach consensus among movement disorder specialists regarding key patient characteristics indicating transition to APD and guiding appropriate use of device-aided therapies in the management of PD symptoms.

Methods: A Delphi-panel approach was utilized to synthesize opinions of movement disorder specialists and build consensus.