Study Rationale: Researchers recently proposed defining Parkinson’s disease (PD) based on a test for abnormal alpha-synuclein in spinal fluid and adopting a staging system based on measures (or scales) of cognitive and physical functional abilities as assessed in the clinic. This project will examine how individuals change from one stage to another over time and will evaluate how meaningful the differences between stages are, as reported by people with PD. Finally, we will compare the performance of the scale cutoffs that separate the stages to cut-off values that had been previously proposed to distinguish PD severity.
Hypothesis: We hypothesize that examination of data obtained from tracking people with PD over time will allow us to assess whether the newly proposed definitions of PD stages require adjustment to improve their performance as measures of PD severity.
Study Design: For this project we will use data that has already been collected in previous or ongoing research projects that followed people with PD over time.
Impact on Diagnosis/Treatment of People with Parkinson’s disease: Our results will determine whether or not the newly proposed definitions of stages of PD require adjustment to improve their performance as measures of PD severity that are meaningful to people with PD.
Next Steps for Development: Based on our findings, we will either encourage the use of the newly proposed stage definitions or promote the improvement of the scales to produce measures that are meaningful to people with PD.