Development of standardized regression-based formulas to assess meaningful cognitive change in early Parkinson's disease.

Objective: Longitudinal assessment of cognitive and emotional functioning in patients with Parkinson's disease (PD) is helpful in tracking progression of the disease, developing treatment plans, evaluating outcomes, and educating patients and families. Determining whether change over time is meaningful in neurodegenerative conditions, such as PD, can be difficult as repeat assessment of neuropsychological functioning is impacted by factors outside of cognitive change. Regression-based prediction formulas are one method by which clinicians and researchers can determine whether an observed change is meaningful.