We previously developed and validated the PD-HI in accordance with FDA guidelines using large-scale patient data. This two-year natural history study will obtain longitudinal metrics of the instrument and identify faster or slower disease progression among demographic and clinical subgroups.

To further validate the Parkinson’s Disease-Health Index (PD-HI), a patient-reported outcome (PRO) measure for serially tracking disease burden in Parkinson’s disease (PD).

Adults with PD are participating in a 24-month longitudinal study, completing assessments at baseline, 6, 12, 18, and 24 months. At each time point, participants are completing the PD-HI, NeuroQol, and parts Ib and II of the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). During the 6-24 month assessments, participants are asked to respond to a global impression of change survey and complete a survey preference form. This data will determine the responsiveness of the PD-HI for detecting therapeutic gains, determine the minimal clinical important difference (MCID) for the instrument and its subscales, and inform participant PRO preferences. The natural history data collected will provide insight on PD symptom progression for various demographic and clinical subgroups.

One hundred and ninety-nine individuals with PD were enrolled and 128 individuals completed all baseline and 6-month assessments. Participants are currently completing 12-month assessments. The PD-HI and six of its subscales detected a statistically significant change in disease burden over 6 months; only one of 13 Neuro-QoL subscales detected a statistically significant change in PD health over 6 months. All PD-HI subscales correlated with baseline MDS-UPDRS scores.

The PD-HI is capable of detecting clinically meaningful changes in disease burden over time. Forthcoming data will identify demographic and clinical subgroups associated with various symptom progression, obtain instrument performance metrics to maximize clinical trial efficiency, and further evaluate the responsiveness of the PD-HI compared to other PROs.