Meaningful digital mobility outcomes for people with Parkinson's disease: Insights grounded in diverse lived experience

BackgroundDigital mobility outcomes (DMOs) have been cited as potential clinical endpoints for trials in Parkinson's disease (PD). Current evidence from the Mobilise-D consortium suggests that selected DMOs are technically valid, with emerging research on their clinical validity. However, regulatory qualification of DMOs requires additional evidence of their meaningfulness to people with PD.ObjectiveTo identify meaningful DMOs by understanding how mobility symptoms impact aspects of health that matter to people with PD.MethodsPurposive sampling recruited a diverse sample of people with PD to participate in semi-structured interviews. Content analysis identified frequent and bothersome mobility symptoms and their impacts on meaningful aspects of health. Twelve experts mapped meaningful symptoms to relevant DMOs through a nominal group consensus.ResultsSeventy-two people with PD participated, inclusive of under-served groups: ethnic minorities (14%) or LGBTQIA + backgrounds (14%), in older age (3%) or with young-onset PD (13%), living rurally (31%) or in a deprived area (19%). Shuffling gait, bradykinesia and balance issues were the most frequent symptoms, and the most bothersome and impactful on meaningful aspects of health (i.e., activities of daily living, life-space mobility, emotional wellbeing) among participants who experienced them. Less frequent, but still highly bothersome and impactful symptoms included freezing of gait, fatigue and weakness. Expert consensus suggested that walking speed, stride length and turn duration were the most relevant DMOs to reflect these meaningful symptoms.ConclusionFindings offer an inclusive, meaningful framework for digital assessment of mobility in PD, grounded in lived experience and consistent with regulatory guidance.