Exclusion of older patients from randomized clinical trials in Parkinson’s disease

Prevalence of Parkinson’s disease (PD) increases with age. The purpose of this study was to evaluate the eligibility criteria in randomized clinical trials (RCTs) in PD, especially those limiting the enrollment of older adults. We examined RCTs of pharmacological and non-pharmacological anti-parkinsonian interventions registered with ClinicalTrials.gov and started from 2013 through 2022. Primary outcome was proportion of RCTs with an upper age limit of 85 years of age or less. Secondary outcome was proportion of RCTs with other exclusion criteria. Associations between trial characteristics and the presence of the age limits were determined using logistic regression. Our study included 420 RCTs. Two hundred thirty-nine (57