UC San Diego

Background and objectives

Representation of persons from marginalized racial and ethnic groups in Parkinson disease (PD) trials has been low, limiting the generalizability of therapeutic options for individuals with PD. Two large phase 3 randomized clinical trials sponsored by the National Institute of Neurological Disorders and Stroke (NINDS), STEADY-PD III and SURE-PD3, screened participants from overlapping Parkinson Study Group clinical sites under similar eligibility criteria but differed in participation by underrepresented minorities. The goal of this research is to compare recruitment strategies of PD participants belonging to marginalized racial and ethnic groups.

Methods

A total of 998 participants with identified race and ethnicity consented to STEADY-PD III and SURE-PD3 from 86 clinical sites. Demographics, clinical trial characteristics, and recruitment strategies were compared. NINDS imposed a minority recruitment mandate on STEADY-PD III but not SURE-PD3.

Results

Ten percent of participants who consented to STEADY-PD III self-identified as belonging to marginalized racial and ethnic groups compared to 6.5% in SURE-PD3 (difference = 3.9%, 95% confidence interval [CI] 0.4%-7.5%, p value = 0.034). This difference persisted after screening (10.1% of patients in STEADY-PD III vs 5.4% in SURE-PD 3, difference = 4.7%, 95% CI 0.6%-8.8%, p value = 0.038).

Discussion

Although both trials targeted similar participants, STEADY-PD III was able to consent and recruit a higher percentage of patients from racial and ethnic marginalized groups. Possible reasons include differential incentives for achieving minority recruitment goals.

Trial registration information

This study used data from The Safety, Tolerability, and Efficacy Assessment of Isradipine for Parkinson Disease (STEADY-PD III; NCT02168842) and the Study of Urate Elevation in Parkinson's Disease (SURE-PD3; NCT02642393).