Alzheimer’s Disease Clinical Trial Decision-Making Among Patients with Mild Cognitive Impairment and Their Study Partners

. Prodromal Alzheimer's disease (AD) clinical trials enroll patients with mild cognitive impairment (MCI) and their study partners. This study examined trial enrollment decision-making and risk for misunderstanding trial information presented in an informed consent process for prodromal AD trials. . We performed structured interviews with patients with MCI and individuals who could serve as their study partners. We presented details of a hypothetical prodromal AD trial, followed by questionnaires to assess involvement of the study partner in trial decisions, patient capacity to consent, and patient health numeracy skills. . Among 65 patient participants, most were male (66%) and non-Hispanic White (88%) with a mean (standard deviation) age of 74.9 (8.4) years. Among 57 study partners, most were spouses (83%), female (74%), and non-Hispanic White (91%) with a mean (standard deviation) age of 70.3 (13.6). Most patient participants (66%) and study partners (72%) reported they would make enrollment decisions in partnership; 28% of patient participants said they would make the decision themselves, with input from a study partner. Twenty-five patient participants (38%) lacked capacity to consent to the trial; 38% demonstrated impaired health numeracy. Seventeen patient participants (26%) demonstrated both a lack of capacity and impaired health numeracy, among whom seven reported they would make enrollment decisions on their own, with input from a study partner. . Some patients with MCI demonstrated a lack of capacity to consent, impaired health numeracy, or both, putting them at risk for misunderstanding trial information in the consent process for a prodromal AD clinical trial.