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

Background. 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.

Methods. 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.

Results. 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.

Conclusions. 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.