Participants

Older Black participants of the Rush Alzheimer's Disease Center (RADC) Minority Aging Research Study (MARS; Barnes et al., 2012) and the Rush Memory and Aging Project (MAP; Bennett et al., 2018) completed a decision making substudy which included a susceptibility to scams measure. MARS and MAP are large longitudinal cohort studies of aging based in the greater Chicago region and are harmonized in data collection and data management approaches. This harmonization facilitates data pooling across studies. The RADC decision making substudy began in 2010 in MAP and in 2017 in MARS. Among 775 older Black participants in MARS, 306 enrolled in the decision making substudy and completed decision making measures and a clinical evaluation. Eight were excluded due to a dementia diagnosis, and 2 were excluded due to missing data on key variables of interest, leaving 296 Black participants. Next, we identified White participants with decision making data. There were 1,187 White participants who could serve as potential matches for Black participants. Among those, 62 had dementia, and 7 had missing data on variables of interest, leaving 1,118 potential White participant matches.

Mahalanobis Distance matching was used to identify an equal number of White participants (N = 296) to Black participants (N = 296) according to the pre-selected variables of age, education, sex, and global cognition for this study. Age (calculated from birthdate to date of decision making assessment), sex (male coded as 1 and female coded as 0), and education (self-reported number of years completed) were included as matching variables since these have previously demonstrated associations with susceptibility to scams (James et al., 2014). Global cognition was included as a matching variable (in addition to demographics) as it has been shown to be associated with susceptibility to scams (James et al., 2014) and because there are well-documented racial differences in level of cognitive performance in old age (Weuve et al., 2018), including for Black and White adults in the current research cohorts (Wilson et al., 2015b). Age was matched according to four categories: ≥60 years old to <70 years old, ≥70 years old to <80 years old, ≥to 80 years old to 90 years old, and ≥90 years old to <100 years old. Education was matched according to three categories: from 0 to 12 years of education, 13 to 16 years of education, and >16 years of education. Global cognition was matched within a range of ± 0.25 z-score at the individual level. This Mahalanobis Distance matching approach has been utilized in previous work by our group (Han et al., 2020).