How does what study partners report differ based on their relationship to the primary subject?

Abstract

AbstractBackgroundStudies of persons with Alzheimer’s disease (AD) and related dementias typically require “study partners” (SPs) to report on the subject’s wellbeing and function. But little is known about how who a SP is might impact on these reports. Knowing this may help inform the interpretation of AD research.MethodsWe analyzed data from 730 older adults and their SPs enrolled in the Aging, Demographics and Memory Study (ADAMS). SPs provided data on their assessment of subjects’ functioning through the following: (1) the Blessed Dementia Rating Scale (BDRS), a multi‐domain informant measure of functional capacity; (2) three single‐item ratings of the subject’s “memory at the present time,” ability “in making judgments and decisions,” and ability to “organize his/her daily activities”; (3) instrumental/basic activities of daily living (IADL/BADL) scales. Subject cognition was assessed in an independent neuropsychological assessment using the mini‐mental status exam (MMSE), Trails A/B, Serial 7s, Boston Naming, and Animal Fluency. Bivariate and multivariable regression analyses were used to examine differences in SP reports based on their relationship to the subject. Demographics of SPs and subjects were also analyzed.ResultsOf SPs, 34.9% (n=255) were spouses, 38.4% (n=281) were adult children, and 26.6% (n=194) had a different relationship to the subject. In bivariate models, adult children were more likely to be college educated and provide care to the subject than spouses. In bivariate analyses, adult children rated subjects as more impaired on the BDRS and single‐item measures of memory, judgment and organizational abilities than did spouses(p<0.05). In multivariable analyses that controlled for differences in cognitive and functional performances, adult children, on average, rated subjects as less impaired on measures of memory, judgment, and organizational abilities than spouses(p<0.05). But, reporting varied in subgroups; in cognitively unimpaired subjects (MMSE>28), only 63.0% of child SPs reported a BDRS that indicated lack of impairment while 90.8% of spousal SPs did so (p<0.05).ConclusionsSpouses and adult children are similarly likely to serve as SPs, but there are differences in how they report on subject functioning. Our findings have important implications for interpreting informant reports, particularly, of persons with no or mild cognitive impairment.