Everyday Functioning in a Community-Based Volunteer Population: Differences Between Participant- and Study Partner-Report

Abstract

Introduction: Impaired awareness in dementia caused by Alzheimer’s disease and related disorders made study partner-report the preferred method of measuring interference in “instrumental activities of daily living” (IADL). However, with a shifting focus toward earlier disease stages and prevention, the question arises whether self-report might be equally or even more appropriate. The aim of this study was to investigate how participant- and study partner-report IADL perform in a community-based volunteer population without dementia and which factors relate to differences between participant- and study partner-report.Methods: Participants (N = 3,288; 18–97 years, 70.4% females) and their study partners (N = 1,213; 18–88 years, 45.8% females) were recruited from the Dutch Brain Research Registry. IADL were measured using the Amsterdam IADL Questionnaire. The concordance between participant- and study partner-reported IADL difficulties was examined using intraclass correlation coefficient (ICC). Multinomial logistic regressions were used to investigate which demographic, cognitive, and psychosocial factors related to participant and study partner differences, by looking at the over- and underreport of IADL difficulties by the participant, relative to their study partner.Results: Most A-IADL-Q scores represented no difficulties for both participants (87.9%) and study partners (89.4%). The concordance between participants and study partners was moderate (ICC = 0.55, 95% confidence interval [CI] = [0.51, 0.59]); 24.5% (N = 297) of participants overreported their IADL difficulties compared with study partners, and 17.8% (N = 216) underreported difficulties. The presence of depressive symptoms (odds ratio [OR] = 1.31, 95% CI = [1.12, 1.54]), as well as memory complaints (OR = 2.45, 95% CI = [1.80, 3.34]), increased the odds of participants overreporting their IADL difficulties. Higher IADL ratings decreased the odds of participant underreport (OR = 0.71, 95% CI = [0.67, 0.74]).Conclusion: In this sample of community-based volunteers, most participants and study partners reported no major IADL difficulties. Differences between participant and study partner were, however, quite prevalent, with subjective factors indicative of increased report of IADL difficulties by the participant in particular. These findings suggest that self- and study partner-report measures may not be interchangeable, and that the level of awareness needs to be considered, even in cognitively healthy individuals.

Everyday Functioning and Entorhinal and Inferior Temporal Tau Burden in Cognitively Normal Older Adults

“…Conversely, the finding of participant underreport might reflect a decrease in awareness. Our findings add to a growing body of literature indicating that participants and study partners report differently on the participants' cognitive and functional performance, even when participants are cognitively normal (14,(26)(27)(28)(29). As both self-reported and study partner-reported IADL functioning has been related to objective cognitive performance and future cognitive decline (15,17), including both assessments in early disease stages may have added value and be beneficial for identifying those at risk for disease progression.…”

“…Slightly more than half the dyads were in concordance, while approximately a quarter of participants self-reported more difficulty and approximately a fifth of participants self-reported less difficulty than their study partners. Another study previously found a similar proportion of cognitively normal participants who reported more difficulties than their study partners (14).…”

“…While a third of our sample reported at least some difficulty with one or more of the activities, the range in total scores was restricted and the ADCS ADL-PI showed a ceiling effect. Impairments in everyday functioning are uncommon in cognitively normal individuals, but more subtle difficulties carrying out activities do occur and have been reported in other cohorts as well (14). Because changes in daily functioning may be considered an early marker of cognitive decline, it is relevant to investigate these subtle difficulties even in early stages of AD.…”

“…IADL performance is usually rated by a study partner, but self-report in the preclinical stage may also be of value. There is evidence arguing for the utility of both self-and study partner-report, as both have been shown to be related to subjective memory concerns (14), objective cognitive performance (15,16), and future cognitive decline (17,18). As such, both sources may provide valuable information and the combination of the two may be greater than the sum of its parts.…”

Changes in self‐ and study partner–perceived cognitive functioning in relation to amyloid status and future clinical progression: Findings from the SCIENCe project

“…One of these characteristics is the confirmation of cognitive decline by an observer: when an observer, such as a partner, relative, or friend, corroborates the experience of impairments in cognitive functioning, this may be considered an objective confirmation of the individual's self‐perceived impairment in cognitive functioning. A discrepancy between self and study partner report has been found in multiple studies 12–15 . In an analysis of various items probing self‐perceived cognitive functioning, Amariglio et al 16 .…”