Study partner‐ and self‐reported difficulties in cognitively complex everyday activities in participants without objective cognitive impairment

Abstract

AbstractBackgroundStudy partner report is used to assess cognitively complex everyday activities, or instrumental activities of daily living (IADL). Because a study partner is not always available, the question arises whether IADL can also be evaluated using self‐report. The aim of this study is to investigate the relationship between study partner‐ and self‐report IADL in individuals without objective cognitive impairment, and to explore its associated factors.MethodParticipants (N=3,295; mean age 61.0±12.1 years, 70.3% female; Table 1.) and their study partners (N=1,225) were recruited from the Dutch Brain Research Registry. They completed self‐ and study partner‐report versions of the Amsterdam IADL Questionnaire. For the 1,225 dyads, linear regression analyses were used to investigate the relationship between self‐ and study partner report. Age, sex, cohabitation, marital status, education and subjective memory complaints were explored as potential confounders and effect‐modifiers.ResultA total of 1,544 (46.9%) participants and study partners (n=497, 40.6%) reported an increased level of difficulty in at least one IADL activity (Figure 1). Absolute agreement between self and study partner on item level was high, ranging from 93.3–99.2%. Participants self‐reported more IADL difficulties (M=65.9±SD=4.7), compared to their study partners (M=66.1±SD=4.6; p<0.05). The study partner‐ and self‐ reported IADL scores were significantly associated (B=0.54). When participants experienced memory complaints, both the participant and study partner reported more IADL difficulties (both p<0.001, Figure 2). Furthermore, we found an interaction effect indicating that the association between self and study partner was lower for those without memory complaints (B= 0.42, Figure 3). In addition, the association between self‐ and proxy was slightly lower for highly educated participants (B=0.47).ConclusionSubtle difficulties in IADL were present in about half of the population, and a high level of agreement between self and study partner was observed on both item and scale level IADL. We found several factors influencing the level of agreement, and in a next step we will include objective cognitive markers to explore the etiology of these differences. These findings provide support for the use of IADL self‐report in cognitively unimpaired individuals, in particular for use in primary or secondary prevention trials.