Associations Between Self- and Informant-Reported Abilities of Instrumental Activities of Daily Living and Cognitive Functions in Older Adults With Mild Cognitive Impairment

OBJECTIVE: Older adults (OAs) with mild cognitive impairment (MCI) show disabilities in instrumental activities of daily living (IADLs), which have been linked to compromised cognitive functioning. However, it is unclear which cognitive functions are primarily involved. The present study sought to identify the cognitive function(s) most strongly associated with the IADL limitations in MCI. METHOD: OAs with MCI (N = 120) completed cognitive tasks measuring general cognitive processing speed, working memory (WM) maintenance and updating, inhibition, and shifting ability. IADL abilities were assessed through both self- and informant reports. RESULTS: Self-reported IADL abilities were positively associated with both cognitive processing speed and WM updating capacity. Informant-reported IADL abilities were also positively associated with processing speed and WM updating, in addition to cognitive shifting ability. CONCLUSION: Both general processing speed and WM updating capacity were consistently predictive of IADL abilities. These results might inform the design of training programs aimed at maintaining or improving functional independence in individuals with MCI to focus more on these cognitive functions. However, the strength of the association between specific cognitive functions and IADL abilities in OAs with MCI depends on the source of the information about the IADL abilities, which highlights the need for gathering data from both the examinee and informants.