Abstract
In the present study we explored cognitive and functional deficits in patients with multidomain mild cognitive impairment (MCI), patients with dementia, and healthy age-matched control participants using the Cognitive Scale for Basic and Instrumental Activities of Daily Living, a new preliminary informant-based assessment tool. This tool allowed us to evaluate four key cognitive abilities—task memory schema, error detection, problem solving, and task self-initiation—in a range of basic and instrumental activities of daily living (BADL and IADL, respectively). The first part of the present study was devoted to testing the psychometric adequateness of this new informant-based tool and its convergent validity with other global functioning and neuropsychological measures. The second part of the study was aimed at finding the patterns of everyday cognitive factors that best discriminate between the three groups. We found that patients with dementia exhibited impairment in all cognitive abilities in both basic and instrumental activities. By contrast, patients with MCI were found to have preserved task memory schema in both types of ADL; however, such patients exhibited deficits in error detection and task self-initiation but only in IADL. Finally, patients with MCI also showed a generalized problem solving deficit that affected even BADL. Studying various cognitive processes instantiated in specific ADL differing in complexity seems a promising strategy to further understand the specific relationships between cognition and function in these and other cognitively impaired populations.
We wish to acknowledge Estrella Ródenas and María Torres Rivas for their assistance with data collection. We would also like to thank Juan Montes, the neurologist in charge of the Neurology Service of San Cecilio Hospital in Granada, Spain, for providing us with full access and facilities to test patients with dementia and mild cognitive impairment. Finally, we are grateful to participants and their family members for their cooperation.
Notes
1 In order to avoid a major loss of data on these important ADL, we decided to include two items to measure the same cognitive process. For participants reported to have never prepared complex meals or performed difficult home care tasks in their lives, the task memory schema category was still assessed based on their score on preparing simple meals and performing easy home care tasks.
2 We used stepwise regressions because there is no corpus of previous research to support specific predictions about the relationship between our four cognitive items and specific neuropsychological scores.
* In participants who usually prepared complex meals in the past, the memory schema item was obtained as the mean between their score in preparing both basic and complex meals.