To validate an informant-based tool – the extended version of the Cognitive Scale of Basic and Instrumental Activities of Daily Living (BADL and IADL) or Ext. Cog-ADL Scale – in a larger sample and with a broader range of cognitive-functional items related to activities of daily living (ADL).

The Ext. Cog-ADL Scale was administered to family informants of 42 patients with dementia, 43 patients with multidomain mild cognitive impairment (mdMCI), and 23 healthy control participants. We analyzed the convergent and concurrent validity and external validity of this scale.

The Ext. Cog-ADL Scale demonstrated good psychometric properties. Episodic and working memory tests were the main predictors of most cognitive-functional items of the scale. While patients with dementia obtained lower scores in most error categories of the scale, affecting both BADL and IADL, mdMCI patients showed a more specific pattern of difficulties. Apart from the typical alterations in IADL, mdMCI patients also showed difficulties in several error categories related to BADL (i.e., error detection, problem solving, task self-initiation, distraction inhibition, and restore).

The Ext. Cog-ADL Scale seems to be an adequate tool to capture the specific pattern of cognitive alterations related to IADL and BADL that differentiates dementia from mdMCI and healthy aging; it shows that mdMCI can involve specific cognitive difficulties that affect even BADL.