The concept of cognitive frailty has recently been proposed by an International Consensus Group as the presence of physical frailty and cognitive impairment [defined using the Clinical Dementia Ratings (CDR)=0.5], without concurrent dementia. However, CDR is difficult to implement and not often available in epidemiologic studies or busy clinical settings, and an alternative to CDR is required. We suggest an alternative definition of cognitive frailty as: 1) physical frailty, 2) more than 1.5 standard deviation below the mean for age-, gender-, and education-adjusted norms on any cognitive function test (e.g., the Montreal Cognitive assessment test, the Alzheimer's disease assessment scale-cognitive subscale, verbal learning test, Digit Span, Boston Naming Test, Trail Making Test, and Frontal Assessment Battery), and 3) no dependency in instrumental activities of daily living. The redefined criteria for cognitive frailty would be more feasible to implement and thus more applicable in epidemiologic studies and busy clinical settings.
Keywords: Cognitive frailty; Frailty; Instrumental activities of daily living; Mild cognitive impairment.