Temporal Order of Cognitive and Functional Loss in a Nursing Home Population

Objective: The order in which cognition and the ability to perform activities of daily living (ADLs) are lost in an institutionalized aged population was examined. Understanding the order of loss of function is important for preparing caregivers and planning of care.

Method: The conditional probabilities of the inability to perform activity A when there exists the inability to perform activity B were explored in secondary analyses of cross-sectional data describing 408 nursing home residents. Residents' abilities to perform ADLs were rated by nursing staff using Linn and Linn's Rapid Disability Rating Scale (RDRS-2); cognitive functioning was rated by social workers and nursing staff using a modified version of Reisberg et al.'s Brief Cognitive Rating Scale (BCRS, with 4 axes: orientation, concentration, recent memory, and past memory).

Results: The results regarding ADLs confirm previous findings of a natural order of loss of ability (from the one lost first to last): bathing, dressing, grooming, toileting, walking, and eating. The examination of order in the loss of concentration, recent memory, past memory, and orientation revealed that these seem to be lost concurrently when the cutpoint was 3 (i.e., relatively normal functioning vs. moderate and severe dementia). When the cutpoint was 6 (i.e., severe dementia vs. higher levels of functioning), the order that emerged was: recent memory, past memory, concentration, and orientation.

Conclusions: Although there is a significant relationship between loss of ability to perform ADLs and stage of cognitive impairment, the loss of any specific ADL is not uniquely related to any one stage of cognitive deterioration in this diverse population. This may be explained by the high prevalence of disease in this institutionalized population, as exemplified by the 60% suffering from arthritis and the 17% suffering from neurological disorders other than dementia.