U.S. National Profile of Older Adults with Cognitive Impairment Alone, Physical Frailty Alone, and Both

Abstract

Background/objectives: To obtain national and regional estimates of prevalence of frailty with or without cognitive impairment, and cognitive impairment with or without frailty among older adults in the United States, and to identify profiles of characteristics that distinguish their joint versus separate occurrence.

Design: Cross-sectional.

Setting: Community or non-nursing home residential care settings.

Participants: A U.S. nationally representative sample of 7,497 older adults aged 65 and older from the National Health and Aging Trends Study.

Measurements: Frailty was measured by the physical frailty phenotype. Cognitive impairment was assessed by cognitive performance testing of executive function and memory or by proxy reports. Multinomial logistic regression was used to identify profiles of demographic, socioeconomic, health, behavioral, and psychosocial characteristics that distinguish four subgroups: not-frail and cognitively intact ("neither"), not-frail and cognitively impaired ("Cog. only"), frail and cognitively intact ("frailty only"), and frail and cognitively impaired ("both").

Results: The prevalence of "Cog. only," "frailty only," and "both" was 25.5%, 5.6%, and 8.7%, respectively. Individuals with"frailty only" had the highest prevalence of obesity, current smoking, comorbidity, lung disease, and history of surgery. The "both" group had the highest prevalence of dementia, depression, cardiovascular diseases, and disability. No significant differences were found between the "Cog. only" group and the "neither" group with respect to history of surgery and comorbidity burden. The prevalence of dementia in the "Cog. only" was less than half of that in the "both" group.

Conclusion: The finding of sizable subgroups having physical frailty but not cognitive impairment, and vice versa, suggests that the two cannot be considered necessarily as antecedent or sequela of one another. The study provided empirical data supporting the prioritization of comorbidity, obesity, surgery history, and smoking status in clinical screening of frailty and cognitive impairment before formal diagnostic assessments.

Keywords: aging phenotype; comorbidity; dementia; measurement; vulnerability.