Aging
The association between frailty and incident dementia among older adults in the National Health and Aging Trends Study (NHATS) Bailey Reutinger* Bailey Reutinger Allison Musty Hannah Lee Anna Kuzma Emilie D Duchesneau
Background
Frailty, an age-related syndrome characterized by reduced physiologic reserve, is a risk factor for adverse health outcomes including cognitive decline. We quantified the association between frailty and 5-year dementia risk in older adults.
Methods
We used Rounds 5-10 (2015-2020) of NHATS, a nationally-representative longitudinal cohort of older adults (≥65 years) with annual assessments of age-related conditions. We included community and non-nursing home residential care dwelling older adults without dementia in Round 5 (baseline). Frailty was assessed using the Fried frailty phenotype, which characterizes frailty as having 3-5 symptoms (exhaustion, low physical activity, shrinking, slowness, weakness). Dementia was assessed using a validated measure based on self-reported diagnoses, the AD8 screening tool, and assessments of memory, orientation, and executive function. Multiple imputation accounted for missing data. Standardized mortality ratio (SMR) weights standardized the age, gender, and race distributions for frail and non-frail individuals. We used crude and SMR-weighted Aalen-Johansen estimators to compare 5-year dementia risk between frail and non-frail individuals, accounting for death as a competing risk. 95% CIs were estimated using bootstrapping.
Results
Among 6204 older adults, 16% were frail and 84% were non-frail. Frail participants were more likely to be older, female, and have diabetes than non-frail older adults. The crude 5-year incidence of dementia was higher in frail vs. non-frail older adults (Figure; 20% vs. 10%; difference=10%, 95% CI 7-12%). Differences attenuated slightly after standardization (20% vs. 14%; difference=6%, 95% CI 3-8%).
Conclusions
After standardizing demographic factors, frail older adults are at higher risk of dementia compared to non-frail counterparts. Targeted interventions, such as physical activity programs or nutritional support, may help mitigate dementia and frailty risk in this vulnerable population.
