Predicting Cognitive and Functional Trajectories in People With Late-Onset Dementia: 2 Population-Based Studies

Objectives: Previous studies have shown large heterogeneity in the progression of dementia, both within and between patients. This heterogeneity offers an opportunity to limit the global and individual burden of dementia through the identification of factors associated with slow disease progression in dementia. We explored the heterogeneity in dementia progression to detect disease, patient, and social context factors related to slow progression. Design: Two longitudinal population-based cohort studies with follow-up across 12 years. Setting and Participants: 512 people with incident dementia from Stockholm (Sweden) contributed to the Kungsholmen Project and the Swedish National Study of Aging and Care in Kungsholmen. Methods: We measured cognition using the Mini-Mental State Examination and daily functioning using the Katz Activities of Daily Living Scale. Latent classes of trajectories were identified using a bivariate growth mixture model. We then used bias-corrected logistic regression to identify predictors of slower progression. Results: Two distinct groups of progression were identified; 76% (n = 394) of the people with dementia exhibited relatively slow progression on both cognition and daily functioning, whereas 24% (n = 118) demonstrated more rapid worsening on both outcomes. Predictors of slower disease progression were Alzheimer's disease (AD) dementia type [odds ratio (OR) 2.07, 95% confidence interval (CI) 1.15-3.71], lower age (OR 0.88, 95% CI 0.83-0.94), fewer comorbidities (OR 0.77, 95% CI 0.66-0.90), and a stronger social network (OR 1.72, 95% CI 1.01-2.93). Conclusions/Implications: Lower age, AD dementia type, fewer comorbidities, and a good social network appear to be associated with slow cognitive and functional decline. These factors may help to improve the counseling of patients and caregivers and to optimize the planning of care in dementia.