High Levels of Comorbidity and Disability Cancel Out the Dementia Effect in Predictions of Long-Term Mortality after Discharge in the Very Old

Abstract

Background/Aims: The relative weight of various etiologies of dementia as predictors of long-term mortality after other risk factors have been taken into account remains unclear. We investigated the 5-year mortality risk associated with dementia in elderly people after discharge from acute care, taking into account comorbid conditions and functionality. Methods: A prospective cohort study of 444 patients (mean age: 85 years; 74% female) discharged from the acute geriatric unit of Geneva University Hospitals. On admission, each subject underwent a standardized diagnostic evaluation: demographic variables, cognitive, comorbid medical conditions and functional assessment. Patients were followed yearly by the same team. Predictors of survival at 5 years were evaluated by Cox proportional hazards models. Results: The univariate model showed that being older and male, and having vascular and severe dementia, comorbidity and functional disability, were predictive of shorter survival. However, in the full multivariate model adjusted for age and sex, the effect of dementia type or severity completely disappeared when all the variables were added. In multivariate analysis, the best predictor was higher comorbidity score, followed by functional status (R² = 23%). Conclusions: The identification of comorbidity and functional impairment effects as predictive factors for long-term mortality independent of cognitive status may increase the accuracy of long-term discharge planning.

Survival in the pre-senile dementia frontotemporal lobar degeneration with TDP-43 proteinopathy: effects of genetic, demographic and neuropathological variables

“…This result is similar to that previously reported for FTD-MND, which exhibited substantially reduced survival (median survival 3 years) [33]. Similarly in AD, the presence of at least one co-morbidity decreased survival [5,67] and the presence of combined co-morbidity and functional disability was an important predictor of lower survival [66]. In FTLD-TDP, however, the presence of associated AD or HS increased survival, suggesting possible synergistic interactions between competing pathologies.…”

“…The objective of the present study was to investigate the influence of genetics, demographic variables, co-morbidity, and neuropathology on survival, as measured by duration of dementia, in a sample of well-documented FTLD-TDP cases [10]. Kaplan-Meier survival analysis was used to determine whether survival was influenced by genetics, demographic factors, or co-morbidity, while Cox regression analysis was used to determine whether there were correlations between survival and predictor variables such as the densities of TDP-43-reactive inclusions in various brain regions [33,48,66].…”

Longitudinal Associations between Survival in Alzheimer's Disease and Cholinesterase Inhibitor Use, Progression, and Community-Based Services

“…Comorbidity and concomitant medications are common in older people and complicate analyses of the direct impact of AD on mortality [37]. Antidiabetic drugs implied a 50-60% increased risk of death in the SATS, whereas antihypertensive/cardiac therapy was an independent significant predictor in the univariate, but not multivariate, Cox models.…”

Factors Determining Disease Duration in Alzheimer’s Disease: A Postmortem Study of 103 Cases Using the Kaplan-Meier Estimator and Cox Regression

“…The Kaplan-Meier estimator and Cox regression analysis (proportional hazard model) were used to study the survival function of the AD patients and to test specific hypotheses [19–21]. …”