Objectives: To create a systematic synthesis of the published evidence about the prevalence of eight geriatric syndromes and their association with survival and institutionalization, and to provide a review of models that report survival in elderly populations.
Data Sources: Original epidemiologic studies were sought from several databases to identify articles published in English from January 1, 1990 to April 25, 2010.
Review Methods: We identified studies of multiple morbidities, mild cognitive impairment, frailty, disability, sarcopenia, malnutrition, homeostenosis (i.e., impaired homeostasis), and chronic inflammation in the general elderly population and age, race, and sex subgroups. We developed standardized forms using different definitions of these syndromes and abstracted prevalence of the syndromes. Multivariate adjusted risks of mortality and institutionalization for elderly patients with syndromes were abstracted to calculate remaining life expectancy. Pooled analyses were conducted with random effects models. Statistical and decisionmaking models were appraised for content, simplicity, and validation.
Results: Of the 2,377 publications retrieved, 509 publications of 123 studies were eligible for review. Definitions varied within each syndrome and overlapped across all syndromes. Prevalence estimates increased with age. African Americans had higher prevalence of multiple morbidities, frailty, malnutrition, and disability when compared to Caucasians. Evidence on other minority subgroups was sparse. All syndromes were associated with increased risk of death and institutionalization. A negative association between prevalence of a syndrome and its effect on survival was evident across all syndromes. Impaired homeostasis and dementia were associated with the lowest survival among elderly persons when compared to the general population. In the young-old, ages 65–74 years, those with homeostenosis, poor health, or advanced dementia suffered significant decreases in predicted life expectancy. The syndromes affected the likelihood of death more among the young-old. In those older than age 90 years, the added value of factoring in conditions and syndromes to evaluate the link to mortality beyond 1 year was minimal. Complexity was not associated with better mortality models in elderly persons.
Conclusions: Syndromes are not independent; definitions and prevalence estimates overlap substantially. Some minority subpopulations had higher prevalence of the syndromes. Less inclusive definitions had lower prevalence but were better predictors of outcomes. Complex mortality models added less benefit to simpler models that included age, specific diseases, and impact on overall health and functioning. For younger old persons, syndromes most strongly linked to mortality were homeostenosis, poor health, and dementia.