title: Dynamical network model for age-related health deficits and mortality.
abstract: How long people live depends on their health, and how it changes with age. Individual health can be tracked by the accumulation of age-related health deficits. The fraction of age-related deficits is a simple quantitative measure of human aging. This quantitative frailty index (F) is as good as chronological age in predicting mortality. In this paper, we use a dynamical network model of deficits to explore the effects of interactions between deficits, deficit damage and repair processes, and the connection between the F and mortality. With our model, we qualitatively reproduce Gompertz's law of increasing human mortality with age, the broadening of the F distribution with age, the characteristic nonlinear increase of the F with age, and the increased mortality of high-frailty individuals. No explicit time-dependence in damage or repair rates is needed in our model. Instead, implicit time-dependence arises through deficit interactions-so that the average deficit damage rates increase, and deficit repair rates decrease, with age. We use a simple mortality criterion, where mortality occurs when the most connected node is damaged.
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2.|Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2Y9.|Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2E1.
authors.forename: Swadhin
authors.initials: S
authors.lastname: Taneja
authors.affiliation: Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2Y9.
authors.forename: Arnold B
authors.initials: AB
authors.lastname: Mitnitski
authors.affiliation: Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2Y9.|Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2E1.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Rockwood
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Rutenberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D016330:Frail Elderly; D006304:Health Status; D006801:Humans; D008875:Middle Aged; D015233:Models, Statistical; D009026:Mortality; D013269:Stochastic Processes