Association of frailty with survival: a systematic literature review

Frailty is a known risk factor for those aged 65 and over, and its prevalence increases with age. Definitions of frailty vary widely, and prevalence estimates are affected by the way frailty is defined. Systematic reviews have yet to examine the literature on the association between definitions of frailty and mortality. We examined the definitions and prevalence of frailty and its association with survival in older community-dwelling adults. We conducted a systematic review of observational population-based studies published in English. We calculated pooled prevalence of frailty with a random effects model. We identified 24 population-based studies that examined frailty in community-dwelling older adults. The pooled prevalence was 14% when frailty was defined as a phenotype exhibiting three or more of the following: weight loss, fatigue/exhaustion, weakness, low physical activity/slowness, and mobility impairment. The pooled prevalence was 24% when frailty was defined by accumulation of deficits indices that included up to 75 diseases and impairments. The prevalence of frailty increased with age and was greater in women and in African Americans. Frailty in older adults was associated with poor survival with a dose-responsive reduction in survival per increasing number of frailty criteria. Taking into account population prevalence and multivariate adjusted relative risks, we estimated that 3-5% of deaths among older adults could be delayed if frailty was prevented. Frailty is a prevalent and important geriatric syndrome associated with decreased survival. Geriatric assessment of frailty provides clinically important information about functional status and survival of older adults.