The world's population is rapidly aging, and for the first time in history, most people can expect to live to age 60 and beyond.1 In developed countries, longevity is mainly due to technological and drug medical advancements and disease prevention.2 This added to the drop in birth rates caused a rapid aging of the population worldwide.3 In 2019, the proportion of people 65 and older was 1 in 11 (9 %). However, it is expected by 2050, to be one in four people in Europe and North America.4

Aging entails a time-dependent functional decline that affects the physiological integrity of organs and systems, finally leading to death.5 At the population level, the pattern of aging is remarkably diverse. The variability in age-related phenotypes is determined by genetics, environment, lifestyle, comorbidity, and the interaction among those factors, together with age itself.6 The interactions of individual characteristics with the environment are complex and determine the process of aging, which results in some people living independently into their 90's. In contrast, other need help with daily routines at an earlier age, typically related to associated comorbidity.7 The evidence indicates that most older people have chronic diseases that present as a multiple morbidity picture and that increase with aging.8 This association of multimorbidity experienced by some people over time has been termed "Accelerated Aging," and the severity of multimorbidity can be viewed as an indirect measure of the "force of aging".9

Frailty is a preventable and reversible condition characterized by a marked vulnerability due to decreased functional capacity and failure of multiple physiological systems to cope with daily stressors in older people.10 In addition, frailty is not only associated with age but is also influenced by risk factors that include limited activities of daily living, chronic diseases, depression, poor lifestyle habits, and geriatric syndromes that reduce people's quality of life.11, 12 The model proposed by Fried et al., in 2001 sought to define frailty by the presence of two or more characteristics out of a total of five: (a) Involuntary weight loss, (b) Exhaustion, (c) Low level of physical activity, (d) Slow walking speed and (e) Muscle weakness.13 It has been reported that the prevalence of frailty in different countries around the world is close to 25 %, while in Chile it is approximately 20 %.14 Limitations in functional independence entail a significant burden for society, the healthcare system, and affected people themselves. This is because functional dependence requires extra social and medical care.15 For example, Spanish older adults with frailty and pre-frailty cost in average to the healthcare system USD 3189 per year and USD 2648 per year, respectively, while non-frail older adults cost USD 1568 per year.16

Several studies described frailty as an independent predictor of mortality.17,18 However, few addressed the association of frailty with premature mortality in older people, considering the context of comorbidities, nutrition, socioeconomic, cognition, and quality of life. Our study primarily aimed at examining the association of frailty with all-cause mortality in the context of socio-economic and cognitive status in a cohort of community-dwelling elderly residents in Chile. In addition, we describe the differences in demographic and anthropometric characteristics, comorbidity, socioeconomic situation, physical activity, and lifestyles between frail and non-frail people