Frailty is a central research topic in clinical geriatrics, geroscience, and public health. It is variably defined but almost always includes loss of physiological reserve and lower tolerance for stressful events. The most common definition requires the presence of 3 or more of 5 indicators—weight loss, exhaustion, weakness, slowness, and low physical activity—with prefrail defined as meeting 1 to 2 indicators.1 Other definitions are broader and include a wider array of symptoms, signs, functional impairment, and abnormal laboratory values.2 Frailty is a risk factor for many population health outcomes, including falls, functional decline and disability, long-term care need, and death. Frail patients are also at higher risk for delirium and prolonged hospitalization after medical treatment, with greater costs and increased need for rehabilitative services. More than 30 years ago, Kane3 spoke of functional assessment and disability in the activities of daily living (ADL) as a “clinical Swiss army knife” because ADL disability was associated with so many health outcomes. It may be time now to replace “ADL disability” with “frailty” as an earlier, more upstream risk factor.
Given its centrality for disease management and population health, the incidence of frailty among robust older adults is a key health indicator. Therefore, the systematic review and meta-analysis by Ofori-Asenso et al4 is very welcome for providing estimates of the incidence of frailty and prefrailty among community-dwelling older adults 60 years or older. In their meta-analysis, the authors assessed 46 observational studies involving 120 805 nonfrail (robust or prefrail) participants from 28 countries across 5 continents. The analysis followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) and MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines.
With a median of 3.0 years of follow-up, the incidence of frailty among robust older adults 60 years or older was 43.4 (95% CI, 37.3-50.4) cases per 1000 person-years.4 For the onset of prefrailty, the incidence over a median of 2.5 years of follow-up was 150.6 (95% CI, 123.3-184.1) cases per 1000 person-years. Taking death into account as a competing risk lowered the incidence to 35.9 cases per 1000 person-years for frailty and 110.6 cases per 1000 person-years for prefrailty.
Notably, the meta-analysis4 showed a higher incidence of frailty among women (44.8 vs 24.3 cases per 1000 person-years for men) and demonstrated variation by country income level, definition of frailty (Fried criteria used in 40 of 46 studies vs other), and duration of follow-up. Ofori-Asenso et al4 report no evidence of publication bias according to funnel plot visualization or Egger test.
Disaggregating the onset of frailty and prefrailty and initial frailty status, the meta-analysis by Ofori-Asenso et al4 suggests that 12 robust older people will develop frailty and 151 will develop prefrailty per 1000 person-years. Given this incidence, the high prevalence of frailty or prefrailty (17% across this series of cohorts), the significance of frailty for population health, and an increasingly older population, delaying the onset of frailty is clearly a critical public health challenge.
How should we address this challenge? Ofori-Asenso et al4 suggest greater screening and a need for interventions to prevent or slow frailty onset. Screening should be helpful in identifying the prefrail and steering them to medical care and allied health services that should, in principle, redress emerging deficits or work with preserved areas of function to compensate for weaker domains. Yet, experience with falls risk screening and referral, for example, suggests that these efforts are more complicated than they seem. In a population-based effort to screen for falls risk and refer at-risk older adults to their physicians, only 21.5% of older adults with performance assessments indicating high falls risk followed up with physician referrals.5 Even if these older adults see community physicians, it remains unclear how physicians screen for falls risk or whether they are likely to change care plans based on falls assessments.
Perhaps increased availability of effective interventions will lead to boosts in screening. For falls risk, a variety of effective interventions are available. Physical therapy, group exercise classes, home modification, medication therapy review, assistive device consults, vision assessment, and patient education have all shown benefit. It is less clear what the appropriate intervention is for frailty. A perhaps unexpected candidate, at least for the two-thirds of US older adults who are overweight or obese, is weight loss. The results of a study6 suggested benefits in gait speed, reversing slowness, simply by virtue of losing weight, without an exercise component. The challenges of reducing slowness in old age are well illustrated by the Lifestyle Interventions and Independence for Elders (LIFE) study,7 which showed that a program of structured physical activity could increase stamina and gait speed but did not offer clear benefit for many other outcomes.
Limitations in the meta-analysis mentioned by Ofori-Asenso et al4 include the absence of age-specific frailty incidence rates and reliance on the median follow-up duration to calculate person-year denominators. These limitations should be addressed in future studies. Another limitation not mentioned by the authors is a narrow view of the dynamics of frailty. The authors note that frailty is a “dynamic process with an identifiable intermediate stage, usually referred to as prefrailty,”4 and they duly assess transitions from robust to prefrailty and frailty and from prefrailty to frailty. Missing is information on the incidence of recovery or reversion, people who move from frailty to prefrailty, or those who move from prefrailty to robust (or even from frailty to robust). The incidence of these transitions is required for a complete picture of the dynamics of frailty. It may be this process, observed in well-designed cohort studies, that offers the most insight on reversing frailty and a more complete picture of population health.
Published: August 2, 2019. doi:10.1001/jamanetworkopen.2019.8438
Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2019 Albert SM. JAMA Network Open.
Corresponding Author: Steven M. Albert, PhD, MS, Department of Behavioral and Community Health Sciences, Graduate School of Public Health, University of Pittsburgh, 130 DeSoto St, Pittsburgh, PA 15232 (firstname.lastname@example.org).
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported by grant P30 AG024827 from the National Institutes of Health.
Role of the Funder/Sponsor: The funding source had no role in the preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
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Albert SM. The Dynamics of Frailty Among Older Adults. JAMA Netw Open. Published online August 02, 20192(8):e198438. doi:10.1001/jamanetworkopen.2019.8438
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