Frailty measurement in research and clinical practice: A review

Abstract

One of the leading causes of morbidity and premature mortality in older people is frailty. Frailty occurs when multiple physiological systems decline, to the extent that an individual’s cellular repair mechanisms cannot maintain system homeostasis. This review gives an overview of the definitions and measurement of frailty in research and clinical practice, including: Fried’s frailty phenotype; Rockwood and Mitnitski’s Frailty Index (FI); the Study of Osteoporotic Fractures (SOF) Index; Edmonton Frailty Scale (EFS); the Fatigue, Resistance, Ambulation, Illness and Loss of weight (FRAIL) Index; Clinical Frailty Scale (CFS); the Multidimensional Prognostic Index (MPI); Tilburg Frailty Indicator (TFI); PRISMA-7; Groningen Frailty Indicator (GFI), Sherbrooke Postal Questionnaire (SPQ); the Gérontopôle Frailty Screening Tool (GFST) and the Kihon Checklist (KCL), among others. We summarise the main strengths and limitations of existing frailty measurements, and examine how well these measurements operationalise frailty according to Clegg’s guidelines for frailty classification – that is: their accuracy in identifying frailty; their basis on biological causative theory; and their ability to reliably predict patient outcomes and response to potential therapies.

Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Frailty assessment instruments: Systematic characterization of the uses and contexts of highly-cited instruments

Abstract

The medical syndrome of frailty is widely recognized, yet debate remains over how best to measure it in clinical and research settings. This study reviewed the frailty-related research literature by (a) comprehensively cataloging the wide array of instruments that have been utilized to measure frailty, and (b) systematically categorizing the different purposes and contexts of use for frailty instruments frequently cited in the research literature. We identified 67 frailty instruments total; of these, nine were highly-cited (≥ 200 citations). We randomly sampled and reviewed 545 English-language articles citing at least one highly-cited instrument. We estimated the total number of uses, and classified use into eight categories: risk assessment for adverse health outcomes (31% of all uses); etiological studies of frailty (22%); methodology studies (14%); biomarker studies (12%); inclusion/exclusion criteria (10%); estimating prevalence as primary goal (5%); clinical decision-making (2%); and interventional targeting (2%). The most common assessment context was observational studies of older community-dwelling adults. Physical Frailty Phenotype was the most used frailty instrument in the research literature, followed by the Deficit Accumulation Index and the Vulnerable Elders Survey. This study provides an empirical evaluation of the current uses of frailty instruments, which may be important to consider when selecting instruments for clinical or research purposes. We recommend careful consideration in the selection of a frailty instrument based on the intended purpose, domains captured, and how the instrument has been used in the past. Continued efforts are needed to study the validity and feasibility of these instruments.

Copyright © 2015 Elsevier B.V. All rights reserved.

Measures of frailty in population-based studies: an overview

Abstract

Background: Although research productivity in the field of frailty has risen exponentially in recent years, there remains a lack of consensus regarding the measurement of this syndrome. This overview offers three services: first, we provide a comprehensive catalogue of current frailty measures; second, we evaluate their reliability and validity; third, we report on their popularity of use.

Methods: In order to identify relevant publications, we searched MEDLINE (from its inception in 1948 to May 2011); scrutinized the reference sections of the retrieved articles; and consulted our own files. An indicator of the frequency of use of each frailty instrument was based on the number of times it had been utilized by investigators other than the originators.

Results: Of the initially retrieved 2,166 papers, 27 original articles described separate frailty scales. The number (range: 1 to 38) and type of items (range of domains: physical functioning, disability, disease, sensory impairment, cognition, nutrition, mood, and social support) included in the frailty instruments varied widely. Reliability and validity had been examined in only 26% (7/27) of the instruments. The predictive validity of these scales for mortality varied: for instance, hazard ratios/odds ratios (95% confidence interval) for mortality risk for frail relative to non-frail people ranged from 1.21 (0.78; 1.87) to 6.03 (3.00; 12.08) for the Phenotype of Frailty and 1.57 (1.41; 1.74) to 10.53 (7.06; 15.70) for the Frailty Index. Among the 150 papers which we found to have used at least one of the 27 frailty instruments, 69% (n = 104) reported on the Phenotype of Frailty, 12% (n = 18) on the Frailty Index, and 19% (n = 28) on one of the remaining 25 instruments.

Conclusions: Although there are numerous frailty scales currently in use, reliability and validity have rarely been examined. The most evaluated and frequently used measure is the Phenotype of Frailty.

The identification of frailty: a systematic literature review

Abstract

An operational definition of frailty is important for clinical care, research, and policy planning. The literature on the clinical definitions, screening tools, and severity measures of frailty were systematically reviewed as part of the Canadian Initiative on Frailty and Aging. Searches of MEDLINE from 1997 to 2009 were conducted, and reference lists of retrieved articles were pearled, to identify articles published in English and French on the identification of frailty in community-dwelling people aged 65 and older. Two independent reviewers extracted descriptive information on study populations, frailty criteria, and outcomes from the selected papers, and quality rankings were assigned. Of 4,334 articles retrieved from the searches and 70 articles retrieved from the pearling, 22 met study inclusion criteria. In the 22 articles, physical function, gait speed, and cognition were the most commonly used identifying components of frailty, and death, disability, and institutionalization were common outcomes. The prevalence of frailty ranged from 5% to 58%. Despite significant work over the past decade, a clear consensus definition of frailty does not emerge from the literature. The definition and outcomes that best suit the unique needs of the researchers, clinicians, or policy-makers conducting the screening determine the choice of a screening tool for frailty. Important areas for further research include whether disability should be considered a component or an outcome of frailty. In addition, the role of cognitive and mood elements in the frailty construct requires further clarification.

© 2011, Copyright the Authors Journal compilation © 2011, The American Geriatrics Society.

Outcome instruments to measure frailty: a systematic review

Abstract

Frailty is one of the greatest challenges for healthcare professionals. The level of frailty depends on several interrelated factors and can change over time while different interventions seem to be able to influence the level of frailty. Therefore, an outcome instrument to measure frailty with sound clinimetric properties is needed. A systematic review on evaluative measures of frailty was performed in the databases PubMed, EMBASE, Cinahl and Cochrane. The results show numerous instruments that measure the level of frailty. This article gives a clear overview of the content of these frailty instruments and describes their clinimetric properties. Frailty instruments, however, are often developed as prognostic instruments and have also been validated as such. The clinimetric properties of these instruments as evaluative outcome measures are unclear.

Copyright © 2010 Elsevier B.V. All rights reserved.

Toward a conceptual definition of frail community dwelling older people

In order to be able to identify frail community-dwelling older people, a reliable and valid definition of the concept of frailty is necessary. The aim of this study was to provide an overview of the literature on conceptual and operational definitions of frailty, and to determine which definitions are most appropriate for identifying frail community-dwelling older people. Therefore, a computerized search was performed in the PubMed database, Web of Science and PsychInfo. A successful definition of frailty reflects a multidimensional approach, makes clear its dynamic state, predicts adverse outcomes, does not include disease, comorbidity or disability, and meets the criterion of practicability. None of the current conceptual and operational definitions meet these criteria. In this article a new integral conceptual definition of frailty is proposed which meets the criteria of a successful definition.