Background and Purpose: Frailty is a significant challenge for health care. Therefore, it is important to identify frail individuals. Theoretical Framework: The Vulnerability/Risk/ Human Response/Care Model. The purpose of this study was to develop and validate a measure to identify frail older adults. Methods: Instrument development encompassed the following: delineation of content domains, item generation, content validity, quantitative content validity analysis, and psychometric analysis. Results: Findings indicated the following: (a) Frailty is a complex concept, (b) the Frailty Index for Elders (FIFE) is composed of 10 items, (c) FIFE was able to predict depression, and (d) FIFE was able to differentiate differences in demographic profiles by social support environment. Conclusions: FIFE is a valid instrument. FIFE can be used to study the relationships among frailty determinants, provide standardized measurement, and develop and measure interventional studies.Keywords: instrument development; frailty; elderly; older adultsThe term frailty is often used within the field of geriatrics to describe older adults who are in poor health and vulnerable to stressors resulting in worsening mor- bidity, disability, and mortality. Although considered to be an easily recognized geriatric syndrome, there is no universal definition, thus challenging the ability to char- acterize frailty. Initial conceptual and operational definitions of frailty focused on physi- ological causes of frailty (Brown, Sinacore, Binder, & Kohrt, 2000; Dayhoff, Suhrheinrich, Wigglesworth, Topp, & Moore, 1998; Fried et al., 2001). As the concept has evolved, researchers have recognized frailty as a multifactorial paradigm and have included psy- chological and social domains in its measurement. Inclusion of multiple health domains supports the central tenet that frailty is an accumulation of decrements that affect multiple systems (Ahmed, Mandel, & Fain, 2007; Bortz, 2002; Campbell & Buchner, 1997; Fried et al., 2001; Lally & Crome, 2007; Rockwood, Fox, Stolee, Robertson, & Beattie, 1994).The effect of multiple system decrements is a heightened vulnerability to stressors that increase morbidity and mortality. The health trajectory of frail older adults is of a slow decline, with steadily progressive disability. As the older adult population increases, society will experience the burden of increasing numbers of frail older adults. These frail individuals will have a substantial need for support and interventions. Therefore, it is important to develop an instrument to identify individuals as frail or at risk for frailty. A valid frailty instrument would allow clinicians to rapidly initiate intervention programs to minimize risk of poor outcomes. Without the ability to screen and assess older adults for frailty, effective management and coordination of health team member efforts to prevent the downward trajectory of disability and mortality will be thwarted. A valid frailty mea- sure is also needed to aid researchers in the development and application of interventions to prevent or reverse frailty. The purpose of this study was to develop and validate a mea- sure to identify frail older adults.BACKGROUND AND CONCEPTUAL FRAMEWORKBackgroundThe development of instruments to measure frailty has been limited to geriatric research and practice. A prominent frailty measure, the Phenotype of Frailty (Fried et al., 2001), is one-dimensional and addresses only physiological components. Several frailty measures were developed to include physiological and psychosocial domains of frailty. These mea- sures require multidimensional clinical data from a comprehensive geriatric assessment and have limited applicability to research or geriatric practices (Jones, Song, Mitnitski, & Rockwood, 2005; Kulminski et al., 2008; Rockwood, 2005; Searle, Mitnitski, Gahbauer, Gill, & Rockwood, 2008; Studenski et al., 2004). …