University of Groningen Measurement Properties of the Groningen Frailty Indicator in Home-Dwelling and Institutionalized Elderly

Objectives: To enable prevention of poor outcome in elderly people, a valid instrument is required to detect individuals at high risk. The concept of frailty is a better predictor than age alone. The Groningen Frailty Indicator (GFI) has been developed to identify frailty. We assessed feasibility, reliability, and construct validity of the self-assessment version of the GFI. Design: Cross-sectional. Setting: Community-based. Participants: Home-dwelling and institutionalized elderly persons were included in the study (n 1⁄4 353) who met the following inclusion criteria: persons 65 years and older who were able to fill out questionnaires. Measurements: The feasibility of the GFI was assessed by determining the proportion of missing values per item. The internal consistency reliability of the GFI was established by calculating the KR-20. MannWhitney and Kruskal-Wallis tests were applied to assess discrimination between specific subgroups (known group validity). Convergent and discriminant validity was assessed using Spearman Rank correlations between GFI and diseases and disorders, case complexity, and health care needs (INTERMED), life satisfaction (Cantril Ladder of Life), activities of daily living (Katz), quality of life (EQ5D), and mental health (SF-36). Finally, we used multivariate regression analyses to evaluate the cutoff score of the GFI (<4 versus 4). Results: A total of 296 (84%) of the participants completed all items of the GFI; the internal consistency was 0.68. The GFI yielded statistically significant GFI scores for subgroups (known group validity). The correlations for the convergent (range 0.45 to 0.61) and discriminant validity (range 0.08 to 0.50) were also as hypothesized. In contrast with nonfrail participants, frail older persons had higher levels of case complexity, disability, and lower quality of life and life satisfaction. Conclusions: This study supports the feasibility, reliability, and validity of the self-assessment version of the GFI in home-dwelling and institutionalized elderly people. Copyright 2012 American Medical Directors Association, Inc. Since the introduction of the concept of frailty, several instruments have been developed to determine the level of frailty among elderly people.1 Although researchers disagree on a precise definition, it is commonly accepted that frailty indicates a state of vulnerability regarding the future occurrence of poor health outcomes, such as wdthe Netherlands Organi00-98-218). ZonMw had no ata interpretation, writing of for publication. Finally, the t might lead to a conflict of Department of Epidemiology n, University of Groningen, merican Medical Directors Associa mortality, hospitalization, institutionalization, chronic conditions, and/or loss of function in one or more domains (ie, the physical, psychological, cognitive, and social domains). 2e5 Frailty is not only associated with quality of life and life satisfaction of individuals, but also has an effect on health care demands, as the numbers of frail elderly people in our aging population will increase.6,7 A valid screening tool to identify frailty is essential from both a clinical and a social perspective. Without such an instrument, tailoring preventive interventions for elderly people who are at risk of adverse events will be difficult to attain. The current instruments differ in their perspective on frailty, and, as a consequence, different domains are included to measure the construct.1,4,5,8e15 More recently, frailty has been considered as a multidimensional construct comprising several domains (eg, physical, psychological, social, and cognitive domains). 1,8,16 Several multidimensional frailty