R. Gobbens

The Tilburg Frailty Indicator: Psychometric Properties

OBJECTIVES To assess the reliability, construct validity, and predictive (concurrent) validity of the Tilburg Frailty Indicator (TFI), a self-report questionnaire for measuring frailty in older persons. DESIGN Cross-sectional. SETTING Community-based. PARTICIPANTS Two representative samples of community-dwelling persons aged 75 years and older (n = 245; n = 234). MEASUREMENTS The TFI was validated using the LASA Physical Activity Questionnaire, BMI, Timed Up & Go test, Four test balance scale, Grip strength test, Shortened Fatigue Questionnaire, Mini-Mental State Examination, Center for Epidemiologic Studies Depression Scale, Anxiety subscale of the Hospital Anxiety and Depression Scale, Mastery Scale, Loneliness Scale, and the Social Support List. Adverse outcomes were measured using the Groningen Activity Restriction Scale and questions regarding health care use. Quality of life was measured using the WHOQOL-BREF. RESULTS The test-retest reliability of the TFI was good: 0.79 for frailty, and from 0.67 to 0.78 for its domains for a 1-year time interval. The 15 single components, and the frailty domains (physical, psychological, social) of the TFI correlated as expected with validated measures, demonstrating both convergent and divergent construct validity of the TFI. The predictive validity of the TFI and its physical domain was good for quality of life and the adverse outcomes disability and receiving personal care, nursing, and informal care. CONCLUSION This study demonstrates that the psychometric properties of the TFI are good, when performed in 2 samples of community-dwelling older people. The results regarding the TFIs validity provide strong evidence for an integral definition of frailty consisting of physical, psychological, and social domains.

Determinants of Frailty

OBJECTIVES To determine which determinants predict frailty and domains of frailty (physical, psychological, social) in a community-dwelling sample of elderly persons. DESIGN Cross-sectional. SETTING Community-based. PARTICIPANTS A representative sample of 484 community-dwelling persons aged 75 years and older. MEASUREMENTS The Tilburg Frailty Indicator (TFI), a self-report questionnaire, was used to collect information about determinants of frailty and to assess frailty and domains of frailty (physical, psychological, social). RESULTS Results were obtained by regression and mediation analyses. The 10 determinants explain about 35% of the variance of frailty. After controlling for other determinants, medium income, an unhealthy lifestyle, and multimorbidity predicted frailty. The effects of other determinants differed across domains of frailty; age predicted physical frailty, life events predicted psychological frailty, whereas being a woman predicted social frailty because older women have a higher probability of living alone. CONCLUSION Our finding that the effect of the determinants of frailty differs across frailty domains suggests that it is essential to divide the concept of frailty into domains.

In search of an integral conceptual definition of frailty: opinions of experts.

INTRODUCTION There are many different conceptual definitions of frailty in circulation. Most of these definitions focus mainly on physical problems affecting older people. Only a few also draw attention to other domains of human functioning such as the psychological domain. The authors of this article fear that this could lead to fragmentation of care for frail older people. The aim is to develop an integral conceptual definition of frailty that starts from the premise of a holistic view of the person. METHODS To achieve this, a literature search was carried out. Thereafter a group of experts (N=20) were consulted, both verbally during 2 expert meetings and via a written questionnaire. These experts were asked which existing conceptual definition of frailty places most stress on the integral functioning of older people. RESULTS The experts expressed a clear preference for one of the conceptual definitions. The result of the literature search and the consultation with the experts led to a new integral conceptual definition of frailty. CONCLUSION The conceptual definition is intended to offer a framework for an operational definition of frailty for identifying frail older people.

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.

TOWARDS AN INTEGRAL CONCEPTUAL MODEL OF FRAILTY

OBJECTIVES Most conceptual and operational definitions of frailty place heavy emphasis on the physical problems encountered by older people. The accompanying models are based largely on a medical model. An integral approach is almost never adopted. This study aims to develop both an integral operational definition of frailty and an integral conceptual model of frailty. DESIGN In order to achieve these aims, a thorough literature search was performed on components of operational definitions and models of frailty. In addition, experts (N=17) were consulted during two expert meetings. RESULTS There was consensus among the experts on the inclusion of the following components in the operational definition of frailty: strength, balance, nutrition, endurance, mobility, physical activity and cognition. Some respondents indicated that they would wish to add components from the psychological or social domain. Supported by results from the literature search, a new integral operational definition of frailty was developed. This operational definition lies at the heart of an integral conceptual working model of frailty. This model expresses the relationships between three domains of frailty, adverse outcomes such as disability and the determinants. CONCLUSION The model should be able to serve as a basis for further scientific research on frailty. The model also provides a framework for the development of a measurement instrument which can be used for the identification of frail elderly persons.

The Predictive Validity of the Tilburg Frailty Indicator: Disability, Health Care Utilization, and Quality of Life in a Population at Risk

PURPOSE To assess the predictive validity of frailty and its domains (physical, psychological, and social), as measured by the Tilburg Frailty Indicator (TFI), for the adverse outcomes disability, health care utilization, and quality of life. DESIGN AND METHODS The predictive validity of the TFI was tested in a representative sample of 484 community-dwelling persons aged 75 years and older in 2008 (response rate 42%). A subset of all respondents participated 1 year later (N = 336, 69%) and again 2 years later (N = 266, 55%). We used the TFI, the Groningen Activity Restriction Scale assessing disability, seven indicators of health care utilization, and a brief version of the World Health Organization Quality of Life questionnaire (WHOQOL-BREF). The WHOQOL-BREF was assessed in 2008 and 2010; all others were assessed in 2008, 2009, and 2010. RESULTS The predictive validity of the TFI assessed in 2008 for disability, health care utilization, and quality of life was corroborated by (a) medium to very large associations of frailty with adverse outcomes 1 or 2 years later; (b) mostly good to excellent area under the curve of total frailty; and (c) an increase in predictive accuracy of most adverse outcomes, even after controlling for that same adverse outcome in 2008, and life-course determinants and multimorbidity. Physical frailty was mostly responsible for the predictive validity of the TFI. IMPLICATIONS This study showed that the TFI is a valid instrument to predict disability, many indicators of health care utilization, and quality of life of older people, 1 and 2 years later.

Testing an integral conceptual model of frailty.

AIM This paper is a report of a study conducted to test three hypotheses derived from an integral conceptual model of frailty. BACKGROUND   The integral model of frailty describes the pathway from life-course determinants to frailty to adverse outcomes. The model assumes that life-course determinants and the three domains of frailty (physical, psychological, social) affect adverse outcomes, the effect of disease(s) on adverse outcomes is mediated by frailty, and the effect of frailty on adverse outcomes depends on the life-course determinants. METHODS In June 2008 a questionnaire was sent to a sample of community-dwelling people, aged 75 years and older (n = 213). Life-course determinants and frailty were assessed using the Tilburg frailty indicator. Adverse outcomes were measured using the Groningen activity restriction scale, the WHOQOL-BREF and questions regarding healthcare utilization. The effect of seven self-reported chronic diseases was examined. RESULTS Life-course determinants, chronic disease(s), and frailty together explain a moderate to large part of the variance of the seven continuous adverse outcomes (26-57%). All these predictors together explained a significant part of each of the five dichotomous adverse outcomes. The effect of chronic disease(s) on all 12 adverse outcomes was mediated at least partly by frailty. The effect of frailty domains on adverse outcomes did not depend on life-course determinants. CONCLUSION Our finding that the adverse outcomes are differently and uniquely affected by the three domains of frailty (physical, psychological, social), and life-course determinants and disease(s), emphasizes the importance of an integral conceptual model of frailty.

Frailty and its prediction of disability and health care utilization: The added value of interviews and physical measures following a self-report questionnaire

AIMS To establish whether the prediction of the adverse outcomes disability and six indicators of health care utilization one and two years later by the three frailty domains (physical, psychological, social) of the Tilburg Frailty Indicator (TFI) is improved by adding interview and physical measures of frailty. MATERIALS AND METHODS A representative sample of 245 Dutch community-dwelling persons aged 75 years and older (response rate 53%) participated in 2008, one year later in 2009 (n=179, 73%) and again two years later in 2010 (n=141, 58%). Frailty was assessed with the TFI, an easy to administer self-report measure. Disability was measured using the Groningen Activity Restriction Scale (GARS). Indicators of health care utilization were: visit to a general practitioner (gp), contacts with health care professionals (hcps), hospital admission, receiving personal care, receiving nursing care, and receiving informal care. RESULTS After controlling for background characteristics, the TFI predicted disability and the indicators of health care utilization. Interviews and physical measures of frailty improved the prediction of disability. The Hospital Anxiety and Depression Scale (HADS-A) improved the prediction of contacts with hcps, but the interview and physical measures of frailty did not improve the predictions of the other indicators of health care utilization. CONCLUSIONS Assessment by the self-report TFI is sufficient for predicting six indicators of health care utilization, but for predicting disability the use of both the TFI and the Timed Up & Go (TUG) test is recommended. It is advisable assessing all three frailty domains when examining frailty and its prediction of adverse outcomes.

The comprehensive frailty assessment instrument: Development, validity and reliability

Population aging forces governments to change their policy on elderly care. Older people, even if they are frail and disabled, are motivated to stay in their own homes and environment for as long as possible. Consequently, the early detection of frail older persons is appropriate to avoid adverse outcomes. Several instruments to detect frailty exist, but none use environmental indicators. This study addresses the development and psychometric properties of the Comprehensive Frailty Assessment Instrument (CFAI). This new self-reporting instrument includes physical, psychological, social and environmental domains. The CFAI showed good fit indices and a high reliability. The underlying structure of the CFAI demonstrates the multidisciplinary nature of frailty. Using the CFAI can stimulate nurses and other community healthcare providers toward a more holistic approach of frailty and can guide them to take appropriate interventions to prevent adverse outcomes such as disabilities or hospitalization.

A comparison between uni- and multidimensional frailty measures: prevalence, functional status, and relationships with disability

Background Over the years, a plethora of frailty assessment tools has been developed. These instruments can be basically grouped into two types of conceptualizations – unidimensional, based on the physical–biological dimension – and multidimensional, based on the connections among the physical, psychological, and social domains. At present, studies on the comparison between uni- and multidimensional frailty measures are limited. Objective The aims of this paper were: 1) to compare the prevalence of frailty obtained using a uni- and a multidimensional measure; 2) to analyze differences in the functional status among individuals captured as frail or robust by the two measures; and 3) to investigate relations between the two frailty measures and disability. Methods Two hundred and sixty-seven community-dwelling older adults (73.4±6 years old, 59.9% of women) participated in this cross-sectional study. The Cardiovascular Health Study (CHS) index and the Tilburg Frailty Indicator (TFI) were used to measure frailty in a uni- and multidimensional way, respectively. The International Physical Activity Questionnaire, the Center of Epidemiologic Studies Depression scale, and the Loneliness Scale were administered to evaluate the functional status. Disability was assessed using the Groningen Activity Restriction Scale. Data were treated with descriptive statistics, one-way analysis of variance, correlations, and receiver operating characteristic analyses through the evaluation of the areas under the curve. Results Results showed that frailty prevalence rate is strictly dependent on the index used (CHS =12.7%; TFI =44.6%). Furthermore, frail individuals presented differences in terms of functional status in all the domains. Frailty measures were significantly correlated with each other (r=0.483), and with disability (CHS: r=0.423; TFI: r=0.475). Finally, the area under the curve of the TFI (0.833) for disability was higher with respect to the one of CHS (0.770). Conclusion Data reported here confirm that different instruments capture different frail individuals. Clinicians and researchers have to consider the different abilities of the two measures to detect frail individuals.