Establishing an objective tool for evaluating frailty in older populations

Background <br><br> Frailty is a serious geriatric health condition, as it is associated with a wide range of adverse health outcomes from declines in mobility and muscle mass and strength to falls, injuries, disabilities and mortality. Frailty has become an increasing problem within the past 20 to 30 years, due to the global rise in life expectancy. Screening tools that can identify persons at immediate risk of developing frailty can assist carers to implement intervention programs to reduce the likelihood of falls. A variety of objective physical measures have been used to screen for frailty such as the hand grip strength, chair stand, gait speed and timed up and go tests. However, it is apparent that these measures are not being applied in a consistent and standard way between clinics or between studies due to the application of different measurement protocols, and this inconsistency reduces the accuracy of diagnosis and limits the comparison of data. Furthermore, the suitability of some of these tests for screening frail persons has been questioned. <br><br> Aims<br><br> There were three aims in this research project. The first was to systematically review those published studies that have used the above-mentioned tests for frailty, in order to understand their suitability for the frail elderly and the degree of variability that exists in the application of these measures. The second aim was to apply the knowledge gained from the reviews to develop and describe a more appropriate tool for the objective assessment of frailty. The third aim was to pilot the new screening tool with a cohort of residents in a nursing home to assess its feasibility and reliability. <br><br> Studies 1-3<br><br> Systematic reviews of the literature were individually conducted of the hand grip strength test, chair stand test and gait speed test. Safety concerns were identified with the use of the timed up and go test on frail persons, while the hand grip strength test, chair stand test and gait speed test were found to be more suitable. However, the reviews revealed that there has been considerable variability in the application and measurement of these tests, with several key variables not being described or controlled; such limitations prevent these studies from being accurately replicated and will introduce error into any comparisons made between datasets. Another limitation is that screens for frailty designate subjects as 'frail' or 'not frail'; this classification system is too broad to enable the identification of individuals who are at risk of becoming frail. A further limitation of many frailty tests is that they assume frail individuals to have a low body mass index (BMI), which precludes the possibility of frailty in heavier individuals. <br><br> Studies 4-5<br><br> A new assessment tool was proposed in study 4 that combines the hand grip strength test, chair stand test and gait speed test. The findings from the literature has contributed to the face and content validity of the tool. These tests were conducted under carefully prescribed conditions and an aggregate score was derived that designates the individual as `not frail¿, `pre-frail¿, `frail¿ or `very frail¿. The new frailty measure was evaluated at the Assisi Aged Care nursing home in Melbourne, Australia. The eligibility criteria for admission to a nursing home in Australia requires older persons who are no longer able to live independently at home and, younger persons with a disability, dementia or who require other special care needs (Australian Government, 2018). Forty individuals (8 male, 32 female) aged 71-100 years (mean 86.9 ± 5.4) were tested; the screening tool required less than five minutes to be conducted, was well tolerated by participants, and no adverse events were reported. Each individual was tested on two different occasions, simultaneously rated by two investigators who were blinded from each other. <br><br> Outcome measures for reliability of the tool indicated good to excellent inter-rater reliability and moderate to good intra-rater reliability. The lower intra-rater reliability was indicated to be due to changes in frailty in individuals from week to week, rather than to inconsistencies in following the assessment protocols. There was no significant correlation between frailty and age; however, there was a systemic increase of frailty with increasing age. The prevalence of frailty in this sample of older adults was estimated to be 47.5% (35% frail, 12.5% very frail), with no significant difference between males and females. Although frailty and BMI were not correlated, a high proportion of frail and very frail individuals were overweight or obese; there were no underweight individuals within the sample. The total frailty score from the tool was significantly correlated with medical conditions such as fractures and amnesia. From the obtained results, it was evident that certain medical conditions are over-represented in frailty. The incidence of psychological conditions such as depression increased as the severity of frailty increased, whereas dementia was found to be less frequent in the very frail; however, this may have been related to the fact that the current cohort were drawn from patients requiring low care while most dementia patients require high care. The duration of stay at the nursing home was also shown to be correlated with the frailty score, where frailty was found to be more common in individuals who had stayed over a year at the residential facility. <br><br> Conclusions <br><br> The new screening tool is suitable for the assessment of frailty in older adults who are in an institutionalised care setting, and it may offer advantages over existing screening tools as it identifies those who are at risk of becoming frail and those who are very frail; furthermore, it does not exclude those with a high BMI and the testing method is easily replicated. It is recommended that independent trials of this tool be conducted in a variety of community and institutional settings to further validate its usefulness in identifying the prevalence and severity of frailty in older populations. Furthermore, it would be useful to conduct studies on lifestyle factors such as diet, medication use and, daily physical activity as well as psychological factors, as these factors may impact on the progression of frailty and hence may be important targets in the management of frailty in older adults.