Greene BR, Doheny EP, O’Halloran A, Anne Kenny R

Age Ageing 2014;43:406-11

Publication date: May 1, 2014


The concept of frailty in older adults has emerged as an important geriatric syndrome. It is a multi-factorial condition, influenced by the combination of a person’s physical, psychological and social health. Prompt and accurate identification of a person’s frailty state could allow effective multi-factorial intervention which has been shown to improve health outcomes.

The Timed Up and Go (TUG) test is a standard mobility assessment. The time taken to complete the test has been shown to be a strong predictor of frailty and is commonly used for assessing risk of falls in older adults. In this study, 399 community-dwelling older adults were assessed using Fried’s frailty phenotype and the TUG test. Tests were quantified using shank-mounted inertial sensors and a regression-based method for assessment of frailty using inertial sensor data obtained during TUG. For comparison, frailty was also assessed using the same method based on grip strength and manual TUG time.

Thirty participants were categorized as frail, 185 as pre-frail and 184 as robust using the Fried frailty criteria. Grouping the participants as frail or non-frail gave 184 non-frail and 215 participants categorized as frail. The mean age of the cohort at the time of initial evaluation was 73.6 years.

When stratified by gender, maximum grip strength and manual TUG time produced mean classification accuracies of 77.65% (male: 76.83%; female: 78.47%) and 71.82% (male: 73.97%; female: 69.76%), respectively. When stratified by gender, logistic regression models based on the sensor data were found to be significantly more accurate (mean accuracy of 75.20%) (P < 0.05) than the manual TUG time. Maximum grip strength was not found to be significantly more accurate than the sensor based model for females but was found to be significantly more accurate for males.

The authors conclude that a simple protocol using the TUG and inertial sensors can be a fast and effective means of automatic, non-expert assessment of frailty.


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