Associate Professor Kim Delbaere

PUBLICATIONS

White matter hyperintensities are associated with falls in older people with dementia.

Taylor ME, Lord SR, Delbaere K, Wen W, Jiang J, Brodaty H, Kurrle SE, Stefanie Mikolaizak A, Close JCT

White Matter Hyperintensities (WMHs) are associated with impaired gait, balance and cognition and increased fall risk in cognitively healthy older people. However, few studies have examined such relationships in older people with dementia. Understanding the role of WMHs in falls may assist in developing effective fall prevention strategies. We investigated the relationship between baseline WMHs, cognitive and sensorimotor function and prospective falls in older people with dementia. Twenty-eight community-dwelling older people with mild-moderate dementia (MMSE 11-23; ACE-R < 83) underwent magnetic resonance imaging and assessment of sensorimotor and cognitive (global and processing speed) function at baseline. WMHs, were quantified using a fully automated segmentation toolbox, UBO Detector ( https://cheba.unsw.edu.au/group/neuroimaging-pipeline ). Falls were ascertained prospectively for 12-months using monthly calendars with the assistance of carers. The median age of the participants was 83 years (IQR 77-86); 36% were female; 21 (75%) fell during follow-up. Using Generalized Linear Models, larger volumes of total WMHs were found to be significantly associated with poorer global cognitive and sensorimotor function. Using modified Poisson regression, total, periventricular and deep WMHs were each associated with future falls while controlling for age, sex, intracranial volume and vascular risk. Each standard deviation increase in total and periventricular WMH volume resulted in a 33% (RR 1.33 95%CI 1.07-1.66) and 30% (RR 1.30 95%CI 1.06-1.60) increased risk of falling, respectively. When the deep WMH volume z-scores were dichotomized at the median, individuals with greater deep WMH volumes had an 81% (RR 1.81 95% CI 1.02-3.21) increased risk of falling. WMHs were associated with poorer sensorimotor and cognitive function in people with dementia and total, periventricular and deep WMHs were associated with falls. Further research is needed to confirm these preliminary findings and explore the impact of vascular risk reduction strategies on WMHs, functional performance and falls.

Reducing the burden of dizziness in middle-aged and older people: A multifactorial, tailored, single-blind randomized controlled trial.

Menant JC, Migliaccio AA, Sturnieks DL, Hicks C, Lo J, Ratanapongleka M, Turner J, Delbaere K, Titov N, Meinrath D, McVeigh C, Close JCT, Lord SR

A multifactorial tailored approach for treating dizziness was effective in reducing dizziness handicap in community-living people aged 50 years and older. No difference was seen on the other primary outcomes. Our findings therefore support the implementation of individualized, multifaceted evidence-based therapies to reduce self-perceived disability associated with dizziness in middle-aged and older people.

The role of cognitive function and physical activity in physical decline in older adults across the cognitive spectrum.

Taylor ME, Boripuntakul S, Toson B, Close JCT, Lord SR, Kochan NA, Sachdev PS, Brodaty H, Delbaere K

The aim of this study was to investigate physical decline over 1-year in a cohort of older people across the cognitive spectrum.

Translation and validation study of the Chinese version Iconographical Falls Efficacy Scale-Short Version (Icon-FES).

Chan PPW, Chan APS, Lau E, Delbaere K, Chan YH, Jin XK, Poon CK, Lai CF, Ng MF, Wong WM, Lam AYK

The Chinese Icon-FES is a valid, efficient and easy-to-use instrument for understanding of local Chinese older people's concerns about falling in Hong Kong.

Cross-cultural adaptation and measurement properties testing of the Iconographical Falls Efficacy Scale (Icon-FES).

Franco MR, Pinto RZ, Delbaere K, Eto BY, Faria MS, Aoyagi GA, Steffens D, Pastre CM

To perform a cross-cultural adaptation and to assess the measurement properties of the 30-item and 10-item Icon-FES in a community-dwelling Brazilian older population. Icon-FES-Brazil is a semantically and linguistically appropriate tool with acceptable measurement properties to evaluate concern about falling among the community-dwelling older population.

Deep white matter hyperintensities, microstructural integrity and dual task walking in older people.

Ghanavati T, Smitt MS, Lord SR, Sachdev P, Wen W, Kochan NA, Brodaty H, Delbaere K

To examine neural, physiological and cognitive influences on gait speed under single and dual-task conditions. Sixty-two community-dwelling older people (aged 80.0 ± 4.2 years) participated in our study. Gait speed was assessed with a timed 20-meter walk under single and dual-task (reciting alternate letters of the alphabet) conditions. Participants also underwent tests to estimate physiological fall risk based on five measures of sensorimotor function, cognitive function across five domains, brain white matter (WM) hyperintensities and WM microstructural integrity by measuring fractional anisotropy (FA). Univariate linear regression analyses showed that global physiological and cognitive measures were associated with single (β = 0.594 and β=-0.297, respectively) and dual-task gait speed (β = 0.306 and β=-0.362, respectively). Deep WMHs were associated with dual-task gait speed only (β = 0.257). Multivariate mediational analyses showed that global and executive cognition reduced the strength of the association between deep WMHs and dual-task gait speed by 27% (β = 0.188) and 44% (β = 0.145) respectively. There was a significant linear association between single-task gait speed and mean FA values of the genu (β=-0.295) and splenium (β=-0.326) of the corpus callosum, and between dual-task gait speed and mean FA values of Superior Cerebellar Peduncle (β=-0.284), splenium of the Corpus Callosum (β=-0.286) and Cingulum (β=-0.351). Greater deep WMH volumes are associated with slower walking speed under dual-task conditions, and this relationship is mediated in part by global cognition and executive abilities specifically. Furthermore, both cerebellum and cingulum are related to dual-task walking due to their role in motor skill performance and attention, respectively.

Development and initial validation of the Retrospective Indigenous Childhood Enrichment scale (RICE).

Minogue C, Delbaere K, Radford K, Broe T, Forder WS, Lah S

ABSTRACTBackground:Years of education is the most commonly used proxy measure of cognitive reserve. Other forms of cognitive stimulation in childhood may provide similar protection against cognitive decline, particularly in Indigenous groups, where education may have been lacking in quality or quantity. The Retrospective Indigenous Childhood Enrichment (RICE) scale was developed to measure non-school-based activities and environmental stimulation during childhood that are likely to have enhanced cognitive reserve. The aim of the study was to assess the validity and reliability of the RICE scale with a group of older Aboriginal Australians.

Risk factors for falls among older Aboriginal and Torres Strait Islander people in urban and regional communities.

Lukaszyk C, Radford K, Delbaere K, Ivers R, Rogers K, Sherrington C, Tiedemann A, Coombes J, Daylight G, Draper B, Broe T

To examine associations between fall risk factors identified previously in other populations and falls among Aboriginal people aged 60 years and older, living in New South Wales, Australia. Falls were experienced by one-quarter of study participants. Fall risk factors identified for older Aboriginal people appear to be similar to those identified in the general population. Understanding of fall risk factors may assist with the development of appropriate and effective community-led fall prevention programs.

Does dual task training improve walking performance of older adults with concern of falling?

Wollesen B, Schulz S, Seydell L, Delbaere K

The results showed that DT managing training can improve walking performance under ST and DT conditions in people with and without CoF. Additional treatment to directly address CoF, such as cognitive behavioural therapy, should be considered to further improve the cautious gait pattern (as evidenced by reduced foot rolling movements).

Slow gait speed is associated with executive function decline in older people with mild to moderate dementia: A one year longitudinal study.

Taylor ME, Lasschuit DA, Lord SR, Delbaere K, Kurrle SE, Mikolaizak AS, Kvelde T, Close JCT

This study aimed to document change in neuropsychological, physical and functional performance over one year and to investigate the relationship between baseline gait speed and cognitive decline in this period in older people with dementia. Older people with mild to moderate dementia demonstrate significant decline in neuropsychological, physical and functional performance over one year. Baseline gait speed is associated with decline in executive function over one year, suggesting shared pathways/pathology between gait and cognition.

Childhood Stress and Adversity is Associated with Late-Life Dementia in Aboriginal Australians.

Radford K, Delbaere K, Draper B, Mack HA, Daylight G, Cumming R, Chalkley S, Minogue C, Broe GA

High rates of dementia have been observed in Aboriginal Australians. This study aimed to describe childhood stress in older Aboriginal Australians and to examine associations with late-life health and dementia. Childhood stress appears to have a significant impact on emotional health and dementia for older Aboriginal Australians. The ongoing effects of childhood stress need to be recognized as people grow older, particularly in terms of dementia prevention and care, as well as in populations with greater exposure to childhood adversity, such as Aboriginal Australians.

Comparison of Three Cognitive Screening Tools in Older Urban and Regional Aboriginal Australians.

Radford K, Mack HA, Draper B, Chalkley S, Delbaere K, Daylight G, Cumming RG, Bennett H, Broe GA

The MMSE is an effective cognitive screening tool in urban Aboriginal populations. The mKICA is a good alternative when illiteracy, language or cultural considerations deem it appropriate. The RUDAS also has adequate validity in this population.

Prevalence of dementia in urban and regional Aboriginal Australians.

Radford K, Mack HA, Draper B, Chalkley S, Daylight G, Cumming R, Bennett H, Delbaere K, Broe GA

Consistent with previous findings in a remote population, urban and regional Aboriginal Australians face high rates of dementia at younger ages, most commonly Alzheimer's dementia.

Concern about falls elicits changes in gait parameters in conditions of postural threat in older people.

Delbaere K, Sturnieks DL, Crombez G, Lord SR

These findings suggest that walking performance is influenced by both physiological and psychological factors. Physiological falls risk appears to determine walking speed under optimal conditions, whereas concern about falling elicits greater (possibly excessive) gait adjustments under conditions of postural threat.

The association between choice stepping reaction time and falls in older adults--a path analysis model.

Pijnappels M, Delbaere K, Sturnieks DL, Lord SR

to investigate how physiological and cognitive factors mediate the association between CSRT performance and multiple falls by use of path analysis. this study provides an example of how path analysis can reveal mediators for the association between a functional measure and falls. Our model identified inter-relationships (with relative weights) between physiological and cognitive factors, CSRT and multiple falls.

Consequences of lower extremity and trunk muscle fatigue on balance and functional tasks in older people: a systematic literature review.

Helbostad JL, Sturnieks DL, Menant J, Delbaere K, Lord SR, Pijnappels M

Taken together, the findings suggest that balance and functional task performance are impaired with fatigue. Future studies should assess whether fatigue is related to increased risk of falling and whether exercise interventions may decrease fatigue effects.

Relationships between serum vitamin D levels, neuromuscular and neuropsychological function and falls in older men and women.

Menant JC, Close JC, Delbaere K, Sturnieks DL, Trollor J, Sachdev PS, Brodaty H, Lord SR

These findings highlight the associations between vitamin D insufficiency and impairments in physiological and neuropsychological function that predispose older people to fall. The significant relationship between vitamin D insufficiency and falls found in the men may relate to the stronger association found between serum 25OHD levels and dynamic balance measures evident in this male population.

Implementing falls prevention research into policy and practice: an overview of a new National Health and Medical Research Council Partnership Grant.

Lord SR, Delbaere K, Tiedemann A, Smith ST, Sturnieks DL

Preventing falls and fall-related injuries among older people is an urgent public health challenge. This paper provides an overview of the background to and research planned for a 5-year National Health and Medical Research Council Partnership Grant on implementing falls prevention research findings into policy and practice. This program represents a partnership between key Australian falls prevention researchers, policy makers and information technology companies which aims to: (1) fill gaps in evidence relating to the prevention of falls in older people, involving new research studies of risk factor assessment and interventions for falls prevention; (2) translate evidence into policy and practice, examining the usefulness of new risk-identification tools in clinical practice; and (3) disseminate evidence to health professionals working with older people, via presentations, new evidence-based guidelines, improved resources and learning tools, to improve the workforce capacity to prevent falls and associated injuries in the future.

Mild cognitive impairment as a predictor of falls in community-dwelling older people.

Delbaere K, Kochan NA, Close JC, Menant JC, Sturnieks DL, Brodaty H, Sachdev PS, Lord SR

: Incidence of falls in people with cognitive impairment with or without a formal diagnosis of dementia is estimated to be twice that of cognitively intact older adults. This study aimed to investigate whether mild cognitive impairment (MCI) is associated with falls in older people. : The findings indicate that objectively defined MCI is an independent risk factor for injurious or multiple falls in a representative sample of community-dwelling older people. The presence of nonamnestic MCI, based primarily on executive function, was found to be an important factor in increasing fall risk.

Pain and anxiety mediate the relationship between dizziness and falls in older people.

Menant JC, Wong A, Sturnieks DL, Close JC, Delbaere K, Sachdev PS, Brodaty H, Lord SR

To identify medical, psychological, and physiological mediators of the relationship between dizziness and falls in older adults. Suffering from neck and back pain and anxiety were mediators of the relationship between dizziness and falls after controlling for poor sensorimotor function and balance. Older people with dizziness might benefit from interventions targeting these mediators such as pain management and cognitive behavioral therapy.

Angiotensin system-blocking medications are associated with fewer falls over 12 months in community-dwelling older people.

Wong AK, Lord SR, Sturnieks DL, Delbaere K, Trollor JN, Close JC

To investigate relationships between the use of cardiovascular medications, including angiotensin system-blocking medications (ASBMs), orthostatic hypotension (OH), fall risk, and falls in community-dwelling older people. The use of cardiovascular medications in older people did not increase the risk of falls, and the use of ASBMs was associated with lower fall risk. The mechanisms for this apparent protective effect are unclear and appear not to be directly related to muscle strength. More research is required to elucidate the possible protective effects of certain cardiovascular medications in relation to falls in older people.

Force-controlled balance perturbations associated with falls in older people: a prospective cohort study.

Sturnieks DL, Menant J, Delbaere K, Vanrenterghem J, Rogers MW, Fitzpatrick RC, Lord SR

Balance recovery from an unpredictable postural perturbation can be a challenging task for many older people and poor recovery could contribute to their risk of falls. This study examined associations between responses to unpredictable perturbations and fall risk in older people. 242 older adults (80.0 ± 4.4 years) underwent assessments of stepping responses to multi-directional force-controlled waist-pull perturbations. Participants returned monthly falls calendars for the subsequent 12 months. Future falls were associated with lower force thresholds for stepping in the posterior and lateral but not anterior directions. Those with lower posterior force thresholds for stepping were 68% more likely to fall at home than those with higher force thresholds for stepping. These results suggest that amount of force that can be withstood following an unpredictable balance perturbation predicts future falls in community-dwelling older adults. Perturbations in the posterior direction best discriminated between future fallers and non-fallers.

Force-controlled balance perturbations associated with falls in older people: a prospective cohort study.

Sturnieks DL, Menant J, Delbaere K, Vanrenterghem J, Rogers MW, Fitzpatrick RC, Lord SR

Balance recovery from an unpredictable postural perturbation can be a challenging task for many older people and poor recovery could contribute to their risk of falls. This study examined associations between responses to unpredictable perturbations and fall risk in older people. 242 older adults (80.0 ± 4.4 years) underwent assessments of stepping responses to multi-directional force-controlled waist-pull perturbations. Participants returned monthly falls calendars for the subsequent 12 months. Future falls were associated with lower force thresholds for stepping in the posterior and lateral but not anterior directions. Those with lower posterior force thresholds for stepping were 68% more likely to fall at home than those with higher force thresholds for stepping. These results suggest that amount of force that can be withstood following an unpredictable balance perturbation predicts future falls in community-dwelling older adults. Perturbations in the posterior direction best discriminated between future fallers and non-fallers.

High arterial pulse wave velocity is a risk factor for falls in community-dwelling older people.

Wong AK, Lord SR, Trollor JN, Sturnieks DL, Delbaere K, Menant J, Brodaty H, Sachdev PS, Close JC

To examine whether arterial stiffness is a risk factor for falls in community-dwelling older people. In community-dwelling older people, high PWV (as a measure of arterial stiffness) was a risk factor for falls after adjusting for potential demographic, anthropometric, disease, and medication confounders. Further research is required to investigate mediators for this association and the effect of lowering arterial stiffness on falls in older people.

Gait as a biomarker? Accelerometers reveal that reduced movement quality while walking is associated with Parkinson's disease, ageing and fall risk.

Brodie MA, Lovell NH, Canning CG, Menz HB, Delbaere K, Redmond SJ, Latt M, Sturnieks DL, Menant J, Smith ST, Lord SR

Humans are living longer but morbidity has also increased; threatening to create a serious global burden. Our approach is to monitor gait for early warning signs of morbidity. Here we present highlights from a series of experiments into gait as a potential biomarker for Parkinson's disease (PD), ageing and fall risk. Using body-worn accelerometers, we developed several novel camera-less methods to analyze head and pelvis movements while walking. Signal processing algorithms were developed to extract gait parameters that represented the principal components of vigor, head jerk, lateral harmonic stability, and oscillation range. The new gait parameters were compared to accidental falls, mental state and co-morbidities. We observed: 1) People with PD had significantly larger and uncontrolled anterioposterior (AP) oscillations of the head; 2) Older people walked with more lateral head jerk; and, 3) the combination of vigorous and harmonically stable gait was demonstrated by non-fallers. Our findings agree with research from other groups; changes in human gait reflect changes to well-being. We observed; different aspects of gait reflected different functional outcomes. The new gait parameters therefore may be complementary to existing methods and may have potential as biomarkers for specific disorders. However, further research is required to validate our observations, and establish clinical utility.

Wearable pendant device monitoring using new wavelet-based methods shows daily life and laboratory gaits are different.

Brodie MA, Coppens MJ, Lord SR, Lovell NH, Gschwind YJ, Redmond SJ, Del Rosario MB, Wang K, Sturnieks DL, Persiani M, Delbaere K

Morbidity and falls are problematic for older people. Wearable devices are increasingly used to monitor daily activities. However, sensors often require rigid attachment to specific locations and shuffling or quiet standing may be confused with walking. Furthermore, it is unclear whether clinical gait assessments are correlated with how older people usually walk during daily life. Wavelet transformations of accelerometer and barometer data from a pendant device worn inside or outside clothing were used to identify walking (excluding shuffling or standing) by 51 older people (83 ± 4 years) during 25 min of 'free-living' activities. Accuracy was validated against annotated video. Training and testing were separated. Activities were only loosely structured including noisy data preceding pendant wearing. An electronic walkway was used for laboratory comparisons. Walking was classified (accuracy ≥97 %) with low false-positive errors (≤1.9%, κ ≥ 0.90). Median free-living cadence was lower than laboratory-assessed cadence (101 vs. 110 steps/min, p < 0.001) but correlated (r = 0.69). Free-living step time variability was significantly higher and uncorrelated with laboratory-assessed variability unless detrended. Remote gait impairment monitoring using wearable devices is feasible providing new ways to investigate morbidity and falls risk. Laboratory-assessed gait performances are correlated with free-living walks, but likely reflect the individual's 'best' performance.

The influence of age, anxiety and concern about falling on postural sway when standing at an elevated level.

Sturnieks DL, Delbaere K, Brodie MA, Lord SR

Psychological processes may influence balance and contribute to the risk of falls in older people. While a self-reported fear of falling is associated with increased postural sway, inducing fear using an elevated platform can lead to reduced sway, suggesting different underlying mechanisms whereby fear may influence balance control. This study examined changes in postural sway, muscle activity and physiological measures of arousal while standing on a 65cm elevated platform, compared to floor level, in young and older adults. The older adults were classified as fall concerned or not fall concerned based on the Falls Efficacy Scale-International and anxious or not anxious based on the Goldberg Anxiety Scale. Fall concern did not affect the physiological and sway response to the elevated platform. In response to the postural threat, the anxious participants increased their sway frequency (p=0.001) but did not reduce sway range (p=0.674). Conversely, non-anxious participants showed an adaptive tightening of balance control, effectively reducing sway range in the elevated condition (p<0.001). Generalised anxiety in older adults appears to differentially affect postural control strategies under threatening conditions.

Tailored multifactorial intervention to improve dizziness symptoms and quality of life, balance and gait in dizziness sufferers aged over 50 years: protocol for a randomised controlled trial.

Menant JC, Migliaccio AA, Hicks C, Lo J, Meinrath D, Ratanapongleka M, Turner J, Sturnieks DL, Delbaere K, Titov N, McVeigh C, Close JC, Lord SR

Use of a physiological profile to document motor impairment in ageing and in clinical groups.

Lord SR, Delbaere K, Gandevia SC

Comparison of Three Cognitive Screening Tools in Older Urban and Regional Aboriginal Australians.

Radford K, Mack HA, Draper B, Chalkley S, Delbaere K, Daylight G, Cumming RG, Bennett H, Broe GA

The MMSE is an effective cognitive screening tool in urban Aboriginal populations. The mKICA is a good alternative when illiteracy, language or cultural considerations deem it appropriate. The RUDAS also has adequate validity in this population.

Prevalence of dementia in urban and regional Aboriginal Australians.

Radford K, Mack HA, Draper B, Chalkley S, Daylight G, Cumming R, Bennett H, Delbaere K, Broe GA

Consistent with previous findings in a remote population, urban and regional Aboriginal Australians face high rates of dementia at younger ages, most commonly Alzheimer's dementia.

Evaluating the effectiveness of a home-based exercise programme delivered through a tablet computer for preventing falls in older community-dwelling people over 2 years: study protocol for the Standing Tall randomised controlled trial.

Delbaere K, Valenzuela T, Woodbury A, Davies T, Yeong J, Steffens D, Miles L, Pickett L, Zijlstra GA, Clemson L, Close JC, Howard K, Lord SR

Validity and reliability of a simple 'low-tech' test for measuring choice stepping reaction time in older people.

Delbaere K, Gschwind YJ, Sherrington C, Barraclough E, Garrués-Irisarri MA, Lord SR

To establish the psychometric properties of a simple 'low-tech' choice stepping reaction time test (CSRT-M) by investigating its validity and test-retest reliability. A simple test of unplanned volitional stepping (CSRT-M) has excellent predictive validity for future falls, good inter-day test-retest reliability and excellent criterion validity with respect to the well-validated CSRT-E. The CSRT-M, therefore, may be a useful fall risk screening tool for older people.

The design of a purpose-built exergame for fall prediction and prevention for older people.

Marston HR, Woodbury A, Gschwind YJ, Kroll M, Fink D, Eichberg S, Kreiner K, Ejupi A, Annegarn J, de Rosario H, Wienholtz A, Wieching R, Delbaere K

The iStoppFalls fall prevention program, used in conjunction with the multifactorial fall risk assessment tool, aims to provide a comprehensive and individualised, yet novel fall risk assessment and prevention program that is feasible for widespread use to prevent falls and fall-related injuries. This work provides a new approach to engage older people in home-based exercise programs to complement or provide a potentially motivational alternative to traditional exercise to reduce the risk of falling.

The effect of sensor-based exercise at home on functional performance associated with fall risk in older people - a comparison of two exergame interventions.

Gschwind YJ, Schoene D, Lord SR, Ejupi A, Valenzuela T, Aal K, Woodbury A, Delbaere K

The findings suggest that it is feasible for older people to conduct an unsupervised exercise program at home using exergames. Both interventions reduced fall risk and SMT additionally improved specific cognitive functions. However, further refinement of the systems is required to improve adherence and maximise the benefits of exergames to deliver fall prevention programs in older people's homes.

Exercise for reducing fear of falling in older people living in the community: Cochrane systematic review and meta-analysis.

Kumar A, Delbaere K, Zijlstra GA, Carpenter H, Iliffe S, Masud T, Skelton D, Morris R, Kendrick D

to determine the effect of exercise interventions on fear of falling in community-living people aged ≥65. exercise interventions probably reduce fear of falling to a small to moderate degree immediately post-intervention in community-living older people. The high risk of bias in most included trials suggests findings should be interpreted with caution. High-quality trials are needed to strengthen the evidence base in this area.