Showing papers by "Kim Delbaere published in 2019"
TL;DR: CMI was not significantly different between fallers and non-fallers or people with and without CoF; however, the taxonomy revealed a large variety of cognitive conditions and a higher number of studies using mental tracking tasks, which make it impossible to draw firm conclusions.
Abstract: Walking in natural environments can be considered a dual-task (DT) scenario that requires increasing cognitive resources with advancing age. Previous reviews concluded that gait speed under DT conditions is equivalent to gait speed as a single task (ST) in the prediction of future falls in older people. However, without a clear taxonomy, these conclusions might be premature. The aim of this review is to use a taxonomy for classifying cognitive tasks of cognitive-motor interference (CMI) paradigms while walking to identify which task domains lead to more pronounced cognitive-motor decrements due to fall risk and concern about falling (CoF) in older people. A systematic literature research following PRISMA guidelines was conducted using MEDLINE, Psych-Info and EMBASE. Inclusion criteria were: older people ≥60 years with a previous fall or CoF, use of a DT paradigm to discriminate fallers and non-fallers, straight overground walking, reported gait measurements during ST and DT conditions. A meta-analysis estimated the effect of DT costs for the cognitive task domain and spatiotemporal gait parameters. N = 3737 studies were found within the databases. Nineteen studies were included (n = 14 for meta-analysis). Fallers and people with CoF showed reduced walking speed for ST and DT conditions. Effects of DT were examined for mental tracking tasks. The combined odds ratio (OR [95% confidence interval]) for fallers vs. non-fallers for ST was 3.13 [0.47, 5.80] with moderate heterogeneity (I 2 = 48%). For DT, the OR was 5.17 [2.42, 7.93] with low heterogeneity (I 2 = 37%). Comparing participants with and without CoF, the OR for ST was 12.41 [9.97, 14.84] with high heterogeneity (I 2 = 85%) and OR for mental tracking DT was 10.49 [7.58, 13.40] with moderate heterogeneity (I 2 = 51%). CMI was not significantly different between fallers and non-fallers or people with and without CoF; however, our taxonomy revealed a large variety of cognitive conditions and a higher number of studies using mental tracking tasks, which make it impossible to draw firm conclusions. Future studies should use a more standardised and ecologically valid approach when evaluating the validity of DT gait performance in the prediction of falls, CoF or other age-related conditions. This review was registered at Prospero with the ID: CRD42017068912.
37 citations
TL;DR: Examination of potential risk factors for dementia in the majority urban and regional population of Aboriginal Australians highlights that life-course social determinants of health, in addition to neurological disorders, likely play an important role in elevating dementia risk.
Abstract: Dementia prevalence in Aboriginal and Torres Strait Islander Australians is three to five times higher than the general Australian population. A better understanding of the underlying biomedical and social risk factors is needed to guide dementia prevention in Aboriginal Australians. The current study is the first to examine potential risk factors for dementia in the majority urban and regional population, with a representative sample of 336 Aboriginal Australians aged 60 years and older. Participants included 45 people with a dementia diagnosis (n = 27 probable/possible Alzheimer's disease); and 286 people without dementia. Univariate logistic regression analyses (controlling for age) identified childhood trauma, mid-life factors (history of unskilled work, past high-risk alcohol use), and medical factors (history of stroke, head injury with loss of consciousness, epilepsy) as risk factors for dementia. Multivariable analysis revealed age, childhood trauma, unskilled work, stroke, and head injury as independent predictors of all-cause dementia. A range of comorbid factors related to dementia was also identified (i.e., functional impairment, incontinence, recent hospital admission, low body mass index, living in residential care, depression, current high-risk alcohol use, social isolation, low physical activity levels). These findings extend previous outcomes in a remote Aboriginal population by highlighting that life-course social determinants of health, in addition to neurological disorders, likely play an important role in elevating dementia risk. Certain psychosocial and medical exposures are highly prevalent in Aboriginal Australians, similar to other indigenous populations, and should be considered when designing targeted and culturally appropriate prevention initiatives to reduce the burden of dementia.
30 citations
TL;DR: People with dementia are less active in daily-life and present with significant impairments across multiple gait domains when compared to age-sex matched controls, and opportunities for targeted interventions are highlighted.
Abstract: Understanding the characteristics of physical activity and daily-life gait in older people with dementia may help identify those at risk of negative health outcomes and inform targeted interventions. Questionnaires are often used to assess physical activity but may be more affected by recall bias in people with dementia and provide little information about daily-life gait characteristics. The aim of the study was to assess differences in daily-life activity levels and gait characteristics between community-dwelling older people with mild to moderate dementia (n = 45; mean age 81±6 years, 42% female) and age-sex matched (1:2) cognitively-healthy controls (n = 90). Participants wore a tri-axial accelerometer (DynaPort MoveMonitor, McRoberts) on their lower back for 7 days and were assessed on neuropsychological and physical performance. Compared to age-sex matched controls, participants with dementia demonstrated reduced daily-life activity (fewer steps per day, fewer and shorter walking bouts, and lower daily walk time) and walking intensity (reduced speed, stride length and cadence). Participants with dementia also had significantly increased within-walk variability (stride time) and less regular gait (higher sample entropy). Within the group of participants with dementia, higher daily-life activity levels were associated with greater self-reported physical activity and better executive function. Fallers (1+ falls past year) with dementia had significantly reduced daily-life activity and walking speed when compared to non-fallers with dementia. In conclusion, people with dementia are less active in daily-life and present with significant impairments across multiple gait domains when compared to age-sex matched controls. These findings highlight opportunities for targeted interventions and support further research to examine interventions aimed at addressing these deficits.
25 citations
TL;DR: Physical inactivity and executive dysfunction were associated with physical decline in this sample, which included participants with MCI and dementia, indicating that participants with poorer baseline executive function and reduced PA demonstrated greater physical decline when compared to individuals with betterExecutive function and PA respectively.
Abstract: Objectives: The aim of this study was to investigate physical decline over 1-year in a cohort of older people across the cognitive spectrum.Methods: Physical function was assessed using the Physiol...
17 citations
TL;DR: Concern about falling was the strongest predictor of gait speed under all 4 conditions and should be included in routine geriatric assessments, especially under dual-task conditions.
Abstract: Background Higher levels of concern about falling in older people have been associated with slower walking speed and an increased risk of falls. However, it is unclear whether this relationship is independent or confounded by other fall risk factors, such as physical and cognitive function. Objective The aim of this study was to examine the effects of concern about falling on gait speed, adjusted for physiological fall risk and cognitive function. Design This was an observational, cross-sectional study. Methods A total of 204 community-dwelling older people aged 70 years or older were recruited from 2 sites (Germany, n = 94; Australia, n = 110). Walking speed was measured over 6 m under 4 conditions: preferred speed, fast speed, speed while carrying a tray (functional dual task), and speed while answering a question (cognitive dual task). The Falls Efficacy Scale-International was used to assess concern about falling, the Physiological Profile Assessment was used to assess physiological fall risk, and the Digit Symbol Substitution Test and Trail Making Test were used to assess attention and executive function. Results Higher levels of concern about falling were associated with slower gait speed. Following adjustment for age, history of falls, and female sex, and further adjustment for physical and cognitive function, the association between concern about falling and walking speed remained significant, with a considerable effect size (standardized β = 0.18 ± 0.08; P = .037). Limitations The use of walking speed as a sole measure of gait was a limitation of this study. Conclusions Gait speed, especially under dual-task conditions, was affected by concern about falling. Concern about falling was the strongest predictor of gait speed under all 4 conditions and should be included in routine geriatric assessments.
16 citations
TL;DR: To assess the feasibility and safety of StandingTall—an individually tailored, progressive exercise program delivered through tablet computers—in community‐dwelling older people with dementia, a large number of these people have dementia.
Abstract: Objective To assess the feasibility and safety of StandingTall-an individually tailored, progressive exercise program delivered through tablet computers-in community-dwelling older people with dementia. Methods Fifteen community-dwelling older people with dementia (mean age = 83 ± 8 years; Montreal Cognitive Assessment 16 ± 5) received StandingTall for 12 weeks with caregiver assistance. Feasibility and safety were assessed using the System Usability Scale (SUS; scores = 0-100; a priori target >65), Physical Activity Enjoyment Scale (PACES-8; scores = 8-56), adherence (exercise minutes) and adverse events. Results Mean SUS scores were 68 ± 21/69 ± 15 (participants/caregivers). The mean PACES-8 score was 44 ± 8. In week 2, week 7 and week 12, mean (bias-corrected and accelerated 95% CI) exercise minutes were 37 (25-51), 49 (30-69) and 65 (28-104), respectively. In week 12, five participants exercised >115 minutes. One participant fell while exercising, without sustained injury. Conclusions StandingTall had acceptable usability, scored well on enjoyment and was feasible for participants. These results provide support for further evaluation of StandingTall in a randomised controlled trial with falls as the primary outcome.
15 citations
TL;DR: White Matter Hyperintensities were associated with poorer sensorimotor and cognitive function in people with dementia and total, periventricular and deep WMHs wereassociated with falls.
Abstract: 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.
14 citations
TL;DR: The ReacStick is a reliable test of reaction time and inhibitory EF in older people and could have value for fall-risk assessment and an unavoidable time pressure may result in complementary information to the traditional measures.
Abstract: Reduced cognitive function, particularly executive function (EF), is associated with an increased risk of falling in older people. We evaluated the utility of the ReacStick test, a clinical test of reaction time, and inhibitory EF developed, for young athletes, for fall-risk assessment in older people. To evaluate the psychometric properties of ReacStick measures of reaction time and executive functioning in healthy community-dwelling older people. 140 participants (aged 77 ± 5 years) underwent testing. Two test conditions—simple and inhibitory go/no-go—provided measures of reaction time, recognition load (difference in reaction time between conditions), and go/no-go accuracy. Concurrent validity was evaluated against the conventional tests of reaction time and EF (simple hand reaction time, trail-making test, and Stroop colour test). Discriminant ability was determined for fall-risk factors (age, gender, physiological profile assessment, and fall history). Test–retest reliability after 1 week was evaluated in 30 participants. ReacStick reaction time correlated with tests of reaction time and EF, recognition load correlated with inhibitory EF, and go accuracy correlated with reaction time and inhibitory EF. No-go accuracy was not significantly correlated with any of the reaction time and EF tests. Test–retest reliability was good-to-excellent (ICC > 0.6) for all the outcomes. ReacStick reaction time discriminated between groups based on age, recognition load between genders, and no-go accuracy between retrospective fallers and non-fallers. An unavoidable time pressure may result in complementary information to the traditional measures. The ReacStick is a reliable test of reaction time and inhibitory EF in older people and could have value for fall-risk assessment.
12 citations
TL;DR: It seems that higher preoperative PA level may improve postoperative surgical outcomes; however, this preliminary evidence should be confirmed in a larger cohort.
Abstract: The physical activity (PA) level of patients undergoing major cancer surgery remains unclear. This pilot study aimed to: (i) Compare preoperative PA level between patients undergoing major cancer surgery and the general population; (ii) describe PA trajectories following major cancer surgery; (iii) Compare objective versus subjective PA measures in patients undergoing major cancer surgery; and (iv) Investigate the association between preoperative PA level and postoperative outcomes. Patients undergoing pelvic exenteration between September/2016 and September/2017 were included and followed at preoperative, 6-weeks and 6-months postoperative. PA was measured using the International Physical Activity Questionnaire Short-Form and McRoberts activity monitor. Analyses were performed using SPSS. This pilot study included 16 patients. When compared to the general population, patients undergoing major cancer surgery presented a reduced preoperative PA level. PA levels decreased at 6 weeks but returned to preoperative levels at 6 months postoperative. Objective and subjective measures of PA were comparable, with some variables presenting strong correlations. A higher preoperative level PA was associated with an absence of postoperative complications and better quality of life outcomes. Patients undergoing major cancer surgery demonstrated lower PA levels when compared to the general population. PA trajectories decreased at 6 weeks postoperative, returning to preoperative levels within 6-months. In this cohort, it seems that higher preoperative PA level may improve postoperative surgical outcomes; however, this preliminary evidence should be confirmed in a larger cohort.
12 citations
TL;DR: A method to estimate TUG from activities detected in free-living, enabling continuous remote mobility monitoring without expert supervision is introduced, and remote TUG has discriminatory potential for identifying frail elderly and may provide a convenient way to monitor changes in mobility in unsupervised settings.
Abstract: BACKGROUND Mobility impairment is common in older adults and negatively influences the quality of life. Mobility level may change rapidly following surgery or hospitalization in the elderly. The timed up and go (TUG) is a simple, frequently used clinical test for functional mobility; however, TUG requires supervision from a trained clinician, resulting in infrequent assessments. Additionally, assessment by TUG in clinic settings may not be completely representative of the individual's mobility in their home environment. OBJECTIVE In this paper, we introduce a method to estimate TUG from activities detected in free-living, enabling continuous remote mobility monitoring without expert supervision. The method is used to monitor changes in mobility following total hip arthroplasty (THA). METHODS Community-living elderly (n = 239, 65-91 years) performed a standardized TUG in a laboratory and wore a wearable pendant device that recorded accelerometer and barometric sensor data for at least three days. Activities of daily living (ADLs), including walks and sit-to-stand transitions, and their related mobility features were extracted and used to develop a regularized linear model for remote TUG test estimation. Changes in the remote TUG were evaluated in orthopaedic patients (n = 15, 55-75 years), during 12-weeks period following THA. MAIN RESULTS In leave-one-out-cross-validation (LOOCV), a strong correlation (ρ = 0.70) was observed between the new remote TUG and standardized TUG times. Test-retest reliability of 3-days estimates was high (ICC = 0.94). Compared to week 2 post-THA, remote TUG was significantly improved at week 6 (11.7 ± 3.9 s versus 8.0 ± 1.8 s, p < 0.001), with no further change at 12-weeks (8.1 ± 3.9 s, p = 0.37). SIGNIFICANCE Remote TUG can be estimated in older adults using 3-days of ADLs data recorded using a wearable pendant. Remote TUG has discriminatory potential for identifying frail elderly and may provide a convenient way to monitor changes in mobility in unsupervised settings.
11 citations
TL;DR: The study protocol for a three-arm randomised controlled trial to evaluate the effectiveness of home-based cognitive and cognitive-motor training interventions, compared to a minimal-intervention control group, in preventing falls in older people is described.
Abstract: Background Physical and cognitive impairments are important risk factors for falls in older people. However, no studies have been adequately powered to examine whether cognitive or cognitive-motor training can prevent falls in older people. This is despite good evidence of improvements in fall-related cognitive and physical functions following both intervention types. This manuscript describes the study protocol for a three-arm randomised controlled trial to evaluate the effectiveness of home-based cognitive and cognitive-motor training interventions, compared to a minimal-intervention control group, in preventing falls in older people. This trial was prospectively registered with the Australia New Zealand Clinical Trial Registry, number ACTRN12616001325493. Methods and analysis Community-dwelling adults aged 65 years and over, residing in Sydney Australia, will be recruited. Participants (n=750) will be randomly allocated to (1) cognitive-only training, (2) cognitive-motor training or (3) control groups. Both training interventions involve the use of the smart±step home-based computerised game playing system for a recommended 120 min/week for 12 months. Cognitive training group participants will use a desktop electronic touch pad to play games with the smart±step system while seated and using both hands. The cognitive-motor training group participants will use a wireless electronic floor step mat that requires accurate stepping using both legs for playing the same smart±step games, hence incorporating balance exercises. All groups will receive an education booklet on fall prevention. The primary outcome will be rate of falls, reported by monthly diaries during the 12-month duration of the study and analysis will be by intention-to-treat. Secondary outcomes include the proportion of fallers, physical and cognitive performance in 300 participants, and brain structure and function in 105 participants who will undertake MRI scans at baseline and 6 months. Cost-effectiveness will be determined using intervention and health service costs. Ethics and dissemination Ethical approval was obtained from UNSW Ethics Committee in September 2015 (ref number HC15203). Outcomes will be disseminated through publication in peer-reviewed journals and presentations at international conferences. Trial registration number ACTRN12616001325493
TL;DR: Diagnostic interpretation of the ROC curves revealed that low and high LSM groups can be differentiated with the proposed cut-off, and can be recommended to tailor clinical interventions and evaluate change over time.
Abstract: A version of the Life-Space Assessment in persons with cognitive impairment (LSA-CI) has recently been developed. To establish a cut-off value for the newly developed Life-Space Assessment in persons with cognitive impairment (LSA-CI). In a cross-sectional study including 118 multimorbid, older persons with cognitive impairment, life-space mobility (LSM) was documented by the LSA-CI. The analysis was rationalized by Global Positioning System (GPS)-based measures of spatial distance from home. A receiver-operating characteristic (ROC) curve was created and the cut-off point for the LSA-CI was identified with the Youden’s Index. ROC curve analysis indicated a critical value of 26.75 (within a range of 0–90) to differentiate between low and high LSM with a sensitivity of 78.1% and specificity of 84.2%. Diagnostic interpretation of the ROC curves revealed that low and high LSM groups can be differentiated with the proposed cut-off. The proposed LSA-CI cut-off score can be recommended to tailor clinical interventions and evaluate change over time.
TL;DR: The prevalence of dementia and cognitive impairment is higher in Aboriginal Australians compared to the national population, increasing the need to understand cognitive impairment in this at risk group as mentioned in this paper, which is the most at-risk group in Australia.
Abstract: The prevalence of dementia and cognitive impairment is higher in Aboriginal Australians compared to the national population, increasing the need to understand cognitive impairment in this at‐risk p...
TL;DR: These findings reveal that people with higher general concern about falling experienced more difficulties during a dual-task condition than people with lower levels of concern, and graded exposure has potential to reduce concern about fall during fear-evoking activities, especially in conjunction with therapies that improve balance, mood and cognitive function.
Abstract: There is limited understanding of the underlying mechanisms explaining the role of concern about falling on fall risk in older people. Anxiety is known to interact with cognitive resources and, as people get older, they require more cognitive resources to maintain balance. This might affect an individual’s ability to perform cognitive-motor tasks concurrently. The aim of this study was to investigate the effect of a visuospatial dual-task on stepping performance in older people with and without concern about falling and the impact of repeating this task in those with high concern about falling. Three-hundred-eight community-dwelling older people, aged 70 to 90 years old, participated in the study. Participants were asked to perform a Choice Stepping Reaction Time (CSRT) task in two conditions; once without any other tasks (single task condition), and once while simultaneously performing a visuospatial task (dual-task condition). Participants were asked to rate their levels of concern and confidence specifically related to each of the 25 stepping trials (before/after). We also measured general concern about falling, affect, and sensorimotor and cognitive functioning. Total stepping reaction times increased when participants also performed the visuospatial task. The relation between general concern about falling and stepping reaction time, was affected by sensorimotor and executive functioning. Generalised linear mixed models showed that the group with moderate to high levels of general concern about falling had slower total stepping reaction times than those with lower levels of concern about falling, especially during the dual-task condition. Individuals with greater general concern about falling showed reduced confidence levels about whether they could do the stepping tasks under both conditions. Repeatedly performing the stepping task reduced the immediate task-specific concern about falling levels and increased confidence in all participants. These findings reveal that people with higher general concern about falling experienced more difficulties during a dual-task condition than people with lower levels of concern. Of further interest, better sensorimotor and cognitive functioning reduced this effect. Graded exposure has potential to reduce concern about falling during fear-evoking activities, especially in conjunction with therapies that improve balance, mood and cognitive function.