The temporal precision of audiovisual integration is associated with longitudinal fall incidents but not sensorimotor fall risk in older adults.

Sustained multisensory integration over long inter-stimulus time delays is typically found in older adults, particularly those with a history of falls. However, the extent to which the temporal precision of audio-visual integration is associated with longitudinal fall or fall risk trajectories is unknown. A large sample of older adults (N = 2319) were grouped into longitudinal trajectories of self-reported fall incidents (i.e., decrease, stable, or increase in number) and, separately, their performance on a standard, objective measure of fall risk, Timed Up and Go (TUG; stable, moderate decline, severe decline). Multisensory integration was measured once as susceptibility to the Sound-Induced Flash Illusion (SIFI) across three stimulus onset asynchronies (SOAs): 70 ms, 150 ms and 230 ms. Older adults with an increasing fall number showed a significantly different pattern of performance on the SIFI than non-fallers, depending on age: For adults with increasing incidents of falls, those aged 53-59 years showed a much smaller difference in illusion susceptibility at 70 ms versus 150 ms than those aged 70 + years. In contrast, non-fallers showed a more comparable difference between these SOA conditions across age groups. There was no association between TUG performance trajectories and SIFI susceptibility. These findings suggests that a fall event is associated with distinct temporal patterns of multisensory integration in ageing and have implications for our understanding of the mechanisms underpinning brain health in older age.

Susceptibility to the sound-induced flash illusion is associated with gait speed in a large sample of middle-aged and older adults.

BACKGROUND: Multisensory integration is the ability to appropriately merge information from different senses for the purpose of perceiving and acting in the environment. During walking, information from multiple senses must be integrated appropriately to coordinate effective movements. We tested the association between a well characterised multisensory task, the Sound-Induced Flash Illusion (SIFI), and gait speed in 3255 participants from The Irish Longitudinal Study on Ageing. High susceptibility to this illusion at longer stimulus onset asynchronies characterises older adults, and has been associated with cognitive and functional impairments, therefore it should be associated with slower gait speed. METHOD: Gait was measured under three conditions; usual pace, cognitive dual tasking, and maximal walking speed. A separate logistic mixed effects regression model was run for 1) gait at usual pace, 2) change in gait speed for the cognitive dual tasking relative to usual pace and 3) change in maximal walking speed relative to usual pace. In all cases a binary response indicating a correct/incorrect response to each SIFI trial was the dependent variable. The model controlled for covariates including age, sex, education, vision and hearing abilities, Body Mass Index, and cognitive function. RESULTS: Slower gait was associated with more illusions, particularly at longer temporal intervals between the flash-beep pair and the second beep, indicating that those who integrated incongruent sensory inputs over longer intervals, also walked slower. The relative changes in gait speed for cognitive dual tasking and maximal walking speed were also significantly associated with SIFI at longer SOAs. CONCLUSIONS: These findings support growing evidence that mobility, susceptibility to falling and balance control are associated with multisensory processing in ageing.

Using Conditional Inference Forests to Examine Predictive Ability for Future Falls and Syncope in Older Adults: Results from The Irish Longitudinal Study on Ageing.

BACKGROUND: The extent to which gait and mobility measures predict falls relative to other risk factors is unclear. This study examined the predictive accuracy of over 70 baseline risk factors, including gait and mobility, for future falls and syncope using conditional inference forest models. METHODS: Data from 3 waves of The Irish Longitudinal Study on Ageing (TILDA), a population-based study of community-dwelling adults aged ≥50 years were used (n = 4 706). Outcome variables were recurrent falls, injurious falls, unexplained falls, and syncope occurring over 4-year follow-up. The predictive accuracy was calculated using 5-fold cross-validation; as there was a class imbalance, the algorithm was trained using undersampling of the larger class. Classification rate, the area under the receiver operating characteristic curve (AUROC), and area under the precision recall curve (PRAUC) assessed predictive accuracy. RESULTS: Highest overall accuracy was 69.7% for recurrent falls in 50-64-year olds. AUROC and PRAUC were ≤0.69 and ≤0.39, respectively, for all outcomes indicating low predictive accuracy. History of falls, unsteadiness while walking, fear of falling, mobility, medications, mental health, and cardiovascular health and function were the most important predictors for most outcomes. CONCLUSIONS: Conditional inference forest models using over 70 risk factors resulted in low predictive accuracy for future recurrent, injurious and unexplained falls, and syncope in community-dwelling adults. Gait and mobility impairments were important predictors of most outcomes but did not discriminate well between fallers and non-fallers. Results highlight the importance of multifactorial risk assessment and intervention and validate key modifiable risk factors for future falls and syncope.

Exploring bi-directional temporal associations between timed-up-and-go and cognitive domains in the Irish longitudinal study on ageing (TILDA).

INTRODUCTION: The bi-directional longitudinal associations between mobility and cognition in older adults are poorly understood. Our objective was to study the temporal associations between timed-up-and-go (TUG) and five cognitive function domains: global cognition, processing speed, verbal fluency, executive function, and sustained attention. METHODS: We designed two longitudinal samples: A (for cognition as predictor of mobility), and B (for mobility as predictor of cognition). To examine the associations between the five cognitive domains at wave 1 and change in TUG times up to wave 5 (eight years), five linear mixed-effect models were fitted. To examine the associations between TUG times at wave 1 and change in the five cognitive domains between waves 1 and 3 (four years), five linear-regression models were fitted. RESULTS: After removing participants with missing data, sample A numbered 4913 participants (mean age 62), and sample B 3675 (mean age 61). Baseline cognitive domains were all significant predictors of future change in TUG times. Baseline TUG time was also a significant predictor of future change in all five cognitive domains. In both cases, poorer performance at baseline predicted greater future loss of function. CONCLUSION: There was evidence of bi-directional temporal relationships between cognition and mobility. In both directions, the effect of the explanatory variable was small, though cognition as predictor of future mobility may have greater clinical relevance than vice versa. Our findings underscore the importance for clinicians of considering the bi-directional associations between cognition and mobility when observing subtle changes in either, especially as impairments emerge.

Impaired Stabilization of Orthostatic Cerebral Oxygenation Is Associated With Slower Gait Speed: Evidence From The Irish Longitudinal Study on Ageing.

BACKGROUND: Cerebral autoregulation (CAR) systems maintain blood flow to the brain across a wide range of blood pressures. Deficits in CAR have been linked to gait speed (GS) but previous studies had small sample sizes and used specialized equipment which impede clinical translation. The purpose of this work was to assess the association between GS and orthostatic cerebral oxygenation in a large, community-dwelling sample of older adults. METHOD: Data for this study came from the Irish Longitudinal Study on Ageing. A near-infrared spectroscopy (NIRS) device attached to the forehead of each participant (n = 2 708) was used to track tissue saturation index (TSI; the ratio of oxygenated to total hemoglobin) during standing. GS was assessed using a portable walkway. RESULTS: Recovery was impaired in slower GS participants with a TSI value at 20 seconds (after standing) of -0.55% (95% CI: -0.67, -0.42) below baseline in the slowest GS quartile versus -0.14% (95% CI: -0.25, -0.04) in the fastest quartile. Slower GS predicted a lower TSI throughout the 3-minute monitoring period. Results were not substantially altered by adjusting for orthostatic hypotension. Adjustment for clinical and demographic covariates attenuated the association between but differences remained between GS quartiles from 20 seconds to 3 minutes after standing. CONCLUSION: This study reported evidence for impaired recovery of orthostatic cerebral oxygenation depending on GS in community-dwelling older adults. Future work assessing NIRS as a clinical tool for monitoring the relationship between GS and cerebral regulation is warranted.

Translating Frailty Assessment Methodologies and Research-based Evidence to Clinical Education and Practice.

Frailty is a common clinical syndrome that predisposes older adults to an increased risk of adverse health outcomes. With population aging, this will become an increasing challenge for the healthcare services; therefore, different models of healthcare training and provision are required to address these increasing demands. In Ireland, the National Clinical Programme for Older People (NCPOP) has partnered with The Irish Longitudinal Study on Ageing (TILDA) to deliver the National Frailty Education Programme. This demonstrates an innovative way in which evidence-based longitudinal research can be translated into clinical education and practice to improve patient care, following a Knowledge to Action (KTA) process. To the authors' knowledge, it is the first time that a longitudinal research study such as TILDA has employed such methods of translation and therefore, this collaboration could serve as an international model of translation and implementation for frailty and other areas of clinical priority.

Is orthostatic hypotension and co-existing supine and seated hypertension associated with future falls in community-dwelling older adults? Results from The Irish Longitudinal Study on Ageing (TILDA).

Orthostatic hypotension (OH) often co-exists with hypertension. As increasing age affects baroreflex sensitivity, it loses its ability to reduce blood pressure when lying down. Therefore, supine hypertension may be an important indicator of baroreflex function. This study examines (i) the association between OH and future falls in community-dwelling older adults and (ii) if these associations persist in those with co-existing OH and baseline hypertension, measured supine and seated. Data from 1500 community-dwelling adults aged ≥65 years from The Irish Longitudinal Study on Ageing (TILDA) were used. Continuous beat-to-beat blood pressure was measured using digital photoplethysmography during an active stand procedure with OH defined as a drop in systolic blood pressure (SBP) ≥20 mmHg and/or ≥10 mm Hg in diastolic blood pressure (DBP) within 3 minutes of standing. OH at 40 seconds (OH40) was used as a marker of impaired early stabilisation and OH sustained over the second minute (sustained OH) was used to indicate a more persistent deficit, similar to traditional OH definitions. Seated and supine hypertension were defined as SBP ≥140 mm Hg or DBP ≥90 mm Hg. Modified Poisson models were used to estimate relative risk of falls (recurrent, injurious, unexplained) and syncope occurring over four year follow-up. OH40 was independently associated with recurrent (RR = 1.30, 95% CI = 1.02,1.65), injurious (RR = 1.43, 95% CI = 1.13,1.79) and unexplained falls (RR = 1.55, 95% CI = 1.13,2.13). Sustained OH was associated with injurious (RR = 1.55, 95% CI = 1.18,2.05) and unexplained falls (RR = 1.63, 95% CI = 1.06,2.50). OH and co-existing hypertension was associated with all falls outcomes but effect sizes were consistently larger with seated versus supine hypertension. OH, particularly when co-existing with hypertension, was independently associated with increased risk of future falls. Stronger effect sizes were observed with seated versus supine hypertension. This supports previous findings and highlights the importance of assessing orthostatic blood pressure behaviour in older adults at risk of falls and with hypertension. Observed associations may reflect underlying comorbidities, reduced cerebral perfusion or presence of white matter hyperintensities.

Comparison of Gait Speed Reserve, Usual Gait Speed, and Maximum Gait Speed of Adults Aged 50+ in Ireland Using Explainable Machine Learning.

Gait speed is a measure of general fitness. Changing from usual (UGS) to maximum (MGS) gait speed requires coordinated action of many body systems. Gait speed reserve (GSR) is defined as MGS-UGS. From a shortlist of 88 features across five categories including sociodemographic, cognitive, and physiological, we aimed to find and compare the sets of predictors that best describe UGS, MGS, and GSR. For this, we leveraged data from 3,925 adults aged 50+ from Wave 3 of The Irish Longitudinal Study on Ageing (TILDA). Features were selected by a histogram gradient boosting regression-based stepwise feature selection pipeline. Each model's feature importance and input-output relationships were explored using TreeExplainer from the Shapely Additive Explanations explainable machine learning package. The mean R a d j 2 (SD) from fivefold cross-validation on training data and the R a d j 2   score on test data were 0.38 (0.04) and 0.41 for UGS, 0.45 (0.04) and 0.46 for MGS, and 0.19 (0.02) and 0.21 for GSR. Each model selected features across all categories. Features common to all models were age, grip strength, chair stands time, mean motor reaction time, and height. Exclusive to UGS and MGS were educational attainment, fear of falling, Montreal cognitive assessment errors, and orthostatic intolerance. Exclusive to MGS and GSR were body mass index (BMI), and number of medications. No features were selected exclusively for UGS and GSR. Features unique to UGS were resting-state pulse interval, Center for Epidemiologic Studies Depression Scale (CESD) depression, sit-to-stand difference in diastolic blood pressure, and left visual acuity. Unique to MGS were standard deviation in sustained attention to response task times, resting-state heart rate, smoking status, total heartbeat power during paced breathing, and visual acuity. Unique to GSR were accuracy proportion in a sound-induced flash illusion test, Mini-mental State Examination errors, and number of cardiovascular conditions. No interactions were present in the GSR model. The four features that overall gave the most impactful interactions in the UGS and MGS models were age, chair stands time, grip strength, and BMI. These findings may help provide new insights into the multisystem predictors of gait speed and gait speed reserve in older adults and support a network physiology approach to their study.

Longitudinal Associations Between Gait, Falls, and Disability in Community-Dwelling Older Adults With Type II Diabetes Mellitus: Findings From The Irish Longitudinal Study on Ageing (TILDA).

BACKGROUND: Diabetes is associated with gait deficits, future falls, and disability; however, it is unclear if associations remain after controlling for relevant confounders. This study investigated (i) the effects of type II diabetes on spatiotemporal gait parameters in community-dwelling older adults and (ii) if diabetes status was independently associated with future falls and disability, after controlling for gait and other confounders. METHOD: Baseline data were obtained from 2608 community-dwelling adults (≥60 years) participating in The Irish Longitudinal Study on Ageing (TILDA). Diabetes was identified from self-reported doctors' diagnosis, medications, and glycated hemoglobin levels. Gait characteristics were obtained during single- and dual-task walking using a GAITRite mat (n = 2560). Incident falls and disability were collected over 4 years follow-up (n = 2473). Associations between diabetes status and gait (cross-sectional) and falls and disability (longitudinal) were investigated using regression analysis, adjusting for medications, cardiovascular health, neuropsychological function, and fall-related factors. RESULTS: Diabetes (prevalence = 9.1%) was cross-sectionally associated with shorter dual-task step length after adjusting for covariates (ß = -1.59, 95% CI: -3.10, -0.08, p < .05). Diabetes was independently associated with increased risk of future instrumental activity of daily living (IADL) difficulty in those with no prior difficulty (incidence rate ratio [IRR] = 1.51, 95% CI: 1.08, 2.11, p < .05) although dual-task step length was an important confounder in all disability models. No independent associations between diabetes and falls were observed. CONCLUSIONS: Diabetes was independently associated with shorter dual-task step length and increased risk of future IADL difficulty. Multidimensional interventions addressing poor health and function in those with diabetes may help reduce the risk of gait deficits and future disability.

Understanding the aetiology of fear of falling from the perspective of a fear-avoidance model - A narrative review.

Approximately half of older adults experience fear of falling (FoF) but the aetiology is unclear. The aim is to review the literature on physiological, mood and cognitive factors associated with FoF and to interpret these findings in the context of a fear-avoidance model that provides a causal framework for the development of FoF. There is growing evidence that the development of FoF is influenced by balance problems and falls, and emerging evidence for a role for cognitive factors, particularly attention and processing of sensory information. While there may also be a role for mood/temperament in the development of FoF, current evidence is weak. We argue that these factors co-exist and interact, which complicates assessment and design of the most appropriate intervention. The fear avoidance model offers a novel framework for explaining the mechanism of developing FoF and the discrepancy between experienced and perceived fall risk. This model specifically capitalizes on recent insights into fundamental learning mechanisms underlying emotion and fear. The proposed models provide hypotheses for future research and indications for improving efficacy of existing treatment programs.

What Is the Relationship Between Orthostatic Blood Pressure and Spatiotemporal Gait in Later Life?

BACKGROUND/OBJECTIVES: Little work to date has examined the relationship between gait performance and blood pressure (BP) recovery after standing in later life. The aim of this study is to clarify the association of orthostatic BP with spatiotemporal gait parameters in a large cohort of older people. DESIGN: Cross-sectional study using multilevel linear regression to ascertain the difference in orthostatic BP patterns across tertiles of gait speed, and linear regression to analyze the association of orthostatic hypotension 30 seconds after standing (OH-30) with specific gait characteristics. SETTING: The Irish Longitudinal Study on Ageing. PARTICIPANTS: A total of 4311 community-dwelling adults, aged 50 years or older (mean age = 62.2 years; 54% female), one fifth (n = 791) of whom had OH-30. MEASUREMENTS: Continuous orthostatic BP was measured during active stand. OH-30 was defined as a drop in systolic BP of 20 mm Hg or more or drop in diastolic BP of 10 mm Hg or more at 30 seconds. Spatiotemporal gait was assessed using the GAITRite system, reporting gait speed, step length, step width, and double support time in both single and dual (cognitive task) conditions. RESULTS: OH-30 was associated with slower gait speed (ß = -3.01; 95% confidence interval [CI] = -4.46 to -1.56) and shorter step length (ß = -.73; 95% CI = -1.29 to -.16) in fully adjusted models during single task walking. Similar findings were observed in dual task conditions, in addition to increased double support phase (ß = .45; 95% CI = .02-.88). Multilevel models demonstrated that participants in the slowest tertile for gait speed had a significantly larger drop in systolic BP poststanding compared to those with faster gait speeds in single and dual task conditions. CONCLUSIONS: This study demonstrates that slower recovery of BP after standing is independently associated with poorer gait performance in community-dwelling older adults. Given the adverse outcomes independently associated with OH and gait problems in later life, increasing awareness that they commonly coexist is important, particularly as both are potentially modifiable. J Am Geriatr Soc 68:1286-1292, 2020.

Association of Antidepressants With Recurrent, Injurious and Unexplained Falls is Not Explained by Reduced Gait Speed.

OBJECTIVE: To examine if antidepressants at baseline are associated with falls and syncope over 4 years follow-up and if any observed associations are explained by baseline gait speed. DESIGN: Longitudinal study (three waves). SETTING: The Irish Longitudinal Study on Ageing (TILDA), a nationally representative cohort study. PARTICIPANTS: Two thousand ninety-three community-dwelling adults aged ≥60 years. MEASUREMENTS: Antidepressants (ATC code "N06A") were identified. Recurrent falls (≥2 falls), injurious falls (requiring medical attention), unexplained falls, and syncope were reported at either Wave 2 or 3. Usual gait speed was the mean of two walks on a 4.88 m GAITRite walkway. Poisson regression analysis was used to examine associations between baseline antidepressant use and future falls adjusting for sociodemographics, physical, cognitive and mental health, and finally, gait speed. RESULTS: Compared to non-antidepressant users, those on antidepressants at baseline were more likely to report all types of falls (24.8-40.7% versus 9.8-18%) at follow-up. Antidepressants at baseline were independently associated with injurious falls (incidence risk ratio: 1.58, 95% confidence interval: 1.21, 2.06, z = 3.38, p = 0.001, df = 32) and unexplained falls (incidence risk ratio: 1.49, 95% confidence interval: 1.04, 2.15, z = 2.17, p = 0.030, df = 32) independent of all covariates including gait speed. CONCLUSION: There was little evidence to support the hypothesis that gait would (partly) explain any observed associations between baseline use of antidepressants and future falls. The underlying mechanisms of the observed relationships may be related to depression, vascular pathology, or direct effects of antidepressants. Clinicians should identify the best treatment option for an individual based on existing risk factors for outcomes such as falls.

Reliability, measurement error and minimum detectable change in mobility measures: a cohort study of community-dwelling adults aged 50 years and over in Ireland.

OBJECTIVE: To estimate the effects of repeat assessments, rater and time of day on mobility measures and to estimate their variation between and within participants in a population-based sample of Irish adults aged ≥50 years. DESIGN: Test-retest study in a population representative sample. SETTING: Academic health assessment centre of The Irish Longitudinal Study on Ageing (TILDA). PARTICIPANTS: 128 community-dwelling adults from the Survey for Health, Ageing and Retirement in Europe (SHARE) Ireland study who agreed to take part in the SHARE-Ireland/TILDA collaboration. INTERVENTIONS: Not applicable. OUTCOME MEASURES: Participants performed timed up-and-go (TUG), repeated chair stands (RCS) and walking speed tests administered by one of two raters. Repeat assessments were conducted 1-4 months later. Participants were randomised with respect to a change in time (morning, afternoon) and whether the rater was changed between assessments. Within and between-participant variance for each measure was estimated using mixed-effects models. Intraclass correlation (ICC), SE of measurement and minimum detectable change (MDC) were reported. RESULTS: Average performance did not vary between baseline and repeat assessments in any test, except RCS. The rater significantly affected performance on all tests except one, but time of day did not. Reliability varied from ICC=0.66 (RCS) to ICC=0.88 (usual gait speed). MDC was 2.08 s for TUG, 4.52 s for RCS and ranged from 19.49 to 34.73 cm/s for walking speed tests. There was no evidence for lower reliability of gait parameters with increasing time between assessments. CONCLUSIONS: Reliability varied for each test when measurements are obtained over 1-4 months with most variation due to rater effects. Usual and motor dual task gait speed demonstrated highest reliability.

Dental health status of community-dwelling adults aged 50 years and over in Ireland. A cross-sectional analysis of the Wave 3 TILDA cohort.

Background: Little is known about the current oral health status of adults in Ireland. The aim of this study was to assess the dental health of community-dwelling adults aged 50 years and over in Ireland and to compare the current status to previous national surveys.  Methods: The Irish Longitudinal Study on Ageing (TILDA) Wave 3 assessed the dental health of a subset of participants. Respondents attending for health assessments were offered a dental examination. The World Health Organization examination criteria were used. Results: Of the 3111 people who were offered the dental assessment, 2525 were examined. Adults below 50 years of age and respondents whose dental health data were unavailable at the time of analysis were omitted, giving a final sample of 2504.  Among the dental assessment sample, 9.9% (249) were edentate. Of those aged 65 years and older, 15.6% were edentate while for the same age group 40.9% were edentate in the 2000-02 national survey. The mean number of teeth present in those aged 65 years or older was 14.9 for males and 14.2 for females, whereas in 2000-02 it was 9.9 and 7.4, respectively.  56.8% of the dentate sample had 10 or more tooth contacts. The mean DMFT of those aged 50 years or more was 18.5 and the Root Caries Index was 6.3. Between 2000-02 and 2014-5 (this study) in adults aged 65 years and over, the mean DMFT decreased from 25.9 to 20.1 and the Root Caries Index decreased from 11.6 to 9.1. Conclusion: The results indicate improvements in the dental health of community-dwelling adults aged 50 years and over in Ireland as compared to the previous survey of 2000-02. These improvements mean a change in the treatment needs of this age group and will require policy and service adjustments to meet these needs.

Falls, non-accidental falls and syncope in community-dwelling adults aged 50 years and older: Implications for cardiovascular assessment.

OBJECTIVES: To calculate the prevalence of all falls, non-accidental falls and syncope in an older population and characterize cardiovascular risk profiles. DESIGN: Prospective, longitudinal cohort study. SETTING: The first two waves of data from the Irish Longitudinal Study on Ageing (TILDA). PARTICIPANTS: 8172 community-dwelling adults aged 50 years and older resident in the Republic of Ireland. MEASUREMENTS: Self-reported history of all falls, non-accidental falls and syncope in the year preceding the first two waves of data collection. Demographic factors and self-reported cardiovascular conditions were used to characterize cardiovascular risk profiles. RESULTS: The prevalence of all falls in the past year was 19.2% or 192 per thousand persons and increased with age (50-64 years 17.5%; 65-74 years 19.4%; 75+ years 24.4%). Non-accidental falls had an estimated prevalence of 5.1% or 51 falls per thousand persons and accounted for 26.5% of all falls reported and also increased with age (50-64 years 4.0%; 65-74 years 5.5%; 75+ years 8.0%). The prevalence for syncope was estimated to be 4.4% or 44per thousand persons but did not show a similar age gradient. Participants with at least 5 cardiovascular conditions were more likely to report all falls (OR = 2.07, 95% CI 1.18-3.64, p<0.05) and NAF (OR = 2.89, 95%CI 1.28-6.52, p<0.05). CONCLUSIONS: The prevalence of all falls and non-accidental falls increases with age but the same pattern was not consistently observed for syncope. There is an increased odds of reporting all three outcomes with increasing number of self-reported cardiovascular conditions. Further work is needed to uncover the interplay between cardiovascular disease and subsequent falls.

Self-Reported Unsteadiness Predicts Fear of Falling, Activity Restriction, Falls, and Disability.

OBJECTIVE: To determine if self-reported unsteadiness during walking is associated with fear of falling (FOF), fear-related activity restriction, falls, and disability over 2 years in community-dwelling adults. DESIGN: Data were obtained from the first 2 waves of The Irish Longitudinal Study on Ageing, a population-based study. SETTING: Participants completed a home-based interview and a center-based health assessment at baseline and a home-based interview at 2 years follow-up. PARTICIPANTS: Community-dwelling adults aged ≥65 years, with Mini-Mental State Examination score ≥18 at baseline, and fully observed variables were included in the analyses (N = 1621). MEASUREMENTS: Outcome variables were FOF, fear-related activity restriction, recurrent falls, and disability. RESULTS: Unsteadiness was independently associated with an increased risk of all outcomes at follow-up after adjusting for sociodemographic variables, and physical, mental, and cognitive health (Incidence Rate Ratio [IRR] range 1.49-2.29; P < .05). All associations were attenuated after adjusting for usual gait speed but remained consistent in direction. The association was strongest for fear-related activity restriction [IRR = 1.82 (1.21-2.73); P < .01]. There was also evidence of an association between unsteadiness and an increased risk of activity restriction in adults who did not report FOF at baseline [IRR = 1.99 (1.10-3.61); P < .05]. CONCLUSIONS: Self-reported unsteadiness is independently associated with an increased risk of FOF, fear-related activity restriction, recurrent falls, and disability at follow-up. Self-reported balance/steadiness should be included in routine assessment of older adults especially those at risk of falls. As unsteadiness is modifiable, older adults should be targeted for balance-related training or medication review to minimize future risk of these outcomes.

Usual and Dual-Task Walking Speed: Implications for Pedestrians Crossing the Road.

OBJECTIVE: In many countries, pedestrian light crossings require a minimum walking speed of 1.2 m/s. This study examined the proportion of adults in a nationally representative sample whose usual and dual-task walking speeds are <1.2 m/s. METHOD: Community-dwelling adults aged ≥50 years in The Irish Longitudinal Study on Ageing (TILDA) completed walking speed tests on a GAITRite® walkway (N = 4,909). RESULTS: One third of Irish adults aged 65 to 74 years and 61% of adults aged ≥75 years walked slower than 1.2 m/s. In dual-task walking, 54% of adults aged <65 years and 91% of adults aged ≥75 years walked slower than 1.2 m/s. DISCUSSION: Based on these data, many older people would have insufficient time to cross the road at light-controlled pedestrian crossings. Increasing the time provided would be an advantage for many older pedestrians.

Antidepressants are independently associated with gait deficits in single and dual task conditions.

OBJECTIVES: This study examined the relationships between late-onset depressive symptoms, antidepressants, and single and dual task gait in older adults. DESIGN: Cross-sectional study. SETTING: The Irish Longitudinal Study on Ageing (TILDA), a nationally representative cohort study. PARTICIPANTS: Community-dwelling adults aged 60 years and older, with Mini-Mental State Examination score ≥24, no history of Parkinson's disease or early onset depression, and unaided completion of a gait assessment (N = 1,998). This study compared participants with and without potentially clinically relevant depressive symptoms (i.e., ≥16 on the Centre for Epidemiological Studies Depression scale) and participants who were and were not on antidepressant therapy. MEASUREMENTS: Gait measures were obtained during single and dual task (reciting alternate letters of alphabet, A-C-E) walking using a 4.88 m GAITRite walkway. Regression analysis was used to examine the associations between each group and gait adjusting for sociodemographics and health. RESULTS: In the unadjusted models, depressive symptoms and antidepressant use were associated with gait deficits. After adjusting for covariates, antidepressant use was associated with reduced gait speed and stride length in single and dual task walking; depressive symptoms were not associated with any deficits. CONCLUSIONS: As gait impairments are associated with an increased risk of adverse outcomes including falls, clinicians should be aware of the impact of antidepressants on gait in older adults. Subsequent to this, interventions aimed at improving physical function, which is a known precursor to falls and functional disability, should be recommended.

Atrial fibrillation is associated with impaired mobility in community-dwelling older adults.

OBJECTIVES: To examine the independent associations between atrial fibrillation (AF) and objectively measured mobility in a nationally representative cohort. DESIGN: Wave 1 of The Irish Longitudinal Study on Ageing (TILDA), a population-based study assessing health, economic, and social aspects of ageing. SETTING: Community-dwelling adults completed a home-based interview and a center-based health assessment. PARTICIPANTS: Participants aged 50 years or older, with Mini-Mental State Examination score of 24 or higher, and who completed at least 1 mobility test (n = 4525). MEASUREMENTS: Mobility was assessed with the Timed Up-and-Go (TUG) test and usual and dual task gait speed obtained using a 4.88-m GAITRite® mat. AF was diagnosed using a 10-minute surface electrocardiogram recording. Linear regression analyses were performed to compare mobility in participants with and without AF, adjusting for confounders. RESULTS: In this sample (mean age 62.3 years; range 51-89), overall prevalence of AF was 3.1%, increasing to 6.7% in the over 70s (11.8% men; 2.8% women). In multivariate analysis, AF was independently associated with slower TUG (ß 0.37; 95% confidence interval [CI] 0.07-0.71; P = .043) and slower usual gait speed (ß -3.59; 95% CI -7.05 to -0.12; P = .030). There was a significant age*AF interaction effect for usual gait speed (ß -0.480, 95% CI -0.907 to -0.053, P = .028). Adults with AF walked 3.77 cm/s more slowly than adults without AF at age 70, declining by 4.8 cm/s for each additional decade. CONCLUSION: AF is independently associated with lower usual gait speed in community-dwelling adults and this effect is magnified in those aged 70 and older. This may place them at increased risk of falls, hospitalization, cognitive decline, and mortality, as well as stroke and heart failure. Early recognition and treatment of AF is vital to improve physical function and reduce this risk.