Longitudinal associations between falls and future risk of cognitive decline, the Motoric Cognitive Risk syndrome and dementia: the Einstein Ageing Study

Cognitive functioning and falls in older people: A systematic review and meta-analysis

OBJECTIVE

To identify which cognitive functions and specific neuropsychological assessments predict falls in older people living in the community.

METHODS

Five electronic databases were searched until 30/08/2022 for studies assessing the association between specific cognitive functions and faller status (prospective and retrospective), in community-dwelling older people. Risk of bias was assessed with the Newcastle-Ottawa Scale. Meta-analyses synthesised the evidence regarding the associations between different neurocognitive subdomains and faller status.

RESULTS

Thirty-eight studies (20 retrospective, 18 prospective) involving 37,101 participants were included. All but one study was rated high or medium quality. Meta-analyses were performed with data from 28 studies across 11 neurocognitive subdomains and four specific neuropsychological tests. Poor cognitive flexibility, processing speed, free recall, working memory and sustained attention were significantly associated with faller status, but poor verbal fluency, visual perception, recognition memory, visuo-constructional reasoning and language were not. The Trail Making Test B was found to have the strongest association with faller status.

CONCLUSION

Poor performance in neurocognitive subdomains spanning processing speed, attention, executive function and aspects of memory are associated with falls in older people, albeit with small effect sizes. The Trail Making Test, a free-to-use, simple assessment of processing speed and mental flexibility, is recommended as the cognitive screening test for fall risk in older people.

Risk factors associated with the Motoric Cognitive Risk syndrome: A meta-analysis of data from a cross-national study

BACKGROUND

Identifying risk factors associated with the Motoric Cognitive Risk (MCR) syndrome (a pre-dementia syndrome) can assist in developing risk reduction strategies and interventions to delay progression to dementia. Tailored interventions require comparisons of high- and middle-income countries to determine if the same or different risk factors should be targeted. We examined risk factors associated with MCR in seven Health and Retirement Studies with harmonized measures.

METHODS

Data from adults aged ≥65 years (n = 20,036, mean age 71.2(SD 6.2)-80.1(SD 4.1)) from the U.S. Health and Retirement Study, English Longitudinal Study of Aging, Survey of Health, Aging and Retirement in Europe, China Health and Retirement Longitudinal Study, Harmonized Diagnostic Assessment of Dementia for Longitudinal Aging Study in India, Mexican Health and Aging Study, and Brazilian Longitudinal Study of Aging was included. MCR was defined as the presence of cognitive complaints and slow gait (no mobility disability and dementia). Associations of demographic [education], medical [hypertension, diabetes, heart disease, obesity, stroke, Parkinson's, falls], psychological [depressive symptoms, psychiatric problems], sensorimotor [grip strength, hearing], and behavioral factors [smoking, sedentariness, sleep], with prevalent MCR were examined using age- and sex-adjusted logistic regression models. A meta-analysis was performed to compare risk factors for MCR in high- versus middle-income countries.

RESULTS

Except for depressive symptoms and weak grip strength, different risk factor clusters were associated with individual studies. Poor sleep, hearing, weak grip, and multiple falls emerged as novel associations with MCR. When grouped by income, some risk factors (i.e., education) were associated with MCR in high- and middle-income countries. Others (i.e., obesity) were specific to high-income countries.

CONCLUSIONS

This cross-sectional, cross-national study identified new, shared, and specific risk factors associated with MCR in high- and middle-income countries, providing insights to develop public health approaches and interventions to forestall the onset of dementia in those with MCR.

Relationship between falls, cognitive decline, and dementia in older adults: Insights from the Korean longitudinal study of aging, 2006-2020

Limited research has explored the relationship between falls, cognitive decline, and dementia onset in older adults with aging. Therefore, this study aimed to investigate the impact of cognitive function on the development of dementia and explore the association between falls and dementia among older adults. This study utilized data from the Korean Longitudinal Study of Aging, which tracked a sample group at 2-year intervals from the initial wave in 2006 to the eighth wave in 2020. Among the older adults (≥60 years) surveyed, 2829 were included in the analysis, and cognitive function and number of falls per year were recorded. We hypothesized that these variables were associated with dementia and tested the variables using dementia diagnosis data. The participants were assigned to either a dementia group (dementia diagnosis) or a control group (no dementia diagnosis). Analyses were performed to enhance generalizability of the hypothesis to all participants (≥45 years, n = 7130). Cognitive decline and dementia incidence increased with aging among older adults. The dementia group had a significantly higher rate of cognitive decline than the control group, as well as a higher number of falls and magnitude of annual changes in falls. The changes in falls were irregular regardless of cognitive function. Furthermore, falls were associated only with the development of dementia, not cognitive function. Similar trends were observed across the total participant group. Our findings highlight the importance of monitoring cognitive function and falls as potential markers for predicting dementia onset in older adults.

Perturbation-based dual task assessment in older adults with mild cognitive impairment

Background

Dual tasking (i.e., concurrent performance of motor and cognitive task) is significantly impaired in older adults with mild cognitive impairment (OAwMCI) compared to cognitively intact older adults (CIOA) and has been associated with increased fall risk. Dual task studies have primarily examined volitionally driven events, and the effects of mild cognitive impairment on reactive balance control (i.e., the ability to recover from unexpected balance threats) are unexplored. We examined the effect of cognitive tasks on reactive balance control in OAwMCI compared to CIOA.

Methods

Adults >55 years were included and completed the Montreal Cognitive Assessment (MoCA) to categorize them as OAwMCI (MoCA: 18-24, n = 15) or CIOA (MoCA: ≥25, n = 15). Both OAwMCI [MoCA: 22.4 (2.2), 65.4 (6.1) years, 3 females] and CIOA [MoCA: 28.4 (1.3), 68.2 (5.5) years, 10 females] responded to large magnitude stance slip-like perturbations alone (single task) and while performing perceptual cognitive tasks targeting the visuomotor domain (target and tracking game). In these tasks, participants rotated their head horizontally to control a motion mouse and catch a falling target (target game) or track a moving object (track). Margin of stability (MOS) and fall outcome (harness load cell >30% body weight) were used to quantify reactive balance control. Cognitive performance was determined using performance error (target) and sum of errors (tracking). A 3 × 2 repeated measures ANOVA examined the effect of group and task on MOS, and generalized estimating equations (GEE) model was used to determine changes in fall outcome between groups and tasks. 2 × 2 repeated measures ANOVAs examined the effect of group and task on cognitive performance.

Results

Compared to CIOA, OAwMCI exhibited significantly deteriorated MOS and greater number of falls during both single task and dual task (p < 0.05), and lower dual task tracking performance (p < 0.01). Compared to single task, both OAwMCI and CIOA exhibited significantly deteriorated perceptual cognitive performance during dual task (p < 0.05); however, no change in MOS or fall outcome between single task and dual task was observed.

Conclusion

Cognitive impairment may diminish the ability to compensate and provide attentional resources demanded by sensory systems to integrate perturbation specific information, resulting in deteriorated ability to recover balance control among OAwMCI.

Bidirectional association between falls and multimorbidity in middle-aged and elderly Chinese adults: a national longitudinal study

This study explores the bidirectional association between multimorbidity and falls in Chinese middle-aged and elderly adults. Participants aged 45 and above from the China Health and Retirement Longitudinal Study were included. Binary logistic regression assessed the impact of chronic conditions on fall incidence (stage I), while multinomial logistic regression examined the relationship between baseline falls and multimorbidity (stage II). The fully adjusted odds ratios (ORs) for one, two, or three or more chronic conditions were 1.34, 1.65, and 2.02, respectively. Among participants without baseline falls, 28.61% developed two or more chronic conditions during follow-up, compared to 37.4% of those with a history of falls. Fully adjusted ORs for one, two, or three or more chronic conditions in those with a history of falls were 1.21, 1.38 and 1.70, respectively. The bidirectional relationship held in sensitivity and subgroup analyses. A bidirectional relationship exists between multimorbidity and falls in Chinese middle-aged and elderly adults. Strengthening chronic condition screening and treatment in primary healthcare may reduce falls risk, and prioritizing fall prevention and intervention in daily life is recommended.

Attrition from longitudinal ageing studies and performance across domains of cognitive functioning: an individual participant data meta-analysis

OBJECTIVES

This paper examined the magnitude of differences in performance across domains of cognitive functioning between participants who attrited from studies and those who did not, using data from longitudinal ageing studies where multiple cognitive tests were administered.

DESIGN

Individual participant data meta-analysis.

PARTICIPANTS

Data are from 10 epidemiological longitudinal studies on ageing (total n=209 518) from several Western countries (UK, USA, Mexico, etc). Each study had multiple waves of data (range of 2-17 waves), with multiple cognitive tests administered at each wave (range of 4-17 tests). Only waves with cognitive tests and information on participant dropout at the immediate next wave for adults aged 50 years or older were used in the meta-analysis.

MEASURES

For each pair of consecutive study waves, we compared the difference in cognitive scores (Cohen's d) between participants who dropped out at the next study wave and those who remained. Note that our operationalisation of dropout was inclusive of all causes (eg, mortality). The proportion of participant dropout at each wave was also computed.

RESULTS

The average proportion of dropouts between consecutive study waves was 0.26 (0.18 to 0.34). People who attrited were found to have significantly lower levels of cognitive functioning in all domains (at the wave 2-3 years before attrition) compared with those who did not attrit, with small-to-medium effect sizes (overall d=0.37 (0.30 to 0.43)).

CONCLUSIONS

Older adults who attrited from longitudinal ageing studies had lower cognitive functioning (assessed at the timepoint before attrition) across all domains as compared with individuals who remained. Cognitive functioning differences may contribute to selection bias in longitudinal ageing studies, impeding accurate conclusions in developmental research. In addition, examining the functional capabilities of attriters may be valuable for determining whether attriters experience functional limitations requiring healthcare attention.

Blind Spots in Hospital Fall Prevention: Falls in Stroke Patients Occurred Not Only in Those at a High Risk of Falling

OBJECTIVES

Although the standard falls prevention strategy is to identify and respond to patients with high-risk conditions, it remains unclear whether falls in patients with high fall risk account for most observed falls. In this study, fall risk and number of falls were calculated based on patients' motor and cognitive abilities, and the relationship between the two was examined.

DESIGN

We conducted a retrospective cohort study.

SETTING AND PARTICIPANTS

We included 2518 consecutive patients with stroke who were admitted to a rehabilitation hospital.

METHODS

Data on falls during hospitalization and biweekly assessed Functional Independence Measure scores were retrieved from the medical records. The average Functional Independence Measure scores for the motor and cognitive items were obtained and categorized as complete dependence, modified dependence, and independence. The fall rate (falls/1000 person-days) and number of observed falls in each combined condition were investigated.

RESULTS

Modified dependence on motor ability and complete dependence on cognitive ability had the highest risk of falls, with a fall rate of 10.8/1000 person-days and 51 fall observations, which accounted for 4.3% of all falls. Independent motor and cognitive ability had the lowest risk of falls, a fall rate of 2.6/1000 person-days and 146 observed falls, accounting for 12.4% of all falls, which was 2.8 times higher than the number of falls observed in the highest risk of falls condition.

CONCLUSIONS AND IMPLICATIONS

The combined motor-cognitive ability with the highest risk of falls in stroke inpatients did not have the highest number of observed falls. Rather, the combined motor-cognitive ability with the lowest risk of falls tended to have a high number of observed falls. A different strategy is needed to reduce the total number of falls.

Quantitative analysis of balance function characteristics in older patients with mild to moderate cognitive impairment

BACKGROUND

Cognitive decline in older adults may affect balance function, but the relationship between the two is not fully understood, especially in the early stages of cognitive impairment. Mild to moderate cognitive impairment can be assessed with the Montreal Cognitive Assessment (MOCA).

AIM

This study quantitatively analyzed balance function in older adults with mild to moderate cognitive impairment using computerized dynamic posturography (CDP) testing.

METHODS

248 older patients were divided into a cognitive impaired group (MOCA <26, n = 126) and a normal group (MOCA ≥26, n = 122) based on the Montreal Cognitive Assessment (MOCA) Beijing Version. Patients underwent CDP testing, which included the sensory organization test (SOT) and the limits of stability test (LOS).

RESULTS

The cognitive impaired group had significantly lower SOT composite and visual scores, as well as reaction time (RT), movement velocity (MVL), endpoint excursion (EPE), maximum excursion (MXE), and directional control (DCL) of the LOS test. Binary logistic regression analysis revealed that RT and MXE were independent factors significantly associated with MOCA, even after adjustment for age and sex.

CONCLUSIONS

Older patients with mild to moderate cognitive impairment may have reduced sensory integration and balance stability limits, mainly manifested as prolonged motor reaction time and shortened maximum movement distance.

External Causes of Death From Death Certificates in Patients With Dementia

OBJECTIVES

We aim to analyze the risk of death from specific external causes, including falls, complications of medical and surgical care, unintentional injuries, and suicide, in dementia patients.

DESIGN

Swedish nationwide cohort study integrating 6 registers from May 1, 2007, through December 31, 2018, including the Swedish Registry for Cognitive/Dementia Disorders (SveDem).

SETTING AND PARTICIPANTS

Population-based study. Patients diagnosed with dementia from 2007 to 2018 and up to 4 controls matched on year of birth (±3 years), sex, and region of residence.

METHODS

The exposures of this study were diagnosis of dementia and dementia subtypes. Number of deaths and causes of mortality were obtained from death certificates compiled into the Cause of Death Register. Hazard ratios (HRs) and 95% CIs were estimated using Cox and flexible models, adjusted for sociodemographics, medical and psychiatric disorders.

RESULTS

The study population included 235,085 patients with dementia [96,760 men (41.2%); mean age 81.5 (SD 8.5) years] and 771,019 control participants [341,994 men (44.4%); mean age 79.9 (SD 8.6) years], over 3,721,687 person-years. Compared with control participants, patients with dementia presented increased risk for unintentional injuries (HR 3.30, 95% CI 3.19-3.40) and falls (HR 2.67, 95% CI 2.54-2.80) during old age (≥75 y), and suicide (HR 1.56, 95% CI 1.02-2.39) in middle age (<65 y). Suicide risk was 5.04 times higher (HR 6.04, 95% CI 4.22-8.66) in patients with both dementia and 2 or more psychiatric disorders relative to controls (incidence rate per person-years, 1.6 vs 0.3). For dementia subtypes, frontotemporal dementia had the highest risks of unintentional injuries (HR 4.28, 95% CI 2.80-6.52) and falls (HR 3.83, 95% CI 1.98-7.41), whereas subjects with mixed dementia were less likely to die from suicide (HR 0.11, 95% CI 0.03-0.46) and complications of medical and surgical care (HR 0.53, 95% CI 0.40-0.70) compared to controls.

CONCLUSIONS AND IMPLICATIONS

Suicide risk screening and psychiatric disorders management in early-onset dementia and early interventions for unintentional injuries and falls prevention in older dementia patients should be provided.

What Tools Can We Use to Screen for Fall Risk in Older Patients with Mild Cognitive Impairment? Findings from the MEMENTO Cohort

OBJECTIVES

Identifying risk factors for falls can improve outcomes in older patients without cognitive decline. Yet this has not been demonstrated in older people with mild cognitive impairment (MCI). We therefore sought to better identify risk factors for falls in this particular group.

DESIGN

The analysis was conducted on the MEMENTO cohort, which is a large, French, prospective cohort.

SETTING AND PARTICIPANTS

We included older people (>65 years old) with MCI (defined from neuropsychological scores) and a Short Physical Performance Battery (SPPB) score at baseline.

METHODS

Fallers were defined as participants having fallen at least once during the study's 2-year follow-up period. We compared clinical, neuropsychological, and biological data at baseline in fallers vs nonfallers. Additional analyses were performed on the following subgroups: women, men, people aged ≥75 years.

RESULTS

Of the 1416 people included in our study, 194 (13.5%) fell at least once. A bivariate analysis showed that fallers were older, predominantly women, less independent in activities of daily living, and more apathetic. Fallers performed less well in executive function, balance, and gait tests. In a multivariable analysis, only age, gender, the number of limitations in instrumental activities of daily living, and living alone were significantly associated with falls. In a multivariable analysis of the subgroup of oldest patients and of the subgroup of men, executive function was significantly worse in fallers than in nonfallers.

CONCLUSION AND IMPLICATIONS

Our results demonstrate that easily attainable risk factors can be used to identify individuals with MCI with a higher risk of falls and for whom prevention could be beneficial. Future studies are needed to further evaluate the role of mild executive dysfunction in certain subgroups, such as men and oldest patients.

Chronic pain increases the risk of motoric cognitive risk syndrome at 4 years of follow-up: evidence from the China Health and Retirement Longitudinal Study

BACKGROUND AND PURPOSE

Slower gait speed and subjective cognitive concerns are characteristics of the motoric cognitive risk (MCR) syndrome. This study aimed to examine if changes in pain may be hallmarks of early MCR, through investigating the magnitude of the association of chronic pain and the risk of MCR at 4 years follow-up.

METHODS

In total, 3711 participants without dementia or any mobility disability aged ≥60 years were studied, including 1413 with chronic pain, enrolled in the China Health and Retirement Longitudinal Study, a prospective cohort study. MCR assessed at wave 1 (2011) and wave 3 (2015) was used as the exposure. Cox regression analysis was used to examine the longitudinal association between chronic pain and MCR after adjusting for individual factors, behaviors/physiology factors and societal factors. Four years later, the incident MCR was evaluated.

RESULTS

After adjusting for individual factors, chronic pain was found to increase the risk of MCR development over time by about 1.5 times (hazard ratio 1.562, 95% confidence interval 1.228-1.986; p < 0.001) and to be linked with incident MCR at baseline (odds ratio 1.397, 95% confidence interval 1.149-1.698; p < 0.001). These associations remained substantial when behaviors/physiology factors and societal factors were taken into account in the analytical models.

CONCLUSIONS

The findings of our study imply that incident MCR may be exacerbated by chronic pain. Further exploration is required to find out whether chronic pain is a modifiable risk factor for MCR.

The Nebulous Association between Cognitive Impairment and Falls in Older Adults: A Systematic Review of the Literature

BACKGROUND

In older people, dementia is a well-established risk factor for falls. However, the association and the causal relationship between falls and the earlier stages of cognitive impairment remains unclear. The purpose of the study was to review the literature data on the association between falls and cognitive impairment, no dementia, including Mild Cognitive Impairment.

METHODS

According to PRISMA guidelines, we searched five electronic databases (EMBASE, Web of Science, Medline, CINAHL, and PsychINFO) for articles published between January 2011 and August 2022 on observational studies of older people with a cognitive assessment and/or cognitive impairment diagnosis and a recording of falls. Their quality was reviewed according to the STROBE checklist.

RESULTS

We selected 42 of the 4934 initially retrieved publications. In 24 retrospective studies, a statistically significant association between falls and cognitive status was found in only 15 of the 32 comparisons (47%). Of the 27 cross-sectional analyses in prospective studies, only eight (30%) were positive and significant. We counted four longitudinal analyses, half of which suggested a causal relationship between falls and cognitive impairment. The investigational methods varied markedly from one study to another.

CONCLUSION

It is still not clear whether falls are associated with cognitive impairment, no dementia. Data in favor of a causal relationship are scarce. Further studies are needed to clarify their relationship.

Longitudinal association between falls and motoric cognitive risk syndrome among community-dwelling older adults

The motoric cognitive risk (MCR) syndrome is a predementia syndrome associated with dementia and mortality risk. This longitudinal study aimed to investigated the longitudinal association between MCR and falls in older adults, including 3,720 participants in the China Health and Retirement Longitudinal Study. A total of 482 participants (13.0%) met the MCR requirements at baseline. There were 226 incident cases of MCR (13.0%) throughout follow-up (duration: 4 years). Controlling for microsystem factors, a single fall (OR: 2.412, 95 % CI: 1.100-5.290; p < .05) was associated with incident MCR at baseline and to almost 2.0 times (HR: 2.021, 95 % CI: 1.031-3.961; p < .05) more inclined to develop MCR over time, compared to those without falls. These associations remained significant when meso/ exosystem factors and macrosystem factors were included in the analytic models. Falls may be useful in predicting MCR risk in the near future among Chinese older adults.

Injurious falls before, during and after dementia diagnosis: a population-based study

BACKGROUND

the timing of incident injurious falls at different stages of dementia diagnosis is unclear.

OBJECTIVES

to identify when the occurrence of injurious falls begins to increase among individuals who are going to develop dementia, to explore the time point at which people living with dementia are at highest risk of injurious falls and to ascertain differences in fall-related factors pre- and post-dementia diagnosis.

DESIGN

this study included 2,707 participants with incident dementia and 2,707 1:1 matched (i.e. same birth year and sex) controls without dementia.

METHODS

dementia diagnosis and date of onset were identified from the National Patient Registry (NPR) and the Swedish Cause of Death Register following international criteria. Information on injurious falls and history of chronic disease was obtained from the NPR. Data were analysed using conditional Poisson regression and generalized estimating equation models.

RESULTS

compared with controls, the incidence of injurious falls among participants with dementia started to increase beginning 4 years pre-diagnosis (incidence rate ratio [IRR] 1.70, 95% confidence interval [CI] 1.30-2.22), reaching a peak (IRR 3.73, 95% CI 3.16-4.41) in the year of dementia diagnosis. Heavy drinking, physically active and cardiometabolic diseases (CMDs) were associated with incident falls among those with dementia.

CONCLUSION

people with dementia have a higher incidence of injurious falls beginning 4 years leading up to diagnosis and peaking during the year of diagnosis. Older age, female, heavy drinking, physically active and CMDs may predict injurious falls among people with dementia.

How to tackle the global challenge of falls?

Worldwide, falls and accompanying injuries are increasingly common, making their prevention and management a critical global challenge. The wealth of evidence to support interventions to prevent falls has recently (2022) been distilled in the first World Falls Guideline for Prevention and Management for Older Adults. The core of falls prevention includes (i) risk assessment and stratification; (ii) general recommendations on optimising physical function and mobility for all and (iii) offering a holistic, multidomain intervention to older adults at high risk of falls, in which the older adult's priorities, beliefs and resources are carefully considered. In recent decades, sustainable and adequately resourced falls prevention has proved challenging, although evidence suggests that suboptimal implementation of falls prevention is ineffective. Future research should focus on understanding the most successful approaches for implementation. To further optimise falls prevention, recent developments include technological innovation to identify and prevent falls, including exergaming. Further work is warranted to understand how to best incorporate the concepts of frailty and sarcopenia in falls prevention and management. This themed collection includes key articles in the field of falls prevention, covering several topics including risk factors, effective interventions, older adult's views, implementation issues and future perspectives.

Reward System Dysfunction and the Motoric-Cognitive Risk Syndrome in Older Persons

During aging, many physiological systems spontaneously change independent of the presence of chronic diseases. The reward system is not an exception and its dysfunction generally includes a reduction in dopamine and glutamate activities and the loss of neurons of the ventral tegmental area (VTA). These impairments are even more pronounced in older persons who have neurodegenerative diseases and/or are affected by cognitive and motoric frailty. All these changes may result in the occurrence of cognitive and motoric frailty and accelerated progression of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases. In particular, the loss of neurons in VTA may determine an acceleration of depressive symptoms and cognitive and motor frailty trajectory, producing an increased risk of disability and mortality. Thus, we hypothesize the existence of a loop between reward system dysfunction, depression, and neurodegenerative diseases in older persons. Longitudinal studies are needed to evaluate the determinant role of the reward system in the onset of motoric-cognitive risk syndrome.