April 2021

Falls in People with Multiple Sclerosis, Part II: Risk Identification, Intervention, and Future Directions

By Susan Coote, PhD; Laura Comber, PhD; Gillian Quinn, PhD; Carme Santoyo-Medina, MSc; Alon Kalron, PhD, PT; Hilary Gunn, PhD

Falls are highly prevalent in people with multiple sclerosis (MS) and result in a range of negative consequences, such as injury, activity curtailment, reduced quality of life, and increased need for care and time off work. This narrative review aims to summarize key literature and to discuss future work needed in the area of fall prevention for people with MS. The incidence of falls in people with MS is estimated to be more than 50%, similar to that in adults older than 80 years. The consequences of falls are considerable because rate of injury is high, and fear of falling and low self-efficacy are significant problems that lead to activity curtailment. A wide range of physiological, personal, and environmental factors have been highlighted as potential risk factors and predictors of falls. Falls are individual and multifactorial, and, hence, approaches to interventions will likely need to adopt a multifactorial approach. However, the literature to date has largely focused on exercise-based interventions, with newer, more comprehensive interventions that use both education and exercise showing promising results. Several gaps in knowledge of falls in MS remain, in particular the lack of standardized definitions and outcome measures, to enable data pooling and comparison. Moving forward, the involvement of people with MS in the design and evaluation of programs is essential, as are approaches to intervention development that consider implementation from the outset. Int J MS Care. 2020;22:247-255.

The incidence of falls in people with multiple sclerosis (MS) is high, and the consequences of falls are far-reaching for both the person and the health care system. This important topic has received increasing attention as researchers and health care profes­sionals aim to identify the risk factors, context, and con­sequences and to use these data to develop theory-based interventions. This narrative review and position paper is written by members of the Special Interest Group on Mobility of Rehabilitation in Multiple Sclerosis (RIMS, the European network for best practice and research in MS) and aims to summarize the key literature in the area and to identify gaps in knowledge, challenges, and ways forward. Part I covered the Incidence of Falls, Consequences of Falls, Factors Associated with and Predictive of Falls, and Conclusion and Way Forward.

Treatment

Given the complexity in causes and risk factors of falls in MS, a multifactorial approach seems to be the most appropriate strategy; however, much research to date considers exercise only. Two systematic reviews of interventions to reduce falls exist. Sosnoff and Sung identified ten studies, four of which were randomized controlled trials (RCTs) with a total of 524 participants. The increased focus on this topic resulted in 13 RCTs being included in a recently published Cochrane review. In contrast, a systematic review of exercise interventions for fall prevention in older adults included 108 RCTs with 23,407 participants living in the community in 25 countries. Most MS studies with exercise interventions included conventional balance, sensory-specific, and game-based exercises. Most trials demonstrated a reduction in actual falls and/or fall risk, most often with a concurrent improvement in balance and/or mobility. Despite these encouraging findings, firm conclusions could not be drawn due to the heterogeneity in study designs, small sample sizes, lack of assessor blinding, and limited use of prospective fall monitoring. The review authors highlight the need for additional knowledge regarding risk factors for falls in people with MS and suggest implementation of targeted multifactorial interventions examining both physiological and behavioral risk, as advocated by the International MS Falls Prevention Research Network (IMSFPRN).

A related review concerning interventions to improve balance in people with MS found that specificity is important (ie, balance and functional exercises had the largest effect on balance) and that dose of intervention is related to outcome. Sherrington et al suggest that more than 50 hours of intervention is required to improve balance, yet, to our knowledge, no study in the MS field has examined an intervention program at this dose. The literature about older adults consistently finds that exercise interventions, although effective, are more impactful as part of multiple-component or multifactorial interventions.

Unfortunately, the strong evidence for multifactorial and multiple-component interventions in older fallers are sparsely replicated in MS. To date, only four multifactorial interventions have been published in MS. Hugos et al performed a retrospective evaluation of an existing exercise and education program for fall prevention in people with MS using the Free from Falls program for older adults with adaptations made for MS-specific symptoms such as fatigue. However, the retrospective nature of the study and the lack of a control group necessitates caution when interpreting these findings, which were a reduction in fall rates and improved balance performance and confidence. Sosnoff et al evaluated a multifactorial approach based on the Safe at Home BAASE program. Their pilot RCT of 34 participants compared four groups: waitlist control, home exercise alone, education targeting behavioral risk, and a combination of home exercise and education. The authors found a reduction in risk of falls for the groups engaged in an exercise component, although with mixed findings for the combined exercise and education arms. Limitations included underpowered sample size and lack of prospective fall monitoring before the intervention. Thus, further research examining multicomponent fall prevention interventions for people with MS is needed.

Exercise interventions, although effective, are more impactful as part of multiple-component or multifactorial interventions

Interventions addressing personal and environmental factors associated with falls are lacking. For example, fear of falling and fall risk are not only associated with falls but are independent fall risk factors, yet to date have had limited attention in interventions. The strong evidence from the older adult literature and our increasing understanding of the role of psychological and environmental aspects of falls in MS suggests that future interventions should address both aspects and be tailored to the individual risk factors and physiological/psychological profile. Therefore, we encourage future trials to investigate the efficacy of adding supportive features (eg, grab bars or handrails) in locations such as stairs and bathrooms in homes of people with MS. In addition, future research should examine the impact of fall prevention programs that include education around the use and training of walking aids or increasing awareness of the outdoor environment and situations that might lead to falls. Other environmental harm-minimization elements, such as fall monitoring devices or pressure sensors, also have not been addressed to date. Another element is that of harm minimization through fracture prevention via routine preventive bone density assessment and intervention to improve bone loss if it presents.

Recent studies have investigated the views and opinions of persons with MS in relation to what they would consider the optimal fall prevention program, highlighting their preference for practical, personalized interventions with peer interaction and ongoing support (either in groups or by other media). Balance/strength exercises and fall prevention/management techniques, as well as services regarding mobility aids and home modification from trained professionals (eg, occupational therapists and physiotherapists), might be included. Something remarkable is that people with MS recognize that personal factors, such as the competence of knowing and accepting their capacity to engage in activities, are crucial in preventing falls.

Gaps in Knowledge

To increase our understanding of falls in people with MS and, hence, their treatment, there are several gaps in knowledge that require attention. Balance impairment is associated with and predictive of falls, but our understanding of what particular postural control deficits are associated with falls is limited. Determining what postural control deficit or what element of balance (eg, proprioceptive deficits, reduced strength, cognitive motor interference, or reaction time) is most associated with falls will allow more targeted and tailored approaches and could potentially increase the efficacy of exercise interventions.

In addition, our understanding of the protective versus predictive nature of these deficits and their contribution to falls is limited. For example, if an individual walks at a slower gait speed with a wider base of support, this may be a compensatory mechanism to increase stability. Therefore, attempts to normalize this pattern of gait, such as increasing speed, may be inherently disadvantageous to reducing fall risk. Similarly, if imbalance occurs due to fast walking speed, a reduction in gait speed may be seen as a positive outcome of intervention. Longitudinal observational studies of clinical measures and posturography should be implemented, with fall incidence assessed prospectively before and after assessment. Such investigations may enable more targeted rehabilitation strategies for fall prevention in people with MS.

An associated issue is the choice of balance measures used to establish fall risk. For example, people with MS fall while standing, turning, and walking, yet many balance measures capture balance with feet in a static position. Posturography seems promising as a fall risk tool, but the static foot plate does not mirror the dynamic activities where falls occur, and access to this in many clinics is limited, with some systems requiring technical expertise. The use of sensor-based measures of balance during gait may be an option worth pursing because it would allow the collection of ecologically valid postural control data, potentially in remote settings.

When conducting studies to evaluate multiple component risk prediction tools, the model first needs to be developed, and it subsequently needs to be validated; none of the existing MS fall risk prediction tools have been validated to date. The model development study often tends to overestimate predictive ability of a model, either due to overfitting if the sample size is small or if there are too few outcome events relative to the number of predictor variables. External validation applies the model and assesses its predictive performance for a new sample who were not involved in the model development study. Model impact studies are recommended after external validation to assess the effect on the change in behavior of clinicians, on cost-effectiveness, and on health outcomes. In addition to including analysis of the traditional predictive values (eg, sensitivity, specificity, area under the curve), impact studies must also consider safety and efficiency.

Determining what postural control deficit or what element of balance is most associated with falls will allow more targeted and tailored approaches

Arguably fall prevention interventions for people with MS are in their infancy, although the start is promising. One concern is the mismatch between the range of physiological and psychological risk factors and the predominance to date of exercise-only interventions; however, more recent interventions are acknowledging this and evaluate multiple-component and multifactorial interventions. Intervention development is complex, and for this multifactorial, variable, and individualized problem, the challenges will be many. Frameworks such as the Medical Research Council (MRC) development of complex interventions may assist with this challenging process. An additional consideration as this field progresses is the need to articulate the theory behind the interventions, an aspect of intervention development for which the rehabilitation field has previously been criticized. It is essential that transparent dissemination of the development processes behind complex interventions occurs and that theoretical underpinnings and mechanisms of intended action are clearly articulated so that the intervention is developed in line with best practice.

It is likely that a range of interventions considering either group or individual treatment, using face-to-face or remote methods and in-hospital, outpatient, and community settings, and with a range of international health care and social contexts will be needed; one size certainly will not fit all for the issue of falls in MS.

Challenges

One key challenge in pooling and comparing data is the lack of standardization of fall definitions, faller classifications, and fall outcomes to date. The use of frameworks such as Core Outcome Measures in Effectiveness Trials (COMET) to develop and apply core outcome sets for MS fall interventions is recommended to overcome the current issue of multiple definitions, classifications, and outcomes. Most concerning is the limited input to date from people with MS in deciding study outcomes, which requires attention in future work.

The issue of “dose” of intervention required to improve postural control is a challenge, and a fine balance between the optimal dose/duration and the practicalities involved in engaging with and delivering such a program needs to be considered. Evidence from a range of groups highlights sustained engagement as a major challenge to fall prevention interventions and suggests that programs need to be easy to access, perform, and embed into a person’s daily life for initial improvements to be sustained. There are also significant resource implications in the provision of such interventions that may challenge existing models of health care. Supplementing face-to-face delivery with the provision of Web-based resources or telephone or e-mail contact to support engagement seems promising, as do programs that embed a supported self-management approach.

Perhaps the greatest challenge in reducing fall risk and, hence, falls is variability. Presentations and symptoms of MS (and thus fall risk factors) vary significantly between people and over time, which necessitates flexible intervention programs that can be individually targeted and that support people to be able to self-assess their changing symptoms and adjust their programs effectively on an ongoing basis. Additional variability in personal, environmental, and social factors means that programs need to be adaptable and responsive to needs and circumstances. Such programs require input from highly trained clinicians who are supported to use a wide range of skills and present feasibility and sustainability issues for many models of health care delivery. For researchers, this degree of variability is also a significant challenge, particularly in achieving a high degree of flexibility in program provision while maintaining the degree of standardization and intervention fidelity necessary to ensure methodological rigor in clinical trials. Collaboration, nationally and internationally, will be vital for recruiting sufficient numbers of people to undertake the large-scale studies that are essential to develop a robust evidence base, although the variety of health care settings internationally adds another challenge.

Practice Points

  • Falls are prevalent in people with MS and have significant negative consequences. Clinicians should ask about falls at all stages of the condition and refer for appropriate interventions in a timely manner.
  • Falls are multifactorial and complex, and there are many, varied risk factors. The most reliable predictor of future falls is a history of falls.
  • Interventions should target physiological risk factors (eg, balance and strength impairments), personal risk factors (eg, fear of falling, matching physical ability to the task) and environmental risk factors (eg, use of appropriate assistive devices).

The introduction of wearable electronic technology, worn on the body or embedded into mobile and portable solutions (smartphones, watches, etc.), creates a new challenge for those investigating falls in people with MS. Although the potential of these devices to identify risk factors for falls is clear, their benefits are still to be verified. Importantly, these devices enable the research field to detect movement behavior of people with MS outside the laboratory and/or clinical facilities. This opportunity might uncover new “real-life” risk factors that were not previously considered.

Conclusion and Way Forward

It is probable that we cannot prevent all falls; however, our aim should be to prevent as many falls as possible. Falls that require medical attention are particularly burdensome for both the person and the health care system and might be prioritized; however, even minor falls may have a profound effect on well-being and on activity participation and, therefore, warrant intervention to prevent them.

Falls are common and have a wide range of negative effects. Research to date suggests that there are a variety of physiological, personal, and environmental factors that contribute to falls for people with MS; a better understanding of these factors will lead to improved risk prediction tools and interventions for this cohort. Interventions to date have largely comprised exercise-only interventions; these show promise and suggest that challenging, functional balance programs targeting individual risk factors, which are structured to support people to engage at a high intensity over a long duration, are most likely to be effective. However, large-scale effectiveness trials are urgently required to determine the key components that should form the basis of MS fall exercise interventions, regardless of delivery method or health care setting.

Given the range of issues contributing to falls in MS, future interventions should consider other aspects of fall risk, particularly the psychological and MS-specific risk factors. This also necessitates a recognition that not all risk factors will be modifiable and that people will often choose to accept a degree of risk to maintain their participation in daily activities. Alongside assessing and optimizing modifiable individual fall risk factors, programs need to support people to develop effective, realistic strategies to manage fall risk while maintaining engagement; to recognize when changes to their strategies are required; and to access further support as necessary. As in other groups, perhaps the focus of programs should move away from emphasizing fall reduction and instead move toward approaches that aim to maximize “safe mobility.”

The way forward is undoubtedly through collaboration: nationally, internationally, across disciplines, and with people with MS. A better understanding of this complex, individual, and multifactorial issue will assist in designing, evaluating, and implementing interventions to prevent or reduce falls for people with MS.


Editor’s Note: Part I of this series appeared in our March 2021 issue, page 37. Part II picks up with Treatment, Gaps in Knowledge, and Challenges. This 2-part series appears with permission from the Consortium of Multiple Sclerosis Centers; references have been deleted for brevity, but can be found with the original article at the URL below. The original article, “Falls in People with Multiple Sclerosis: Risk Identification, Intervention, and Future Directions,” by the same authors, appeared in the International Journal of MS Care. 2020;22:247-255, available at https://meridian.allenpress.com/ijmsc/article/22/6/247/443994/Falls-in-People-with-Multiple-SclerosisRisk.

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