Impact of mobility impairment on the burden of caregiving in individuals with multiple sclerosis

Abstract

Multiple sclerosis (MS) is a chronic, immune-mediated neurologic disease that typically strikes young adults during their most productive years, and is associated with a wide range of functional deficits and progressive disability. Loss of mobility is among the most disabling effects of MS, adversely affecting multiple outcomes, including independence, employment and quality of life. Relative to other common diseases, MS is associated with a disproportionately high socioeconomic burden. Informal and unpaid caregivers, such as family and friends, play a vital, sustained and often difficult role in supporting the ability of MS patients to live and function at home. However, there are few data characterizing caregiver burden in MS. This review was conducted to examine the need and impact of caregiving for patients with MS, focusing on the contribution of mobility impairment to loss of patient independence.

Keywords::

• caregiver burden
• costs of care
• difficulty walking
• healthcare expenditures
• mobility impairment
• multiple sclerosis
• quality of life

Figure 1. Relationships among patient perceptions and themes related to mobility and its loss in individuals with multiple sclerosis.

MS: Multiple sclerosis.

Reprinted with permission from [6].

Figure 2. Path analysis for evaluating the relationship of overall symptoms of multiple sclerosis, and the specific symptoms of depression, pain, fatigue and difficulty walking, to physical activity.

Coefficients are standardized estimates; solid lines are statistically significant, dashed lines are nonsignificant. Outcomes were evaluated using the following instruments: symptoms, Multiple Sclerosis Symptom Inventory; pain, short-form McGill Pain Questionnaire; depression, Center for Epidemiological Studies Depression Scale; fatigue, Fatigue Severity Scale; walking, 12-item Multiple Sclerosis Walking Scale; physical activity, Godin Leisure-Time Exercise Questionnaire.

Reprinted with permission from [21].

Figure 3. Factors (variables) contributing to caregiver burden and health.

Reprinted with permission from [31].

Figure 4. Proportion of patients with multiple sclerosis (n = 345) and their caregivers (n = 345) reporting ‘no care required’ on three domains of activities of daily living.

Data from [7].

Multiple sclerosis (MS) is a chronic, immune-mediated neurologic disease that often results in progressive disability. Its pathophysiology involves inflammatory demyelination and degeneration of axons within the CNS, resulting in impaired signal conduction [1–3]. The disease course is frequently characterized by periods of relapse followed by remission, and neurologic deficits accumulate over time, contributing to the progressive disability [4]. Clinically, MS is characterized by a variety of impairments that may include vision problems, difficulty walking, weakness, imbalance, sensory loss, pain, cognitive changes, depression, spasticity, and bladder or bowel dysfunction.

Loss of mobility is one of the most visible and disabling effects of MS. Mobility is defined by the International Classification of Functioning, Disability, and Health (ICF) as “…moving by changing body position or location or by transferring from one place to another, by carrying, moving or manipulating objects, by walking, running or climbing, and by using various forms of transportation” [101]. Walking is the physical manifestation of locomotion. Difficulty walking is the primary factor contributing to loss of mobility in MS. Included within the ICF definition of mobility is the use of assistive devices for walking and other mechanical aids such as wheelchairs, which are frequently required by individuals with MS because of impaired walking ability [101].

Estimates from a longitudinal study suggest that by 15 years after diagnosis, patients face an approximate 40% probability of the need for some form of walking assistance and a 25% probability for use of a wheelchair [5]. From the individual’s perspective, the impact of loss of mobility is complex, affecting a variety of outcomes such as independence, employment, mental health and quality of life (QOL), and, ultimately, the interdependence of these factors (Figure 1)[6]. Patients also state that specific processes and considerations for their future must be addressed to accommodate anticipated losses and the resulting burden on their caregivers.

With greater loss of mobility, the ability to perform activities of daily living (ADL) decreases and dependence upon the assistance of others increases [7,8]. This assistance, in the form of caregiving on an intermittent or regular basis, is most often performed by informal caregivers who are family members, friends or neighbors. The caregivers themselves are often faced with significant social, physical, psychological and economic burdens. The ultimate goal for individuals with MS and their caregivers is to use medical care, therapy and in-home caregiving to prolong the period of time before the patient is in need of institutionalization [6].

Relative to other prevalent disease states, MS is associated with a disproportionately high socioeconomic burden, which in the USA has been estimated at a lifetime cost in excess of US$2 million per individual [9]. Although increased costs are associated with greater disability [10–15], the high socioeconomic burden of MS is primarily caused by the fact that disease onset occurs during the most productive years of life, generally within the third or fourth decade, and the approximately normal life expectancy of an individual with MS [4,16,17].

The economic burden of MS has been consistently reported to be driven by nonmedical costs, comprised of direct costs such as assistive aids, home adaptations, and formal or informal care; as well as indirect costs, especially those related to lost productivity [9,10,12–15]. Health-related quality of life (HR-QOL), a concept that describes the impact on QOL of an illness and its treatment from the patient’s perspective, is substantially reduced in individuals with MS relative to the general population and to those with other chronic disorders [18,19]. Although HR-QOL is generally considered an ‘intangible cost’ because of the difficulty in determining its monetary value, reduced HR-QOL in individuals with MS has been shown to contribute to the economic burden by increasing the total disease-related costs [12,20]. It may also be proposed that the presence of specific impairments including loss of mobility, as well as symptoms such as fatigue, spasticity and pain increase the overall socioeconomic burden, not only through an increased need for healthcare resource utilization [16,17], but through their impact on reducing HR-QOL [18,19].

The purpose of this article is to review and discuss the burden of caregiving for individuals with MS as it relates to decreased mobility, and the associated implications for managed care professionals and decision-makers. The article considers the burden of caregiving for individuals with MS to be defined as the social, psychological or economic impact placed on the patient by the need for care. Although the primary focus is on the patient burden and the role that loss of independence as a result of mobility impairment contributes to this burden, it is necessary to review the burden to caregivers, since this burden may also be important from the managed care perspective. Although not an exhaustive systematic search, available references were searched in PubMed from January 1980 through January 2009. Articles were identified from the literature based on searches using ‘multiple sclerosis’ in combination with the terms ‘caregiving’, or ‘caregiver’. The relevancy of articles for inclusion was determined based on their evaluation of mobility-related issues as a factor in patient independence and the need for caregiving, or a discussion of the burden of caregiving from the patient’s or caregiver’s perspective. Abstracts of returned citations were reviewed for relevancy based on whether caregiving was specifically mentioned as part of the evaluation, in which case the full article was obtained to determine appropriateness for inclusion in the review. Reference lists of included articles were additionally hand-searched for potential studies that may have been missed in the original search.

Disability, dependence & the need for care

Disease progression in people with MS includes both physical and cognitive deficits, resulting in impairments and disabilities that affect a variety of outcomes related to maintaining independence, such as walking and mobility. Using path analysis, a statistical method for evaluating the strength of causal relationships, Motl et al. showed a direct inverse relationship between difficulty walking and physical activity (β = -0.23) [21]. As illustrated in Figure 2, while overall symptom intensity had significant direct (γ = -0.34) and indirect effects on physical activity, the indirect effects of overall symptoms were mediated through walking impairment.

The importance of mobility to independence was also suggested in an interview study by Finlayson et al. of 27 older adults (age range: 55–81 years), some of whom had impaired mobility at baseline [22]. Further losses of mobility and independence were the primary fears and concerns among this cohort of interviewees. These concerns were of primary importance regardless of the individual’s status with respect to current disability, mobility impairment or independence.

Consistent with these findings suggesting the relationship of mobility to physical independence, mobility was rated as the most important of the eight domains that comprise the Impact on Participation and Autonomy[23]. This instrument specifically considers self-care and appearance, mobility, household tasks and family role, financial independence, leisure, social relationships, work, and education and learning, and evaluates the relationship between participation in life events and the person-perceived concept of autonomy, which is distinguished from physical independence [24].

Loss of mobility and reduced independence is also related to the ability to perform ADL. In individuals with MS, limitations in ADL may be seen at any stage of disease including when neurological deficits and impairments may be mild. However, as the disease progresses and disability increases, the ability to perform ADL declines and the patient experiences an increasing level of dependence on the help of others [25,26]. In one study, two-thirds of individuals with MS (n = 166) were dependent upon others in the performance of ADL [26]. The activities most affected were mobility-related and included walking outside, cleaning indoors, negotiating stairs, dressing, outdoor transportation, and social and lifestyle activities.

Self-efficacy, defined as the belief that one can competently accomplish a challenging task [27], is one factor that may play a role in the strong inverse relationship between physical activity and MS symptoms, especially motor symptoms [28]. Overall symptoms, as well as motor disabilities in particular, may operate directly on physical activity and indirectly through the patient’s feeling of self-efficacy for physical activity. Self-efficacy may be a strong predictor of health status in patients with MS, and is modifiable through encouragement, learning and modeling experiences, and successful experiences in coping with a challenging situation [29]. With less physical activity, patients may be at risk of further exacerbation of symptoms, impairments and onset of other health conditions, which may increase the need for care. The corollary is that any positive efforts for improving physical activity may be reflected in increased self-efficacy, resulting in an ability to maintain a level of independence for a greater period of time, thus reducing the need for care.

Qualitative data indicate that the impact of disability is perceived as a gradual process of ‘restricting choices’ and ‘limiting independence’ for both the person with MS and those in their household. These restrictions affect several domains, including employment and educational opportunities, household modifications, standard of living, intimate relationships and social life [30]. At lower levels of disability the impact is felt primarily by the affected individual. As the patient’s level of disability increases, there is a progressive increase in impact on other members of the household.

Caregiver profile, activities & challenges

Informal caregivers are the primary resource allowing individuals with MS to remain in their homes and their communities, filling the gap while other resources may be unaffordable, unavailable or inaccessible in the community setting [7,8]. However, few studies have addressed the characteristics, challenges and needs of these caregivers.

In a population-based study of 697 individuals with MS who responded to a questionnaire, 92% lived with a spouse or with children, and 65% reported having a primary caregiver. Only 20% of the caregivers were employed and not related to the patient [7]. Informal caregivers are primarily spouses, parents and children of the individual with MS [31]. Primary caregivers lived with the person they cared for in 75% of the cases, and were the sole caregiver in 42%. The average duration of providing care was 9 years, suggesting substantial long-term commitment, and burden. Among these individuals with MS, fatigue and problems with walking were the most prevalent MS symptoms and impairments. A total of 58% required a mobility aid.

The burden associated with caregiving is both objective, in the tasks caregivers perform, and subjective, in how caregivers feel about what they do and how they perceive the challenges they face [32]. It is important to realize that the interaction is dyadic, with the caregiver’s role intimately connected to the relationship with, and the health and emotional status of, the person they care for, such that the health of the recipient and caregiver may be shared as a unit (Figure 3)[31].

Perceptions regarding care are often at variance between caregivers and recipients. In the study by Aronson et al., caregivers generally reported providing more frequent care than was reported by those receiving the care [7]. Among individuals with MS (n = 345) and their caregivers (n = 345), the caregivers reported a greater need for care (Figure 4). In the total MS population of this study (n = 697), 34% of individuals reported that they required assistance daily, yet 69% of caregivers reported providing care on a daily basis. Additionally, caregivers reported that the MS symptoms were more severe than reported by those receiving care, and caregivers perceived a greater burden of caregiving than the recipients of their care. Among these individuals, many of the ADL most frequently requiring assistance were related to mobility, such as housekeeping, shopping, transportation to appointments and meal preparation. Assistance for personal finances and personal care were reported as less frequently required. As mobility decreased and disease severity increased, there was a significantly greater need for assistance (p < 0.001).

In a study of 302 caregivers associated with individuals with MS, as part of the National Multiple Sclerosis Society (NMSS) or the North American Research Committee on Multiple Sclerosis (NARCOMS) patient registry, spousal caregivers were found to provide assistance with more activities than were nonspousal caregivers [8]. As in the Aronson study [7], many of the activities for which assistance was most often provided were mobility-related, such as providing a hot meal, transportation, doing heavy and light housework, moving around inside the house and getting dressed. Less frequent assistance was provided for managing bowels and bladder, getting on and off of the toilet, getting in and out of the shower or tub, and eating. Many of these tasks would need to be performed several times a day. Nonspousal caregivers were more likely to report that providing assistance with tub or shower transfers and bladder management were the most challenging tasks, although these tasks were more likely to be provided by spousal caregivers [8].

Taken in total, the reviewed literature suggests that many caregiver tasks require specific physical skills and abilities, for which the caregiver may or may not be adequately prepared, especially when informal care is initiated. In addition, the acquisition of these skills may be important in helping them perform their tasks competently and efficiently while avoiding injury to themselves and the individuals they care for. These factors, as well as the physical, psychological, economic and emotional toll of providing daily care, are part of the burden borne by caregivers.

Not surprisingly, disease impact as measured by the MS Impact Scale-29 (MSIS-29), a patient-based rating scale that assesses the impact of MS on day-to-day life over a 2-week period, positively correlated with caregiver activities. Furthermore, disease impact negatively correlated with caregiver perceived burden, as measured by the Caregiver’s Reaction Assessment Scale. Caregiver’s Reaction Assessment Scale scores are transformed so that the lower the score, the higher the perceived burden [31]. Importantly, disease impact also correlated with caregiver care-related health problems as well as physical health status and mental health status. The most severe and common health problems were anxiety, tiredness, depression, back pain, insomnia and shortness of breath. Less frequent but, nevertheless, severe, were sexual and relationship problems. Many of these problems, particularly those related to mental and emotional health, and sexual and relationship problems, were mirrored as problems experienced by the person with MS. In fact, this dyadic relationship, or the shared mental and physical health statuses of the caregiver and patient, was a contributory factor to the health of the caregiver. However, caregivers also experienced a worsening of their health and an increasing burden in relation to higher levels of care activities, independent of the effects of disease impact and the age of the caregiver [31].

The needs of caregivers

Caregiver QOL is affected by their responsibilities and activities, and the health status of the person they care for [33]. Poorer caregiver QOL was associated with being a spouse, longer duration of caregiving, moderate or worse MS symptoms in the person cared for, and was most strongly related to an unstable disease course in the MS patient [33,34].

Informal caregivers have been described as the ‘hidden patient’ because of the physical, emotional, psychological, social and economic burdens that are either placed upon them or which they assume [32]. Pozzilli et al., based upon their study of 133 informal caregivers of MS patients, concluded that the caregiver should be seen as an appropriate and independent target for focused therapeutic strategies [35].

As recently reviewed, multiple studies have provided descriptions of the needs of caregivers of persons with MS [36]. Among these needs are factors that directly affect the recipient of care, in particular, training in the skills needed for caring for persons with MS throughout the disease course. Of equal importance is the need for reducing the physical, emotional and economic burden of caregiving, which are especially important when the caregiver is a spouse or partner. These needs require the development of coping strategies, as well as appropriate financial planning and support, and help in maintaining an identity apart from that of the caregiver role. One of the main goals of the overall treatment of MS should be the training of nonprofessional caregivers by the team of medical professionals who follow the patients.

Economics of informal care

Studies in several countries have examined the costs associated with MS care. In general, studies have shown that: costs increase with increasing disease progression and patient disability; the costs associated with the loss of employment exceed the costs of health and social services; a primary cost factor is inpatient care; and, a large proportion of the costs are borne by informal caregivers. In one study, 81% of the total costs could be accounted for by the combination of lost productivity (33%) and informal care (48%) [14].

In a prospective cost-of-illness analysis associated with unpaid home caregiving across a socioeconomic spectrum of households (n = 130), it was found that the time spent on direct patient care rose dramatically with increasing level of disability [37]. Furthermore, for patients with moderate and severe disability, the time spent in informal care for just the core activities (mobility assistance, nursing care and personal care) was greater than the professional medical and paramedical care that was provided at home.

Indirect caregiver time for housekeeping and various help and social activities for the moderately and severely disabled was also greater than the time of professional community assistance. When all categories of homecaring are included, patients with increasing disability cared for at home received levels of informal help which were four- to six-times greater than the total of professional care and help [37]. The monetary value of the cost of direct care, excluding housekeeping and ‘keeping company’, for patients at all levels of disability in this Belgian study was approximately three-times that of the cost of formal professional in-home care (€23,681 vs €8554) [37].

A significant cost of caregiving is the loss, modification or restriction of employment including loss of work, increased number of days off, taking less demanding work, or reduced or abandoned promotion prospects. Importantly, the adverse impact on employment of MS for the patient and others in the household invariably decreases the household’s income and standard of living through reductions in salary or loss of future earnings [30].

Expert commentary

As noted above, informal caregivers in MS have been described as the ‘hidden patient’ [32]. This obscured status is mostly attributable to the failure of researchers to acknowledge and study this important aspect of the burden of MS until recently. Research into the stresses and strains of caregiving for chronic diseases in general, ‘caregiver burden’, did not substantially begin until approximately 1980, and articles reporting specifically on caregiver burden in MS first appeared in the literature only approximately 20 years ago [38]. Studying the specific characteristics of caregiver burden in MS is vital given the particular and even unique features of this disease. These include its occurrence in young adulthood, during the prime years of productivity; its uncertain prognosis and unpredictable symptomatology; and its long, chronic course, extending to approximately a normal lifespan. MS patients are often married or in a relationship at onset of the disease, and the burden of care for them is borne to a large extent by their spouse, family and friends.

The objective of caregiving in MS is not only to assist in the performance of daily activities and to help maintain some independence, but also to prolong for as long as possible the time the individual can remain in their own home and community. This is a particularly essential role today, given the aging of the population, the increased need for long-term care services associated with this trend, and the probability that costs for such services will continue to rise and further strain public and private financial resources. This importance of the caregiving role in MS underlines the need to understand the burdens on MS caregivers and to provide the support that will allow them to maintain their role.

Informal caregivers experience a series of complex challenges in this role, often with debilitating effects on their physical, emotional, mental, social and economic well-being. The need for, and the extent of, caregiving increases with the level of disability, with the loss of mobility substantially contributing to the need for assistance. Heightened awareness of the broad impact of MS may assist agencies that provide care for people with MS and their families to enable them to develop strategies to enhance their day-to-day social and economic well-being, as well as slow disease progression [30]. Medications, as well as medical and social services, may also help delay the institutionalization of patients until they are no longer able to be reasonably cared for in their home. In addition to improving HR-QOL, healthcare costs and caregiver burden may potentially be reduced if disease progression is slowed or if those impairments or symptoms contributing to the need for caregiver assistance can be ameliorated.

Given the toll on caregivers as well as their recipients, managed care should consider approaches to easing the burden by initiating available therapies, which may include pharmacologic and rehabilitative therapies, either alone or in combination, that can prolong patient independence and delay the need for caregiving. Additional research is warranted to evaluate and understand how levels of disability and mobility affect the need for caregiving, the dynamic relationship between caregivers and recipients, and the costs of care borne by the different stakeholders; patients, caregivers, managed care organizations and society.

Five-year view

Although the study of caregiver burden in MS is only 20 years old, enough data have been accumulated to establish that it is a significant contributor to the overall societal burden of MS, and that caregivers play a vital role in reducing the need for paid healthcare services outside the home. Therefore, over the next 5 years, it is likely that further studies will be conducted to clarify the components of caregiver burden in MS and to investigate the medical and socioeconomic efficacy of interventions, such as psychotherapy or counseling, to provide support for caregivers. Another area that is likely to draw increased attention from researchers is the question of which specific symptoms and problems in MS have the most adverse impact on caregivers. As discussed above, the dyadic relationship between the problems experienced by MS patients and their caregivers has been described mostly in general terms. Only a few studies have ventured to specify the impact of specific symptoms, and their methods and findings have varied. One study found that difficulty walking caused the most distress to MS caregivers [38], while other studies have found that memory loss [39] and depression in MS patients [40] were particularly important contributors to caregiver burden. Further research to follow up on these findings is likely, in part because it may help prioritize patient and caregiver needs for therapy and support.

In addition, over the next 5 years, effect on caregiver burden may become increasingly viewed as a potential indicator of the efficacy of approaches to MS management, and could possibly be used as an outcome in studies of interventions and therapies for MS patients. In general, patient and caregiver burden in MS are likely to be seen in the coming years as two closely related dimensions, if not mirror images, of the burden of disease.

Key issues

• • Multiple sclerosis (MS) is associated with a particularly high socioeconomic burden, primarily because onset occurs during the most productive years of the patient, and life expectancy is approximately normal, relative to the general population.

• • Even mild MS disease reduces mobility, exerting a substantial toll on caregivers.

• • 75% of primary caregivers live with the patient; and 42% are the sole caregiver. The average duration for care is 9 years.

• • The health problems of MS patients are mirrored in their caregivers in a dyadic relationship.

• • Common health problems for caregivers include anxiety, tiredness, depression, back pain, insomnia, shortness of breath, and sexual and relationship problems.

• • Caregivers may not be prepared for the physical tasks required.

• • Caregivers are an appropriate and independent target for therapeutic strategies.

• • Caregivers need to be trained in caring for MS patients.

• • Managed care should initiate available therapies (pharmacologic/rehabilitative) that prolong patient independence.

Financial & competing interests disclosure

This project was supported by Acorda Therapeutics, (NY, USA). Jeffrey Dunn previously served as a consultant to Acorda. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Jeffrey Dunn received editorial support from The Curry Rockefeller Group, LLC.