Arthritis and Health-related Quality of Life

by Kevin Fontaine, Ph.D.

Introduction

An estimated 42.7 million Americans (15% of the population) had some form of arthritis in 1995 and, due to the increasing average age of the population, this total is expected to rise to 59.4 million (18.2%) by the year 2020(1,2). Consistent with this, it was recently estimated that, since 1990, the prevalence of arthritis has increased by 750,000 cases per year(3). The estimated total economic cost to the United States of arthritis is over $65 billion annually(4).

Although the medical and economic consequences of arthritis are of great concern to researchers and clinicians, this disease also affects an individual’s capacity to live a full and active life. Thus, it has increasingly become clear that the problems associated with arthritis are not simply medical ones; it also appears to have a substantial impact on a person’s functional capacity and quality of life(5).

Definitions of Quality of Life

Many terms are used interchangeably (e.g., quality of life, health status, health-related quality of life) to discuss the effect of diseases, such as arthritis, on functioning and sense of well-being. At the broadest level, quality of life refers not only to health status, but also to environmental and economic factors (e.g., income, educational attainment) that can substantially influence well-being. Thus, different conceptual frameworks guide how quality of life is defined and measured(6). For example, investigators who are interested in the evaluation of the quality of medical care outcomes tend to place greater emphasis on the development of measures that focus on overall well-being. In contrast, those operating from a medical ethics perspective tend to develop measures assessing the importance that an individual places upon his/her quality of life. As a result, there are hundreds of tests purporting to measure different aspects of quality of life(7). However, when the focus is on the impact of a disease or medical condition on functional health status and well-being as perceived and reported by the patient, health-related quality of life (HRQL) generally is considered the most appropriate aspect of quality of life for investigation. HRQL encompasses emotional, physical, social and subjective feelings of well being that reflect an individual’s subjective evaluation and reaction to his/her illness.

Why Assess HRQL?

Traditionally, outcomes in medicine and health care have largely been determined by the objective medical evaluation (e.g., measurable changes in health parameters, disease status, cost of care). Increasingly, it has become clear that the perspective of the patient is also a critical variable. As a result, emphasis has shifted gradually toward including evaluations of medical/health-related outcomes from the patient’s perspective.

Such assessments potentially are of use to clinicians, researchers, administrators, and policy makers since they offer a profile of the current state of an individual who is experiencing a particular illness or chronic disease. This provides additional information beyond that offered by traditional medical and clinical measures, and, thus is valuable in helping to understand the wide variability in individual responses to similar conditions. For example, some individuals with severe arthritis remain active in their work and social relationships, while others with the same or lesser degree of arthritis become virtually housebound and isolated. HRQL measures are also valuable in evaluating the effects of treatment, as well as the cost effectiveness of treatments.

It seems particularly appropriate to measure HRQL in arthritis patients because the chronic debilitating nature of this disease likely takes a considerable toll on HRQL. If this is indeed the case, and it appears to be (5), then the assessment of HRQL in arthritis patients is critical because this chronic disease does not typically cause death, but has a substantial effect on health, fitness, and physical, emotional, and social functioning. Therefore, HRQL is likely to be a good indicator of both the global effects of arthritis on a patient’s life, as well as the effects of treatment.

How is HRQL Measured?

There are two basic approaches to measuring HRQL. The first involves the use of generic instruments that measure broad aspects of HRQL. These instruments are not designed to assess HRQL relative to a particular medical condition, but rather to provide a general sense of the effects of an illness. Medical Outcomes Study Short-Form Health Survey (SF-36)(8) is the best-known generic HRQL instrument. It measures HRQL along 8 different domains: physical functioning, role limitations due to physical problems, bodily pain, general health perception, vitality, social functioning, role limitations due to emotional problems, and mental health. Other generic instruments that have been used with arthritis patients include the Satisfaction with Life Scale, the Extended Satisfaction with Life Scale, and the Quality of Life Inventory.

Generic measures allow for comparisons of HRQL across a variety of medical conditions and, thus, can be administered to different populations to examine the impact of various health care/therapeutic programs on HRQL. The major limitation of generic HRQL instruments is that they do not assess potential condition-specific domains of HRQL. Because of this, they may not be sensitive enough to detect subtle treatment effects. For example, a SF-36 assessment of an arthritis patient will not provide a great deal of information on important aspects of the illness such as the effect of joint pain, stiffness and related symptoms on function, attitude, and mood.

The second approach to measuring HRQL involves the use of instruments that are specific to a disease (e.g., osteoporosis), a population (e.g., the elderly), or clinical problem (e.g., pain). Measures geared toward specific diseases or populations are likely to be more sensitive, and therefore, to have greater relevance to practicing clinicians. The Arthritis Impact Measurement Scale (AIMS)(9) is a prime example of an arthritis-specific HRQL instrument that has been developed. The AIMS measures physical, social, and emotional well-being along 9 dimensions including dexterity, mobility, pain, physical and social activity, and depression and anxiety.

Whether disease-specific instruments provide “better” assessments of HRQL than generic instruments depends on the purpose of the assessment. Disease-specific instruments are likely to be more powerful at detecting treatment effects than are generic instruments. Thus, there is some consensus among quality of life researchers that both generic and disease-specific instruments should be used to provide the most comprehensive assessment of HRQL possible(10).

Arthritis and HRQL

There is a great deal of information suggesting that arthritis has a devastating effect on HRQL(5). One recent large survey makes this point well. Data from 32,322 adults in 11 states from the 1998 Behavioral Risk Factor Surveillance Survey (BRFSS), a health survey given annually in the United States, indicates that adults with arthritis report significantly greater HRQL impairment compared to adults without arthritis(11). Specifically, those who have arthritis reported fair to poor health approximately three times more often than did those without arthritis (28.6% vs. 8.3%). They also reported a significantly greater number of days when physical and mental health were not good, and when usual activities were limited. In other words, their arthritis made it difficult for them to live the kind of lives they desired.

Clinical Implications of HRQL Assessment for the Management of Arthritis

Assessment of HRQL provides a way for rheumatologists and arthritis researchers to better understand the effect of this chronic disease on overall functioning and well-being. Such an understanding promises to influence the quality of care provided to arthritis patients. That is, discussing the results of an HRQL assessment with an arthritis patient can stimulate a conversation that focuses explicitly on the impact his/her condition has had on the way he/she lives his/her life. Since the progression of the disease can sometimes be slow and gradual, many patients are not aware of the impact their arthritis has had upon important dimensions of their lives such as social functioning and energy level until specific attention is given to them. Examining the impact of their arthritis on these dimensions will allow clinicians to personalize treatment and better outline the potential benefits that can come from taking concrete steps to adhere to their prescribed treatment regimens. For example, one patient may have given up playing tennis because of knee pain and not noticed, until the results of his HRQL assessment were discussed, that he had also abandoned many activities (e.g., attending sporting events, mowing his lawn) that he had previously enjoyed.

Thus, as a result of the HRQL assessment, it is possible to identify significant areas of patients’ lives that have suffered and to help patients focus more acutely on their treatment and self-management efforts so that they can “reclaim” their former lives. This awareness, in conjunction with a clear discussion of what treatment may do to improve their HRQL, is vital in providing the comprehensive care required to adequately address a disorder as complicated and multi-faceted as arthritis.

Conclusion

Arthritis diseases are a major public health problem. Not only are they progressive debilitating diseases with no known cure, but they also have a devastating impact on HRQL. Persons with arthritis tend to report that they are hampered severely in their capacity to perform their day-to-day physical and social activities, and those with more severe disease tend to have the worst HRQL. This means that the effect of arthritis on public health goes far beyond its medical and economic consequences; it also produces profound decrements in functioning and sense of well being that, for many persons, may be of greater relevance to them than the symptoms of arthritis itself. Since arthritis takes such a terrible toll on HRQL, it is essential that we find ways to promote positive changes in the HRQL of persons with arthritis. As treatments improve and we find new and better ways to assist arthritis patients in taking a more active role in managing their disease (for example, trying to be more physically active, controlling their weight), we can expect to see this translate into great improvements in the HRQL of arthritis patients in the coming years.

References

1. CDC. National Arthritis Action Plan: A Public Health Strategy. Atlanta, GA: Arthritis Foundation, Association of state and Territorial Health Officials, and CDC. 1999.

2. Lawrence R.C., Helmick C.G., Arnett F.C., Deyo R.A., Felson D.T., Giannini E.H., Heyse S.P., Hirsch R., Hochberg M.C., Hunder G.G., Liang M.H., Pillemer S.R., Steen V.D., & Wolfe F. Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States. Arthritis & Rheumatism 41:778-799, 1998.

3. MMWR (2001a). Prevalence of Arthritis – United State. Morbidity and Mortality Weekly Report 50:334-336, 1997.

4. Yelin E.. The economics of osteoarthritis. In: Brandt K, Doherty M, Lohmander L.S. eds. Osteoarthritis. New York: Oxford University Press (pp 23-30), 1998.

5. Scott DL, Garrood T. Quality of life measures: use and abuse. Bailliere’s Best Practice and Research in Clinical Rheumatology 14, 663-687, 2000.

6. Wan GJ, Counte MA, Cella DF. A framework for organizing health-related quality of life research. J Rehabil Outcomes Meas 1:31-7, 1997.

7. Fallowfield LJ. Quality of quality of life data. Lancet 348:421, 1996.

8. Ware JE, Snow KK, Kosinski M, et al. SF-36 Health Survey: Manual and Interpretation guide. Boston MA: New England Medical Center, 1993.

9. Meenan RF, Gertman PM, Mason JH. Measuring health status in arthritis: The Arthritis Impact Measurement Scale. Arthritis & Rheumatism 23, 146-152, 1980.

10. Guyatt GH, Feeny DH, Patrick DL. Measuring health-related quality of life. Ann Intern Med 118:622-29, 1993.

11. MMWR (2000). Health-related quality of life among adults with arthritis-Behavioral Risk Factor Surveillance System, 11 states, 1996-1998. Morbidity and Mortality Weekly Report, 49, 366-369.

Updated: October 13, 2011

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