Although the medical consequences of arthritis are of great concern, arthritic diseases also affect an individual's capacity to live a full and active life.1 Clinicians, researchers and others tend to use terms such as quality of life or health-related quality of life interchangeably when it comes to discussing the effect of diseases such as arthritis upon physical, social, and emotional well-being. At the broadest level, quality of life refers not only to one’s health but also to environmental and economic factors (i.e., income, educational attainment) that can substantially influence well–being. Accordingly, there are different conceptual frameworks that guide how one defines and measures a person’s quality of life.2

For example, investigators who are interested in evaluating 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 that assess the importance that individuals place upon their quality of life. As a result, there are dozens of tests that measure different aspects of quality of life.3

However, when the focus is on the influence of a disease on functional health status and well–being, as perceived and reported by the patient, health–related quality of life (HRQL) is generally considered the most appropriate aspect of quality of life to assess. Health-related quality of life encompasses emotional, physical, social and subjective feelings of well-being that reflect an individual's subjective evaluation and reaction to the illness. Indeed, HRQL focuses on the patients’ perception of their disease as opposed to more objective evaluations of functional health status such as grip strength or gait.

Understanding The Impact Of HRQL
Outcomes in medicine and health care have largely been determined by the objective medical evaluation (i.e., measurable changes in health parameters, cost of care). It has become clear however that the perspective of the patient is important as it can influence function, one’s response to treatment and even become a target for intervention itself. Accordingly, assessing outcomes that are derived from the patient’s perspective is increasingly common.

Apart from the inherent value of having the patient provide his or her own perspective on how arthritis influences his or her life, such assessments are also useful for clinicians, researchers and policy makers since they offer a profile of the current state of an individual. This information, beyond that offered by traditional medical and clinical measures, is valuable in helping to understand the variability in individual responses. 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 disabled and isolated.

It is particularly appropriate to measure HRQL in patients with arthritic disease because the disease does not typically cause death but has a substantial effect on health, fitness and physical, emotional and social functioning.

How To Measure HRQL
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 for arthritis per se but rather provide a general sense of the effects of illness.

The Medical Outcomes Study Short–Form Health Survey (SF–36) is the best–known generic HRQL instrument.4 It measures HRQL along eight different domains with higher scores indicative of better HRQL. Other generic instruments that investigators have used with arthritis patients include the Satisfaction with Life Scale, the Extended Satisfaction with Life Scale and the Quality of Life Inventory.



An advantage of generic measures is that they allow for comparisons of HRQL across a variety of medical conditions. The major limitation of generic HRQL instruments is they do not assess potential condition–specific domains of HRQL. Accordingly, they may not be sensitive enough to detect subtle treatment effects. For example, a SF–36 assessment of an arthritis patient will not provide information on how specific arthritis symptoms (i.e., joint pain, fatigue, stiffness) influence the patient’s HRQL.

The second approach to measuring HRQL involves using instruments that are specific to a disease, a particular patient population or clinical problem. Such measures are likely to be more sensitive and therefore would have greater relevance to practicing clinicians. The Arthritis Impact Measure-ment Scale (AIMS) is a prime example of an arthritis–specific HRQL instrument that has been developed.5 It measures physical, social and emotional well–being along nine 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 generic instruments whereas generic instruments allow for HRQL comparisons across different diseases. There is some consensus that one should utilize both generic and disease–specific instruments in order to provide the most comprehensive assessment of HRQL.6

The largest arthritis-HRQL study to date involved over 32,000 adults who completed the 1998 Behavioral Risk Factor Surveillance Survey HRQL assessment.7 This study indicates that adults with arthritis report significantly greater HRQL impairment compared to adults without arthritis. Specifically, those who have arthritis reported fair to poor health approximately three times more often than those without arthritis (28.6 percent vs. 8.3 percent). They also reported a significantly greater number of days when their physical health and mental health were not good, and when usual activities were limited by their arthritis.

Emphasizing The Clinical Implications Of HRQL
Assessment of HRQL provides a way to better understand the effect of arthritic diseases on overall functioning and well–being. Such an understanding promises to influence the quality of care clinician provide for patients with arthritis. Indeed, discussing the results of an HRQL assessment with patients can stimulate a conversation that focuses on the influence their disease has on the way they live their lives. Since the progression of the disease can sometimes be slow and gradual, many patients are not aware of the impact their arthritis has on their HRQL until they have reached a critical level of impairment.

Assessing HRQL also allows 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 been required to give up playing tennis because of knee pain and had not realized, until the results of her HRQL assessment were discussed, that she also abandoned many other activities (i.e., attending sporting events, gardening) that she had previously enjoyed.

Assessing one’s HRQL makes it possible to identify significant areas of patients’ lives that have suffered and helps patients focus more acutely on treatment and self–management efforts so they can work toward reclaiming aspects of 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 multifaceted as arthritis.

In Conclusion
Arthritic diseases are a major public health problem. Most are progressive, have no cure and can significantly impair HRQL. People with arthritis tend to report severe limitations in their capacity to perform day–to–day physical and social activities. Those with more severe disease tend to have the worst HRQL.

The effect of arthritis goes far beyond its medical consequences. It also produces profound declines in function and well-being that, for many, may be of greater relevance to them than the symptoms themselves. Since arthritis takes such a terrible toll on HRQL, it is essential we find ways to promote positive changes in the HRQL of people 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), hopefully we will see great improvements in the HRQL of these patients in the coming years.