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QUALITY OF LIFE IN PATIENTS WITH ANKYLOSING SPONDYLITIS
0889-857)
SPONDYLOARTHROPATHIES
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QUALITY OF LIFE IN PATIENTS WITH ANKYLOSING SPONDYLITIS Michael M. Ward, MD, MPH -4
Health-related quality of life may be defined as the “net consequence of a disease and its treatment on a patient’s perception of his ability to live a useful and fulfilling life.51”By its nature, quality of life is subjective and based on a patient’s perceived experience, and it is also multidimensional. Health-related quality of life is usually considered to be comprised of several domains, including symptoms, physical functioning, work or role functioning, social interactions, psychological states, and treatment side effects, listed below. Some conceptualizations include the financial costs of illness as an additional domain.I9 Each of these domains, in turn, is comprised of several components. For example, symptoms may include pain, stiffness, or fatigue, and social interactions may include interactions with family members, friends, or coworkers. Such a schema permits an organized and complete assessment of the impact of a disease on affected individuals. Components of health-related quality of life:
Symptoms Pain Stiffness Physical Functioning Self-care Mobility
Fatigue Poor sleep Household tasks
Supported in part by the Bartman Foundation From the Veterans Affairs Palo Alto Health Care System, and Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, California
RHEUMATIC DISEASE CLINICS OF NORTH AMERICA
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VOLUME 24 NUMBER 4 * NOVEMBER 1998
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Role Functioning Work School Home Social Interactions Marriage Coworkers Family Community Friends Leisure time Psychological Functioning Depression Health distress Anxiety Coping mechanisms Treatment Side Efects (some examples) Dyspepsia Skin rash Gastrointestinal bleeding Financial Costs Direct costs Indirect costs Along with mortality and measures of physiological or anatomical impairment, quality of life is a major component of health outcomes. Research in health-related quality of life in general, and in patients with rheumatic diseases in particular, has expanded greatly in the past 15 years. This article focuses on studies published since 1980 concerning the quality of life of patients with ankylosing spondylitis (AS). SYMPTOMS Pain, stiffness, and fatigue are the most commonly reported symptoms of patients with AS. As in most rheumatic diseases, the severity of symptoms varies greatly among patients and varies over time in individual patients. In a prospective longitudinal study in which 22 patients were examined monthly for 1 year, all had at least one exacerbation of symptoms and several had recurrent flares and subsequent improvementsZ2Daily pain and stiffness are common, being reported by more than 70% of patients.23In general, most reports find the average severity of pain and stiffness reported by patients with AS to be less than or comparable to that reported by patients with rheumatoid arthritis.43, For example, scores on the total pain index of the McGill Pain Questionnaire (possible range 0 to 100; higher scores indicate greater pain severity) averaged 32 in a group of patients with AS attending a rheumatology clinic, compared to 42 in a group of patients with rheumatoid arthriti~?~ Another method to assess symptom severity is to ask patients, in a hypothetical scenario, what degree of risk they would be willing to take to obtain complete relief of their symptoms. A willingness to take greater risks would indicate not only that the symptom was severe but also that its relief was important to the patient. Using the standard gamble technique to present such scenarios to 50 patients with AS who were either outpatients in a rheumatology clinic or inpatients receiving extensive physical therapy, O’Brien et a1 found that, on average, patients were willing to risk an 11%chance of death to obtain either complete relief of pain or complete relief of stiffness In comparison, patients with
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range of possible risk factors, and only one study used multivariate statistical techniques to determine the independent contribution of different factors to the risk of work disability.26 Although most patients with AS maintain employment, 8% to 37% of patients reported changing occupations, in most instances owing to 42, 48, 6o Most changes were to a job that was less physically their AS.39* demanding. In addition, up to one third of patients reported having at least one prolonged sick leave.26,6o The likelihood that a person with AS would have a lengthy sick leave was increased among those with peripheral arthritis and those whose work required carrying heavy loads.26
SOCIAL INTERACTION Limitations in social interactions can occur in the context of marriage, family, friends, coworkers, and the general community. There has been little research dedicated specifically to limitations in social interactions among patients with AS, perhaps because of the perception that few problems exist in this area. In a survey of 129 patients with AS, only 1%reported concerns about limitations in social interactions, 2% reported concerns about limitations in communication, and 6% reported limitations in leisure activities.2 A study of sexual problems in patients with AS found no problems among men, but women with AS reported less sexual enjoyment and preferred to have intercourse less frequently In a survey of 100 patients with a mean age than unaffected of 42 years and a mean duration of AS of 20 years, 7% reported severe discomfort during intercourse (4 out of 21 women; 3 out of 79 men), and 27% reported mild discomfort (7 out of 21 women; 20 out of 79 men).60These limited findings indicate that sexual functioning may be a substantial problem and an area of concern for some patients.
PSYCHOLOGICAL FUNCTIONING Problems with emotional health have been reported by 20% of patients with AS, and emotional problems were identified as the second most frequent problem causing a limitation in functioning.2Despite this substantial effect, there have been few studies that specifically examine psychological functioning in patients with AS. The prevalence of depression in patients with AS was measured in a cross-sectional survey of a group of 177 patients with a mean age of 43 and a mean duration of AS of 18 years, who were recruited from rheumatology clinics and patient education groups.6 Based on the Centers for Epidemiological StudiesDepression Scale, 31% of patients were depressed; depression was more common among women in this survey (46%) than among men (26%). The main correlates of the level of depression were pain severity among women, and functional disability and pain severity among men. Similar
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for patients with AS, the major benefit of such therapy may be preservation of spinal motion, as decreases in pain and stiffness have not consis29, 30,36, 50, 57,59 Intensive inpatient therapy, as is tently been documented.20, the practice in some European countries, may afford greater benefit. For patients with severe hip arthritis, total hip arthroplasty commonly affords sustained relief of hip pain.s,52-54 PHYSICAL FUNCTIONING
Physical disability or functional disability refers to limitations in self-care activities, mobility, and performance of household tasks. Assessment of functional disability is commonly done by patient self-report using validated questionnaires. These questionnaires may be generic and applicable in any disease, such as the Sickness Impact Profile or Medical Outcomes Study-Short Form 36, or may be more arthritis-specific, such as the Health Assessment Questionnaire or the Arthritis Impact Measurement Scales. Some investigators have suggested that questionnaires specific for patients with spondyloarthropathies are needed, based on the belief that axial arthritis results in functional impairments and disability not captured adequately by more generic instruments. Spondylitis-specific measures of functional disability might, therefore, be more relevant to the assessment of functional difficulties in patients with AS, and might be more sensitive to change with treatment.', 7, 9, 15*l6 Four spondylitis-specific measures of functional disability have recently been pr0posed.l.9, 15,l6 One is a modification of the Health Assessment Questionnaire, with two additional scales dealing with driving and posture-related activitie~.'~ The three other measures are newly devised questionnaires, each of which has undergone initial validation and assessment for sensitivity to change.', l6 Whether these spondylitisspecific questionnaires provide better information about functional disability in patients with AS, or are more sensitive to change than more generic functional status instruments, remains to be determined. However, it is clear that patient self-report questionnaires accurately capture functional disabilities in patients with AS.31 As measured by these instruments, functional disability appears to be mild in most patients with AS (Table 1).In most studies, mean scores were in the lowest third of the possible range. Because patients in these studies were recruited from rheumatology clinics or specialized rheumatic disease hospitals, or were participants in controlled trials, they might be expected to be more severely affected than the typical patient with AS. The level of functional disability might be even less in a population-based study. Similar findings of generally low levels of functional disability were reported in three studies using the American Rheumatism Association (ARA) functional classification to grade physical disability. In these studies, patients in ARA class I11 or IV comprised 4%, 22'7'0, and 20% of the groups that were examined after a mean duration of AS of 38 years, 18 years, and 20 years, respectively.12,41, 6o 97
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Table 1. MEASUREMENT OF FUNCTIONAL DISABILITY IN PATIENTS WITH ANKYLOSING SPONDYLITIS Mean Mean age duration Reference Number (years) (years)
9
42 163
47.7
24.7
15 16 23 29
44 80 100 144
38.5
13.7
41.8 42.0
16.5
1
-
-
4.5
Measure* Leeds Disability BASFI Functional Index HAQ-S Functional Index ADL score HAQ-S Functional Index
Possible range Mean f SD
0-3 0-10 0-40
0-3 0-40 51-0
0-3 0-40
1.23 2 0.8 4.0 ? 2.1 2.6 2 1.7 0.5 2 0.5 9.8 2 5.8 39.7 0.35 7.8
-I
'BASFI = Bath Ankylosing Spondylitis Functional Index; HAQ-S = Health Assessment Questionnaire for the. Spondyloarthropathies; ADL score = Activities of Daily Living score. For each measure except the ADL score, higher values indicate greater functional disability. SD = standard deviation.
When problems with functional abilities do occur, they appear to be related more to mobility than to self-care activities. A survey of 129 patients found that 47% reported problems with mobility, while only 6% reported problems with self-care.* In addition to the duration of AS, risk factors for greater functional disability include the presence of peripheral arthritis?" 26, 6o hip arthriti~?~ and the neck involvement,41 younger age at onset,lO,26 being presence of comorbid illness.23Greater disease activity, manifested by more pain and stiffness, has been associated with greater functional disability, as has depression, anxiety, and a diminished sense by the patient that he or she has control over his or her health outcomes?, 32 The degree of functional disability may correlate only weakly with measures of physical impairment, such as the Schober test, occiput to wall distance, or cervical rotation.', 15, l6 Most studies of risk factors for functional disability examined only a limited range of possible risk factors, and few used multivariate statistical techniques to allow identification of those factors that were independently associated with functional disability. A more complete assessment of risk factors for functional disability is needed that would simultaneously examine a broad range of potential risk factors. Functional disability has not commonly been measured in controlled trials on nonsteroidal anti-inflammatory drugs, although treatment with these medications can result in improvements in function.16Measures of functional disability have been more widely used in controlled trials of sulfasalazine in AS, with conflicting results.14,17, 3s In contrast, physical therapy has been consistently shown to improve functional disability or stabilize functional decline when exercise has been continued for periods from 2 weeks to 18 months.30,36, s9 Total hip arthroplasty can also improve functioning in patients with hip arthritis.53Surgical correction of severe spinal kyphosis may also improve function in patients with these deformities.28
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WORK ABILITY
Nine studies have reported on the work ability of patients with AS (Table 2).* All but one of these studies was a cross-sectional survey of patients attending rheumatology clinics or of members of patient education groups, so the representativeness of the samples may be limited. In these studies, 60% to 85% of patients remained employed after mean durations of AS of 14 years or more. Because work disability increases cumulatively with age and with the duration of AS, it is more informative to report the proportion of patients who remain employed at specific durations of AS, rather than the proportion employed of a group of patients with varying durations of disease. Three studies report cumulative proportions, with employment ranging from 79% to 85% after 20 years of AS, and from 53% to 81% after 30 years of AS.39* 42, 48 The patients in these studies were predominantly young or middleaged men, and most studies were done in Northern or Western Europe. Because age, sex, and the societal response to unemployment may influence the likelihood with which people stop working, these factors should also be considered in studies of work disability. A study that followed patients over time would also be a more appropriate way in which to assess the time to work disability. Factors associated with continued employment include higher socioeconomic status, possibly because the physical demands of the jobs of persons with higher socioeconomic status are less.23,26, 49 Vocational counseling has been associated with a decrease of 62% in the risk of employment disability.26Other risk factors for work disability include indicators of active AS, such as pain and greater functional 42 hip arthritis or hip replacedisabilityz3,49 restricted lumbar m0bility,2~, ment,42and comorbid illne~ses.2~ As was the case for physical disability, most studies of risk factors for work disability considered a limited 397
*References 12, 23, 25, 26, 39, 42, 48, 49, and 60.
Table 2. EMPLOYMENT IN PATIENTS WITH ANKYLOSING SPONDYLITIS
Reference
Number
12 23 25 26 39 42 48 49 60
51 100 122 182 76 60 231 1044 100
Mean age (years) 62 42 39
44 45 43 42
Mean duration (years) 38 16 15 14
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24 21 21 20
YO Male 100 67 67 88 89 78 63 100 79
Mean YO employed 54 63 68 64
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85 68 85 84
Yo Employed at 20 years
at 30 years
-
-
82 79 85
53 73 81
-
-
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range of possible risk factors, and only one study used multivariate statistical techniques to determine the independent contribution of different factors to the risk of work disability.26 Although most patients with AS maintain employment, 8% to 37% of patients reported changing occupations, in most instances owing to 42, 48, 6o Most changes were to a job that was less physically their AS.39* demanding. In addition, up to one third of patients reported having at least one prolonged sick leave.26,6o The likelihood that a person with AS would have a lengthy sick leave was increased among those with peripheral arthritis and those whose work required carrying heavy loads.26
SOCIAL INTERACTION Limitations in social interactions can occur in the context of marriage, family, friends, coworkers, and the general community. There has been little research dedicated specifically to limitations in social interactions among patients with AS, perhaps because of the perception that few problems exist in this area. In a survey of 129 patients with AS, only 1%reported concerns about limitations in social interactions, 2% reported concerns about limitations in communication, and 6% reported limitations in leisure activities.2 A study of sexual problems in patients with AS found no problems among men, but women with AS reported less sexual enjoyment and preferred to have intercourse less frequently In a survey of 100 patients with a mean age than unaffected of 42 years and a mean duration of AS of 20 years, 7% reported severe discomfort during intercourse (4 out of 21 women; 3 out of 79 men), and 27% reported mild discomfort (7 out of 21 women; 20 out of 79 men).60These limited findings indicate that sexual functioning may be a substantial problem and an area of concern for some patients.
PSYCHOLOGICAL FUNCTIONING Problems with emotional health have been reported by 20% of patients with AS, and emotional problems were identified as the second most frequent problem causing a limitation in functioning.2Despite this substantial effect, there have been few studies that specifically examine psychological functioning in patients with AS. The prevalence of depression in patients with AS was measured in a cross-sectional survey of a group of 177 patients with a mean age of 43 and a mean duration of AS of 18 years, who were recruited from rheumatology clinics and patient education groups.6 Based on the Centers for Epidemiological StudiesDepression Scale, 31% of patients were depressed; depression was more common among women in this survey (46%) than among men (26%). The main correlates of the level of depression were pain severity among women, and functional disability and pain severity among men. Similar
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studies have not been performed to examine anxiety or health distress among patients with AS. In addition to being an important component of health status in its own right, psychological functioning may influence other aspects of health status. Depression and anxiety are among the factors associated 49 However, because with poorer functional ability and ~nemployment.~~, these studies were cross-sectional, it is unclear whether depression or anxiety was a cause or a consequence of poorer physical or work functioning. The coping mechanisms used to deal with stressful situations were examined among 76 men with AS.27Compared to unaffected controls, patients with AS were more likely to mitigate stressful situations by comparing themselves to others and by finding alternative sources of gratification, and were less likely to use self-accusation or resignation. The coping mechanisms used did not vary with the duration of AS. These findings indicate the use of adaptive coping mechanisms, in general, by patients with AS. In coping with pain, the use of active or passive coping mechanisms was not found to differ between 31 patients with AS and patients with either rheumatoid arthritis or fibr~myalgia.~~ TREATMENT-RELATED SIDE EFFECTS
Side effects are unfortunately common with the medications most often used to treat AS.24 In a survey of 1034 members of a patient education group in Britain, 47% of patients reported experiencing a serious adverse drug reacti0n.4~The nature of these reactions was not described. A related study on the same group of patients found that 30% to 40% of patients treated with indomethacin, naproxen, piroxicam, or diclofenac stopped these medications because of side effects.” These proportions are similar to the proportions of patients with rheumatoid arthritis who discontinue use of nonsteroidal anti-inflammatory drugs due to Seventeen of 20 patients with AS (85%) who were treated with sulfasalazine reported some side effect from this medication, compared to 68% of patients with rheumatoid arthritis.37Although most of these side effects were mild, 40% of patients with AS discontinued sulfasalazine because of them, as did 48% of patients with rheumatoid arthritis. Although the evidence is limited, in general, medication side effects do not appear to occur with increased frequency or severity among patients with AS, compared to patients with other rheumatic diseases. Studies have not specifically examined the importance of medication side effects in patients’ overall assessments of their quality of life. FINANCIAL COSTS
Financial costs of an illness may be categorized as direct costs, which represent the expenditures made or the value of health care
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services consumed in the provision of medical care, and indirect costs, which represent, for the most part, the amount of income foregone by the patient and his or her caregivers because of the illness. One Dutch study has examined the direct costs of AS among 111 patients who participated in a clinical trial of group physical therapy? Annual direct costs were estimated to be $800 (in 1991 US dollars) in the year before the trial. Thirty-three percent of the direct costs were attributable to hospitalizations, 31% to medications, 8% to physician visits, and 27% to other services (e.g., visits to therapists). These costs are substantially lower than those estimated for patients with rheumatoid arthritis, systemic lupus erythematosus, and fibromyalgia, although precise comparisons are difficult because of differences in study settings and methodologies.21,40, 58 One reason for the apparently low direct costs associated with AS may be the preservation of functional ability in most patients with AS. Greater functional disability has consistently been found to be a major 21,40, 58 The AS patients included in the predictor of direct medical cost study had relatively short durations of AS (mean of 7 years), and low levels of functional di~ability.~~ These factors likely contributed to the low estimated direct costs, and costs might be expected to be higher in a group with a wider spectrum of ages, durations of AS, and functional abilities. Even with these considerations, however, the costs associated with AS may still be lower than those of other chronic rheumatic diseases. -4
MEASUREMENT OF GLOBAL HEALTH STATUS In addition to examining individual aspects of quality of life, it is at times desirable to have a single global measure of health that considers symptoms, functioning, social interactions, psychological state, and treatment side effects together. One approach to obtaining such an estimate is to use preference ratings, or utilities.55,56 Preference ratings are measures of the desirability of a particular state of health, compared to some alternative state, such as perfect health or death. The classical method for determining preference ratings is the standard gamble, in which respondents are presented with a situation involving a choice between remaining in their current state of health, or accepting a gamble with a given risk of death and a complementary chance of life in perfect health. The greater an individual's preference for his or her current health state, the less risk he or she would be expected to accept for a chance at perfect health, and the higher his or her preference, or utility, for his or her current health state. Compared to measures of individual aspects of health or functioning, preference ratings have the advantage of integrating all aspects of a person's health perceptions in a single measure. The standard gamble was used to estimate the preferences of 59 patients with AS who were participants in a clinical trial of group physical therapy (mean age 44 years; mean duration of AS 6 year^).^
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Using a scale with a score of 1.0 equal to perfect health and a score of 0 equal to death, the average utility among these patients was 0.84, indicating a quite high preference for their current state of health and a reluctance to risk death for a chance at a cure. Results were strikingly similar in another study using the standard gamble in a group of 50 patients (mean age 45 years; mean duration of AS 14 years), in which the mean utility was 0.85.44These findings suggest that although patients with AS recognize decrements in their health, most are generally satisfied with their current health status.
CONCLUSION
The available literature on the quality of life of patients with AS indicates that most patients have moderately severe symptoms of pain, stiffness, and fatigue; that symptoms periodically flare; and that symptoms persist throughout much of the course of AS. Despite these symptoms, however, most patients maintain good functional ability, remain employed, and do not have substantial limitations in social interactions because of their AS. Prolonged sick leaves are not uncommon, and clinically significant depression may affect up to one third of patients. Although information on financial costs is limited, the direct costs of AS appear to be lower than those of many other chronic rheumatic diseases. Most of these findings are based on studies of patients who either attended rheumatology clinics or hospitals, or were members of patient education groups. Because these patients may be more severely affected than the typical patient with AS, these studies may present a view of the quality of life of patients with AS that is skewed somewhat toward the experience of more severely affected patients. Results of populationbased studies might present an even more optimistic picture. To better define the development of functional disability and work disability, prospective studies, ideally of cohorts of patients studied from the time their symptoms begin, are needed. Identification of subgroups of patients at risk for severe persistent symptoms, premature functional or work disability, and problems in psychological functioning are also needed to focus treatment and research efforts appropriately.
References 1. Abbott CA, Helliwell PS, Chamberlain MA: Functional assessment in ankylosing spondylitis: Evaluation of a new self-administered questionnaire and correlation with anthropometric variables. Br J Rheumatol 33:1060, 1994 2. Bakker C, van der Linden S, van Santen-Hoeufft M, et a1 Problem elicitation to assess patient priorities in ankylosing spondylitis and fibromyalgia. J Rheumatol22:1304,1995 3. Bakker C, Boers M, van der Linden S: Measures to assess ankylosing spondylitis: Taxonomy, review and recommendations. J Rheumatol 201724, 1993 4. Bakker C, Hidding A, van der Linden S, et al: Cost effectiveness of group physical
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therapy compared to individualized therapy for ankylosing spondylitis. A randomized controlled trial. J Rheumatol 21:264, 1994 5. Bakker C, Rutten-van Molken, Hidding A, et al: Patient utilities in ankylosing spondylitis and the association with other outcome measures. J Rheumatol 21:1298, 1994 6. Barlow JH, Macey SJ, Struthers GR: Gender, depression, and ankylosing spondylitis. Arthritis Care Res 6:45, 1993 7. Calin A: The individual with ankylosing spondylitis: Defining disease status and the impact of the illness. Br J Rheumatol 34663, 1995 8. Calin A, Elswood J: The outcome of 138 total hip replacements and 12 revisions in ankylosing spondylitis: High success rate after a mean follow-up of 7.5 years. J Rheumatol 16:955, 1989 9. Calin A, Garrett S, Whitelock H, et al: A new approach to defining functional ability in ankylosing spondylitis: The development of the Bath Ankylosing Spondylitis Functional Index. J Rheumatol 21:2281, 1994 .a 10. Calin A, Elswood J, Rigg S, et al: Ankylosing spondylitis-An analytical review of 1500 patients: The changing pattern of disease. J Rheumatol 15:1234, 1988 11. Calin A, Elswood J: A prospective nationwide cross-sectional study of NSAID usage in 1331 patients with ankylosing spondylitis. J Rheumatol 17801, 1990 12. Carette S, Graham D, Little H, et a1 The natural disease course of ankylosing spondylitis. Arthritis Rheum 26:186, 1983 13. Clarke AE, Esdaile JM, Bloch DA, et al: A Canadian study of the total medical costs for patients with systemic lupus erythematosus and the predictors of costs. Arthritis Rheum 36:1548, 1993 14. Clegg DO, Reda DJ, Weisman MH, et al: Comparison of sulfasalazine and placebo in the treatment of ankylosing spondylitis. A Department of Veterans Affairs Cooperative Study. Arthritis Rheum 39:2004, 1996 15. Daltroy LH, Larson MG, Roberts WN, et al: A modification of the Health Assessment Questionnaire for the spondyloarthropathies. J Rheumatol 17946, 1990 16. Dougados M, Gueguen A, Nakache J-P, et al: Evaluation of a functional index and an articular index in ankylosing spondylitis. J Rheumatol 15:302, 1988 17. Dougados M, Boumier P, Amor B: Sulfasalazine in ankylosing spondylitis: A double blind controlled study in 60 patients. BMJ 293911, 1986 18. Elst P, Sybesma T, van der Stadt RJ, et al: Sexual problems in rheumatoid arthritis and ankylosing spondylitis. Arthritis Rheum 27217, 1984 19. Fries JF: The assessment of disability: From first to future principles. Br J Rheumatol 22 (suppl):48, 1983 20. Garrett S, Jenkinson T, Kennedy LG, et al: A new approach to defining disease status in ankylosing spondylitis: The Bath Ankylosing Spondylitis Disease Activity Index. J Rheumatol 212286, 1994 21. Gironimi G, Clarke AE, Hamilton VH, et al: Why health care costs more in the U.S. Comparing health care expenditures between systemic lupus erythematosus patients in Stanford and Montreal. Arthritis Rheum 39:979, 1996 22. Goodacre JA, Mander M, Dick WC: Patients with ankylosing spondylitis show individual patterns of variation in disease activity. Br J Rheumatol 30:336, 1991 23. Gran JT, Skomsvoll JF: The outcome of ankylosing spondylitis: A study of 100 patients. Br J Rheumatol36:766, 1997 24. Gran JT, Husby G: Ankylosing spondylitis. Current drug treatment. Drugs 44:585,1992 25. Gran JT, Ostensen M, Husby G: A clinical comparison between males and females with ankylosing spondylitis. J Rheumatol 12:126, 1985 26. Guillemin F, Braincon S, Pourel J, et al: Long-term disability and prolonged sick leaves as outcome measurements in ankylosing spondylitis. Possible predictive factors. Arthritis Rheum 33:1001, 1990 27. Gunther V, Mur E, Traweger C, et al: Stress coping of patients with ankylosing spondylitis. J Psychosom Res 38:419, 1994 28. Halm H, Metz-Stevenhagen P, Zielke K Results of surgical correction of kyphotic deformities of the spine in ankylosing spondylitis on the basis of the Modified Arthritis Impact Measurement Scales. Spine 20:1612, 1995 29. Hidding A, van der Linden S, Boers M, et al: Is group physical therapy superior to
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individual therapy in ankylosing spondylitis? A randomized controlled trial. Arthritis Care Res 6:117, 1993 30. Hidding A, van der Linden S, Gielen X, et al: Continuation of group physical therapy is necessary in ankylosing spondylitis. Results of a randomized controlled trial. Arthritis Care Res 790,1994 31. Hidding A, van Santen M, de Klerk E, et a1 Comparison between self-report measures and clinical observations of functional disability in ankylosing spondylitis, rheumatoid arthritis and fibromyalgia. J Rheumatol 21:818, 1994 32. Hidding A, de Witte L, van der Linden S: Determinants of self-reported health status in ankylosing spondylitis. J Rheumatol 21:275, 1994 33. Jones SD, Koh WH, Steiner A, et al: Fatigue in ankylosing spondylitis: Its prevalence and relationship to disease activity, sleep, and other factors. J Rheumatol 23487, 1996 34. Kennedy LG, Edmunds L, Calin A: The natural history of ankylosing spondylitis. Does it burn out? J Rheumatol20:688, 1993 35. Kirwan J, Edwards A, Buitfeldt B, et al: The course of established ankylosing spondylitis and the effects of sulfasalazine over 3 years. Br J Rheumatol 32729, 1993 36. Kraag G, Stokes B, Groh J, et a1 The effects of comprehensive home physiotherapy and supervision on patients with ankylosing spondylitis-A randomized controlled trail. J Rheumatol 17:228, 1990 37. Laasila K, Leirisalo-Rep0 M: Side effects of sulfasalazine in patients with rheumatic diseases or inflammatory bowel disease. Scand J Rheumatol 23338, 1994 38. Laurent MR, Buchanan WW, Bellamy N Methods of assessment used in ankylosing spondylitis clinical trials: A review. Br J Rheumatol 30326, 1991 39. Lehtinen K Working ability of 76 patients with ankylosing spondylitis. Scand J Rheumatol 10:263, 1981 40. Lubeck DP, Spitz PW, Fries JF, et al: A multicenter study of annual health service utilization and costs in rheumatoid arthritis. Arthritis Rheum 291, 1986 41. Mau A, Zeidler H, Mau R, et al: Clinical features and prognosis of patients with possible ankylosing spondylitis. Results of a 10-year follow-up. J Rheumatol 15:1109, 1988 42. McGuigan LE, Hart HH, Gow PJ, et al: Employment in ankylosing spondylitis. Ann Rheum Dis 43:604, 1984 43. Mengshoel AM, Farre 0: Pain and fatigue in patients with rheumatic disorders. Clin Rheumatol 12515, 1993 44. OBrien BJ, Elswood J, Calin A: Willingness to accept risk in the treatment of rheumatic disease. J Epidemiol Community Health 44:249, 1990 45. OBrien BJ, Elswood J, Calin A: Perception of prescription drug risks: A survey of patients with ankylosing spondylitis. J Rheumatol 17503, 1990 46. Pincus T, Marcum SB, Callahan LF, et al: Long-term drug therapy for rheumatoid arthritis in seven rheumatology private practices: 1. Nonsteroidal anti-inflammatory drugs. J Rheumatol 19:1874, 1992 47. Ringsdal VS, Andreasen JJ: Ankylosing spondylitis-experience with a self-administered questionnaire: An analytical study. Ann Rheum Dis 48:924, 1989 48. Ringsdal VS, Helin P: Ankylosing spondylitis-Education, employment and invalidity. Dan Med Bull 38:282, 1991 49. Roussou E, Kennedy LG, Garrett S, et al: Socioeconomic status in ankylosing spondylitis: Relationship between occupation and disease activity. J Rheumatol 24:908, 1997 50. Russell P, Unsworth A, Haslock I: The effect of exercise on ankylosing spondylitis-A preliminary study. Br J Rheumatol32498, 1993 51. Schipper H, Clinch JJ, Olweny CLM: Quality of life studies: Definitions and conceptual issues. In Spilker B (ed): Quality of Life and Pharmacoeconomics in Clinical Trials, ed 2. Philadelphia, Lippincott-Raven Publishers, 1996, p 11 52. Shanahan WR, Kaprove RE, Major PA, et al: Assessment of long-term benefit of total hip replacement in patients with ankylosing spondylitis. J Rheumatol 9:101, 1982 53. Shih L-Y, Chen T-H, Lo W-H, et al: Total hip arthroplasty in patients with ankylosing spondylitis: Long-term follow-up. J Rheumatol 221704, 1995 54. Sochart DH, Porter ML: Long-term results of total hip replacement in young patients who had ankylosing spondylitis. J Bone Joint Surg [Am] 79:1181, 1997
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55. Torrence G W Measurement of health state utilities for economic appraisal. Journal of Health Economics 5:1, 1986 56. Torrence GW: Utility approach to measuring health-related quality of life. Journal of Chronic Disease 40:593, 1987 57. Viitanen JV, Lehtinen K, Suni J, et a1 Fifteen months’ follow-up of intensive inpatient physiotherapy and exercise in ankylosing spondylitis. Clin Rheumatol 14:413, 1995 58. Wolfe F, Anderson J, Harkness D, et a1 A prospective, longitudinal multicenter study of service utilization and costs in fibromyalgia. Arthritis Rheum 401560, 1997 59. Wordsworth BP, Pearcy MJ, Mowat AG: Inpatient regime for the treatment of ankylosing spondylitis: An appraisal of improvement in spinal mobility and the effects of corticotrophin. Br J Rheumatol23:39, 1984 60. Wordsworth BP, Mowat AG: A review of 100 patients with ankylosing spondylitis with particular reference to socio-economic effects. Br J Rheumatol 25:175, 1986 Address-tzprinf requests to Dr. Michael Ward VA Palo Alto Health Care System l l l G 3801 Miranda Avenue Palo Alto, CA 94304
SPONDYLOARTHROPATHIES
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QUALITY OF LIFE IN PATIENTS WITH ANKYLOSING SPONDYLITIS Michael M. Ward, MD, MPH -4
Health-related quality of life may be defined as the “net consequence of a disease and its treatment on a patient’s perception of his ability to live a useful and fulfilling life.51”By its nature, quality of life is subjective and based on a patient’s perceived experience, and it is also multidimensional. Health-related quality of life is usually considered to be comprised of several domains, including symptoms, physical functioning, work or role functioning, social interactions, psychological states, and treatment side effects, listed below. Some conceptualizations include the financial costs of illness as an additional domain.I9 Each of these domains, in turn, is comprised of several components. For example, symptoms may include pain, stiffness, or fatigue, and social interactions may include interactions with family members, friends, or coworkers. Such a schema permits an organized and complete assessment of the impact of a disease on affected individuals. Components of health-related quality of life:
Symptoms Pain Stiffness Physical Functioning Self-care Mobility
Fatigue Poor sleep Household tasks
Supported in part by the Bartman Foundation From the Veterans Affairs Palo Alto Health Care System, and Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, California
RHEUMATIC DISEASE CLINICS OF NORTH AMERICA
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VOLUME 24 NUMBER 4 * NOVEMBER 1998
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Role Functioning Work School Home Social Interactions Marriage Coworkers Family Community Friends Leisure time Psychological Functioning Depression Health distress Anxiety Coping mechanisms Treatment Side Efects (some examples) Dyspepsia Skin rash Gastrointestinal bleeding Financial Costs Direct costs Indirect costs Along with mortality and measures of physiological or anatomical impairment, quality of life is a major component of health outcomes. Research in health-related quality of life in general, and in patients with rheumatic diseases in particular, has expanded greatly in the past 15 years. This article focuses on studies published since 1980 concerning the quality of life of patients with ankylosing spondylitis (AS). SYMPTOMS Pain, stiffness, and fatigue are the most commonly reported symptoms of patients with AS. As in most rheumatic diseases, the severity of symptoms varies greatly among patients and varies over time in individual patients. In a prospective longitudinal study in which 22 patients were examined monthly for 1 year, all had at least one exacerbation of symptoms and several had recurrent flares and subsequent improvementsZ2Daily pain and stiffness are common, being reported by more than 70% of patients.23In general, most reports find the average severity of pain and stiffness reported by patients with AS to be less than or comparable to that reported by patients with rheumatoid arthritis.43, For example, scores on the total pain index of the McGill Pain Questionnaire (possible range 0 to 100; higher scores indicate greater pain severity) averaged 32 in a group of patients with AS attending a rheumatology clinic, compared to 42 in a group of patients with rheumatoid arthriti~?~ Another method to assess symptom severity is to ask patients, in a hypothetical scenario, what degree of risk they would be willing to take to obtain complete relief of their symptoms. A willingness to take greater risks would indicate not only that the symptom was severe but also that its relief was important to the patient. Using the standard gamble technique to present such scenarios to 50 patients with AS who were either outpatients in a rheumatology clinic or inpatients receiving extensive physical therapy, O’Brien et a1 found that, on average, patients were willing to risk an 11%chance of death to obtain either complete relief of pain or complete relief of stiffness In comparison, patients with
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range of possible risk factors, and only one study used multivariate statistical techniques to determine the independent contribution of different factors to the risk of work disability.26 Although most patients with AS maintain employment, 8% to 37% of patients reported changing occupations, in most instances owing to 42, 48, 6o Most changes were to a job that was less physically their AS.39* demanding. In addition, up to one third of patients reported having at least one prolonged sick leave.26,6o The likelihood that a person with AS would have a lengthy sick leave was increased among those with peripheral arthritis and those whose work required carrying heavy loads.26
SOCIAL INTERACTION Limitations in social interactions can occur in the context of marriage, family, friends, coworkers, and the general community. There has been little research dedicated specifically to limitations in social interactions among patients with AS, perhaps because of the perception that few problems exist in this area. In a survey of 129 patients with AS, only 1%reported concerns about limitations in social interactions, 2% reported concerns about limitations in communication, and 6% reported limitations in leisure activities.2 A study of sexual problems in patients with AS found no problems among men, but women with AS reported less sexual enjoyment and preferred to have intercourse less frequently In a survey of 100 patients with a mean age than unaffected of 42 years and a mean duration of AS of 20 years, 7% reported severe discomfort during intercourse (4 out of 21 women; 3 out of 79 men), and 27% reported mild discomfort (7 out of 21 women; 20 out of 79 men).60These limited findings indicate that sexual functioning may be a substantial problem and an area of concern for some patients.
PSYCHOLOGICAL FUNCTIONING Problems with emotional health have been reported by 20% of patients with AS, and emotional problems were identified as the second most frequent problem causing a limitation in functioning.2Despite this substantial effect, there have been few studies that specifically examine psychological functioning in patients with AS. The prevalence of depression in patients with AS was measured in a cross-sectional survey of a group of 177 patients with a mean age of 43 and a mean duration of AS of 18 years, who were recruited from rheumatology clinics and patient education groups.6 Based on the Centers for Epidemiological StudiesDepression Scale, 31% of patients were depressed; depression was more common among women in this survey (46%) than among men (26%). The main correlates of the level of depression were pain severity among women, and functional disability and pain severity among men. Similar
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for patients with AS, the major benefit of such therapy may be preservation of spinal motion, as decreases in pain and stiffness have not consis29, 30,36, 50, 57,59 Intensive inpatient therapy, as is tently been documented.20, the practice in some European countries, may afford greater benefit. For patients with severe hip arthritis, total hip arthroplasty commonly affords sustained relief of hip pain.s,52-54 PHYSICAL FUNCTIONING
Physical disability or functional disability refers to limitations in self-care activities, mobility, and performance of household tasks. Assessment of functional disability is commonly done by patient self-report using validated questionnaires. These questionnaires may be generic and applicable in any disease, such as the Sickness Impact Profile or Medical Outcomes Study-Short Form 36, or may be more arthritis-specific, such as the Health Assessment Questionnaire or the Arthritis Impact Measurement Scales. Some investigators have suggested that questionnaires specific for patients with spondyloarthropathies are needed, based on the belief that axial arthritis results in functional impairments and disability not captured adequately by more generic instruments. Spondylitis-specific measures of functional disability might, therefore, be more relevant to the assessment of functional difficulties in patients with AS, and might be more sensitive to change with treatment.', 7, 9, 15*l6 Four spondylitis-specific measures of functional disability have recently been pr0posed.l.9, 15,l6 One is a modification of the Health Assessment Questionnaire, with two additional scales dealing with driving and posture-related activitie~.'~ The three other measures are newly devised questionnaires, each of which has undergone initial validation and assessment for sensitivity to change.', l6 Whether these spondylitisspecific questionnaires provide better information about functional disability in patients with AS, or are more sensitive to change than more generic functional status instruments, remains to be determined. However, it is clear that patient self-report questionnaires accurately capture functional disabilities in patients with AS.31 As measured by these instruments, functional disability appears to be mild in most patients with AS (Table 1).In most studies, mean scores were in the lowest third of the possible range. Because patients in these studies were recruited from rheumatology clinics or specialized rheumatic disease hospitals, or were participants in controlled trials, they might be expected to be more severely affected than the typical patient with AS. The level of functional disability might be even less in a population-based study. Similar findings of generally low levels of functional disability were reported in three studies using the American Rheumatism Association (ARA) functional classification to grade physical disability. In these studies, patients in ARA class I11 or IV comprised 4%, 22'7'0, and 20% of the groups that were examined after a mean duration of AS of 38 years, 18 years, and 20 years, respectively.12,41, 6o 97
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Table 1. MEASUREMENT OF FUNCTIONAL DISABILITY IN PATIENTS WITH ANKYLOSING SPONDYLITIS Mean Mean age duration Reference Number (years) (years)
9
42 163
47.7
24.7
15 16 23 29
44 80 100 144
38.5
13.7
41.8 42.0
16.5
1
-
-
4.5
Measure* Leeds Disability BASFI Functional Index HAQ-S Functional Index ADL score HAQ-S Functional Index
Possible range Mean f SD
0-3 0-10 0-40
0-3 0-40 51-0
0-3 0-40
1.23 2 0.8 4.0 ? 2.1 2.6 2 1.7 0.5 2 0.5 9.8 2 5.8 39.7 0.35 7.8
-I
'BASFI = Bath Ankylosing Spondylitis Functional Index; HAQ-S = Health Assessment Questionnaire for the. Spondyloarthropathies; ADL score = Activities of Daily Living score. For each measure except the ADL score, higher values indicate greater functional disability. SD = standard deviation.
When problems with functional abilities do occur, they appear to be related more to mobility than to self-care activities. A survey of 129 patients found that 47% reported problems with mobility, while only 6% reported problems with self-care.* In addition to the duration of AS, risk factors for greater functional disability include the presence of peripheral arthritis?" 26, 6o hip arthriti~?~ and the neck involvement,41 younger age at onset,lO,26 being presence of comorbid illness.23Greater disease activity, manifested by more pain and stiffness, has been associated with greater functional disability, as has depression, anxiety, and a diminished sense by the patient that he or she has control over his or her health outcomes?, 32 The degree of functional disability may correlate only weakly with measures of physical impairment, such as the Schober test, occiput to wall distance, or cervical rotation.', 15, l6 Most studies of risk factors for functional disability examined only a limited range of possible risk factors, and few used multivariate statistical techniques to allow identification of those factors that were independently associated with functional disability. A more complete assessment of risk factors for functional disability is needed that would simultaneously examine a broad range of potential risk factors. Functional disability has not commonly been measured in controlled trials on nonsteroidal anti-inflammatory drugs, although treatment with these medications can result in improvements in function.16Measures of functional disability have been more widely used in controlled trials of sulfasalazine in AS, with conflicting results.14,17, 3s In contrast, physical therapy has been consistently shown to improve functional disability or stabilize functional decline when exercise has been continued for periods from 2 weeks to 18 months.30,36, s9 Total hip arthroplasty can also improve functioning in patients with hip arthritis.53Surgical correction of severe spinal kyphosis may also improve function in patients with these deformities.28
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WORK ABILITY
Nine studies have reported on the work ability of patients with AS (Table 2).* All but one of these studies was a cross-sectional survey of patients attending rheumatology clinics or of members of patient education groups, so the representativeness of the samples may be limited. In these studies, 60% to 85% of patients remained employed after mean durations of AS of 14 years or more. Because work disability increases cumulatively with age and with the duration of AS, it is more informative to report the proportion of patients who remain employed at specific durations of AS, rather than the proportion employed of a group of patients with varying durations of disease. Three studies report cumulative proportions, with employment ranging from 79% to 85% after 20 years of AS, and from 53% to 81% after 30 years of AS.39* 42, 48 The patients in these studies were predominantly young or middleaged men, and most studies were done in Northern or Western Europe. Because age, sex, and the societal response to unemployment may influence the likelihood with which people stop working, these factors should also be considered in studies of work disability. A study that followed patients over time would also be a more appropriate way in which to assess the time to work disability. Factors associated with continued employment include higher socioeconomic status, possibly because the physical demands of the jobs of persons with higher socioeconomic status are less.23,26, 49 Vocational counseling has been associated with a decrease of 62% in the risk of employment disability.26Other risk factors for work disability include indicators of active AS, such as pain and greater functional 42 hip arthritis or hip replacedisabilityz3,49 restricted lumbar m0bility,2~, ment,42and comorbid illne~ses.2~ As was the case for physical disability, most studies of risk factors for work disability considered a limited 397
*References 12, 23, 25, 26, 39, 42, 48, 49, and 60.
Table 2. EMPLOYMENT IN PATIENTS WITH ANKYLOSING SPONDYLITIS
Reference
Number
12 23 25 26 39 42 48 49 60
51 100 122 182 76 60 231 1044 100
Mean age (years) 62 42 39
44 45 43 42
Mean duration (years) 38 16 15 14
-
24 21 21 20
YO Male 100 67 67 88 89 78 63 100 79
Mean YO employed 54 63 68 64
-
85 68 85 84
Yo Employed at 20 years
at 30 years
-
-
82 79 85
53 73 81
-
-
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range of possible risk factors, and only one study used multivariate statistical techniques to determine the independent contribution of different factors to the risk of work disability.26 Although most patients with AS maintain employment, 8% to 37% of patients reported changing occupations, in most instances owing to 42, 48, 6o Most changes were to a job that was less physically their AS.39* demanding. In addition, up to one third of patients reported having at least one prolonged sick leave.26,6o The likelihood that a person with AS would have a lengthy sick leave was increased among those with peripheral arthritis and those whose work required carrying heavy loads.26
SOCIAL INTERACTION Limitations in social interactions can occur in the context of marriage, family, friends, coworkers, and the general community. There has been little research dedicated specifically to limitations in social interactions among patients with AS, perhaps because of the perception that few problems exist in this area. In a survey of 129 patients with AS, only 1%reported concerns about limitations in social interactions, 2% reported concerns about limitations in communication, and 6% reported limitations in leisure activities.2 A study of sexual problems in patients with AS found no problems among men, but women with AS reported less sexual enjoyment and preferred to have intercourse less frequently In a survey of 100 patients with a mean age than unaffected of 42 years and a mean duration of AS of 20 years, 7% reported severe discomfort during intercourse (4 out of 21 women; 3 out of 79 men), and 27% reported mild discomfort (7 out of 21 women; 20 out of 79 men).60These limited findings indicate that sexual functioning may be a substantial problem and an area of concern for some patients.
PSYCHOLOGICAL FUNCTIONING Problems with emotional health have been reported by 20% of patients with AS, and emotional problems were identified as the second most frequent problem causing a limitation in functioning.2Despite this substantial effect, there have been few studies that specifically examine psychological functioning in patients with AS. The prevalence of depression in patients with AS was measured in a cross-sectional survey of a group of 177 patients with a mean age of 43 and a mean duration of AS of 18 years, who were recruited from rheumatology clinics and patient education groups.6 Based on the Centers for Epidemiological StudiesDepression Scale, 31% of patients were depressed; depression was more common among women in this survey (46%) than among men (26%). The main correlates of the level of depression were pain severity among women, and functional disability and pain severity among men. Similar
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studies have not been performed to examine anxiety or health distress among patients with AS. In addition to being an important component of health status in its own right, psychological functioning may influence other aspects of health status. Depression and anxiety are among the factors associated 49 However, because with poorer functional ability and ~nemployment.~~, these studies were cross-sectional, it is unclear whether depression or anxiety was a cause or a consequence of poorer physical or work functioning. The coping mechanisms used to deal with stressful situations were examined among 76 men with AS.27Compared to unaffected controls, patients with AS were more likely to mitigate stressful situations by comparing themselves to others and by finding alternative sources of gratification, and were less likely to use self-accusation or resignation. The coping mechanisms used did not vary with the duration of AS. These findings indicate the use of adaptive coping mechanisms, in general, by patients with AS. In coping with pain, the use of active or passive coping mechanisms was not found to differ between 31 patients with AS and patients with either rheumatoid arthritis or fibr~myalgia.~~ TREATMENT-RELATED SIDE EFFECTS
Side effects are unfortunately common with the medications most often used to treat AS.24 In a survey of 1034 members of a patient education group in Britain, 47% of patients reported experiencing a serious adverse drug reacti0n.4~The nature of these reactions was not described. A related study on the same group of patients found that 30% to 40% of patients treated with indomethacin, naproxen, piroxicam, or diclofenac stopped these medications because of side effects.” These proportions are similar to the proportions of patients with rheumatoid arthritis who discontinue use of nonsteroidal anti-inflammatory drugs due to Seventeen of 20 patients with AS (85%) who were treated with sulfasalazine reported some side effect from this medication, compared to 68% of patients with rheumatoid arthritis.37Although most of these side effects were mild, 40% of patients with AS discontinued sulfasalazine because of them, as did 48% of patients with rheumatoid arthritis. Although the evidence is limited, in general, medication side effects do not appear to occur with increased frequency or severity among patients with AS, compared to patients with other rheumatic diseases. Studies have not specifically examined the importance of medication side effects in patients’ overall assessments of their quality of life. FINANCIAL COSTS
Financial costs of an illness may be categorized as direct costs, which represent the expenditures made or the value of health care
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services consumed in the provision of medical care, and indirect costs, which represent, for the most part, the amount of income foregone by the patient and his or her caregivers because of the illness. One Dutch study has examined the direct costs of AS among 111 patients who participated in a clinical trial of group physical therapy? Annual direct costs were estimated to be $800 (in 1991 US dollars) in the year before the trial. Thirty-three percent of the direct costs were attributable to hospitalizations, 31% to medications, 8% to physician visits, and 27% to other services (e.g., visits to therapists). These costs are substantially lower than those estimated for patients with rheumatoid arthritis, systemic lupus erythematosus, and fibromyalgia, although precise comparisons are difficult because of differences in study settings and methodologies.21,40, 58 One reason for the apparently low direct costs associated with AS may be the preservation of functional ability in most patients with AS. Greater functional disability has consistently been found to be a major 21,40, 58 The AS patients included in the predictor of direct medical cost study had relatively short durations of AS (mean of 7 years), and low levels of functional di~ability.~~ These factors likely contributed to the low estimated direct costs, and costs might be expected to be higher in a group with a wider spectrum of ages, durations of AS, and functional abilities. Even with these considerations, however, the costs associated with AS may still be lower than those of other chronic rheumatic diseases. -4
MEASUREMENT OF GLOBAL HEALTH STATUS In addition to examining individual aspects of quality of life, it is at times desirable to have a single global measure of health that considers symptoms, functioning, social interactions, psychological state, and treatment side effects together. One approach to obtaining such an estimate is to use preference ratings, or utilities.55,56 Preference ratings are measures of the desirability of a particular state of health, compared to some alternative state, such as perfect health or death. The classical method for determining preference ratings is the standard gamble, in which respondents are presented with a situation involving a choice between remaining in their current state of health, or accepting a gamble with a given risk of death and a complementary chance of life in perfect health. The greater an individual's preference for his or her current health state, the less risk he or she would be expected to accept for a chance at perfect health, and the higher his or her preference, or utility, for his or her current health state. Compared to measures of individual aspects of health or functioning, preference ratings have the advantage of integrating all aspects of a person's health perceptions in a single measure. The standard gamble was used to estimate the preferences of 59 patients with AS who were participants in a clinical trial of group physical therapy (mean age 44 years; mean duration of AS 6 year^).^
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Using a scale with a score of 1.0 equal to perfect health and a score of 0 equal to death, the average utility among these patients was 0.84, indicating a quite high preference for their current state of health and a reluctance to risk death for a chance at a cure. Results were strikingly similar in another study using the standard gamble in a group of 50 patients (mean age 45 years; mean duration of AS 14 years), in which the mean utility was 0.85.44These findings suggest that although patients with AS recognize decrements in their health, most are generally satisfied with their current health status.
CONCLUSION
The available literature on the quality of life of patients with AS indicates that most patients have moderately severe symptoms of pain, stiffness, and fatigue; that symptoms periodically flare; and that symptoms persist throughout much of the course of AS. Despite these symptoms, however, most patients maintain good functional ability, remain employed, and do not have substantial limitations in social interactions because of their AS. Prolonged sick leaves are not uncommon, and clinically significant depression may affect up to one third of patients. Although information on financial costs is limited, the direct costs of AS appear to be lower than those of many other chronic rheumatic diseases. Most of these findings are based on studies of patients who either attended rheumatology clinics or hospitals, or were members of patient education groups. Because these patients may be more severely affected than the typical patient with AS, these studies may present a view of the quality of life of patients with AS that is skewed somewhat toward the experience of more severely affected patients. Results of populationbased studies might present an even more optimistic picture. To better define the development of functional disability and work disability, prospective studies, ideally of cohorts of patients studied from the time their symptoms begin, are needed. Identification of subgroups of patients at risk for severe persistent symptoms, premature functional or work disability, and problems in psychological functioning are also needed to focus treatment and research efforts appropriately.
References 1. Abbott CA, Helliwell PS, Chamberlain MA: Functional assessment in ankylosing spondylitis: Evaluation of a new self-administered questionnaire and correlation with anthropometric variables. Br J Rheumatol 33:1060, 1994 2. Bakker C, van der Linden S, van Santen-Hoeufft M, et a1 Problem elicitation to assess patient priorities in ankylosing spondylitis and fibromyalgia. J Rheumatol22:1304,1995 3. Bakker C, Boers M, van der Linden S: Measures to assess ankylosing spondylitis: Taxonomy, review and recommendations. J Rheumatol 201724, 1993 4. Bakker C, Hidding A, van der Linden S, et al: Cost effectiveness of group physical
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therapy compared to individualized therapy for ankylosing spondylitis. A randomized controlled trial. J Rheumatol 21:264, 1994 5. Bakker C, Rutten-van Molken, Hidding A, et al: Patient utilities in ankylosing spondylitis and the association with other outcome measures. J Rheumatol 21:1298, 1994 6. Barlow JH, Macey SJ, Struthers GR: Gender, depression, and ankylosing spondylitis. Arthritis Care Res 6:45, 1993 7. Calin A: The individual with ankylosing spondylitis: Defining disease status and the impact of the illness. Br J Rheumatol 34663, 1995 8. Calin A, Elswood J: The outcome of 138 total hip replacements and 12 revisions in ankylosing spondylitis: High success rate after a mean follow-up of 7.5 years. J Rheumatol 16:955, 1989 9. Calin A, Garrett S, Whitelock H, et al: A new approach to defining functional ability in ankylosing spondylitis: The development of the Bath Ankylosing Spondylitis Functional Index. J Rheumatol 21:2281, 1994 .a 10. Calin A, Elswood J, Rigg S, et al: Ankylosing spondylitis-An analytical review of 1500 patients: The changing pattern of disease. J Rheumatol 15:1234, 1988 11. Calin A, Elswood J: A prospective nationwide cross-sectional study of NSAID usage in 1331 patients with ankylosing spondylitis. J Rheumatol 17801, 1990 12. Carette S, Graham D, Little H, et a1 The natural disease course of ankylosing spondylitis. Arthritis Rheum 26:186, 1983 13. Clarke AE, Esdaile JM, Bloch DA, et al: A Canadian study of the total medical costs for patients with systemic lupus erythematosus and the predictors of costs. Arthritis Rheum 36:1548, 1993 14. Clegg DO, Reda DJ, Weisman MH, et al: Comparison of sulfasalazine and placebo in the treatment of ankylosing spondylitis. A Department of Veterans Affairs Cooperative Study. Arthritis Rheum 39:2004, 1996 15. Daltroy LH, Larson MG, Roberts WN, et al: A modification of the Health Assessment Questionnaire for the spondyloarthropathies. J Rheumatol 17946, 1990 16. Dougados M, Gueguen A, Nakache J-P, et al: Evaluation of a functional index and an articular index in ankylosing spondylitis. J Rheumatol 15:302, 1988 17. Dougados M, Boumier P, Amor B: Sulfasalazine in ankylosing spondylitis: A double blind controlled study in 60 patients. BMJ 293911, 1986 18. Elst P, Sybesma T, van der Stadt RJ, et al: Sexual problems in rheumatoid arthritis and ankylosing spondylitis. Arthritis Rheum 27217, 1984 19. Fries JF: The assessment of disability: From first to future principles. Br J Rheumatol 22 (suppl):48, 1983 20. Garrett S, Jenkinson T, Kennedy LG, et al: A new approach to defining disease status in ankylosing spondylitis: The Bath Ankylosing Spondylitis Disease Activity Index. J Rheumatol 212286, 1994 21. Gironimi G, Clarke AE, Hamilton VH, et al: Why health care costs more in the U.S. Comparing health care expenditures between systemic lupus erythematosus patients in Stanford and Montreal. Arthritis Rheum 39:979, 1996 22. Goodacre JA, Mander M, Dick WC: Patients with ankylosing spondylitis show individual patterns of variation in disease activity. Br J Rheumatol 30:336, 1991 23. Gran JT, Skomsvoll JF: The outcome of ankylosing spondylitis: A study of 100 patients. Br J Rheumatol36:766, 1997 24. Gran JT, Husby G: Ankylosing spondylitis. Current drug treatment. Drugs 44:585,1992 25. Gran JT, Ostensen M, Husby G: A clinical comparison between males and females with ankylosing spondylitis. J Rheumatol 12:126, 1985 26. Guillemin F, Braincon S, Pourel J, et al: Long-term disability and prolonged sick leaves as outcome measurements in ankylosing spondylitis. Possible predictive factors. Arthritis Rheum 33:1001, 1990 27. Gunther V, Mur E, Traweger C, et al: Stress coping of patients with ankylosing spondylitis. J Psychosom Res 38:419, 1994 28. Halm H, Metz-Stevenhagen P, Zielke K Results of surgical correction of kyphotic deformities of the spine in ankylosing spondylitis on the basis of the Modified Arthritis Impact Measurement Scales. Spine 20:1612, 1995 29. Hidding A, van der Linden S, Boers M, et al: Is group physical therapy superior to
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55. Torrence G W Measurement of health state utilities for economic appraisal. Journal of Health Economics 5:1, 1986 56. Torrence GW: Utility approach to measuring health-related quality of life. Journal of Chronic Disease 40:593, 1987 57. Viitanen JV, Lehtinen K, Suni J, et a1 Fifteen months’ follow-up of intensive inpatient physiotherapy and exercise in ankylosing spondylitis. Clin Rheumatol 14:413, 1995 58. Wolfe F, Anderson J, Harkness D, et a1 A prospective, longitudinal multicenter study of service utilization and costs in fibromyalgia. Arthritis Rheum 401560, 1997 59. Wordsworth BP, Pearcy MJ, Mowat AG: Inpatient regime for the treatment of ankylosing spondylitis: An appraisal of improvement in spinal mobility and the effects of corticotrophin. Br J Rheumatol23:39, 1984 60. Wordsworth BP, Mowat AG: A review of 100 patients with ankylosing spondylitis with particular reference to socio-economic effects. Br J Rheumatol 25:175, 1986 Address-tzprinf requests to Dr. Michael Ward VA Palo Alto Health Care System l l l G 3801 Miranda Avenue Palo Alto, CA 94304