Skip to main content
Key Specialties
Cardiology Diabetology Endocrinology Gastroenterology Geriatrics and Gerontology Gynecology and Obstetrics Hematology Infectious Disease Internal Medicine Nephrology Neurology Oncology Pediatrics Respiratory Medicine Rheumatology Surgery
Congress Coverage
2024 ACC Congress 2023 ESMO Congress 2023 EASD Congress 2023 ERS Congress 2023 ESC Congress 2023 EHA Congress 2023 ASCO Annual Meeting
Clinical Collections
Advances in Alzheimer’s

At a glance: The ONWARDS insulin icodec trials

A round-up of the ONWARDS phase 3 clinical trials evaluating the novel weekly insulin icodec in people with diabetes.
ADVANCED SEARCH
Log in
Top
PharmacoEconomics
Published in: PharmacoEconomics 1/2004

01-09-2004 | Original Review Article

Epidemiology and burden of illness of rheumatoid arthritis

Author: Dr Tore K. Kvien

Published in: PharmacoEconomics | Special Issue 1/2004

Login to get access

Abstract

Rheumatoid arthritis (RA) is a chronic, generally progressive autoimmune disease that causes functional disability, significant pain and joint destruction, and leads to premature mortality. It is estimated to affect between 0.5 and 1.0% of the adult population worldwide, increases in prevalence with age and affects more women than men. The magnitude of the severe long-term economic consequences of RA has been underestimated in the past. Most patients with the disease require continuous treatment to retard or stop progression and to control disease flares. Many also require surgery, such as total hip or knee replacement. In addition to these direct costs, work disability leads to reduced productivity and early retirement, and as a result, substantial indirect costs. The individual and his or her family must cope with the feeling of loss of contribution to society combined with redefined social roles, and the effects of pain, fatigue, low self-esteem, mental distress and depression.
A number of countries in North America and Europe have reported a decline in the incidence of RA in recent years, although geographical differences remain that may be associated with genetic, environmental or cultural factors. Nevertheless, patients with RA have not shared the improvements in survival rates seen with other diseases over the last 40 years, and have a mean reduction in life expectancy of between 5 and 10 years. Disease severity, activity and disability are strongly linked to premature mortality in patients with RA. The high direct and indirect costs associated with RA, together with the substantial morbidity and mortality affecting millions of people worldwide, underline the potential benefits of improved treatments for this chronic disease to patients, their families and society.
Literature
1.
Lubeck DP. A review of the direct costs of rheumatoid arthritis: managed care versus fee-for-service settings. Pharmacoeconomics 2001; 19 (8): 811–8PubMedCrossRef
2.
Hunsche E, Chancellor JV, Bruce N. The burden of arthritis and nonsteroidal anti-inflammatory treatment. A European literature review. Pharmacoeconomics 2001; 19 Suppl. 1: 1–15PubMedCrossRef
3.
Pincus T. The underestimated long term medical and economic consequences of rheumatoid arthritis. Drugs 1995; 50 Suppl. 1: 1–14PubMedCrossRef
4.
Arnett FC, Edworthy SM, Bloch DA, et al. The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis. Arthritis Rheum 1988; 31 (3): 315–24PubMedCrossRef
5.
Abdel-Nasser AM, Rasker JJ, Valkenburg HA. Epidemiological and clinical aspects relating to the variability of rheumatoid arthritis. Semin Arthritis Rheum 1997; 27 (2): 123–40PubMedCrossRef
6.
Isomäki HA. Prevalence and social impact of rheumatic diseases in Finland. J Rheumatol 1983; 10 Suppl.: 29–33
7.
Knorr U. [A panorama of rheumatic diseases]. Versicherungsmedizin 1994; 46 (6): 212–5PubMed
8.
Lawrence RC, Helmick CG, Arnett FC, et al. Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States. Arthritis Rheum 1998; 41 (5): 778–99PubMedCrossRef
9.
Rubin LA and Voorneveld CR. High prevalence of rheumatoid arthritis among North American Native Indians (NANI): support for the New World theory of RA. Arthritis Rheum 1991; 34 Suppl. 9: S181
10.
Boyer GS, Templin DW, Lanier AP. Rheumatic diseases in Alaskan Indians of the southeast coast: high prevalence of rheumatoid arthritis and systemic lupus erythematosus. J Rheumatol 1991; 18 (10): 1477–84PubMed
11.
Boyer GS, Benevolenskaya LI, Templin DW, et al. Prevalence of rheumatoid arthritis in circumpolar native populations. J Rheumatol 1998; 25 (1): 23–9PubMed
12.
Del Puente A, Knowler WC, Pettitt DJ, Bennett PH. High incidence and prevalence of rheumatoid arthritis in Pima Indians. Am J Epidemiol 1989; 129 (6): 1170–8PubMed
13.
Guillemin F, Briancon S, Klein JM, Sauleau E, Pourel J. Low incidence of rheumatoid arthritis in France. Scand J Rheumatol 1994; 23 (5): 264–8PubMedCrossRef
14.
Gran JT, Magnus J, Mikkelsen K. The incidence of classical and definite rheumatoid arthritis in Lillehammer, Norway. Scand J Rheumatol 1986; 15 Suppl. 59: 7–11
15.
Uhlig T, Kvien TK, Glennas A, Smedstad LM, Forre O. The incidence and severity of rheumatoid arthritis, results from a county register in Oslo, Norway. J Rheumatol 1998; 25 (6): 1078–84PubMed
16.
Symmons DP, Barrett EM, Bankhead CR, Scott DG, Silman AJ. The incidence of rheumatoid arthritis in the United Kingdom: results from the Norfolk Arthritis Register. Br J Rheumatol 1994; 33 (8): 735–9PubMedCrossRef
17.
Doran MF, Pond GR, Crowson CS, O’Fallon WM, Gabriel SE. Trends in incidence and mortality in rheumatoid arthritis in Rochester, Minnesota, over a forty-year period. Arthritis Rheum 2002; 46 (3): 625–31PubMedCrossRef
18.
Gabriel SE, Crowson CS, O’Fallon WM. The epidemiology of rheumatoid arthritis in Rochester, Minnesota, 1955–1985. Arthritis Rheum 1999; 42 (3): 415–20PubMedCrossRef
19.
Jacobson DL, Gange SJ, Rose NR, Graham NM. Epidemiology and estimated population burden of selected autoimmune diseases in the United States. Clin Immunol Immunopathol 1997; 84 (3): 223–43PubMedCrossRef
20.
Chan KW, Felson DT, Yood RA, Walker AM. Incidence of rheumatoid arthritis in central Massachusetts. Arthritis Rheum 1993; 36 (12): 1691–6PubMedCrossRef
21.
Dugowson CE, Koepsell TD, Voigt LF, Bley L, Nelson JL, Daling JR. Rheumatoid arthritis in women. Incidence rates in group health cooperative, Seattle, Washington, 1987–1989. Arthritis Rheum 1991; 34 (12): 1502–7PubMedCrossRef
22.
Linos A, Worthington JW, O’Fallon WM, Kurland LT. The epidemiology of rheumatoid arthritis in Rochester, Minnesota: a study of incidence, prevalence, and mortality. Am J Epidemiol 1980; 111 (1): 87–98PubMed
23.
Jacobsson LT, Hanson RL, Knowler WC, et al. Decreasing incidence and prevalence of rheumatoid arthritis in Pima Indians over a twenty-five-year period. Arthritis Rheum 1994; 37 (8): 1158–65PubMedCrossRef
24.
Wiles N, Symmons DP, Harrison B, et al. Estimating the incidence of rheumatoid arthritis: trying to hit a moving target? Arthritis Rheum 1999; 42 (7): 1339–46PubMedCrossRef
25.
Kvien TK, Glennas A, Knudsrod OG, Smedstad LM, Mowinckel P, Forre O. The prevalence and severity of rheumatoid arthritis in Oslo. Results from a county register and a population survey. Scand J Rheumatol 1997; 26 (6): 412–8PubMedCrossRef
26.
Wiles NJ, Lunt M, Barrett EM, et al. Reduced disability at five years with early treatment of inflammatory polyarthritis: results from a large observational cohort, using propensity models to adjust for disease severity. Arthritis Rheum 2001; 44 (5): 1033–42PubMedCrossRef
27.
Bukhari MA, Wiles NJ, Lunt M, et al. Influence of diseasemodifying therapy on radiographic outcome in inflammatory polyarthritis at five years: results from a large observational inception study. Arthritis Rheum 2003; 48 (1): 46–53PubMedCrossRef
28.
Mottonen T, Hannonen P, Korpela M, et al. Delay to institution of therapy and induction of remission using singledrug or combination-disease-modifying antirheumatic drug therapy in early rheumatoid arthritis. Arthritis Rheum 2002; 46 (4): 894–8PubMedCrossRef
29.
Lard LR, Visser H, Speyer I, et al. Early versus delayed treatment in patients with recent-onset rheumatoid arthritis: comparison of two cohorts who received different treatment strategies. Am J Med 2001; 111 (6): 446–51PubMedCrossRef
30.
Stenger AA, Van Leeuwen MA, Houtman PM, et al. Early effective suppression of inflammation in rheumatoid arthritis reduces radiographic progression. Br J Rheumatol 1998; 37 (11): 1157–63PubMedCrossRef
31.
Egsmose C, Lund B, Borg G, et al. Patients with rheumatoid arthritis benefit from early 2nd line therapy: 5 year followup of a prospective double blind placebo controlled study. J Rheumatol 1995; 22 (12): 2208–13PubMed
32.
van der Heide A, Jacobs JW, Bijlsma JW, et al. The effectiveness of early treatment with “second-line” antirheumatic drugs. A randomized, controlled trial. Ann Intern Med 1996; 124 (8): 699–707PubMed
33.
Buckwalter JA and Lappin DR. The disproportionate impact of chronic arthralgia and arthritis among women. Clin Orthop 2000 (372): 159–68
34.
James WH. Rheumatoid arthritis, the contraceptive pill, and androgens. Ann Rheum Dis 1993; 52 (6): 470–4PubMedCrossRef
35.
Hall GM, Perry LA, Spector TD. Depressed levels of dehydroepiandrosterone sulphate in postmenopausal women with rheumatoid arthritis but no relation with axial bone density. Ann Rheum Dis 1993; 52 (3): 211–4PubMedCrossRef
36.
Valentino R, Savastano S, Tommaselli AP, et al. Hormonal pattern in women affected by rheumatoid arthritis. J Endocrinol Invest 1993; 16 (8): 619–24PubMed
37.
Brennan P and Silman A. Breast-feeding and the onset of rheumatoid arthritis. Arthritis Rheum 1994; 37 (6): 808–13PubMedCrossRef
38.
Katz PP and Criswell LA. Differences in symptom reports between men and women with rheumatoid arthritis. Arthritis Care Res 1996; 9 (6): 441–8PubMedCrossRef
39.
Hochberg MC. Changes in the incidence and prevalence of rheumatoid arthritis in England and Wales, 1970–1982. Semin Arthritis Rheum 1990; 19 (5): 294–302PubMedCrossRef
40.
Kaipiainen-Seppänen O, Aho K, Isomäki HA, Laakso M. Incidence of rheumatoid arthritis in Finland during 1980–1990. Ann Rheum Dis 1996; 55 (9): 608–11PubMedCrossRef
41.
Shichikawa K, Inoue K, Hirota S, et al. Changes in the incidence and prevalence of rheumatoid arthritis in Kamitonda, Wakayama, Japan, 1965–1996. Ann Rheum Dis 1999; 58 (12): 751–6PubMedCrossRef
42.
Hazes JM, Dijkmans BC, Vandenbroucke JP, de Vries RR, Cats A. Reduction of the risk of rheumatoid arthritis among women who take oral contraceptives. Arthritis Rheum 1990; 33 (2): 173–9PubMedCrossRef
43.
Riise T, Jacobsen BK, Gran JT. Incidence and prevalence of rheumatoid arthritis in the county of Troms, northern Norway. J Rheumatol 2000; 27 (6): 1386–9PubMed
44.
Imanaka T, Shichikawa K, Inoue K, Shimaoka Y, Takenaka Y, Wakitani S. Increase in age at onset of rheumatoid arthritis in Japan over a 30 year period. Ann Rheum Dis 1997; 56 (5): 313–6PubMedCrossRef
45.
Kaipiainen-Seppanen O, Aho K, Isomaki H, Laakso M. Shift in the incidence of rheumatoid arthritis toward elderly patients in Finland during 1975–1990. Clin Exp Rheumatol 1996; 14 (5): 537–42PubMed
46.
Heiberg T, Kvien TK. Preferences for improved health examined in 1,024 patients with rheumatoid arthritis: pain has highest priority. Arthritis Rheum 2002; 47 (4): 391–7PubMedCrossRef
47.
Smedstad LM, Moum T, Guillemin F, et al. Correlates of functional disability in early rheumatoid arthritis: a crosssectional study of 706 patients in four European countries. Br J Rheumatol 1996; 35 (8): 746–51PubMedCrossRef
48.
Smedstad LM, Moum T, Vaglum P, Kvien TK. The impact of early rheumatoid arthritis on psychological distress. A comparison between 238 patients with RA and 116 matched controls. Scand J Rheumatol 1996; 25 (6): 377–82PubMedCrossRef
49.
Smedstad LM, Vaglum P, Moum T, Kvien TK. The relationship between psychological distress and traditional clinical variables: a 2 year prospective study of 216 patients with early rheumatoid arthritis. Br J Rheumatol 1997; 36 (12): 1304–11PubMedCrossRef
50.
Sharpe L, Sensky T, Allard S. The course of depression in recent onset rheumatoid arthritis: the predictive role of disability, illness perceptions, pain and coping. J Psychosom Res 2001; 51 (6): 713–9PubMedCrossRef
51.
Wright GE, Parker JC, Smarr KL, et al. Risk factors for depression in rheumatoid arthritis. Arthritis Care Res 1996; 9 (4): 264–72PubMedCrossRef
52.
Belza BL, Henke CJ, Yelin EH, Epstein WV, Gillis CL. Correlates of fatigue in older adults with rheumatoid arthritis. Nurs Rsch 1993; 2 (2): 93–9
53.
Riemsma RP, Rasker JJ, Taal E, Griep EN, Wouters JM, Wiegman O. Fatigue in rheumatoid arthritis: the role of self-efficacy and problematic social support. Br J Rheumatol 1998; 37 (10): 1042–6PubMedCrossRef
54.
Fifield J, McQuillan J, Tennen H, et al. History of affective disorder and the temporal trajectory of fatigue in rheumatoid arthritis. Ann Behav Med 2001; 23 (1): 34–41PubMedCrossRef
55.
Wolfe F, Hawley DJ, Wilson K. The prevalence and meaning of fatigue in rheumatic disease. J Rheumatol 1996; 23 (8): 1407–17PubMed
56.
Belza BL. Comparison of self-reported fatigue in rheumatoid arthritis and controls. J Rheumatol 1995; 22 (4): 639–43PubMed
57.
Dadoniene J, Uhlig T, Stropuviene S, Venalis A, Boonen A, Kvien TK. Disease activity and health status in rheumatoid arthritis: a case-control comparison between Norway and Lithuania. Ann Rheum Dis 2003; 62 (3): 231–5PubMedCrossRef
58.
Kvien TK, Uhlig T, Kristiansen IS. Patients with rheumatoid arthritis (RA) are gaining quality adjusted life years (QALYs) with access to new therapies. Arthritis Rheum 2002; 46 Suppl. 342
59.
Pincus T, Swearingen C, Gibson M, Sokka T. Is rheumatoid arthritis becoming a (slightly) milder disease? Improvement in hematologic status of patients with rheumatoid arthritis between 1982 and 2001. Arthritis Rheum 2002; 46 Suppl.: 833
60.
Wolfe F, Mitchell DM, Sibley JT, et al. The mortality of rheumatoid arthritis. Arthritis Rheum 1994; 37 (4): 481–94PubMedCrossRef
61.
Yelin E, Trupin L, Wong B, Rush S. The impact of functional status and change in functional status on mortality over 18 years among persons with rheumatoid arthritis. J Rheumatol 2002; 29: 1851–7PubMed
62.
Mitchell DM, Spitz PW, Young DY, Bloch DA, McShane DJ, Fries JF. Survival, prognosis, and causes of death in rheumatoid arthritis. Arthritis Rheum 1986; 29 (6): 706–14PubMedCrossRef
63.
Symmons DP, Jones MA, Scott DL, Prior P. Longterm mortality outcome in patients with rheumatoid arthritis: early presenters continue to do well. J Rheumatol 1998; 25 (6): 1072–7PubMed
64.
Wållberg-Jonsson S, Öhman ML, Dahlqvist SR. Cardiovascular morbidity and mortality in patients with seropositive rheumatoid arthritis in Northern Sweden. J Rheumatol 1997; 24 (3): 445–51PubMed
65.
Riise T, Jacobsen BK, Gran JT, Haga HJ, Arnesen E. Total mortality is increased in rheumatoid arthritis. A 17-year prospective study. Clin Rheumatol 2001; 20 (2): 123–7PubMedCrossRef
66.
Gabriel SE, Crowson CS, O’Fallon WM. Mortality in rheumatoid arthritis: have we made an impact in 4 decades? J Rheumatol 1999; 26 (12): 2529–33PubMed
67.
Chehata JC, Hassell AB, Clarke SA, et al. Mortality in rheumatoid arthritis: relationship to single and composite measures of disease activity. Rheumatology 2001; 40: 447–52PubMedCrossRef
68.
Myllykangas-Luosujarvi R, Aho K, Kautiainen H, Isomäki HA. Shortening of life span and causes of excess mortality in a population-based series of subjects with rheumatoid arthritis. Clin Exp Rheumatol 1995; 13 (2): 149–53PubMed
69.
Cooper NJ. Economic burden of rheumatoid arthritis: a systematic review. Rheumatology 2000; 39: 28–33PubMedCrossRef
70.
Allaire SH, Prashker MJ, Meenan RF. The costs of rheumatoid arthritis. Pharmacoeconomics 1994; 6 (6): 513–22PubMedCrossRef
71.
Jonsson B, Rehnberg C, Borgquist L, Larsson SE. Locomotion status and costs in destructive rheumatoid arthritis. A comprehensive study of 82 patients from a population of 13,000. Acta Orthopaedica Scandinavica 1992; 63 (2): 207–12PubMedCrossRef
72.
Meenan RF, Yelin EH, Henke CJ, Curtis DL, Epstein WV. The costs of rheumatoid arthritis. A patient-oriented study of chronic disease costs. Arthritis Rheum 1978; 21 (7): 827–33PubMedCrossRef
73.
Doyle JJ. Economic and quality-of-life impact of rheumatoid arthritis. Managed Care 2001; 10 Suppl. 7: 15–8PubMed
74.
Gabriel SE, Crowson CS, Campion ME, O’Fallon WM. Direct medical costs unique to people with arthritis. J Rheumatol 1997; 24 (1): 719–25PubMed
75.
Lubeck DP, Spitz PW, Fries JF, Wolfe F, Mitchell DM, Roth SH. A multicenter study of annual health service utilization and costs in rheumatoid arthritis. Arthritis Rheum 1986; 29 (4): 488–93PubMedCrossRef
76.
Meenan RF, Yelin EH, Nevitt M, Epstein WV. The impact of chronic disease: a sociomedical profile of rheumatoid arthritis. Arthritis Rheum 1981; 24 (3): 544–9PubMedCrossRef
77.
Lanes SF, Lanza LL, Radensky PW, et al. Resource utilization and cost of care for rheumatoid arthritis and osteoarthritis in a managed care setting: the importance of drug and surgery costs. Arthritis Rheum 1997; 40 (8): 1475–81PubMedCrossRef
78.
Yelin E and Wanke LA. An assessment of the annual and long-term direct costs of rheumatoid arthritis: the impact of poor function and functional decline. Arthritis Rheum 1999; 42 (6): 1209–18PubMedCrossRef
79.
Clarke AE, Zowall H, Levinton C, et al. Direct and indirect medical costs incurred by Canadian patients with rheumatoid arthritis: a 12 year study. J Rheumatol 1997; 24 (6): 1051–60PubMed
80.
Yelin E. The costs of rheumatoid arthritis: absolute, incremental, and marginal estimates. J Rheumatol 1996; 44 Suppl.: 47–51
81.
Wolfe F, Kleinheksel SM, Spitz PW, et al. A multicenter study of hospitalization in rheumatoid arthritis: effect of health care system, severity, and regional difference. J Rheumatol 1986; 13 (2): 277–84PubMed
82.
83.
van Jaarsveld CH, Jacobs JW, Schrijvers AJ, Heurkens AH, Haanen HC, Bijlsma JW. Direct cost of rheumatoid arthritis during the first six years: a cost-of-illness study. Br J Rheumatol 1998; 37 (8): 837–47PubMedCrossRef
84.
Kobelt G, Eberhardt K, Jonsson L, Jonsson B. Economic consequences of the progression of rheumatoid arthritis in Sweden. Arthritis Rheum 1999; 42 (2): 347–56PubMedCrossRef
85.
van Jaarsveld CH, Jacobs JW, Schrijvers AJ, Van Albada-Kuipers GA, Hofman DM, Bijlsma JW. Effects of rheumatoid arthritis on employment and social participation during the first years of disease in the Netherlands. Br J Rheumatol 1998; 37 (8): 848–53PubMedCrossRef
86.
Sokka T, Kautiainen H, Mottonen T, Hannonen P. Work disability in rheumatoid arthritis 10 years after the diagnosis. J Rheumatol 1999; 26 (8): 1681–5PubMed
87.
Merkesdal S, Ruof J, Schoffski O, Bernitt K, Zeidler H, Mau W. Indirect medical costs in early rheumatoid arthritis: composition of and changes in indirect costs within the first three years of disease. Arthritis Rheum 2001; 44 (3): 528–34PubMedCrossRef
88.
Newhall-Perry K, Law NJ, Ramos B, Sterz M, Wong WK. Direct and indirect costs associated with the onset of seropositive rheumatoid arthritis. J Rheumatol 2000; 27: 1156–63PubMed
89.
Kobelt G, Jonsson L, Lindgren P, Young A, Eberhardt K. Modeling the progression of rheumatoid arthritis: a twocountry model to estimate costs and consequences of rheumatoid arthritis. Arthritis Rheum 2002; 46 (9): 2310–9PubMedCrossRef
90.
Gabriel SE, Crowson CS, Campion ME, O’Fallon WM. Indirect and nonmedical costs among people with rheumatoid arthritis and osteoarthritis compared with nonarthritic controls. J Rheumatol 1997; 24 (1): 43–8PubMed
91.
Birnbaum HG, Barton M, Greenberg PE, et al. Direct and indirect costs of rheumatoid arthritis to an employer. J Occup Environ Med 2000; 42 (6): 588–96PubMedCrossRef
92.
Young A, Dixey J, Kulinskaya E, et al. Which patients stop working because of rheumatoid arthritis? Results of five years’ follow up in 732 patients from the Early RA Study (ERAS). Ann Rheum Dis 2002; 61 (4): 335–40PubMedCrossRef
93.
The burden of rheumatoid arthritis. Based on a presentation by Frederick Wolfe, MD. Am J Manag Care 1999; 5 Suppl. 14: S852–9; discussion S866-9
94.
Gabriel SE, Crowson CS, Luthra HS, Wagner JL, O’Fallon WM. Modeling the lifetime costs of rheumatoid arthritis. J Rheumatol 1999; 26: 1269–74PubMed
95.
Aho K, Heliovaara M, Sievers K, Maatela J, Isomäki H. Clinical arthritis associated with positive radiological and serological findings in Finnish adults. Rheumatol Int 1989; 9 (1): 7–11PubMedCrossRef
96.
Aho K, Kaipiainen-Seppänen O, Heliövaara M, Klaukka T. Epidemiology of rheumatoid arthritis in Finland. Semin Arthritis Rheum 1998; 27 (5): 325–34PubMedCrossRef
Metadata
Title
Epidemiology and burden of illness of rheumatoid arthritis
Author
Dr Tore K. Kvien
Publication date
01-09-2004
Publisher
Springer International Publishing
Published in
PharmacoEconomics / Issue Special Issue 1/2004
Print ISSN: 1170-7690
Electronic ISSN: 1179-2027
DOI
https://doi.org/10.2165/00019053-200422001-00002

Other articles of this Special Issue 1/2004

PharmacoEconomics 1/2004 Go to the issue

Original Review Article

Patient-reported outcomes and their role in the assessment of rheumatoid arthritis

EditorialNotes

Foreword

Original Review Article

Review of health economics modelling in rheumatoid arthritis

Original Review Article

Pursuit of optimal outcomes in rheumatoid arthritis

Original Review Article

Drugs that block tumour necrosis factor: Experience in patients with rheumatoid arthritis