Arthritis Information

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Arthritis is a term that describes over 100 rheumatic conditions that are typically characterized by inflammation, tissue destruction, pain and stiffness of joint tissues (e.g., bone, cartilage, synovial fluid, ligaments, tendons, muscles and connective tissue)[1].

Arthritis is the most prevalent musculoskeletal condition of adults.

Approximately 52.5 million adults in the United States self-report physician-diagnosed arthritis. By 2030, 67 million – 25% of the adult U.S. population – are expected to have arthritis [2], and by 2040, the number of U.S. adults with doctor-diagnosed arthritis is projected to increase 49% to 78.4 million (25.9%) of all adults[3]. In addition, 43.2% of people with arthritis report arthritis attributable activity limitation[4]. Knee osteoarthritis (OA) is the most prevalent type of arthritis and affects approximately 37% of the adult population with arthritis[5].

  • Symptomatic knee OA—radiographic knee OA with frequent knee joint pain—is present in approximately 17% of adults over the age of 45 and 12% of adults over the age of 60[6]
  • Gout, rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE) are less prevalent affecting an estimated 8.3 million, 1.3 million, and 161,000-322,000 adults in the United States, respectively[7].
  • Adults are not the only ones to get arthritis—294,000 children have juvenile arthritis[8].

Disability Due To Arthritis

The evidence:
Longitudinal studies among persons with inflammatory arthritis show significant risks of progressive disability in task performance and home and work roles[9]. In a sample of adults ages 65 and over who reported frequent knee pain, Miller et al.[10] found that 45% experienced progression of disability over 15-months and 53% experienced progression over 30-months. Others show a decline in balance, strength, and function over time among older adults with symptomatic knee OA[11] showed persons at risk for symptomatic knee OA have high rates of disease progression over 30-months—if disease progression were related to disability, this would suggest a high rate of disability progression.

The effects:
Work loss, a type of participation restriction that is specifically tied to work performance and employment, can be substantial among persons with arthritis and can have enormous impact on those affected[12].

  • In clinical samples of persons with rheumatoid arthritis, 40-50% of persons are unemployed after one decade of disease[13].
  • In the 2001-2002 National Health Interview Survey (NHIS) data, 31% of persons with arthritis—or 8.3 million people— reported a work limitation that was at least partially related to their musculoskeletal condition[14].

In recognition of the critical importance of work outcomes among people with arthritis and the limited evidence-based intervention approaches, the Centers for Disease Control Health People 2020 objectives[15] and the current National Institute on Disability, Independent Living, and Rehabilitation Research agenda specifically address work outcomes[16].

Arthritis Treatment

To date, there are no “cures” for arthritis.

Current treatment for most rheumatological conditions focuses on disease management with the goal of preventing joint destruction, minimizing pain, and optimizing function[17].

  • Significant advances have been made with current medications for RA and gout, but few medications exist for OA.
  • Total joint replacement is typically the intervention choice for end-stage joint disease with the goal of improving pain and function and decreasing disability. Long-term outcomes, however, of joint replacements show mixed outcomes 2 years after surgery especially for knee replacement[18].

Non-invasive strategies are increasingly promoted for disease management and functional outcomes. Physical activity and strength training are now well recognized as critical components of disease management[19]. However, despite the strong evidence supporting beneficial effects at decreasing pain and improving function, the vast majority of persons with arthritis are not meeting recommended levels of activity and exercise and adherence to programs is poor[20].

Research has drawn increased attention to the role factors outside of the biomedical model—e.g., the environment, social support, and empowerment—have on disability[21]. These factors are clear targets for interventions aimed at work disability. Studies of the effectiveness of vocational rehabilitation work retention programs show that programs aimed at changing the work environment are more effective than those with a primarily medical approach[22].

Most of today’s intervention approaches treat disease processes or disease impairments (e.g., pain, strength). While critical, these interventions may not fully address the challenges people with arthritis face in the context of engaging in broader life roles such as work, volunteering, and engaging in social and community activities. Interventions aimed at these outcomes most likely need to incorporate elements beyond biomedical disease processes such as environmental and behavioral factors[23]. These interventions, however, are sparse. ENACT was established to identify effective interventions aimed at optimizing activity and participation outcomes, foster exercise adherence, measure functional outcomes , and develop rheumatological rehabilitation scholars; in order to improve the lives of persons with arthritis.


1. Wikipedia. Arthritis.

2. Centers for Disease Control and Prevention (2013).

3. Hootman JM, Helmick CG, Barbour KE, Theis KA, Boring MA.  Updated projected prevalence of self-reported doctor-diagnosed arthritis and arthritis-attributable activity limitation among US adults, 2015-2040.  Arthritis & Rheumatology. 2016 Mar 25. [Epub ahead of print]. doi: 10.1002/art.39692. PubMed PMID: 27015600. abstract

4. Barbour KE, Helmick CG, Theis KA, Murphy LB, Hootman JM, Brady TJ, Cheng YJ. Prevalence of doctor-diagnosed arthritis and arthritis-attributable activity limitation-United States, 2010-2012. MMWR 2013;62 (44):869-873.  html [PDF-542KB]

5. Dillon CF, Rasch EK, Gu Q, Hirsch R. Prevalence of knee osteoarthritis in the United States: arthritis data from the Third National Health and Nutrition Examination Survey 1991-94. J Rheumatol. 2006;33(11):2271-9.

6. Jordan JM, Helmick CG, Renner JB, et al. Prevalence of knee symptoms and radiographic and symptomatic knee osteoarthritis in African Americans and Caucasians: The Johnston County Osteoarthritis Project. J Rheumatol. 2007;34(1):172-180.

7. Chandratre P, Roddy E, Clarson L, Richardson J, Hider SL, Mallen CD. Health-related quality of life in gout: a systematic review. Rheumatology (Oxford). 2013; 52(11): 2031–2040.

8. Helmick CG, Felson DT, Lawrence RC, et al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part I. Arthritis Rheum. 2008;58(1):15-25.

9. Allaire S, Wolfe F, Niu J, LaValley MP, Zhang B, Reisine S. Current risk factors for work disability associated with rheumatoid arthritis: recent data from a U.S. national cohort. Arthritis Rheum. 2009;61(3):321-328.

10. Miller ME, Rejeski WJ, Messier SP, Loeser RF. Modifiers of change in physical functioning in older adults with knee pain: the Observational Arthritis Study in Seniors (OASIS). Arthritis Rheum. 2001;45(4):331-9.

11. Felson DT, Nevitt MC, Yang M, et al. A new approach yields high rates of radiographic progression in knee osteoarthritis. J Rheumatol. 2008;35(10):2047-2054.

12. Allaire S, Wolfe F, Niu J, Lavalley M, Michaud K. Work disability and its economic effect on 55-64-year-old adults with rheumatoid arthritis. Arthritis Rheum. 2005;53(4):603-608.

13. Sokka T, Kautiainen H, Pincus T, et al. Work disability remains a major problem in rheumatoid arthritis in the 2000s: data from 32 countries in the QUEST-RA study. Arthritis Res Ther. 2010;12(2):R42.

14. Centers for Disease Control and Prevention (CDC). Racial/ethnic differences in the prevalence and impact of doctor-diagnosed arthritis–United States, 2002. MMWR 2005;54(5):119-123.

15. Centers of Disease Control and Prevention (CDC). Healthy People 2020. Accessed March 21, 2010.

16. National Institute of Disability and Rehabilitation Research. NIDILRR Program Directory: Employment Outcomes. Accessed March 21, 2010.

17. Felson DT, Lawrence RC, Dieppe PA, et al. Osteoarthritis: New insights. Part 1: The disease and its risk factors. Ann Intern Med. 2000;133(8):635-46.

18. Gandhi R, Dhotar H, Razak F, Tso P, Davey JR, Mahomed NN. Predicting the longer term outcomes of total knee arthroplasty. Knee. 2010;17(1):15-18.

19. Fransen M, McConnell S. Land-based exercise for osteoarthritis of the knee: a metaanalysis of randomized controlled trials. J Rheumatol. 2009;36(6):1109-1117.

20. Marks R, Allegrante JP. Chronic osteoarthritis and adherence to exercise: a review of the literature. J Aging Phys Activity. 2005;13(4):434-460.

21. Reisine ST, Grady KE, Goodenow C, Fifield J. Work disability among women with rheumatoid arthritis. The relative importance of disease, social, work, and family factors. Arthritis Rheum. 1989;32(5):538-543.

22. Allaire SH, Li W, LaValley MP. Reduction of job loss in persons with rheumatic diseases receiving vocational rehabilitation: A randomized controlled trial. Arthritis Rheum. 2003;48(11):3212-3218.

23. Keysor J. How does the environment influence disability? Examining the evidence. In: Field M, Jette A, Martin L, eds. Workshop on Disability in America: A New Look. Washington D.C.: Institute of Medicine; 2005:88-100.