• 1
    Arnett FC, Edworthy SM, Bloch DA, McShane DJ, Fries JF, Cooper NS, et al. The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis. Arthritis Rheum 1988; 31: 31524.
  • 2
    Hochberg MC, Chang RW, Dwosh I, Lindsey S, Pincus T, Wolfe F. The American College of Rheumatology 1991 revised criteria for the classification of global functional status in rheumatoid arthritis. Arthritis Rheum 1992; 35: 498502.
  • 3
    Roubenoff R, Roubenoff RA, Cannon JG, Kehayias JJ, Zhuang H, Dawson-Hughes B, et al. Rheumatoid cachexia: cytokine-driven hypermetabolism accompanying reduced body cell mass in chronic inflammation. J Clin Invest 1994; 93: 237986.
  • 4
    Felson DT, Anderson JJ, Boers M, Bombardier C, Furst D, Goldsmith C, et al. American College of Rheumatology preliminary definition of improvement in rheumatoid arthritis. Arthritis Rheum 1995; 38: 72735.
  • 5
    Physician Quality Reporting Initiative. 2009 measures groups specifications manual: Centers for Medicare & Medicaid Services. Washington, DC: US Department of Health and Human Services; 2009. p. 4955.
  • 6
    Physical Activity Guidelines Advisory Committee. Physical Activity Guidelines Advisory Committee report, 2008. Washington, DC: US Department of Health and Human Services; 2008.
  • 7
    Erlichman J, Kerbey AL, James WP. Physical activity and its impact on health outcomes. II. Prevention of unhealthy weight gain and obesity by physical activity: an analysis of the evidence. Obes Rev 2002; 3: 27387.
  • 8
    Warburton DE, Nicol CW, Bredin SS. Health benefits of physical activity: the evidence. CMAJ 2006; 174: 8019.
  • 9
    US Department of Health and Human Services. Physical activity and health: a report of the Surgeon General. Atlanta (GA): US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion; 1996. p. 1468.
  • 10
    Metsios GS, Stavropoulos-Kalinoglou A, Veldhuijzen van Zanten JJ, Treharne GJ, Panoulas VF, Douglas KM, et al. Rheumatoid arthritis, cardiovascular disease and physical exercise: a systematic review. Rheumatology (Oxford) 2008; 47: 23948.
  • 11
    Metsios GS, Stavropoulos-Kalinoglou A, Panoulas VF, Wilson M, Nevill AM, Koutedakis Y, et al. Association of physical inactivity with increased cardiovascular risk in patients with rheumatoid arthritis. Eur J Cardiovasc Prev Rehabil 2009; 16: 18894.
  • 12
    Tourinho TF, Capp E, Brenol JC, Stein A. Physical activity prevents bone loss in premenopausal women with rheumatoid arthritis: a cohort study. Rheumatol Int 2008; 28: 10017.
  • 13
    Turesson C, Jacobsson LT, Matteson EL. Cardiovascular co-morbidity in rheumatic diseases. Vasc Health Risk Manag 2008; 4: 60514.
  • 14
    Kitas GD, Erb N. Tackling ischaemic heart disease in rheumatoid arthritis. Rheumatology (Oxford) 2003; 42: 60713.
  • 15
    Mancuso CA, Rincon M, Sayles W, Paget SA. Comparison of energy expenditure from lifestyle physical activities between patients with rheumatoid arthritis and healthy controls. Arthritis Rheum 2007; 57: 6728.
  • 16
    Roubenoff R, Walsmith J, Lundgren N, Snydman L, Dolnikowski GJ, Roberts S, et al. Low physical activity reduces total energy expenditure in women with rheumatoid arthritis: implications for dietary intake recommendations. Am J Clin Nutr 2002; 76: 7749.
  • 17
    Sokka T, Hakkinen A, Kautiainen H, Maillefert JF, Toloza S, Hansen TM, et al, on behalf of the QUEST-RA Group. Physical inactivity in patients with rheumatoid arthritis: data from twenty-one countries in a cross-sectional, international study. Arthritis Rheum 2008; 59: 4250.
  • 18
    Beaule PE, Dorey FJ, Hoke R, Leduff M, Amstutz HC. The value of patient activity level in the outcome of total hip arthroplasty. J Arthroplasty 2006; 21: 54752.
  • 19
    Frisard MI, Fabre JM, Russell RD, King CM, DeLany JP, Wood RH, et al, for the Louisiana Healthy Aging Study. Physical activity level and physical functionality in nonagenarians compared to individuals aged 60–74 years. J Gerontol A Biol Sci Med Sci 2007; 62: 7838.
  • 20
    Morlock M, Schneider E, Bluhm A, Vollmer M, Bergmann G, Müller V, et al. Duration and frequency of every day activities in total hip patients. J Biomech 2001; 34: 87381.
  • 21
    Motl RW, McAuley E. Longitudinal analysis of physical activity and symptoms as predictors of change in functional limitations and disability in multiple sclerosis. Rehabil Psychol 2009; 54: 20410.
  • 22
    Wagenmakers R, van den Akker-Scheek I, Groothoff JW, Zijlstra W, Bulstra SK, Kootstra JW, et al. Reliability and validity of the short questionnaire to assess health-enhancing physical activity (SQUASH) in patients after total hip arthroplasty. BMC Musculoskelet Disord 2008; 9: 141.
  • 23
    James NT, Miller CW, Fos PJ, Zhang L, Wall P, Welch C. Health status, physical disability, and obesity among adult Mississippians with chronic joint symptoms or doctor-diagnosed arthritis: findings from the Behavioral Risk Factor Surveillance System, 2003. Prev Chronic Dis 2008; 5: A85.
  • 24
    Manini TM, Everhart JE, Patel KV, Schoeller DA, Cummings S, Mackey DC, et al. Activity energy expenditure and mobility limitation in older adults: differential associations by sex. Am J Epidemiol 2009; 169: 150716.
  • 25
    Schott LL, Kao AH, Cunningham A, Wildman RP, Kuller LH, Sutton-Tyrrell K, et al. Do carotid artery diameters manifest early evidence of atherosclerosis in women with rheumatoid arthritis? J Womens Health (Larchmt) 2009; 18: 219.
  • 26
    Prevoo ML, van't Hof MA, Kuper HH, van Leeuen MA, van de Putte LB, van Riel PL. Modified disease activity scores that include twenty-eight–joint counts: development and validation in a prospective longitudinal study of patients with rheumatoid arthritis. Arthritis Rheum 1995; 38: 448.
  • 27
    Bruce B, Fries JF. The Stanford Health Assessment Questionnaire: a review of its history, issues, progress, and documentation. J Rheumatol 2003; 30: 16778.
  • 28
    Curb JD, Ceria-Ulep CD, Rodriguez BL, Grove J, Guralnik J, Willcox BJ, et al. Performance-based measures of physical function for high-function populations. J Am Geriatr Soc 2006; 54: 73772.
  • 29
    Cesari M, Kritchevsky SB, Newman AB, Simonsick EM, Harris TB, Penninx BW, et al, for the Health, Aging and Body Composition Study. Added value of physical performance measures in predicting adverse health-related events: results from the Health, Aging and Body Composition Study. J Am Geriatr Soc 2009; 57: 2519.
  • 30
    Simonsick EM, Newman AB, Nevitt MC, Kritchevsky SB, Ferrucci L, Guralnik JM, et al, for the Health ABC Study Group. Measuring higher level physical function in well-functioning older adults: expanding familiar approaches in the Health ABC study. J Gerontol A Biol Sci Med Sci 2001; 56: M6449.
  • 31
    Guralnik JM, Seeman TE, Tinetti ME, Nevitt MC, Berkman LF. Validation and use of performance measures of functioning in a non-disabled older population: MacArthur studies of successful aging. Aging (Milano) 1994; 6: 4109.
  • 32
    Jette AM, Jette DU, Ng J, Plotkin DJ, Bach MA. Are performance-based measures sufficiently reliable for use in multicenter trials? Musculoskeletal Impairment (MSI) Study Group. J Gerontol 1999; 54: M36.
  • 33
    Cereda E, Turrini M, Ciapanna D, Marbello L, Pietrobelli A, Corradi E, et al. Assessing energy expenditure in cancer patients: a pilot validation of a new wearable device. JPEN J Parenter Enteral Nutr 2007; 31: 5027.
  • 34
    Cole PJ, LeMura LM, Klinger TA, Strohecker K, McConnell TR. Measuring energy expenditure in cardiac patients using the Body Media Armband versus indirect calorimetry: a validation study. J Sports Med Phys Fitness 2004; 44: 26271.
  • 35
    Jakicic JM, Marcus M, Gallagher KI, Randall C, Thomas E, Goss FL, et al. Evaluation of the SenseWear Pro Armband to assess energy expenditure during exercise. Med Sci Sports Exerc 2004; 36: 897904.
  • 36
    Papazoglou D, Augello G, Tagliaferri M, Savia G, Marzullo P, Maltezos E, et al. Evaluation of a multisensor armband in estimating energy expenditure in obese individuals. Obesity (Silver Spring) 2006; 14: 221723.
  • 37
    Pedhazur EJ. Multiple regression in behavioral research: explanation and prediction. 2nd ed. New York: Holt, Rinehart, and Winston; 1982.
  • 38
    Conn VS, Hafdahl AR, Minor MA, Nielsen PJ. Physical activity interventions among adults with arthritis: meta-analysis of outcomes. Semin Arthritis Rheum 2008; 37: 30716.
  • 39
    Gregg EW, Cauley JA, Stone K, Thompson TJ, Bauer DC, Cummings SR, et al, for the Study of Osteoporotic Fractures Research Group. Relationship of changes in physical activity and mortality among older women. JAMA 2003; 289: 237986.
  • 40
    LIFE Study Investigators, Pahor M, Blair SN, Espeland M, Fielding R, Gill TM, et al. Effects of a physical activity intervention on measures of physical performance: results of the lifestyle interventions and independence for Elders Pilot (LIFE-P) study. J Gerontol A Biol Sci Med Sci 2006; 61: 115765.
  • 41
    Stuck AE, Walthert JM, Nikolaus T, Bula CJ, Hohmann C, Beck JC. Risk factors for functional status decline in community-living elderly people: a systematic literature review. Soc Sci Med 1999; 48: 44569.
  • 42
    Wannamethee SG, Shaper AG, Walker M. Changes in physical activity, mortality, and incidence of coronary heart disease in older men. Lancet 1998; 351: 16038.
  • 43
    Brodin N, Eurenius E, Jensen I, Nisell R, Opava CH, and the PARA Study Group. Coaching patients with early rheumatoid arthritis to healthy physical activity: a multicenter, randomized, controlled study. Arthritis Rheum 2008; 59: 32531.
  • 44
    Wagenmakers R, Stevens M, van den Akker-Scheek I, Zijlstra W, Groothoff JW. Predictive value of the Western Ontario and McMaster Universities Osteoarthritis Index for the amount of physical activity after total hip arthroplasty. Phys Ther 2008; 88: 2118.
  • 45
    Plasqui G. The role of physical activity in rheumatoid arthritis. Physiol Behav 2008; 94: 2705.
  • 46
    Stratford PW, Kennedy D, Pagura SM, Gollish J. The relationship between self-report and performance-related measures: questioning the content validity of timed tests. Arthritis Rheum 2003; 49: 53540.
  • 47
    Terwee CB, van der Slikke RM, van Lummel RC, Benink RJ, Meijers WG, de Vet HC. Self-reported physical functioning was more influenced by pain than performance-based physical functioning in knee-osteoarthritis patients. J Clin Epidemiol 2006; 59: 72431.
  • 48
    Terwee CB, Mokkink LB, Steultjens MP, Dekker J. Performance-based methods for measuring the physical function of patients with osteoarthritis of the hip or knee: a systematic review of measurement properties. Rheumatology (Oxford) 2006; 45: 890902.
  • 49
    Elam JT, Graney MJ, Beaver T, el Derwi D, Applegate WB, Miller ST. Comparison of subjective ratings of function with observed functional ability of frail older persons. Am J Public Health 1991; 81: 112730.
  • 50
    Cress ME, Schechtman KB, Mulrow CD, Fiatarone MA, Gerety MB, Buchner DM. Relationship between physical performance and self-perceived physical function. J Am Geriatr Soc 1995; 43: 93101.
  • 51
    Verbunt JA, Huijnen IP, Koke A. Assessment of physical activity in daily life in patients with musculoskeletal pain. Eur J Pain 2009; 13: 23142.
  • 52
    Brodin N, Swardh E, Biguet G, Opava CH. Understanding how to determine the intensity of physical activity: an interview study among individuals with rheumatoid arthritis. Disabil Rehabil 2009; 31: 45865.
  • 53
    Hakkinen A, Arkela-Kautiainen M, Sokka T, Hannonen P, Kautiainen H. Self-report functioning according to the ICF model in elderly patients with rheumatoid arthritis and in population controls using the multidimensional health assessment questionnaire. J Rheumatol 2009; 36: 24653.