AB0367 Influence of Comorbidities on the Functional Capacity and Mobility of Individuals with Rheumatoid Arthritis: A Cross-Sectional Study
Authors: W.V. Marques, V.A. Cruz, J. Rego, N.A. Silva
Journal: Annals of the Rheumatic Diseases (2014)

<h3>Background</h3> Comorbidities in rheumatoid arthritis (RA) are associated with different outcomes.<sup>1</sup> Although some studies have shown associations between such comorbidities and functional incapacity, studies are needed to assess their influence on the mobility of individuals with RA.<sup>2,3</sup> <h3>Objectives</h3> To establish the prevalence of comorbidities in RA patients and to assess their influence on the functional capacity and mobility of the affected individuals. <h3>Methods</h3> In a cross-sectional study we included 60 patients with RA fulfilling the American College of Rheumatology criteria (ACR, 1987) over a period of 11 months. Comorbidities were assessed by means of three indicators: (i) total number of comorbidities; (ii) the Charlson Comorbidity Index (CCI)<sup>4</sup>; and (iii) the Functional Comorbidity Index (FCI)<sup>5</sup>. The activity of disease was evaluated by the Disease Activity Score 28 (DAS28/ESR). The participants9 functional capacity was measured using the Health Assessment Questionnaire (HAQ), and their mobility was measured using the Five-Times-Sit-to-Stand (FTSTS)<sup>6</sup> and Timed Get Up and Go (TUG)<sup>7</sup> tests. Statistical analysis was performed using log-linear stepwise multiple regression at 5% significance level. <h3>Results</h3> The prevalence of comorbidities in the investigated sample of patients with RA was 90% when the total number of comorbidities was taken into consideration. In the final multiple regression model, the independent factors that influenced functional capacity (HAQ) were activity of disease (DAS28/ESR) and comorbidities, as assessed by FCI. The adjusted R<sup>2</sup> of these factors taken as a whole was 0.329. With respect to the participants9 mobility (FTSTS and TUG), only the independent factor comorbidities (FCI) exerted a significant influence on the results. The FCI scores explained 19.1% of the FTSTS variability (R<sup>2</sup>=0.191) and 19.5% of the TUG variability (R<sup>2</sup>=0.195). <h3>Conclusions</h3> Comorbidities were highly prevalent in individuals with RA and exerted a negative influence on their functional capacity and mobility. FCI proved to be satisfactory to assess the association between comorbidities and physical function in individuals with RA. <h3>References</h3> Gullick NJ, Scott DL. Co-morbidities in established rheumatoid arthritis. Best Pract Res Clin Rheumatol 2011; 25:469-483. Radner H, Smolen JS, Aletaha D. Impact of comorbidity on physical function in patients with rheumatoid arthritis. Ann Rheum Dis 2010; 69:536-541. Norton S, Koduri G, Nikiphorou E, et al. A study of baseline prevalence and cumulative incidence of comorbidity and extra-articular manifestations in RA and their impact on outcome. Rheumatology (Oxford) 2013; 52:99-110. Charlson ME, Pompei P, Ales KL, et al. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987;40:373-383. Groll DL, To T, Bombardier C, et al. The development of a comorbidity index with physical function as the outcome. J Clin Epidemiol 2005;25:595-602. Bohannon RW. Sit-to-stand test for measuring performance of lower extremity muscles. Percept Mot Skills 1995;80:163-6. Podsiadlo D, Richardson S. The time "Up &amp; Go": a test of basic functional mobility for frail elderly persons. J Am Geriatr Soc 1991;39:142-148. <h3>Disclosure of Interest</h3> None declared <h3>DOI</h3> 10.1136/annrheumdis-2014-eular.1924