AB0544 MULTIFACTORIAL EXPLANATORY MODEL OF SLEEP DISTURBANCE IN PATIENTS WITH RHEUMATOID ARTHRITIS: A STRUCTURAL EQUATION APPROACH
Authors: M. J. Cadório, E. Santos, J. Oliveira, R. J. O. Ferreira, J. A. P. Da Silva, C. Duarte
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Around 38% of people with Rheumatoid Arthritis (RA) have sleep disturbances, a number that increases with disease duration. However, their origin is still poorly understood, and its management frequently neglected.<sup>[1]</sup> <h3>Objectives:</h3> To foster the understanding of sleep disturbances in patients with RA through a multifactorial explanatory model incorporating the influence of disease activity, perceived disease impact, personality traits and comorbidities, namely depression and anxiety. <h3>Methods:</h3> This is a cross-sectional analysis in a cohort from an outpatient clinic in a tertiary Portuguese hospital using a structural equation modelling estimation to analyse the associations between sleep disturbance and disease activity, perceived disease impact, personality traits, and depression and anxiety dimensions. Sleep disturbance was assessed using the Sleep Disturbance item (0-10, NRS) from the Rheumatoid Arthritis Impact of Disease (RAID) questionnaire<sup>[2]</sup>; disease activity through the Disease Activity Score 28 joints in its three variables (3v) and C-reactive protein (CRP) variant (DAS28CRP3v)<sup>[3]</sup>; disease impact by the individual domains of RAID.7 questionnaire<sup>[4,5]</sup>; depressive and anxiety symptoms were evaluated using the Hospital Anxiety and Depression Scale (HADS)<sup>[6]</sup>; and personality by the Ten Item Personality Inventory (TIPI)<sup>[7]</sup>. We designated the latent factor derived from TIPI as "Positive" personality, to denote the predominantly adaptive nature of the represented dimensions. Descriptive and correlational analyses were performed using SPSS®, v. 29 (IBM, Armonk NY, USA) software. Statistically significant effects were assumed for <i>p</i>&lt;0.05. <h3>Results:</h3> A total of 302 RA patients were included in this analysis. The results obtained in the structural equation model indicated a good fit to the data, explaining 57% of the variance of the sleep disturbance (<i>R</i><sup>2</sup>=0.57). "Positive" personality and disease activity explained 46% of the variance of perceived impact of disease (<i>R</i><sup>2</sup>=0.46). Furthermore, the results corroborate a direct association between disease activity [DAS28CRP3v] and impact of disease (<i>β</i>=0.24; <i>p</i>&lt;0.001) which, in turn, showed a significant positive direct relation with sleep disturbance (<i>β</i>=0.63; <i>p</i>&lt;0.001). "Positive" personality traits had a total protective effect of <i>β</i>=-0.44 on sleep disturbance, including a direct effect of <i>β</i>=-0.18 (<i>p</i>=0.006) and an indirect effect of <i>β</i>=-0.26 (<i>p</i>=0.001) through perceived impact of disease, indicating a mediating influence in this association. The model also shows a direct negative relation between "positive" personality traits and perceived impact of disease (<i>β</i>=-0.41; <i>p</i>&lt;0.001). Depression showed a significant positive direct relation with impact of disease (<i>β</i>=0.26; <i>p</i>=0.005) and a significant negative direct relation with "positive" personality (<i>β</i>=-0.37; <i>p</i>&lt;0.001). Anxiety showed a significant negative direct relation with "positive" personality (<i>β</i>=-0.37; <i>p</i>&lt;0.001) (Figure 1). <h3>Conclusion:</h3> Positive personality traits and perceived impact of disease seem to have a major role in explaining sleep disturbances in patients with RA. In contrast, disease activity and comorbidities such as depression and anxiety play a secondary role. This evidence reinforces the need to consider a multidisciplinary approach to people living with RA, that goes beyond a treat-to-target strategy focused solely on disease activity. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>