Multifactorial explanatory model of self-reported sleep disturbance in people with rheumatoid arthritis: a structural...

Sleep disturbance is a common and disabling symptom among patients with rheumatoid arthritis (RA). This study aimed to test a multifactorial explanatory model of cross-sectional associations among factors related to self-reported sleep disturbance in RA.

This was an ancillary analysis of an observational, cross-sectional, single-centre study including patients with RA. Sleep disturbance, disease activity, perceived disease impact, depressive and anxiety symptoms, and personality traits were assessed using validated questionnaires. Structural equation modelling (SEM) was used to examine the associations between sleep disturbance and the remaining variables.

A total of 313 patients (82% female; mean age 60±12 years; disease duration 12±9 years) were included. The final model showed an acceptable fit to the data [χ2(71)=178.04, χ2/df=2.50, p<0.005; CFI=0.95; GFI=0.92; TLI=0.94; RMSEA=0.07, p=0.004, 95% CI=0.06 to 0.08] and explained 57% of the variance of self-reported sleep disturbance (R2=0.57). Disease activity was positively associated with disease impact (β=0.23; p<0.001), which was significantly associated with sleep disturbance (β=0.65; p=0.001). 'Positive' personality traits were inversely associated with self-reported sleep disturbance (β= -0.51; p=0.001), with direct (β= -0.16; p=0.006) and indirect associations (β= -0.35; p=0.001) through perceived disease impact. They were also inversely associated with depression (β= -0.77; p=0.001) and anxiety (β= -0.80; p<0.001). Depression and anxiety were positively associated with perceived disease impact (β=0.38; p=0.001 and β=0.30; p<0.001, respectively).

'Positive' personality traits and perceived disease impact appear to be significantly associated with self-reported sleep disturbance in RA patients, while disease activity, depression, and anxiety showed comparatively smaller associations within the model. These findings support the need for a holistic, multidisciplinary approach to RA management.