Abstract
Background Previous research has identified trajectory groups of people with rheumatoid arthritis (RA) characterised by excess disability (with respect to inflammation) 1 . These excess disability trajectories were relatively fixed from symptom onset, indicating that sociodemographic and lifestyle factors prior to onset may partially determine the disability trajectories of people with RA, potentially mediated by patient reported outcomes (PROMs). Objectives To (i) investigate the relationship between social support, financial status and lifestyle factors and excess disability group membership in RA, and (ii) evaluate the mediating effect of pain, fatigue, anxiety and depression on this relationship. Methods Data came from the Etude et Suivi des Polyarthrites Indifférenciées Récentes (ESPOIR) study, a prospective cohort from 14 centres across France. Inclusion criteria were: >2 swollen joints for 6 weeks-6 months, certain / possible diagnosis of RA, aged 18-70 years, and no disease modifying treatments or glucocorticoids for >2 weeks. A previous study applying trajectory analysis to the 10-year disability and inflammation scores of the ESPOIR participants identified pairs of trajectories characterised by similar inflammation but different disability 1 . For the current analysis, those in the higher disability trajectories of each pair were allocated into the “excess disability” group. At baseline, participants reported demographics, patient reported outcomes (pain / fatigue visual analogue scales; anxiety / depression: Arthritis Impact Measurement Scales), social support (availability of financial and accommodation support, family contact, married / co-habiting), financial status (personal and family income, job status and level, home owner, ability to go to the cinema/shows / go on holiday) and lifestyle factors (smoking, alcohol, body mass index [BMI; from height and weight], physical activity). Structural equation modelling was used to combine the social support and financial status data into latent variables, and then assess the direct and indirect (mediated by PROMs) effects of these variables as well as lifestyle factors on excess disability (adjusted for age and gender). Results In total, 538 people with RA were included (mean [standard deviation] age: 48.3 [12.2] years; 79.2% women), 200 (37.2%) of whom had excess disability over 10 years. The excess disability group were older, included more women, and had worse PROMs at baseline compared with the no excess disability group (Table 1). Less social support (β 0.17, 95% CI 0.08, 0.26) and worse financial status (β 0.30, 95% CI 0.19, 0.41) both predicted excess disability group membership, as did lower physical activity (β 0.17, 95% CI 0.09, 0.25) (Figure 1), whereas smoking, alcohol and BMI at baseline did not. Only a small proportion of this effect was mediated by the PROMs (social support: 21%, financial status: 31%, physical activity: 28%; Figure 1). Table 1. Baseline characteristics Excess disability, No excess disability, Mean (SD) / N (%) Mean (SD) / N (%) N 200 338 Age, years 50.4 (10.7) 47.0 (12.8) Women, N(%) 174 (87.0%) 252 (74.6%) Symptom duration, months 3.63 (2.02) 3.36 (1.62) Pain VAS 47.1 (27.4) 37.0 (26.9) Fatigue VAS 59.3 (27.2) 46.5 (26.5) AIMS anxiety 5.61 (2.25) 4.71 (2.27) AIMS depression 4.47 (2.24) 3.47 (1.97) Health Assessment Questionnaire 1.39 (0.64) 0.93 (0.61) DAS28-2C 4.04 (1.28) 3.99 (1.34) AIMS = Arthritis Impact Measurement Scales, DAS28-2C = two-component Disease Activity Score, SD = standard deviation, VAS = visual analogue scale Conclusion Disability resulting from RA is a complex phenomenon, arising from more than just joint inflammation. This analysis indicates that lack of social support, financial instability and lower physical fitness at symptom onset may explain the excess disability associated with RA. As only a small portion of the effect is mediated by PROMs, health and social inequalities may need to be targeted directly by interventions. References [1]Gwinnutt et al (2021), Ann Rheum Dis, 80 (Suppl 1) Disclosure of Interests James Gwinnutt: None declared, Sam Norton: None declared, Kimme Hyrich Speakers bureau: Abbvie, Grant/research support from: Bristol-Myers Squibb, Pfizer, Mark Lunt: None declared, Bernard Combe: None declared, Nathalie Rincheval: None declared, Adeline Ruyssen-Witrand: None declared, Bruno Fautrel: None declared, Suzanne Verstappen: None declared.