0704: Clinically Suspect Arthralgia Patients with a Low Educational Attainment Have an Increased Risk to Develop Inflammatory Arthritis

Sarah J.H. Khidir¹, Anna M.P. Boeren², Annelies Boonen³, Pascal de Jong⁴, Elise van Mulligen⁵ and Annette van der Helm-van Mil⁶, ¹Leiden University Medical Center, Leiden, Netherlands, ²Erasmus MC, Rotterdam, Rotterdam, ³Maastricht University Medical Centre, Maastricht, Netherlands, ⁴ErasmusMC, Hendrik Ido Ambacht, Netherlands, ⁵Erasmus Medical Center, Leiden University Medical Center, Rotterdam, Netherlands, ⁶Leiden University Medical Center, Erasmus Medical Center, Leiden, Netherlands

Background/Purpose: Cross-sectional studies have shown that rheumatoid arthritis (RA) is more prevalent among people with a lower educational attainment. To date, no longitudinal data are present on educational attainment of patients in the at-risk phase of RA: clinically suspect arthralgia (CSA). We aimed to analyze the association between educational attainment and progression from CSA to inflammatory arthritis (IA), and to perform mediation analysis with subclinical joint-inflammation to elucidate pathways of this association.

Methods: 521 consecutive patients from the Leiden CSA-cohort were followed for IA-development during median 25 months. Educational attainment was defined as low (lower secondary vocational education), intermediate, or high (college/university education). Subclinical joint-inflammation was measured at presentation with a unilateral contrast enhanced 1.5T-MRI of hand and foot. Cox-regression was used to analyze IA-development per educational attainment. A three-step mediation analysis evaluated whether subclinical joint-inflammation was intermediary in the path between educational attainment and IA-development, before and after age-correction. Association between educational attainment and IA-development was verified in the independent CSA-cohort of Rotterdam.

Results: Low educational attainment was associated with increased IA-development (HR=2.35, 95%CI=1.27-4.33, p=0.006; Figure 1A), independent of BMI and current smoking-status. Furthermore, patients with a low educational attainment had higher levels of subclinical joint-inflammation, which also associated with IA-development. Partial mediation effect of subclinical joint-inflammation was observed in the relationship between educational attainment and IA-development. Low educational attainment was associated with increased IA-development in the validation CSA-cohort as well (HR=5.72, 95%CI=1.36-24.08, p=0.017; Figure 1B).

Conclusion: This is the first study providing evidence that lower educational attainment is associated with a higher risk of progressing from arthralgia to IA. This effect was partially mediated by subclinical joint-inflammation.
Legend: development of inflammatory arthritis in patients with clinically suspect arthralgia is shown according to level of educational attainment. Patient reported educational attainment was defined as low (lower general secondary vocational education), intermediate, or high (college or university education). In the Leiden CSA-cohort (n=521), low educational attainment was associated with increased IA-development (HR=2.35, 95%CI=1.27-4.33, p=0.006), compared to high educational attainment. In the Rotterdam CSA-cohort (n=59), this association was: HR=5.72, 95%CI=1.36-24.08, p=0.017.
Abbreviations: IA=inflammatory arthritis; CSA=clinically suspect arthralgia.
Disclosures: S. Khidir, None; A. Boeren, None; A. Boonen, None; P. de Jong, None; E. van Mulligen, None; A. van der Helm-van Mil, None.