Background Poor health is associated with low socioeconomic status (SES), with higher prevalence, greater severity and earlier mortality of many diseases, including rheumatoid arthritis (RA). However, a variable describing SES is not included in many clinical research reports, in contrast to age and gender, which are almost always included as demographic potential confounders of differences in patient status and treatment responses. The most easily measured SES variable is formal education level (EDUC), which has been interpreted as an available surrogate for patient actions and attitudes that may affect health.
Objectives To analyze RA core data set variables, as well as rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA), and 4 RA indices for possible associations with EDUC in a cohort of Korean RA patients seen in usual care.
Methods All 7 RA core data set measures are collected in consecutive patients with RA seen in a Korean setting by 4 rheumatologists. Patients were classified in 3 EDUC categories: <7 years (n=77; mean age 62.6 years), 7-9 years (n=102; mean age 58.6), and >9 years (n=220; mean age 52.9). Possible associations with EDUC were analyzed for each of the 7 RA core data set measures, RF, ACPA, and 4 RA indices: DAS28, SDAI, CDAI and RAPID3 [an index of only the 3 patient self-report core data set measures found on an MDHAQ: physical function, pain and patient global estimate of status (PATGL)]. The data were analyzed by analysis of variance (ANOVA) adjusted for age, gender and disease duration, and by regressions for each variable, with EDUC, age, gender and disease duration as independent variables.
Results Patients with lower EDUC had higher scores, indicating more severe disease activity, for all core data set measures, statistically significant for tender joint count (TJC28), physical function, pain, PATGL and ESR, but not for swollen joint count (SJC28), physician global estimate (DOCGL) and CRP. RF and ACPA did not show this trend. All 4 indices – DAS28, SDAI, CDAI and RAPID3 – differed significantly according to EDUC, adjusted for age, gender and disease duration (p<0.001).
Conclusions Significant associations of low EDUC with greater disease severity according to most RA core data set measures and 4 indices were seen in 399 Korean RA patients.
Disclosure of Interest None Declared