Background Inequalities in health between low and high income countries are often reported, but it is not known whether clinical disease activity measures (“objective”) and person reported outcomes (“subjective”) follow the same patterns in patients with RA.
Objectives To investigate the patterns in RA health outcomes across countries with different level of socio-economic development.
Methods Data from a cross-sectional multinational (17 countries) study COMORA was used. Contribution of gross domestic product (GDP) to clinical disease activity measures (DAS28, total joint count (TJC), swollen joint count (SJC), and erythrocyte sedimentation rate (ESR)) and person reported outcomes (Patient global assessment (PatGA), fatigue, Physician global assessment (PhysGA) and function assessed with health assessment questionnaire (HAQ)) was explored. All models were adjusted for potentially relevant confounders, including age, gender, education and comorbidities (Wolfe-Michaud index). Models were computed with and without adjustment for current RA medication (steroids, NSAIDs and DMARDs). Additionally, models with person reported outcomes were adjusted for the presence of erosive disease, TJC, SJC, and ESR. GDP was dichotomized in low and high GDP countries (with a cut-off of 21500 international dollars per capita (adjusted to purchasing power parity), which by data inspection was the one that discriminated best both groups).
Results A total of 3920 RA patients from 17 countries (range 30-411) were included in COMORA (mean age 56 y.o. (SD13), 82% females). In models adjusted for medication, low GDP countries had on average 0.8 higher DAS28, 2.24 and 1.71 higher scores on TJC and SJC, respectively, and 8.92 higher ESR compared to high GDP countries. At the same time, patients from low GDP societies had a 0.44 and 0.14 lower score on patient and physician global assessment, respectively and 0.9 lower score on fatigue compared to high GDP countries. HAQ was not associated with GDP (Table).
Conclusions Patients from countries with lower socio-economic welfare score worse on clinical measures of disease activity (DAS28 and its components), however, score systematically better on person reported outcomes (patient global assessment and fatigue). Cultural factors that may play a role in reporting of more subjective outcomes should be further explored.
Disclosure of Interest P. Putrik: None declared, S. Ramiro: None declared, A. Keszei: None declared, I. Hmamouchi: None declared, M. Dougados: None declared, M. Hifinger Employee of: Hexal AG, Germany (inactive employment, maternity leave), L. Gossec: None declared, A. Boonen: None declared