Associations between Rheumatoid Arthritis and Various Comorbid Conditions in Germany-A Retrospective Cohort Study

The aim of the present study was to estimate the prevalence of physical and mental health comorbidities in patients with rheumatoid arthritis (RA) in Germany, in order to better understand the complex clinical picture and its consequences.

This retrospective cohort study was based on data from the IQVIA Disease Analyzer database and included individuals aged ≥ 16 years with an initial documented diagnosis of RA between 2015 and 2021 (index date). RA patients were matched 1:1 with non-RA individuals using nearest neighbor propensity score matching. The study investigated associations between RA and various disorders documented within 365 days after the index date. The cumulative incidence of defined disorders was calculated for individuals with and without RA. Multivariable logistic regression models were used to study these associations.

Data were available for a total of 49,713 patients with and 49,713 patients without RA (mean age: 60.4 (SD: 15.5) years; 66.7% female). A significant and clinically relevant positive association was observed between RA and seven disorders: soft tissue disorders (Odds Ratio (OR): 1.47; 95% Confidence Interval (CI): 1.42-1.52), renal failure (OR: 1.36; 95% CI: 1.26-1.47), anemia (OR: 1.32; 95% CI: 1.24-1.40), liver diseases (OR: 1.32, 95% CI: 1.23-1.41), osteopathies and chondropathies (OR: 1.28; 95% CI: 1.22-1.3), diseases of the esophagus, stomach and duodenum (OR: 1.18; 95% CI: 1.14-1.22), and nutritional deficiencies (OR: 1.17; 95% CI: 1.10-1.24).

We observed significant associations between RA and several comorbidities, which have clinical relevance for the care of RA patients not only in general practices but also in specialist settings.