Comorbidities Associated With Worse Disease Activity in RA

Clinician examining the hand of a patient with rheumatoid arthritis
Clinician examining the hand of a patient with rheumatoid arthritis
The prevalence of comorbidities in patients with early RA were quantified and the prognostic value of comorbidities for effectiveness outcomes in a randomized trial were determined.

Nearly half of patients with rheumatoid arthritis (RA) have at least 1 clinically important comorbidity at the time of disease onset, and comorbidities in patients with RA may increase the risk for worsened functionality and disease activity during a 2-year period regardless of whether the patient undergoes intensive remission induction therapy, study findings published in Rheumatology suggest.

A total of 379 patients with early RA from the 2-year pragmatic CareRA trial were included in this post hoc analysis study. Participants in the randomized CareRA trial had received a diagnosis of RA less than 1 year before study entry, were naïve to disease-modifying antirheumatic drugs, and were treated-to-target with remission induction therapies.

Researchers of this analysis found that 44% (n=167) of patients with RA in the CareRA trial had at least 1 comorbidity that was clinically important based on the Rheumatic Diseases Comorbidity Index (RDCI; range 0-9).

The relationships between baseline RDCI and outcomes were also assessed. Outcomes of interest included disease activity assessed with the 28-joint Disease Activity Score using C-Reactive Protein (DAS28-CRP), physical function assessed with the Healthcare Access and Quality (HAQ) index, quality of life assessed with the 36-Item Short Form Health Survey (SF-36) domains, and hospitalizations during  2 years.

Up to 17% (n=65) had an RDCI score of 1, 19% (n=70) of patients had a score of 2, and 8% (n=32) had an RDCI score of 3 or greater. Hypertension, the most prevalent comorbidity, was reported in 22% of patients.

Study participants with comorbidities had higher HAQ scores compared with those without comorbidities (β, 0.215; 95% CI, 0.071-0.358; P =.003). The presence of comorbidities was also associated with significantly higher DAS28-CRP (β, 0.225; 95% CI, 0.132-0.319; P <.001) and lower SF-36 physical component summary scores (β, -3.195; 95% CI, -4.844 to -1.546; P <.001) during 2 years. These associations were found in analyses adjusted for potential confounders, such as disease activity and treatment randomization.

In addition, patients with RA who had comorbidities also had lower chances of remission achievement (odds ratio [OR], 0.724; 95% CI, 0.604-0.867; P <.001) and a higher hospitalization risk (OR, 3.725; 95% CI, 2.136-6.494; P <.001).

Limitations of this study included the relatively small sample size as well as the possibility that some comorbidities might not have been registered by treating physicians.

The investigators suggest that rheumatologists should take into consideration “comorbidities in their RA management plan, instead of keeping too narrow a focus on controlling RA disease activity.”


Stouten V, Westhovens R, De Cock D, et al. Having a co-morbidity predicts worse outcome in early rheumatoid arthritis despite intensive treatment: a post hoc evaluation of the pragmatic randomized controlled CareRA trial. Rheumatology (Oxford). Published online January 12, 2021. doi:10.1093/rheumatology/keaa841