Multimorbidity, which is typically associated with seronegative rheumatoid arthritis (RA), was shown to be more predictive of poor outcomes than seropositivity, Cynthia Crowson, PhD, said during her presentation at ACR Convergence 2023 on November 13.

Dr Crowson is lead statistician in the Division of Biomedical Statistics and Informatics with a joint appointment in the Division of Rheumatology at Mayo Clinic in Rochester, Minnesota.

She and colleagues conducted a retrospective, population-based study of patients who fulfilled 1987 ACR criteria for RA during 1999-2014 and evidenced multimorbidity at diagnosis with RA. The investigators used OMERACT definitions for flare and remission, while multimorbidity was defined using 55 chronic conditions. “Binomial mixed models with random effects accounting for multiple visits per patient adjusted for age, sex, RA duration, seropositivity, incidence year, and smoking status were used to assess the association between flare/remission and multimorbidity,” Dr Crowson explained.

Of 625 patients with RA (mean age 55.5 years, 70% female, 88% white, 68% seropositive, 47% current/former smokers, 40% obese) who made 7841 visits during a mean follow-up period of 8.7 years, 36% were in flare and 25% were in remission. “Multimorbidity was modestly associated with flare, but these associations did not reach statistical significance,” Dr Crowson stated.

However, multimorbidity was significantly associated with decreased odds of remission for both patients with 2 or more multimorbidities (OR 0.63; 95%CI 0.46-0.87, p=0.0048) and those with 5 or more multimorbidities (OR 0.64 [95%CI 0.48-0.87, p=0.0046). “Seropositivity was not significantly associated with flare (OR 1.13; 95%CI 0.93-1.40; p=0.21) or remission (OR 1.00; 95%CI 0.75-1.34, p=0.99),” Dr Crown said. Male sex, longer duration of RA, and older age were associated with significantly greater odds of remission, while smoking at baseline was associated with greatly decreased odds of remission. The odds of experiencing a flare of RA were significantly lower with duration, increased age, and increased year of RA index , while current smoking was associated with significantly increased odds of flare.

“Patients with RA and multimorbidity were less likely to achieve remission,” Dr Crowson stated.  “Multimorbidity was a stronger predictor of poor prognosis than seropositivity. These results underscore the importance of considering multimorbidity and not just seropositivity when assessing prognosis for patients with RA.”

Crowson C. 1276: Multimorbidity burden predicts lower likelihood of remission in patients with rheumatoid arthritis. Presented at: ACR Convergence. November 13, 2023.