Cognitive impairment risk in patients with rheumatoid arthritis: a population-based cohort study

This study aimed to evaluate the incidence rate and incident cognitive impairment risk in patients with rheumatoid arthritis (RA) compared with matched controls.

This population-based matched cohort study enrolled patients newly diagnosed with RA (n=26 437) between 2011 and 2014 and 1:1 age-, sex- and index-year-matched controls (n=26 437) from a Korean nationwide claims database. Follow-up spanned the index date to the earliest occurrence of incident cognitive impairment or December 2022. Cognitive impairment was defined using the International Classification of Diseases, 10th Revision, codes (F00-F03, F31.82, F06.7, G30 and G31.00). Incidence rates were calculated as events per 1000 person-years. Multivariable stratified competing risks regression analyses estimated adjusted subdistribution HRs (SHRs) with 95% CIs for incident cognitive impairment, treating death as a competing risk.

During the mean respective follow-up of 9.410±2.271 and 9.508±2.217 years, 2952 (11.17%) and 2388 (9.03%) patients with RA and controls developed incident cognitive impairment, respectively. The cognitive impairment incidence rates in patients with RA and controls were 11.493 (95% CI 7.648 to 15.338) and 9.219 (95% CI 5.386 to 13.052) per 1000 person-years, respectively. Compared with the control individuals, patients with RA had a significantly higher risk of developing cognitive impairment (adjusted SHR, 1.222 (95% CI 1.171 to 1.275)).

These findings suggest that cognitive impairment may represent an important comorbidity in patients with RA that merits clinical awareness and longitudinal monitoring.