AbstractBackgroundRheumatoid arthritis (RA) is a chronic inflammatory disease that affects 0.5‐1% of the population, mainly women and older adults. There is increasing evidence of the presence of cognitive impairment in patients with RA, with a prevalence of around 30%. Some underlying mechanisms involved could be inflammation within the brain, high cardiovascular comorbidity, and the use of immunosuppressive agents that can be neurotoxic with prolonged use, among others. The Montreal Cognitive Assessment (MoCA) is a validated tool for detecting cognitive impairment in our country. The objective of this study is to determine the frequency of cognitive impairment in patients with RA compared to a group of patients with osteoarthritis.MethodWe assessed adult patients diagnosed with RA (2010 ACR/EULAR criteria) and osteoarthritis (ACR criteria) according to selection criteria. Demographic and clinical data were collected. The MoCA test was administered to all patients considering the cut‐off value <26 points to define the presence of cognitive impairment. The study was approved by the institutional ethics and research committee.ResultA total of 60 patients were included: 40 with RA (G1) and 20 with osteoarthritis (G2), the majority being women in both groups, mean age was 66.9 (SD 11.7) years and 71.4 (SD 10.6) years, respectively. There were no statistically significant differences in education, socioeconomic status, or vascular risk factors among groups. The frequency of cognitive impairment was significantly higher in G1 compared to G2: 42.5% (95% CI 28‐58.5) versus 15% (95% CI 4‐40)(p 0.026). Regarding MoCA domains, attention and memory were more affected in G1 compared to G2. In the multivariate analysis, the diagnosis of RA and older age were factors significantly associated with cognitive impairment.ConclusionIn our RA population, the frequency of cognitive impairment was 42.5%. RA diagnosis and older age were factors related to cognitive impairment. A substantial number of patients and the administration of a standard neuropsychological test will help us to validate these results.