“…3 The magnitude of this risk varies across studies, and according to one recent study from the Rochester Epidemiological Project (REP), increased risk has declined over time, narrowing the gap between adults with and without RA. 4 In this issue of The Journal of Rheumatology, Kodishala et al present the results of a retrospective population-based cohort study assessing risk factors for incident dementia in adults with RA from the REP. 5 The REP includes granular data on participants, including diagnosis, comorbid conditions, and treatments, as well as important disease features such as clinical characteristics (eg, erosive disease, extraarticular manifestations) and laboratory markers (eg, presence of rheumatoid factor and/or anticyclic citrullinated peptide antibody, inflammatory markers). Incident dementia, the outcome of interest, was ascertained through the use of International Classification of Disease, 9th and 10th revision codes; despite some limitations, including the inability to distinguish among dementia subtypes, diagnostic code-based algorithms have been shown to have moderate positive predictive value in the identification of all-cause dementia.…”