title: Rheumatoid arthritis and the risk of dementia: A systematic review and meta-analysis.
abstract: BACKGROUND
  The association between chronic inflammation and dementia has been identified in several epidemiologic studies. However, the data on rheumatoid arthritis (RA), one of the most common chronic inflammatory disorders, remains unclear.
  
  
  METHODS
  We conducted a systematic review and meta-analysis of cohort, case-control, and cross-sectional studies that compared the risk of dementia in patients with RA versus non-RA controls. Data from each study were combined using random-effect, generic inverse variance method of DerSimonian and Laird to calculate the pooled risk ratio (RR) and 95% confidence interval (CI).
  
  
  RESULTS
  Three cohort studies and two cross-sectional studies were identified and included in the meta-analysis. We found a significantly increased risk of dementia among patients with RA, with the pooled risk ratio of 1.61 (95% CI, 1.10-2.37). The statistical heterogeneity was high, with an I2 of 91%.
  
  
  CONCLUSIONS
  Our study demonstrated a statistically significant increase in the risk of dementia among patients with RA.
authors.affiliation: Department of Internal Medicine, Division of Rheumatology, Mayo Clinic, Rochester, Minnesota, USA; Department of Medicine, Division of Rheumatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, .
authors.forename: Patompong
authors.initials: P
authors.lastname: Ungprasert
authors.forename: Karn
authors.initials: K
authors.lastname: Wijarnpreecha
authors.forename: Charat
authors.initials: C
authors.lastname: Thongprayoon
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003704:Dementia / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D012307:Risk Factors