TY - JOUR T1 - The prevalence of Rheumatoid Arthritis: A systematic review of population-based studies JF - The Journal of Rheumatology JO - J Rheumatol DO - 10.3899/jrheum.200367 SP - jrheum.200367 AU - Khalid Bander Almutairi AU - Johannes C. Nossent AU - David B. Preen AU - Helen I. Keen AU - Charles A. Inderjeeth Y1 - 2020/10/15 UR - http://www.jrheum.org/content/early/2020/10/13/jrheum.200367.abstract N2 - Objective To estimate the prevalence of Rheumatoid Arthritis (RA) from international population-based studies and investigate the influence of prevalence definition, data sources, classification criteria and geographical area on RA prevalence. Methods A search of ProQuest, MEDLINE, Web of Science, and EMBASE was undertaken to include population-based studies investigating RA prevalence between 1980 and 2019. Studies were reviewed using the Joanna Briggs Institute approach for the systematic review and Preferred Reporting Items for Systematic Reviews guidelines. Results Sixty studies met the inclusion criteria. There was a wide range of point-prevalence reported (0.00% - 2.70%) with a mean 0.56% (S.D= 0.51) between 1986 and 2014 and period-prevalence 0.51% (S.D= 0.35) between 1955 and 2015.. RA point- and period-prevalence was higher in urban settings than rural settings, (0.69% vs 0.48%) and (0.54% vs 0.25%), respectively. The RA diagnosis validated by rheumatologists yielded the highest period-prevalence of RA and was observed in linked databases (0.80%, S.D=0.1). Conclusion The literature reports a wide range of point- and period- prevalence based on population forms and method of data collection, but average point- and period-prevalence of RA were 51/10,000 and 56/10,000, respectively. Higher urban vs rural prevalence may be biased by poor case finding with less health care or reflect risk environment. The population database studies were more consistent than sampling studies, and linked databases in different continents appeared to provide a consistent estimate of RA period-prevalence and confirming the high value of rheumatologist diagnosis as classification criteria. ER -