Cohort Description

This US-Mayo cohort is a population-based longitudinal cohort that was developed using the resources of the Rochester Epidemiology Project (REP), a centralized community-wide medical record linkage system. The unique features of the REP and its capabilities for the population-based research in rheumatic diseases have been described in detail elsewhere [1,2]. The US-Mayo cohort includes both incident and prevalent patients with RA who fulfilled the 1987 ACR criteria for RA and were residents of Olmsted County, Minnesota in 1988-2008. Patients were identified retrospectively and followed through their medical records to death, migration from Olmsted County, or the present. Baseline was defined as the date of criteria fulfillment for the patients with incident RA, and since the prevalent patients were diagnosed with RA prior to living in Olmsted County, their baseline was defined as the date of first medical visit as an Olmsted County resident with RA.


This long-standing cohort was developed with funding from the NIH, which is currently in its 13th year.


  1. Kremers HM, Myasoedova E, Crowson CS, Savova G, Gabriel SE, Matteson EL.The Rochester Epidemiology Project: exploiting the capabilities for population-based research in rheumatic diseases.Rheumatology (Oxford)2011;50:6–15.
  2. Melton LJ III.History of the Rochester Epidemiology Project.Mayo Clin Proc1996;71:266–74.