Defining populations at risk of rheumatoid arthritis: the first steps to prevention.

Preventing disease is a public health priority. In recent years, this focus has evolved to include noncommunicable chronic diseases such as cardiovascular disease and diabetes mellitus but is novel in rheumatic diseases such as rheumatoid arthritis (RA). In order to prevent RA, the 'at-risk' populations need to be defined. To date, a number of studies have attempted to clarify our understanding of these cohorts and how they could be identified. Suggested terminology has now been published to define individuals who might go on to develop RA. This Review considers categories of these 'at-risk' individuals, with a focus on those with systemic autoimmunity. Trials in very early RA demonstrate that disease outcomes can be reduced with early intervention. These principles are widely accepted in other diseases such as type 1 diabetes mellitus, in which steps have been taken to prevent disease in genetically predisposed individuals. Large population-based studies provide insights into potential interventions for RA prevention. By quantifying risk in different populations, the prospect of preventing this disease is feasible.