Preclinical inflammatory rheumatic diseases: an overview and relevant nomenclature.

Chronic inflammatory and autoimmune conditions result from an interplay between genetic and environmental factors culminating in the phenotypes of established disease. The transition from health to established disease is relatively well understood in rheumatoid arthritis (RA), which provides an exemplar for other diseases. This article addresses terminologies to describe the phases of disease leading to RA, disease initiation and the point from which disease duration should be timed, the future research agenda suggested by this approach to the definition of phases of disease, and the importance of capturing the patient perspective in research into the earliest phases of disease.