The five-site health and risk study of blood-borne infections among persons with severe mental illness.

This article outlines the history and rationale of a multisite study of blood-borne infections among persons with severe mental illness reported in this special section of Psychiatric Services. The general problem of blood-borne diseases in the United States is reviewed, particularly as it affects people with severe mental illness and those with comorbid substance use disorders. The epidemiology and natural history of three of the most important infections are reviewed: the human immunodeficiency virus (HIV), the hepatitis B virus, and the hepatitis C virus. Current knowledge about blood-borne diseases among people with severe mental illness as well as information on current treatment advances for hepatitis C are summarized. A heuristic model, based on the pragmatic, empirical, and conceptual issues that influenced the final study design, is presented. The specific rationale of the five-site collaborative design is discussed, as well as the sampling frames, measures, and procedures used at the participating sites. Alternative strategies for analyzing data deriving from multisite studies that use nonrandomized designs are described and compared. Finally, each of the articles in this special section is briefly outlined, with reference to the overall hypotheses of the studies.