Characterizing Multisystem High Users of the Homeless Services, Jail, and Hospital Systems in Chicago, Illinois.

Background: This study investigated the demographic characteristics, service use patterns, and needs of people who were high users of the homeless services, Cook County Jail, or hospital systems in Chicago, Illinois.

Methods: Definitions of "high users" in each system were based on number of stays and days. K-means cluster analysis was performed on the subset of individuals who interacted with all three systems and were high users of at least one system.