The purpose of this study was to assess the effectiveness of a case management and housing program in reducing use of urgent medical services among homeless adults with chronic medical illnesses.

A randomized controlled trial was conducted at a public teaching hospital and a private, nonprofit hospital in Chicago, Illinois. Participants were 407 social worker–referred homeless adults with chronic medical illnesses (89% of referrals) from September 2003 until May 2006, with follow-up through December 2007. Analysis was by intention-to-treat.

Interventions studied were housing offered as transitional housing after hospitalization discharge, followed by placement in long-term housing; case management offered on-site at primary study sites, transitional housing, and stable housing sites. Usual care participants received standard discharge planning from hospital social workers.

Main outcome measures included hospitalizations, hospital days, and emergency department visits measured using electronic surveillance, medical records, and interviews. Models were adjusted for baseline differences in demographics, insurance status, prior hospitalization or emergency department visit, human immunodeficiency virus infection, current use of alcohol or other drugs, mental health symptoms, and other factors.

After adjustment, offering housing and case management to a population of homeless adults with chronic medical illnesses resulted in fewer hospital days and emergency department visits, compared with usual care.