Sarah Wakeman, MD

David Munson, MD

Due to their complex medical and social needs, people with substance use disorder (SUD) and people experiencing homelessness are hospitalized—and rehospitalized—at much higher rates than other patients. This creates a persistent challenge for hospitals working to reduce avoidable readmissions.

Although it is well established that homelessness and SUD each increase the risk of hospital readmission, researchers at Mass General Brigham wanted to better understand the combined impact of these factors, particularly given how frequently they overlap.

This question was explored in a recent study led by David Munson, MD, and Sarah Wakeman, MD, internists in the Department of Medicine at Mass General Brigham.

In the study, the research team looked back at more than 160,000 adult inpatient admissions to Massachusetts General Hospital over a four-year period. They examined 30-day readmissions among patients with substance use disorder, those experiencing homelessness, those with both conditions and those with neither. Using electronic health record data and adjusting for demographics and clinical severity, the investigators assessed how these factors influence post-discharge outcomes.

Clear, though unsurprising, trends emerged. Readmission rates were higher among patients with SUD and among those experiencing homelessness, but were highest by far among patients with both. After adjustment, this group had a 73% greater risk of readmission compared with patients with neither condition.

According to the authors, these findings reinforce the importance of addressing addiction, housing instability, or ideally both during hospitalizations to prevent patients from making quick returns, especially since substance use disorder and homelessness have additive effects when it comes to risk of readmission.

Published in Addiction Research & Theory on February 17, 2026 | Read the paper: “The impact of substance use disorder and homelessness on hospital readmission”

Summary reviewed by: Sarah Wakeman, MD, senior author