When health insurance is not a factor: national comparison of homeless and nonhomeless US veterans who use Veterans Affairs Emergency Departments.

OBJECTIVES: We examined the proportion of homeless veterans among users of Veterans Affairs (VA) emergency departments (EDs) and compared sociodemographic and clinical characteristics of homeless and nonhomeless VA emergency department users nationally. METHODS: We used national VA administrative data from fiscal year 2010 for a cross-sectional study comparing homeless (n = 64,091) and nonhomeless (n = 866,621) ED users on sociodemographics, medical and psychiatric diagnoses, and other clinical characteristics. RESULTS: Homeless veterans had 4 times the odds of using EDs than nonhomeless veterans. Multivariate analyses found few differences between homeless and nonhomeless ED users on the medical conditions examined, but homeless ED users were more likely to have been diagnosed with a drug use disorder (odds ratio [OR] = 4.12; 95% confidence interval [CI] = 3.97, 4.27), alcohol use disorder (OR = 3.67; 95% CI = 3.55, 3.79), or schizophrenia (OR = 3.44; 95% CI = 3.25, 3.64) in the past year. CONCLUSIONS: In a national integrated health care system with no specific requirements for health insurance, the major differences found between homeless and nonhomeless ED users were high rates of psychiatric and substance abuse diagnoses. EDs may be an important location for specialized homeless outreach (or "in" reach) services to address mental health and addictive disorders.