Out-of-hospital and emergency department utilization by adult homeless patients.

STUDY OBJECTIVE Homeless adults visit emergency departments (EDs) nearly 4 times more often than the general population and are among the highest repeat visitors. Little research, however, has determined resource utilization patterns of homeless patients and the extent to which they may benefit from emergency care. The objectives of this study are to describe emergency medical services and hospital utilization by homeless patients and to estimate their benefit of ED care. METHODS This was a retrospective cohort study performed at an urban safety-net hospital. All patients who presented to the ED during 2003 were identified. Simple random samples of 300 homeless adult patients and 300 nonhomeless adult patients were identified and included as the study sample. Variables collected included patient demographics, medical history, ED visit date and times, results of laboratory studies, disposition from the ED, diagnoses, ambulance use, number of previous ED visits, and estimated benefit of emergency treatment as determined by a previously developed consensus-based instrument. RESULTS Homeless patients were slightly older (41 years [interquartile range (IQR) 34 to 48 years] versus 36 years [IQR 25 to 46 years]) and had substantially higher substance abuse histories but had similar medical and psychiatric comorbidities compared with nonhomeless patients. Homeless patients also spent more time in the ED per visit (4.4 hours [IQR 2.6 to 7.5 hours] versus 3.8 hours (IQR 2.1 to 5.7 hours]), were less likely to be admitted to the hospital (8% versus 19%), and were more likely to use ambulance services (51% versus 29%). Finally, homeless patients received a similar level of estimated benefit of emergency treatment compared with nonhomeless patients, and a substantial proportion of their visits was directly related to excessive alcohol use. CONCLUSION Homeless adults commonly use emergency care resources, and medical benefit, although comparable to that of nonhomeless adults, is in many cases uncertain.