title: Predictors of Frequent Emergency Room Visits among a Homeless Population.
abstract: BACKGROUND
  Homelessness, HIV, and substance use are interwoven problems. Furthermore, homeless individuals are frequent users of emergency services. The main purpose of this study was to identify risk factors for frequent emergency room (ER) visits and to examine the effects of housing status and HIV serostatus on ER utilization. The second purpose was to identify risk factors for frequent ER visits in patients with a history of illicit drug use.
  
  
  METHODS
  A retrospective analysis was performed on 412 patients enrolled in a Boston-based health care for the homeless program (HCH). This study population was selected as a 2:1 HIV seronegative versus HIV seropositive match based on age, sex, and housing status. A subgroup analysis was performed on 287 patients with history of illicit drug use. Chart data were analyzed to compare demographics, health characteristics, and health service utilization. Results were stratified by housing status. Logistic models using generalized estimating equations were used to predict frequent ER visits.
  
  
  RESULTS
  In homeless patients, hepatitis C was the only predictor of frequent ER visits (OR 4.49, p<0.01). HIV seropositivity was not predictive of frequent ER visits. In patients with history of illicit drug use, mental health (OR 2.53, 95% CI 1.07-5.95) and hepatitis C (OR 2.85, 95% CI 1.37-5.93) were predictors of frequent ER use. HIV seropositivity did not predict ER use (OR 0.45, 95% CI 0.21 - 0.97).
  
  
  CONCLUSIONS
  In a HCH population, hepatitis C predicted frequent ER visits in homeless patients. HIV seropositivity did not predict frequent ER visits, likely because HIV seropositive HCH patients are engaged in care. In patients with history of illicit drug use, hepatitis C and mental health disorders predicted frequent ER visits. Supportive housing for patients with mental health disorders and hepatitis C may help prevent unnecessary ER visits in this population.
authors.affiliation: Section of Infectious Diseases, Boston Medical Center, Boston, Massachusetts.
authors.forename: Kinna
authors.initials: K
authors.lastname: Thakarar
authors.affiliation: Department of Health Policy and Management, Boston University School of Public Health, Boston, Massachusetts.
authors.forename: Jake R
authors.initials: JR
authors.lastname: Morgan
authors.affiliation: Boston Health Care for the Homeless Program, Boston, Massachusetts; Section of General Internal Medicine, Boston Medical Center, Boston, Massachusetts.
authors.forename: Jessie M
authors.initials: JM
authors.lastname: Gaeta
authors.affiliation: Boston Health Care for the Homeless Program, Boston, Massachusetts; Section of General Internal Medicine, Boston Medical Center, Boston, Massachusetts.
authors.forename: Carole
authors.initials: C
authors.lastname: Hohl
authors.affiliation: Section of Infectious Diseases, Boston Medical Center, Boston, Massachusetts; Department of Health Policy and Management, Boston University School of Public Health, Boston, Massachusetts; Center for Healthcare Organization and Implementation Research, ENRM Memorial VA Hospital, Bedford, Massachusetts.
authors.forename: Mari-Lynn
authors.initials: ML
authors.lastname: Drainoni
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003710:Demography; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000473:pathology; D006526:Hepatitis C / Q000473:pathology; D006703:Ill-Housed Persons / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008297:Male; D001523:Mental Disorders / Q000473:pathology; D008603:Mental Health; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000473:pathology; D055815:Young Adult