title: Estimation of the prevalence of undiagnosed and diagnosed HIV in an urban emergency department.
abstract: OBJECTIVE
  To estimate the prevalence of undiagnosed HIV, the prevalence of diagnosed HIV, and proportion of HIV that is undiagnosed in populations with similar demographics as the Universal Screening for HIV in the Emergency Room (USHER) Trial and the Brigham and Women's Hospital (BWH) Emergency Department (ED) in Boston, MA. We also sought to estimate these quantities within demographic and risk behavior subgroups.
  
  
  METHODS
  We used data from the USHER Trial, which was a randomized clinical trial of HIV screening conducted in the BWH ED. Since eligible participants were HIV-free at time of enrollment, we were able to calculate the prevalence of undiagnosed HIV. We used data from the Massachusetts Department of Public Health (MA/DPH) to estimate the prevalence of diagnosed HIV since the MA/DPH records the number of persons within MA who are HIV-positive. We calculated the proportion of HIV that is undiagnosed using these estimates of the prevalence of undiagnosed and diagnosed HIV. Estimates were stratified by age, sex, race/ethnicity, history of testing, and risk behaviors.
  
  
  RESULTS
  The overall expected prevalence of diagnosed HIV in a population similar to those presenting to the BWH ED was 0.71% (95% CI: 0.63%, 0.78%). The prevalence of undiagnosed HIV was estimated at 0.22% (95% CI: 0.10%, 0.42%) and resultant overall prevalence was 0.93%. The proportion of HIV-infection that is undiagnosed in this ED-based setting was estimated to be 23.7% (95% CI: 11.6%, 34.9%) of total HIV-infections.
  
  
  CONCLUSIONS
  Despite different methodology, our estimate of the proportion of HIV that is undiagnosed in an ED-setting was similar to previous estimates based on national surveillance data. Universal routine testing programs in EDs should use these data to help plan their yield of HIV detection.
authors: Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America. wreichmann@partners.org
authors: William M
authors: WM
authors: Reichmann
authors: Rochelle P
authors: RP
authors: Walensky
authors: Amy
authors: A
authors: Case
authors: Anna
authors: A
authors: Novais
authors: Christian
authors: C
authors: Arbelaez
authors: Jeffrey N
authors: JN
authors: Katz
authors: Elena
authors: E
authors: Losina
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002947:Cities / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D003710:Demography; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology*; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012309:Risk-Taking; D055815:Young Adult