There were 96,711 emergency department visits during the observation period, during which 5340 (5.5%) rapid HIV antibody tests were performed, representing 4827 (91.3%) unique patients. There were 16,662 inpatient admissions (17.2% of emergency department visits), with a median of 738 admissions per month. Of the HIV antibody tests performed, 2430 (45.5%) were on patients who were admitted to the hospital. After the expanded testing launch on December 1, 2008, the number of tests increased from a median of 114 tests per month to 273 tests per month, p=0.004 ().
Number of rapid HIV tests and new HIV diagnoses by month, June 2008 to March 2010.
The first rapid test result for each patient is shown in . Rapid test results were positive for 126 testers (2.6%, 95% confidence interval [CI] 2.2%, 3.1%), of which 10 were false-positive, resulting in 116 confirmed cases of HIV infection. The median age of testers was 44 years, (interquartile range [IQR] 31–55 years). Women accounted for nearly 40% of testers but individuals with positive rapid test results were more likely to be male (p<0.001).
Characteristics of Patients Undergoing Rapid HIV Testing and Testing Newly HIV Positive in the San Francisco General Hospital Emergency Department, June 2008–March 2010
Of the 116 confirmed cases of HIV infection, 55 individuals had known HIV infection, 58 patients had newly diagnosed HIV infection, and 3 patients were suspected new HIV diagnoses, as they had no record of a previous positive test (2 patients left the emergency department prior to disclosure and 1 was intubated in the emergency department and died during hospitalization). In addition to the 61 patients without a prior known HIV diagnosis, 3 patients presented with symptoms consistent with acute retroviral syndrome and were diagnosed with acute HIV infection based on negative rapid HIV antibody test results and HIV RNA levels higher than 500,000 copies per milliliter. Furthermore, 1 patient with a negative HIV test tested HIV positive on a repeat emergency department visit, for a total of 65 new emergency department HIV diagnoses out of the 5340 tests (1.22%: 95% CI, 0.94%–1.55%). The median number of new HIV diagnoses increased from 1.5 per month to 4 per month during the study period p=0.01 (). Patients with newly diagnosed HIV infection were 76.9% male and 37% white (). The median CD4 cell count was 268 cells per microliter, with 40% of patients having CD4 cell counts under 200 cells per microliter.
Of the 65 patients with newly diagnosed HIV infection, 58 patients received results at the time of testing and 49 patients were eligible for linkage to outpatient care. Reasons for ineligibility were discharge to a skilled nursing facility after inpatient admission (n=3), incarceration at time of testing (n=2), private insurance incompatible with the publicly funded SFGH HIV clinic (n=2), death during inpatient admission (n=1), and out-of-county residence (n=1). Forty-six patients (93.9%, 95% CI: 83.1, 98.7%) were successfully linked to care, with 73% linked by 7 days, 84% linked by 30 days, and 90% by 90 days. Of the 7 patients whose results were not disclosed at the time of the test, 4 were able to be contacted with results after discharge and 1 presented to the emergency department at a later date; 4 of these patients were also linked to care. Of the 55 patients with known HIV infection, the majority identified as in care (n=39), while a few had out-of-county residence (n=2) or were incarcerated (n=1). Two patients had unknown care status. Of the remaining 11 patients, 10 (90.9%, 95% CI: 58.7%, 99.8%) were successfully relinked to care.