The cost-effectiveness of voluntary counseling and testing of hospital inpatients for HIV infection.

OBJECTIVE To evaluate the cost-effectiveness of voluntary counseling and testing of US hospital inpatients for the human immunodeficiency virus (HIV). DATA SOURCES Data for entry into the model were derived from a review of the literature, consultation with experts, and consensus of the authors. DATA EXTRACTION We rated our confidence in these probabilities and costs by grading the data inputs using methods adapted from those of the US Preventive Services Task Force. DATA SYNTHESIS Decision analysis models were developed to evaluate two outcomes: (1) cost per health care worker (HCW) HIV infection averted if measures are taken by the HCW to reduce his or her risk of acquiring HIV; and (2) cost per inpatient HIV infection detected. Sensitivity analyses were also conducted. Using baseline input values, testing to avert HCW infection may prevent 3.6 HIV infections per year at a total program cost of $2.7 billion, or a cost of $753 million per infection averted. At baseline assumptions (seroprevalence = 1%), testing to detect inpatient HIV infection would cost $16,104 per year per infection detected. Cost-effectiveness at baseline drops to $8353 per HIV infection detected if the seroprevalence is 10%. If testing is limited to hospitals with inpatient seroprevalences of at least 1%, approximately 5400 persons per year will be falsely labeled HIV-positive. CONCLUSIONS This analysis provides no justification for testing inpatients to prevent HIV infection of HCWs. Screening inpatients to detect HIV infection may be justified at seroprevalences exceeding 1%, but issues of medical or social discrimination, false-positive results, informed consent, and logistics must be resolved first.