Research Article: Cost-Effectiveness of Pooled Nucleic Acid Amplification Testing for Acute HIV Infection after Third-Generation HIV Antibody Screening and Rapid Testing in the United States: A Comparison of Three Public Health Settings

Date Published: September 28, 2010

Publisher: Public Library of Science

Author(s): Angela B. Hutchinson, Pragna Patel, Stephanie L. Sansom, Paul G. Farnham, Timothy J. Sullivan, Berry Bennett, Peter R. Kerndt, Robert K. Bolan, James D. Heffelfinger, Vimalanand S. Prabhu, Bernard M. Branson, Seth C. Kalichman

Abstract: Angela Hutchinson and colleagues conducted a cost-effectiveness analysis of pooled nucleic acid amplification testing following HIV testing and show that it is not cost-effective at recommended antibody testing intervals for high-risk persons except in very high-incidence settings.

Partial Text: Acute HIV infection (AHI) is the stage of disease immediately after HIV acquisition and before HIV antibodies are detectable, when viral replication and shedding peak [1]. Because persons with AHI are highly infectious, are probably unaware of their status, and may still be engaging in high-risk behaviors, identifying persons with AHI offers an important opportunity for HIV prevention. However, the diagnosis of AHI is challenging because it involves expensive laboratory-based nucleic acid testing and modification of current HIV screening algorithms.

Our analysis was conducted concurrently with the Centers for Disease Control and Prevention (CDC) multisite AHI study that used pooled NAAT screening for AHI detection in different clinical settings [15]. We constructed an Excel-based model to compare the cost and effectiveness of screening for AHI after HIV antibody screening. Our analysis, which includes a micro-costing study of NAAT testing and a cost-effectiveness model that incorporates the benefits attributable to reduced HIV transmission, conforms to the reference case recommendations of Gold [16]. All costs are reported in 2008 US dollars, future costs are discounted at a 3% annual rate, and outcomes are expressed as cost per quality-adjusted life year (QALY) gained because of cases of HIV infection averted due to pooled NAAT screening. Our incremental cost-effectiveness analysis compares pooled NAAT screening for AHI with screening for HIV antibodies only.

Total program costs for NAAT screening after testing using a third-generation EIA during the 22-mo study period were approximately US$458,200 for the counseling and testing sites (54,187 specimens), US$76,900 for the community clinic (5,574 specimens), and US$349,900 for the municipal STD clinics (30,973 specimens) (Table 3). Program costs per specimen tested ranged from US$8.46–US$14.14 in the three settings. The calculated program costs per person identified with and notified of AHI were approximately US$90,000 after screening with a third-generation EIA and US$50,000 after screening with a rapid test for both the counseling and testing sites and municipal STD clinics, and US$7,900 and US$3,800, respectively, for the community clinic.

We found that pooled NAAT screening for AHI after a negative third-generation EIA in clinical settings relevant to public health is not likely to be cost-effective for most settings. Pooled NAAT screening for AHI is cost-effective only when targeted to settings with very high HIV incidence, such as the community clinic, where it remained cost-effective compared with retesting for HIV antibody as often as every 3 mo. At US$370,000–US$1 million per QALY gained in counseling and testing sites and STD clinics, pooled NAAT after a negative third-generation EIA was not within acceptable ranges of cost-effectiveness thresholds of US$100,000–US$200,000 per QALY gained [33],[34] unless high-risk persons were retested very infrequently. When we assessed the use of pooled NAAT to detect AHI after negative rapid HIV tests, which are less sensitive during early infection than third-generation EIAs, the pattern of cost-effectiveness remained the same.