David Fisman, MD, MPH¹, Ana Johnson-Masotti, PhD², Larry Lynd, PhD², and Debbie Sheehan, MSW³. (1) Epidemiology and Biostatistics, Drexel School of Public Health, 245 N. 15th Street, Mail Stop 660, Philadelphia, PA 19102-1192, 215-762-3934, DF62@drexel.edu, (2) Center for Evaluation of Medicines, McMaster University, 105 Main Street East, P1, Hamilton, ON L8N 1G6, Canada, (3) STD and Sexual Health Program, Health Protectoin Branch, City of Hamilton Public Health and Community Services Department, 1 Hughson Street North, 4th Floor, Hamilton, ON L8R 3L5, Canada

Background: Early identification of asymptomatic HIV infection through testing programs is believed to benefit population health. Anonymous testing may increase testing in the highest risk individuals, but these gains may be counterbalanced by loss to follow-up of infected individuals and inability to perform subsequent contact tracing. We projected the effectiveness and cost-effectiveness of programs that incorporate the possibility of anonymous testing, relative to confidential testing alone.

Methods: We constructed Monte Carlo simulations of three HIV testing scenarios: (i) confidential testing available; (ii) either confidential or anonymous testing available (“combined testing”); and (iii) testing unavailable. Parameters were estimated using provincial- and municipal-level data on HIV prevalence, use of anonymous testing sites, and program costs.

Results: Both confidential and combined testing programs resulted in health gains and increased net costs relative to no testing. Combined testing provided more health gains at lower cost than confidential testing alone, with favorable cost-effectiveness ratio ($63,000 per quality adjusted life year gained). In sensitivity analyses, combined testing remained the preferred option as long as less than 68% of anonymous testers would use confidential testing if anonymous testing was unavailable. Results were insensitive to variation in HIV prevalence and loss to follow-up.

Conclusions: Using the best available data, we projected that the use of both confidential and anonymous testing services would offer health and economic gains relative to provision of only confidential testing. Notwithstanding concerns about potential loss to follow-up and lost opportunities for contact tracing, anonymous testing is an attractive adjunct to confidential HIV testing programs.

Learning Objectives:

• Participants will be able to identify strengths, weaknesses, and potential tradeoffs associated with different community HIV testing strategies.
• Participants will gain knowledge regarding the use of population simulations as an aid to public health decision-making.
• Participants will be able to identify 3 commonly used thresholds for determination of cost-effectiveness of preventive interventions.

Keywords: HIV/AIDS, Screening

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.