Over The Counter HIV Testing Estimating The Public Health Benefit – Recommendations for Required Accuracy Freya Spielberg, MD MPH

Public Health Risk vs. Benefit  Risks  False negatives – undiagnosed HIV  False positives – negative emotional reactions.  Benefits  Greater knowledge of HIV status – decreased HIV incidence  Early treatment – Decreased morbidity, mortality, negative economic and psychological consequences.

Weighing the Risks and Benefits  Surveys of Acceptability of OTC Testing 1,2  Experience with Home Specimen Collection 3  Self-Testing Study – Positive Perspective 4,5  Effective Sensitivity 6

Public Health Risk vs. Benefit If OTC results in more people overall with HIV learning their status then the benefits will likely outweigh the risks.

Will OTC Reach The Untested?  Two survey studies among high risk (N=460, N=354), Seattle and San Francisco -OTC preferred by 20 to 24% 1,2  OTC significantly preferred by people who had never tested. 1  In self-testing study among 240 people with HIV, 61% preferred to learn their results with OTC over clinic testing. 3,4  Home Specimen Collection (HSC) post marketing study - 49% of 1494 HIV positive users had never tested before. 5  OTC preferred 20 to 24 times more than HSC 1,2 Conclusion: It is likely that an OTC will reach a substantial number of people with HIV who have never tested before.

How Accurate Does an OTC Need to be for the Public Health Benefits to Outweigh the Risks?  Effective Sensitivity – The % of true positives identified in a population when testing is available: Assume performance sensitivity is 99% for staff-testing and 95% for OT C.  If staff-based rapid testing is accepted by 50% of the people with unidentified HIV,  and adding an OTC results in an additional 20% of those infected testing  then the Effective Sensitivity of the staff test would be 49.5% whereas the effective sensitivity in a population where OTC tests were also available would be 66.5%.

A Case for Lowering the Accuracy Bar for FDA approval of an OTC  It is unlikely that people at highest risk will have as high performance accuracy as trained staff.  In our pilot (N=240) of self testing we found 95% self-testing sensitivity 3  Requiring equivalent accuracy to lab-based tests (98%) will discourage companies from performing clinical trials.  Although the test performance sensitivity of an OTC may be somewhat lower than a staff-based test, the overall effective sensitivity of OTC testing will be comparably much higher.

Recommendations for Accuracy Criteria for OTC Approval  Standard Clinical Trails – Require performance sensitivity/specificity of > 95%.  Or require clinical trials that measure effective sensitivity.

References 1. Spielberg F, Branson B, Goldbaum G, Lockhart D, Kurth A, Celum C, Rossini A, Critchlow C, Wood R. Overcoming Barriers to HIV Testing: Preferences for New Strategies Among Clients of a Needle Exchange, an STD Clinic and Sex Venues for MSM. JAIDS 2003; 32(3): Skolnik HS, Phillips KA, Binson D, Dilley JW. Deciding where and how to be tested for HIV: what matters most? J Acquir Immune Defic Syndr 2001; 27: 292– Spielberg F, Levine RO, Weaver M. Self-testing for HIV: a new option for HIV prevention? Lancet Infect Dis Oct;4(10): Review. 4. Spielberg F, Camp S, Ramachandra E. HIV Home Self-Testing: Can It Work? 2003 National HIV Prevention Conference, Atlanta, July , Abstract # Branson B. Home sample collection tests for HIV infection. JAMA 1998; 280: 1699–701.