To Increase Investment in Syringe Exchange in the U.S. would be Cost-saving.

1. To Increase Investment in Syringe Exchange in the U.S. would be Cost-saving. Results from modelinghypothetical syringe coverage levels INTL AIDS CONF – WASHINGTON DC – 23 JULY 2012 T.Q. Nguyen1, B.W. Weir1, S.D. Pinkerton2, D. Des Jarlais3, D. Holtgrave1 1Johns Hopkins Bloomberg School of Public Health, Department of Health, Behavior and Society 2Medical College of Wisconsin, Department of Psychiatry and Behavioral Medicine 3Beth Israel Medical Center and North American Syringe Exchange Network

2. Acknowledgements • amFAR, The Foundation for AIDS Research (with funding from the Elton John Foundation and the Irene Diamond-Tides Foundation) for supporting the Beth Israel/NASEN survey • National Institute on Drug Abuse for supporting B.W. Weir’s training • Johns Hopkins School of Public Health • Sommer Scholars Program for supporting T.Q. Nguyen’s training • Department of Health, Behavior and Society • Student Conference Fund • Researchers and organizations that have contributed to research under this topic • Co-authors: Mr. Brian W. Weir, Dr. David Holtgrave, Dr. Don Des Jarlais and Dr. Steven Pinkerton

3. There is a disconnectbetween injection drug users’ (IDU) share in the HIV epidemic and funding for the effective intervention of syringe exchange. Federal HIV prevention budget Total syringe exchange programs’ budgets Ratio:41 to 1 New HIV infections in the US

4. Study synopsis: ObjectiveTo inform policy decisions, examine if increasing investment in syringe exchange programs (SEPs) would be cost-effective or cost-saving as an HIV prevention intervention. Analysis approachModel HIV incidence due to injection risk in hypothetical cases with higher SEP syringe coverage than current level (base case) QuestionsWhat would happen to HIV incidence if SEP syringe supply were larger?How much would it cost and how much would it save?

5. Method based on Pinkerton’s model used in Pinkerton, S.D. (2010). Is Vancouver Canada’s supervised injection facility cost-saving? Addiction. 105:1429-1436

6. number of new HIV infections due to drug injection risk in a year number of IDUs (full-year equivalent) HIV prevalence among IDUs number of injections with a receptively shared (aka “borrowed”) syringe per IDU per year proportion of syringes that are contaminated with HIV probability of getting infected when using an HIV-contaminated syringe number of injections with a receptively shared (aka “borrowed”) syringe per IDU per year number of new syringes from SEPs per IDU per year number of new syringes from other sources per IDU per year

7. DERIVATION: Starting from equation for HIV incidence number of new infections due to injection risk in a year number of IDUs (full-year equivalent) HIV prevalence probability an uninfected IDU gets infected in the year probability of getting infected when using an HIV-contaminated syringe number of injections using HIV-contaminated syringes per IDU per year number of injections with a receptively shared (aka “borrowed”) syringe per IDU per year proportion of syringes that are contaminated with HIV

8. DERIVATION: Comparing hypothetical case and base case (b/c borrowing is likely to decrease or stay the same) Pinkerton based on Kaplan & O’Keefe’s simplified needle circulation model: number of new syringes per IDU per year number of new syringes from SEPs per IDU per year number of new syringes from other sources per IDU per year

9. Let vary: hyp case = proportion of drug injections “covered” by new syringes from SEPs Calculate:

12. Minimum number of infections averted in a year if SEP syringe coverage is raised from current level of 2.9% of injections to: Cost per additional infection averted: from $111k (SEP 5%) to $129k (SEP 10%) based on “typical” SEP service cost ($0.72 per syringe) or from $55.5k (SEP 5%)to $64.5 (SEP 10%) based on “minimal” service cost ($0.36 per syringe)

13. TYPICAL SERVICE Additional investment required per year & savings in HIV treatment costs (million 2011 USD) for each SEP syringe coverage level Return on investment: from 3.5 (SEP 5%) to 3 (SEP 10%)

14. MINIMAL SERVICE Additional investment required per year & savings in HIV treatment costs (million 2011 USD) for each SEP syringe coverage level Return on investment: from 7 (SEP 5%) to 6 (SEP 10%)

15. Sensitivity analyses

16. Minimum Rate of Return on Investment – dollars saved per dollar invested – based on MINIMAL service cost 2.8 2.7 2.6 2.5 2.9 3.0 3.1 based on TYPICAL service cost BREAK-EVEN LINE

17. Minimum Rate of Return on Investment – dollars saved per dollar invested –

18. Minimum Rate of Return on Investment – dollars saved per dollar invested –

19. Key results (main): If increase SEP syringe coverage from current 2.9% of injections to5% – 10% • Avert about 170 – 500 HIV infections per year • Require 19 – 64 million USD additional funding (for typical SEP services)or 9.4 – 32 million USD (for minimal exchange service) • Save 66 – 193 million USD in HIV treatment cost • Rate of return on investment 3.5 – 3 (or 7 – 6) Conclusion: It would be highly cost-saving to increase investment in syringe exchange in the US. Recommendation: Syringe exchange should be made a priority in HIV prevention in the US. The ban on use of federal funding for syringe exchange should be lifted, and federal funding should be allocated to syringe exchange.

20. THANK YOU!