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

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

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

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

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

DERIVATION: Starting from equation for HIV incidence

(b/c borrowing is likely to decrease or stay the same) DERIVATION: Comparing hypothetical case and base case Pinkerton based on Kaplan & O’Keefe’s simplified needle circulation model:

Calculate: = proportion of drug injections “covered” by new syringes from SEPs

parametervaluesources/basis i1.23m based on IDU pop estimation from Brady et al. (2002), adjusted for cycling in/out of injecting (based on Galai et al., 2003) ii * number of injections per IDU per day (2.8 – Lurie et al., 1998; Tempalski et al., 2008) iii84.9 based on probability of borrowing 8.3% (Pinkerton, 2011; Kaplan, 1993; consistent with NIDA CA data) & number of injections (ii.) iv187.6 based on number of injections (ii.), number of borrows (iii.) & number of times an IDU uses a syringe he/she owns (5 – Huo & Oullet, 2007) v36.8m Beth Israel/NASEN 2009 survey (adjusted for assumed 10% uncounted) vi29.9 vii157.7

parametervaluesources/basis viii SEP syringe coverage /base case 2.9% of injs ix SEP cost per syringe /typical $0.72 average of SEP unit costs (Beth Israel/NASEN survey), converted to 2011 dollars x SEP cost per syringe /minimal $0.36assumed to be half of typical cost (Des Jarlais expert opinion) xi rate at which SEP syringes replace non-SEP syringes 10% xii2575 based on HIV incidence estimates for 2009 (CDC); assuming 1/2 IDU + 1/4 MSM/IDU categories due to injection risk (Des Jarlais expert opinion) xiii per case HIV lifetime treatment cost $388k average lifetime treatment cost for an HIV infected person for 2010 (CDC) converted to 2011 dollars

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)

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

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%)

Sensitivity analysis Parameter Main analysis value LowerHigher 1number of injections per IDU per day borrowing probability proportion SEP syringes uncounted10%5%15% 4number of times an IDU uses one own-syringe547 5proportion of infections due to injecting risk in IDU category50%35%65% in MSM/IDU category25%20%30% 6replacement effect10%5%15% 7number of full-year equivalent IDUs1.23m1.0m1.5m Sensitivity analyses

Minimum Rate of Return on Investment – dollars saved per dollar invested – based on MINIMAL service cost based on TYPICAL service cost BREAK-EVEN LINE

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

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

Key results (main): If increase SEP syringe coverage from current 2.9% of injections to 5% – 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.

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