Below is a compilation of peer-reviewed research about the public health impact of Syringe Service Programs (SSPs) since 2007. SSPs have an extensive evidence base that goes back nearly three decades. Meta-analyses reviewing this body of research are included on this list.
- Year
-
Cost Effectiveness
- Using Interrupted Time Series Analysis to Measure the Impact of Legalized Syringe Exchange on HIV Diagnoses in Baltimore and Philadelphia
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Using Interrupted Time Series Analysis to Measure the Impact of Legalized Syringe Exchange on HIV Diagnoses in Baltimore and PhiladelphiaYear:2019Citation:
Journal of Acquired Immune Deficiency Syndrome. Volume 82, Supplement 2 148-154, doi 10.1097/QAI.0000000000002176
Study Methods:Using surveillance data from Philadelphia (1984–2015) and Baltimore (1985–2013) for IDU-associated HIV diagnoses, we used autoregressive integrated moving averages modeling to conduct 2 tests to measure policy change impact. We forecast the number of expected HIV diagnoses per city had policy not changed in the 10 years after implementation and compared it with the number of observed diagnoses postpolicy change, obtaining an estimate for averted HIV diagnoses. We then used interrupted time series analysis to assess the immediate step and trajectory impact of policy change implementation on IDU-attributable HIV diagnoses.
Gap in evidence addressed:Syringe exchange programs (SEP) reduce HIV incidence associated with injection drug use (IDU), but legislation often prohibits implementation. We examined the policy change impact allowing for SEP implementation on HIV diagnoses among people who inject drugs in 2 US cities.
Key Findings:The Philadelphia (1993–2002) model predicted 15,248 new IDU-associated HIV diagnoses versus 4656 observed diagnoses, yielding 10,592 averted HIV diagnoses over 10 years. The Baltimore model (1995–2004) predicted 7263 IDU-associated HIV diagnoses versus 5372 observed diagnoses, yielding 1891 averted HIV diagnoses over 10 years. Considering program expenses and conservative estimates of public sector savings, the 1-year return on investment in SEPs remains high: $243.4 M (Philadelphia) and $62.4 M (Baltimore). Policy change is an effective structural intervention with substantial public health and societal benefits, including reduced HIV diagnoses among people who inject drugs and
significant cost savings to publicly funded HIV care. - Syringe exchange in the United States: a national level economic evaluation of hypothetical increases in investment.
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Syringe exchange in the United States: a national level economic evaluation of hypothetical increases in investment.Year:2014Citation:
AIDS Behavior 18(11):2144-55. doi: 10.1007/s10461-014-0789-9.
Study Methods:The strategy for answering this question is to start from an equation for the number of new HIV infections due to injection drug use over a 1-year period, and to relate parameters in this equation to syringe supply. Such equation would allow us to estimate how a hypothetical increase in syringe supply would affect the number of new infections. The initial equation is based on the premise that the number of new infections in a year equals the number of uninfected (thus at risk) persons times the probability that an uninfected person becomes infected over the course of the year.
Gap in evidence addressed:The key question is if NSP syringe supply were increased by a certain amount, what would happen to the number of people contracting HIV? If we could answer this question, we could evaluate the cost effectiveness of such hypothetical increase in NSP syringe supply by costing it and estimating savings resulting from infections averted.
Key Findings:In the base case scenario with no additional syringe exchange funding, an estimated 2,575 HIV infections occur in a year due to drug injection risk. Based on lifetime treatment costs of $391,223 in 2011 USD per infection, the total treatment costs for these infections is $1.01 billion. With an annual $10 to $50 million funding increase, 194-816 HIV infections would be averted (cost per infection averted $51,601-$61,302). Contrasted with HIV treatment cost savings alone, the rate of financial return on investment would be 7.58-6.38. Main and sensitivity analyses strongly suggest that it would be cost-saving for the US to invest in syringe exchange expansion. These analyses indicate that it would be highly cost-saving to invest additional funds to expand syringe exchange services in the US. Over the course of 1 year an additional investment of only $10 million would avert an estimated 194 HIV infections and avoid $75.8 million in lifetime HIV treatment costs (saving $65.8 million net), representing a rate of financial return on investment of 7.58. If the investment increase were $50 million, it would also be highly cost-saving: approximately 816 HIV infections would be averted, equivalent to nearly one-third (32 %) of the annual number of new HIV infections due to drug injection risk; $319.1 million of lifetime HIV treatment costs would be avoided (net savings $269.1 million), representing a 6.38 rate of financial return on investment. Sensitivity analyses showed that when uncertainties about parameter values were accounted for, investment increase remained highly cost-saving.
- Estimating the cost-effectiveness of needle-syringe programs in Australia.
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Estimating the cost-effectiveness of needle-syringe programs in Australia.Year:2012Citation:
AIDS 26(17):2201-10. doi: 10.1097/QAD.0b013e3283578b5d.
Study Methods:A health economic analysis was conducted incorporating a mathematical model of HIV and HCV transmission among IDUs. An empirical relationship between syringe availability and receptive syringe sharing (RSS) was assessed. We compared the epidemiological outcomes and costs of NSP coverage (status quo RSS of 15-17%) with scenarios that had no NSPs (RSS of 25-50%). Outcomes included numbers of HIV and HCV infections averted, lifetime health sector costs, and cost per quality-adjusted life year (QALY) gained. Discounting was applied at 3% (sensitivity: 0%, 5%) per annum.
Gap in evidence addressed:To evaluate the impact and cost-effectiveness of needle-syringe programs (NSPs) with respect to HIV and hepatitis C virus (HCV) infections among Australian injecting drug users (IDUs).
Key Findings:We estimated that NSPs reduced incidence of HIV by 34-70% (192-873 cases) and HCV by 15-43% (19?000-77?000 cases) during 2000-2010, leading to 20?000-66?000 QALYs gained. Economic analysis showed that NSP coverage saved A$70-220 million in healthcare costs during 2000-2010 and will save an additional A$340-950 million in future healthcare costs. With NSPs costing A$245 million, the programs are very cost-effective at A$416-8750 per QALY gained. Financial investment in NSPs over 2000-2010 is estimated to be entirely recovered in healthcare cost savings by 2032 with a total future return on investment of $1.3-5.5 for every $1 invested.
- Cost-Effectiveness of Needle and Syringe Exchange for the Prevention of HIV in New York City
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Cost-Effectiveness of Needle and Syringe Exchange for the Prevention of HIV in New York CityYear:2008Citation:
Journal of HIV/AIDS & Social Services, 7(3) 229-240 https://doi.org/10.1080/15381500802307492
Study Methods:Using data specific to the Lower East Side Harm Reduction Center in New York City, we assessed the cost-effectiveness of NSE over a range of conservative estimates of efficacy, obtained from both longitudinal and small-area studies. A decision-analysis model was created to compare the outcomes and costs associated with NSE. Model inputs included the cost of living with HIV and the seroprevalence of HIV among injection drug users in New York City. This analysis was conducted from both the government and societal perspectives.
Gap in evidence addressed:Shared needle and syringe use among injection drug users continues to be a major mode of transmission of HIV. Needle and syringe exchange (NSE) may be a viable strategy to reduce the transmission of the virus; yet the difficulty in measuring the actual efficacy of NSE has limited attempts to evaluate the cost-effectiveness of the intervention.
Key Findings:Tested over a range of conservative parameter estimates, NSE appears to save money and lives. The NSE program we evaluated cost $502 per client and produced a gain of 0.01 quality adjusted life years per client. It also reduced HIV treatment costs by $325,000 per case of HIV averted, and averted 4-7 HIV infections per 1000 clients, producing a net cost savings.
- Author
- Title
-
Publication Topic: Cost Effectiveness
Year Citation Study Methods Gap in evidence addressed Key Findings Cost-Effectiveness of Needle and Syringe Exchange for the Prevention of HIV in New York City (2008) Belani, Hrishikesh, Muennig, 2008 Journal of HIV/AIDS & Social Services, 7(3) 229-240 https://doi.org/10.1080/15381500802307492
Using data specific to the Lower East Side Harm Reduction Center in New York City, we assessed the cost-effectiveness of NSE over a range of conservative estimates of efficacy, obtained from both longitudinal and small-area studies. A decision-analysis model was created to compare the outcomes and costs associated with NSE. Model inputs included the cost of living with HIV and the seroprevalence of HIV among injection drug users in New York City. This analysis was conducted from both the government and societal perspectives.
Shared needle and syringe use among injection drug users continues to be a major mode of transmission of HIV. Needle and syringe exchange (NSE) may be a viable strategy to reduce the transmission of the virus; yet the difficulty in measuring the actual efficacy of NSE has limited attempts to evaluate the cost-effectiveness of the intervention.
Tested over a range of conservative parameter estimates, NSE appears to save money and lives. The NSE program we evaluated cost $502 per client and produced a gain of 0.01 quality adjusted life years per client. It also reduced HIV treatment costs by $325,000 per case of HIV averted, and averted 4-7 HIV infections per 1000 clients, producing a net cost savings.
Estimating the cost-effectiveness of needle-syringe programs in Australia. (2012) Kwon, Anderson, Kerr, Thein, Zhang, Iversen, Dore, Kaldor, Law, Maher, Wilson, 2012 AIDS 26(17):2201-10. doi: 10.1097/QAD.0b013e3283578b5d.
A health economic analysis was conducted incorporating a mathematical model of HIV and HCV transmission among IDUs. An empirical relationship between syringe availability and receptive syringe sharing (RSS) was assessed. We compared the epidemiological outcomes and costs of NSP coverage (status quo RSS of 15-17%) with scenarios that had no NSPs (RSS of 25-50%). Outcomes included numbers of HIV and HCV infections averted, lifetime health sector costs, and cost per quality-adjusted life year (QALY) gained. Discounting was applied at 3% (sensitivity: 0%, 5%) per annum.
To evaluate the impact and cost-effectiveness of needle-syringe programs (NSPs) with respect to HIV and hepatitis C virus (HCV) infections among Australian injecting drug users (IDUs).
We estimated that NSPs reduced incidence of HIV by 34-70% (192-873 cases) and HCV by 15-43% (19?000-77?000 cases) during 2000-2010, leading to 20?000-66?000 QALYs gained. Economic analysis showed that NSP coverage saved A$70-220 million in healthcare costs during 2000-2010 and will save an additional A$340-950 million in future healthcare costs. With NSPs costing A$245 million, the programs are very cost-effective at A$416-8750 per QALY gained. Financial investment in NSPs over 2000-2010 is estimated to be entirely recovered in healthcare cost savings by 2032 with a total future return on investment of $1.3-5.5 for every $1 invested.
Syringe exchange in the United States: a national level economic evaluation of hypothetical increases in investment. (2014) Nguyen, Weir, Des Jarlais, Pinkerton, Holtgrave, 2014 AIDS Behavior 18(11):2144-55. doi: 10.1007/s10461-014-0789-9.
The strategy for answering this question is to start from an equation for the number of new HIV infections due to injection drug use over a 1-year period, and to relate parameters in this equation to syringe supply. Such equation would allow us to estimate how a hypothetical increase in syringe supply would affect the number of new infections. The initial equation is based on the premise that the number of new infections in a year equals the number of uninfected (thus at risk) persons times the probability that an uninfected person becomes infected over the course of the year.
The key question is if NSP syringe supply were increased by a certain amount, what would happen to the number of people contracting HIV? If we could answer this question, we could evaluate the cost effectiveness of such hypothetical increase in NSP syringe supply by costing it and estimating savings resulting from infections averted.
In the base case scenario with no additional syringe exchange funding, an estimated 2,575 HIV infections occur in a year due to drug injection risk. Based on lifetime treatment costs of $391,223 in 2011 USD per infection, the total treatment costs for these infections is $1.01 billion. With an annual $10 to $50 million funding increase, 194-816 HIV infections would be averted (cost per infection averted $51,601-$61,302). Contrasted with HIV treatment cost savings alone, the rate of financial return on investment would be 7.58-6.38. Main and sensitivity analyses strongly suggest that it would be cost-saving for the US to invest in syringe exchange expansion. These analyses indicate that it would be highly cost-saving to invest additional funds to expand syringe exchange services in the US. Over the course of 1 year an additional investment of only $10 million would avert an estimated 194 HIV infections and avoid $75.8 million in lifetime HIV treatment costs (saving $65.8 million net), representing a rate of financial return on investment of 7.58. If the investment increase were $50 million, it would also be highly cost-saving: approximately 816 HIV infections would be averted, equivalent to nearly one-third (32 %) of the annual number of new HIV infections due to drug injection risk; $319.1 million of lifetime HIV treatment costs would be avoided (net savings $269.1 million), representing a 6.38 rate of financial return on investment. Sensitivity analyses showed that when uncertainties about parameter values were accounted for, investment increase remained highly cost-saving.
Using Interrupted Time Series Analysis to Measure the Impact of Legalized Syringe Exchange on HIV Diagnoses in Baltimore and Philadelphia (2019) Ruiz, O’Rourke, Allen, Holtgrave, Metzger, Benitez, Brady, Chaulk, Wen, 2019 Journal of Acquired Immune Deficiency Syndrome. Volume 82, Supplement 2 148-154, doi 10.1097/QAI.0000000000002176
Using surveillance data from Philadelphia (1984–2015) and Baltimore (1985–2013) for IDU-associated HIV diagnoses, we used autoregressive integrated moving averages modeling to conduct 2 tests to measure policy change impact. We forecast the number of expected HIV diagnoses per city had policy not changed in the 10 years after implementation and compared it with the number of observed diagnoses postpolicy change, obtaining an estimate for averted HIV diagnoses. We then used interrupted time series analysis to assess the immediate step and trajectory impact of policy change implementation on IDU-attributable HIV diagnoses.
Syringe exchange programs (SEP) reduce HIV incidence associated with injection drug use (IDU), but legislation often prohibits implementation. We examined the policy change impact allowing for SEP implementation on HIV diagnoses among people who inject drugs in 2 US cities.
The Philadelphia (1993–2002) model predicted 15,248 new IDU-associated HIV diagnoses versus 4656 observed diagnoses, yielding 10,592 averted HIV diagnoses over 10 years. The Baltimore model (1995–2004) predicted 7263 IDU-associated HIV diagnoses versus 5372 observed diagnoses, yielding 1891 averted HIV diagnoses over 10 years. Considering program expenses and conservative estimates of public sector savings, the 1-year return on investment in SEPs remains high: $243.4 M (Philadelphia) and $62.4 M (Baltimore). Policy change is an effective structural intervention with substantial public health and societal benefits, including reduced HIV diagnoses among people who inject drugs and
significant cost savings to publicly funded HIV care.
If you have questions or notice errors in this list, please contact Tim Candela, Drug User Health Coordinator: tim.candela@doh.wa.gov.