Project aimsThis project aimed to:
- Estimate the population benefits of needle and syringe programs (NSPs) on HIV and hepatitis C virus (HCV) related outcomes among injecting drug users (IDUs) in Australia and in each State and Territory over the period from 2000 to 2009.
- Explore changes in the provision of NSPs, populations at risk, and sharing behaviour on these outcomes
- Calculate the net present value and future values and cost-effectiveness of NSPs in terms of HIV and HCV infections averted from a health sector (government as third party payer) perspective.]
Population model methodsA mathematical epidemic model was developed to simulate HIV and HCV transmission among IDUs in Australia. The model was informed by detailed biological data, Australian IDUs behavioural data (e.g., the annual NSP survey/finger prick survey), and the number of injecting equipment units distributed by NSPs each year. The model described IDUs in the community and not those in prisons. The extensive available data enabled the model to describe well the complex injecting behaviour and mixing patterns of Australian IDUs and viral transmissions within this population. The model was used to determine the population-level effectiveness of NSPs in preventing transmissions of HIV and HCV through the distribution of sterile injecting equipment. It accurately reflected the current HIV and HCV epidemiology in Australia. Separate analyses were carried out for IDUs in Australia and by each Australian state and territory as well as Australian Aboriginal and Torres Strait Islander people who inject drugs.
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The decade from 2000-2009 was investigated to estimate the number of HIV and HCV infections with and without NSPs in the past, thus determining the effectiveness of NSPs. The model was then used to forecast epidemic trajectories over the next 70 years (2010-2079) under assumptions that funding and services of NSPs or behaviour of IDUs remain unchanged or according to changes in conditions. This time horizon was chosen in order to consider whole of lifetime impacts. Shorter timeframes are also analysed. These results became inputs into an economic analysis.
Economic analysis methodsAn economic analysis used the epidemic model results and detailed data on costs. Costs associated with NSPs were provided by State and Territory health departments. Healthcare costs for HIV and HCV were estimated from activity-based analysis and national databases. All costs are presented in 2008 Australian dollars. The outcome of interest from the economic analysis was:
- Disability-Adjusted-Life-Years (DALYs).
- Life-time of current IDU cohort.
Summary of investment
- The number of needles and syringes distributed in Australia increased during the past decade (from ~27 million to ~31 million).
- Expenditure on NSPs increased by 36% (adjusted for inflation) over this time period, mostly associated with personnel and not principally for equipment (Table a); a significant portion of the increased investment has been the Illicit Diversion Supporting Measures for NSPs to increase referrals to drug treatment and other services.
- Over the last decade there has been:
- Increases in funding for primary sites.
- Increases in the number of secondary sites.
- Increases (by 15%) in the numbers of units of equipment provided.
- Stable spending on sterile injection equipment.
- At the time of writing there were 85 primary sites, 737 secondary sites, 20 enhanced secondary sites, and 118 vending machines.
Effectiveness of NSPsIt was estimated that over the last decade (2000-2009) NSPs have directly averted:
- 32,050 new HIV infections;
- 96,667 new HCV infections.
Economic analysis of NSPs during 2000-2009During 2000-2009, gross funding for NSP services was $243m. This investment yielded:
- Healthcare costs saved of $1.28 billion ($1.12bn-$1.45bn, IQR).
- Approximately 140,000 DALYs gained.
- Net financial cost-saving of $1.03 billion ($876m-$1.98bn, IQR).
It was estimated that:
- For every one dollar invested in NSPs, more than four dollars were returned (additional to the investment) in healthcare cost-savings in the short-term (ten years) if only direct costs are included; greater returns are expected over longer time horizons.
- NSPs were found to be cost-saving over 2000-2009 in seven of eight jurisdictions and cost-effective in the other jurisdiction. Over the longer term, NSPs are highly cost saving in all jurisdictions.
- The majority of the cost savings were found to be associated with HCV-related outcomes. However, when only HIV-related outcomes were considered in the analysis, it cost $4,500 per DALY gained associated with HIV infection.
- If patient/client costs and productivity gains and losses are included in the analysis, then the net present value of NSPs is $5.85bn; that is, for every one dollar invested in NSPs (2000-2009), $27 is returned in cost savings. This return increases considerably over a longer time horizon.
- NSPs are very cost-effective compared to other common public health interventions, such as vaccinations (median cost per QALY of $58,000), allied health, lifestyle, and in-patient interventions (median cost of $9,000 per DALY gained), and interventions addressing diabetes and impaired glucose tolerance or alcohol and drug dependence (median cost of $3,700 per DALY gained).2
Results about future NSPsIf NSPs were to decrease in size or number, then relatively large increases in both HIV and HCV could be expected with associated losses of health and life and reduced returns on investment (Table d). Significant public health benefits can be attained with further expansion of sterile injecting equipment distribution.
Investment in NSPs was cost-saving for current NSP funding when analysed for all time periods. Cost savings were:
- $782m (2010-2019)
- $3.23bn (2010-2029)
- $17.75bn (2010-2059)
- $28.71bn (2010-2079).
- $641m (2010-2019)
- $2.27bn (2010-2029)
- $8.41bn (2010-2079).
ConclusionsInvestment in NSPs (2000-2009) has resulted in:
- An estimated 32,050 HIV infections and 96,667 HCV infections averted;
- Substantial healthcare cost savings to government related to HCV and HIV;
- Substantial gains in Disability Adjusted Life years.
Results from model-based projections into the future (2010 onwards) suggest that:
- Maintenance of current levels of NSP funding will continue to provide
- substantial and increasing healthcare cost savings;
- gains in life years.
- Increases in the funding and provision of NSPs will:
- avert additional HCV and HIV infections;
- lead to further and increased cost-savings of funding up to 150-200% of current level if met with demand;
- reduce marginal return on investment as funding increased.
- the maximum return would be achieved at 150% to 200% of current levels.
Table a: Investments made by financial year in 2008 Australian dollars (unadjusted financial expenditures and adjusted for consumer price index) ($'000)Note that NSP support includes human resource costs, rent and overheads; support for secondary sites consists of human resource costs.
|Consumables - sterile injecting equipment|
|Consumables - disposal equipment|
|Consumables - safe sex packs|
|NSP support - primary NSP operations|
|NSP support - support for secondary NSPs|
|NSP support - transport|
|NSP support - vending machines|
|NSP support sub-total|
|Total (unadjusted for CPI)|
|Total (adjusted for CPI)|
|Total client costs|
Table b: Estimated HIV- and HCV-related outcomes, with and without NSPs (medians)Table b is separated into 2 smaller tables in this HTML version. It is presented as one table in the PDF version.
HIV related outcomes
|Outcome (2000-2009)||With NSPs||Without NSPs||Cases averted|
|Prevalence of HIV among IDUs (2009)|
|Cumulative incidence of HIV infections|
|Cumulative incidence of HIV-related deaths|
HCV related outcomes
|Outcome (2000-2009)||With NSPs||Without NSPs||Cases averted|
|Prevalence of HCV among IDUs (2009)|
|Cumulative incidence of HCV infections|
|Number of cirrhosis cases (2009)|
|Cumulative incidence of HCC|
|Cumulative incidence of liver failure|
|Cumulative incidence of liver transplants|
|Cumulative number of live-related deaths|
Table c: Net cost of program and gains in DALYs (undiscounted) as well as net present value (discounted (3%) and undiscounted) from the perspective of year 2000
|Costs saved $m |
|NPV current program |
$m (IQR) (undisc.)
|NPV current program |
$m (IQR) (3% disc.)
Table d: Loss of life and reduced return associated with decreased funding period 2010- 2019 (all discounted at 3%)
|NSP funding||Reduction in NSP spending||Loss in DALY vs. current||Reduced return|
|50% of current levels|
|75% of current levels|
|90% of current levels|
Table e: Gain in DALYs and net present value with level of funding in NSPs after ten years (2010-2019) compared to no program
|Level of funding for NSPs||NSP investment||Gain in DALY||Net saving (NPV)||Return on investment|
|100% of current levels|
current investment + 380%
|110% of current levels|
current investment + 360%
|125% of current levels|
current investment + 330%
|150% of current levels|
current investment + 290%
|175% of current levels|
current investment + 270%
|200% of current levels|
current investment + 240%
|300% of current levels|
current investment + 180%