Platt, Lucy and Sweeney, Sedona and Ward, Zoe and Guinness, Lorna and Hickman, Matthew and Hope, Vivian and Hutchinson, Sharon and Maher, Lisa and Iversen, Jenny and Craine, Noel and Taylor, Avril and Munro, Alison and Parry, John V and Smith, Josie and Vickerman, Peter (2017) Assessing the impact and cost-effectiveness of needle/syringe provision and opiate substitution therapy on hepatitis C transmission among people who inject drugs in the United Kingdom: analysis of pooled datasets and economic modeling. Public Health Research, 5, (5), https://doi.org/10.3310/phr05050.
External website: https://www.journalslibrary.nihr.ac.uk/phr/phr0505...
Background - There is limited evidence of the impact of needle and syringe programmes (NSPs) and opioid substitution therapy (OST) on hepatitis C virus (HCV) incidence among people who inject drugs (PWID), nor have there been any economic evaluations.
Objective(s) - To measure (1) the impact of NSP and OST, (2) changes in the extent of provision of both interventions, and (3) costs and cost-effectiveness of NSPs on HCV infection transmission.
Design - We conducted (1) a systematic review; (2) an analysis of existing data sets, including collating costs of NSPs; and (3) a dynamic deterministic model to estimate the impact of differing OST/NSP intervention coverage levels for reducing HCV infection prevalence, incidence and disease burden, and incremental cost-effectiveness ratios to measure the cost-effectiveness of current NSP provision versus no provision.
Setting - Cost-effectiveness analysis and impact modelling in three UK sites. The pooled analysis drew on data from the UK and Australia. The review was international.
Participants - PWID.
Interventions – NSP coverage (proportion of injections covered by clean needles) and OST.
Outcome - New cases of HCV infection.
Results - The review suggested that OST reduced the risk of HCV infection acquisition by 50% [rate ratio (RR) 0.50, 95% confidence interval (CI) 0.40 to 0.63]. Weaker evidence was found in areas of high (≥ 100%) NSP coverage (RR 0.77, 95% CI 0.38 to 1.54) internationally. There was moderate evidence for combined high coverage of NSPs and OST (RR 0.29, 95% CI 0.13 to 0.65). The pooled analysis showed that combined high coverage of NSPs and OST reduced the risk of HCV infection acquisition by 29–71% compared with those on minimal harm reduction (no OST, ≤ 100% NSP coverage). NSPs are likely to be cost-effective and are cost-saving in some settings. The impact modelling suggest that removing OST (current coverage 81%) and NSPs (coverage 54%) in one site would increase HCV infection incidence by 329% [95% credible interval (CrI) 110% to 953%] in 2031 and at least double (132% increase; 95% CrI 51% to 306%) the number of new infections over 15 years. Increasing NSP coverage to 80% has the largest impact in the site with the lowest current NSP coverage (35%), resulting in a 27% (95% CrI 7% to 43%) decrease in new infections and 41% (95% CrI 11% to 72%) decrease in incidence by 2031 compared with 2016. Addressing homelessness and reducing the harm associated with the injection of crack cocaine could avert approximately 60% of HCV infections over the next 15 years.
Limitations - Findings are limited by the misclassification of NSP coverage and the simplified intervention definition that fails to capture the integrated services that address other social and health needs as part of this.
Conclusions - There is moderate evidence of the effectiveness of OST and NSPs, especially in combination, on HCV infection acquisition risk. Policies to ensure that NSPs can be accessed alongside OST are needed. NSPs are cost-saving in some sites and cost-effective in others. NSPs and OST are likely to prevent considerable rates of HCV infection in the UK. Increasing NSP coverage will have most impact in settings with low coverage. Scaling up other interventions such as HCV infection treatment are needed to decrease epidemics to low levels in higher prevalence settings.
Future work - To understand the mechanisms through which NSPs and OST achieve their effect and the optimum contexts to support implementation.
G Health and disease > Disease by cause (Aetiology) > Needle (sharing / injecting)
G Health and disease > Disease by cause (Aetiology) > Communicable / infectious disease > Hepatitis C
HJ Treatment method > Substance disorder treatment method > Substance replacement method (substitution)
HJ Treatment method > Substance disorder treatment method > Substance replacement method (substitution) > Opioid agonist treatment (methadone maintenance / buprenorphine)
J Health care, prevention, harm reduction and rehabilitation > Harm reduction > Substance use harm reduction
J Health care, prevention, harm reduction and rehabilitation > Health related issues > Health information and education > Communicable / infectious disease control
J Health care, prevention, harm reduction and rehabilitation > Health related issues > Health information and education > Communicable / infectious disease control > Needle syringe distribution and exchange
J Health care, prevention, harm reduction and rehabilitation > Health care economics
L Social psychology and related concepts > Physical context, location or place > Safe spaces (injecting facilities / centre / consumption rooms)
T Demographic characteristics > Person who injects drugs (Intravenous / injecting)
VA Geographic area > International
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