Detachable low dead space syringes for the prevention of hepatitis C among people who inject drugs in Bristol, UK: an economic evaluation

BACKGROUND AND AIMS: Traditional detachable syringes used by people who inject drugs (PWID) retain larger volumes of blood when the plunger is depressed than syringes with fixed needles - referred to as high (HDSS) and low dead space syringes (LDSS), respectively. Evidence suggests that using HDSS may result in greater hepatitis C virus (HCV) transmission risk than LDSS. We evaluated the cost-effectiveness of an intervention to introduce detachable LDSS in a needle and syringe programme (NSP).

DESIGN: HCV transmission and disease progression model with cost-effectiveness analysis using a health-care perspective. Detachable LDSS are associated with increased costs (£0.01) per syringe, yearly staff training costs (£536) and an estimated decreased risk (by 47.5%) of HCV transmission compared with HDSS. The intervention was modelled for 10 years, with costs and health benefits (quality-adjusted life-years or QALYs) tracked over 50 years.

SETTING: Bristol, UK PARTICIPANTS/CASES: PWID attending NSP INTERVENTION AND COMPARATOR: Gradual replacement of HDSS at NSP, with 8%, 58% and 95% of HDSS being replaced by detachable LDSS in 2016, 2017 and 2018, respectively. Comparator was continuing use of HDSS.

MEASUREMENTS: Net monetary benefit. Benefits were measured in QALYs.

FINDINGS: Introducing detachable LDSS was associated with a small increase in intervention costs (£21,717) compared with not introducing detachable LDSS, but considerable savings in HCV-related treatment and care costs (£4,138,118). Overall cost savings were £4,116,401 over 50 years and QALY gains were 1,000, with an estimated 30% reduction in new infections over the 10 year intervention period. In all sensitivity analyses, detachable LDSS resulted in cost savings and additional QALYs. Threshold analyses suggested detachable LDSS would need to reduce HCV transmission risk of HDSS by 0.26% to be cost-saving and 0.04% to be cost-effective.

CONCLUSIONS: Replacing high dead space syringes with detachable low dead space syringes in needle and syringe programmes in the UK is likely to be a cost-saving approach for reducing hepatitis C virus transmission.