Impact and cost-effectiveness of scaling up HCV testing and treatment strategies for achieving HCV elimination among people who inject drugs in England: a mathematical modelling study

Background: England aims to reach the World Health Organization (WHO) elimination target of decreasing HCV incidence among people who inject drugs (PWID) to <2 per 100 person-years (/100pyrs) by 2030. We assessed what testing and treatment strategies will achieve this target and whether they are cost-effective.

Methods: A dynamic deterministic HCV transmission model among PWID was developed for four England regions, utilising data on the scale-up of HCV treatment among PWID in prisons, drug treatment centres (DTC, where opioid agonist therapy is provided), and any other setting (e.g., primary care). The model projected whether the elimination target will be reached with existing testing and treatment initiatives ('status quo' model, SQ), or whether improvements are needed from 2024. Cost data was collated through practitioners' interviews and published literature. The mean incremental cost-effectiveness ratio (ICER per quality adjusted life year (QALY) saved, 50-year time horizon; 3.5% discount rate) of SQ (assumes counterfactual of no treatment scale-up post-2015) and improved model (counterfactual: SQ model) was compared to a willingness-to-pay threshold of £20,000/QALY saved.

Findings: The SQ model projects HCV incidence will decrease by 79.7-98.6% (range of medians) over 2015-2030 to 0.2-2.2/100pyrs, with an ICER of £308-1609/QALY saved across the regions. There is >80% probability of achieving the incidence target in three regions, and 40% probability in the other region. If annual testing in DTC increases to 80% (from 27%) or 75% of people get tested during their prison stay (from 55%) from 2024 in the lower impact region, then their probability increases to >65%, with both strategies being highly cost-effective.

Interpretation: Many England regions could reach the WHO HCV elimination target by 2030 under existing testing and treatment pathways. Scaling up of testing in DTC or prisons will help achieve this target and is highly cost-effective.

Funding: NIHR.