Increased short-course DAA therapy cost-effective among PWID with HCV in UK prisons

Using a model of incarcerated individuals and hepatitis C virus infection transmission among people who inject drugs in England, researchers found that increased treatment and shorter duration direct-acting antiviral therapy may be more cost-effective compared with case-finding and current treatment methods, according to findings published in Hepatology.

“Our model shows that baseline [or] existing levels of HCV treatment for [people who inject drugs] in prison and the community are unlikely to result in observable changes in HCV chronic prevalence or incidence among [people who inject drugs] in prison in the next 50 years,” Natasha K. Martin, DPhil, associate professor, division of global public health, University of California San Diego, and colleagues wrote.

Natasha K. Martin

To assess the cost-effectiveness of increased HCV case-finding and treatment in UK prisons with shorter durations of therapy, the researchers used a model that measured the cost-effectiveness of doubling HCV case-finding and increasing treatment in UK prisons then compared it with status quo voluntary risk-based testing. These were compared using both currently recommended therapies (8-24 weeks) or interferon (IFN)-free direct-acting antivirals (DAAs; 8-12 weeks).

The researchers used costs (British pounds) and quality-adjusted life years (QALY) to calculate mean incremental cost-effectiveness ratios (ICERs).

“We assumed 56% referral and 2.5% [of] 25% of referred people who inject drugs (PWID) [or former users] were treated within 2 months of diagnosis in prison,” the researchers wrote. “PWID and [former users] are in prison an average [of] 4 and 8 months, respectively.”

Overall, the model showed that doubling prison HCV testing rates with existing treatments had a mean ICER of 19,850 pounds per QALY gained compared with current testing or treatment. This indicated that this method is 45% likely to be cost-effective under a 20,000 pounds’ willingness-to-pay threshold, according to the abstract. Switching to an 8- to 12-week IFN-free DAA regimen in prisons may increase cost-effectiveness (ICER: 15,090 pounds per QALY gained). Excluding prevention benefit decreases this cost-effectiveness.

In addition, if more than 10% of prisoners who are referred PWID are treated in prison, either treatment could be highly cost-effective (ICER: less than 13,000 pounds). HCV case-finding and IFN-free DAAs could be highly cost-effective if DAA cost is 10% lower or with 8 weeks' duration.

The researchers concluded: “Increased HCV testing in UK prisons is borderline cost-effective compared to status quo voluntary risk-based testing under a 20,000 [pounds] willingness to pay with current treatments, but likely to be cost-effective if short-course IFN-free DAAs are used and could be highly cost-effective if PWID treatment rates were increased.” – by Melinda Stevens