Cost-effectiveness of strategies to improve HCV screening, linkage-to-care and treatment in remand prison settings in England.

Abstract

A simplified cascade-of-care may improve screening and treatment uptake among incarcerated individuals. We assessed the cost-effectiveness of traditional and simplified screening and treatment in a London remand prison. Using empirical data from Her Majesty's Prison (HMP) Wormwood Scrubs, London, we designed a decision tree and Markov transition state model using national average data for HCV screening and treatment for the base-case scenario. This compared two alternative strategies; (a) general prison population screening and treatment and (b) prioritising screening and treatment among people who inject drugs (PWID) combined with general prison population screening and treatment. Strategies varied the rates of screening (47%-90%), linkage-to-care (60%-86%) and treatment (21%-85%). Cost, utility and disease transition rates were obtained from existing literature. Outcome measures were as follows: screening, treatment and disease-related costs per admitted individual, quality-adjusted life years (QALYs). Incremental cost-effectiveness ratios (ICERs) were calculated for each intervention. All costs and utilities were discounted at a rate of 3.5% per annum. Both univariate and probabilistic sensitivity analyses have been conducted. In our cohort of 5239 incarcerated individuals with an estimated chronic HCV prevalence of 2.6%, all strategy ICER values (£3565-10300) fell below the national willingness to pay threshold (£30000). Increased successful treatment (7%-54%) was observed by an optimising cascade-of-care. A robust sensitivity analysis identified treatment cost of, QALY for mild liver disease and probability of completing treatment as important factors that impact the ICER value. In our remand setting, optimising adherence to the cascade-of-care is cost-effective. Where universal screening is not practical, a stratified approach focused on intensive screening and treatment of PWID also results in increased treatment uptake and is highly cost-effective.