Quantifying the impact of a novel virus on the economic value of pathogen reduction technology for platelets.

Background: Pathogen reduction technology (PRT) is an intervention designed to proactively reduce the amount of known and unknown pathogens in donated blood. As current screening for known pathogens is highly effective, some previous evaluations have found that the value of PRT largely hinges on a previously unknown pathogen, most likely a novel virus, emerging and entering the blood supply. In such situations, the risk of emergence can and should be modeled and presented transparently in the cost-effectiveness results for deliberation by decision-makers.

Study design and methods: We built a Markov cohort model assessing the economic value of introducing PRT for platelets in the United Kingdom. Input data were obtained from the existing PRT literature, national sources, or by conservative assumption. The primary objective of the study was to demonstrate methods for modeling and presenting the risk of emergence of a novel virus, using alternative time-to-emergence scenarios in the probabilistic sensitivity analysis.

Results: As expected, PRT will be more cost-effective the sooner the novel virus emerges after the introduction of PRT. In the base-case cost scenario, the deterministic ICER was £270 K/QALY gained if the virus emerged immediately and rose to £3.3 M/QALY gained if the virus emerged after 25 years.

Discussion: At current prices, PRT is unlikely to be cost-effective when judged against thresholds for medicines and treatments. Given significant additional willingness-to-pay for blood safety, PRT is only likely to be cost-effective if a novel virus that causes chronic infection with significant morbidity and mortality emerges very soon after the introduction of PRT.