Cost effectiveness of national hepatitis B vaccination: interim report

In Nederland wordt momenteel overwogen om alle pasgeborenen tegen hepatitis B in te enten. Het RIVM heeft een onderzoek verricht waarin de kosten en effecten van vaccinatie van pasgeborenen vergeleken wordt met het huidige beleid. Dit is gericht op het vaccineren van risicogroepen, zoals homoseksuele mannen en medewerkers in de gezondheidszorg, en op het screenen van zwangeren. Een van de belangrijkste conclusies van het onderzoek is dat het aantal dragers van het virus in Nederland vooral door immigratie van dragers uit het buitenland bepaald wordt. Na invoering van algemene vaccinatie zal het aantal dragers van het virus in Nederland voorlopig niet erg sterk afnemen. De kosten per gewonnen levensjaar van algemene vaccinatie zijn relatief hoog in vergelijking met andere preventieve gezondheidszorgvoorzieningen. Als de kosten van het vaccin in de toekomst echter gaan dalen zal de kosten-effectiviteit van algemene vaccinatie gunstiger worden.In the Netherlands vaccination against hepatitis B has up to now targeted risk groups such as homosexual men, prostitutes, injecting drug users and persons working in the medical professions. At present, there is a discussion going on about whether to introduce hepatitis B vaccination into the national immunisation programme, as advised by the WHO in 1992. The RIVM has been asked to support decision makers by providing a cost-effectiveness analysis of such a programme, based on current knowledge of the epidemiology of hepatitis B infection and the consequent health-care costs. We collected information on hepatitis B epidemiology from various sources, ranging from notification data to preliminary results of an ongoing case-control study on hepatitis B transmission. After consulting on the prevalence of HBV carriers in the various risk groups and the impact of demographic factors, such as immigration of carriers from highly endemic regions, we simulated hepatitis B infection in an age-structured population with a dynamic transmission model. We also investigated the effects of universal vaccination using this model. The incidences computed by the model were then used as a basis for a cost-effectiveness analysis that resulted in estimates for the costs per life year gained. One of the major conclusions was that circulation of the virus is kept up only within small risk groups; therefore the prevalence of HBV carriage in the Netherlands is mainly determined by immigration of carriers. As a consequence, the effects of national vaccination on the prevalence of HBV will be marginal and the cost per life year gained high. However, our estimates on the cost per life year gained depend heavily on future costs of vaccination and on discounting of future effects. When future effects are not discounted, a national vaccination campaign will be more cost-effective.VW