Bmc Public Health Open Access the Average Cost of Measles Cases and Adverse Events following Vaccination in Industrialised Countries

Background: Even though the annual incidence rate of measles has dramatically decreased in industrialised countries since the implementation of universal immunisation programmes, cases continue to occur in countries where endemic measles transmission has been interrupted and in countries where adequate levels of immunisation coverage have not been maintained. The objective of this study is to develop a model to estimate the average cost per measles case and per adverse event following measles immunisation using the Netherlands (NL), the United Kingdom (UK) and Canada as examples. Methods: Parameter estimates were based on a review of the published literature. A decision tree was built to represent the complications associated with measles cases and adverse events following imminisation. Monte-Carlo Simulation techniques were used to account for uncertainty. Results: From the perspective of society, we estimated the average cost per measles case to be US$276, US$307 and US$254 for the NL, the UK and Canada, respectively, and the average cost of adverse events following immunisation per vaccinee to be US$1.43, US$1.93 and US$1.51 for the NL, UK and Canada, respectively. Conclusions: These average cost estimates could be combined with incidence estimates and costs of immunisation programmes to provide estimates of the cost of measles to industrialised countries. Such estimates could be used as a basis to estimate the potential economic gains of global measles eradication. Background In many industrialized countries, high levels of immunisation over a number of years have led to a dramatic reduction in measles incidence. However, measles cases continue to occur in i) countries, such as the United States or Canada, where endemic measles transmission have Published: 19 September 2002 BMC Public Health 2002, 2:22 Received: 25 July 2002 Accepted: 19 September 2002 This article is available from: http://www.biomedcentral.com/1471-2458/2/22 © 2002 Carabin et al; licensee BioMed Central Ltd. This article is published in Open Access: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL. BMC Public Health 2002, 2 http://www.biomedcentral.com/1471-2458/2/22 Page 2 of 13 (page number not for citation purposes) been interrupted and cases are linked to importations [1]; and ii) countries, such as Italy and Germany, where adequate levels of immunisation coverage have not been maintained and measles continues to circulate widely. These cases of measles can lead to serious complications and deaths as recently demonstrated in outbreaks in Ireland [2], Germany [3] and the Netherlands [4,5]. In addition to the economic and public health burden that these cases represent, the maintenance of high levels of vaccine coverage imposes an additional health and economic burden. The health burden is due to the real and perceived occurrence of adverse events following immunisation (AEFI). The economic burden arises through the cost of maintaining coverage levels and surveillance programmes. In this paper we use a simple model to estimate the average cost of measles and measles vaccine associated adverse events, using the Netherlands (NL), the United Kingdom (UK) and Canada as examples. We then compare our estimates with others available in the literature. This is the first step in what would be required to estimate the global cost of measles immunisation and cases in industrialised countries. Methods Estimation of the frequency of measles complications and their treatment A decision tree with the average probabilities used for estimating the cost per average case of measles is shown in Figure 1a. Measles cases are first divided into two distinct groups, according to whether they seek medical attention Figure 1 Decision trees. a) measles cases and b) Adverse Event Following Immunisation (AEFI) with measles vaccines. Legend: This graph shows the proportion of cases with each symptom, complication, sequelae or hospitalisation. A circle corresponds to a chance node (defined by the probability of the event occurring), a triangle represents an end node. The number at the top of each branch shows the proportion of each event occurring at that point in the tree. The total proportion of cases in each group per measles case is written at the right of each branch. 0 . 0 0 0 6 % 0 . 0 0 0 1 % 0 . 0 0 6 5 % 0 . 0 0 0 6 %