Reviewing the cost effectiveness of rotavirus vaccination: the importance of uncertainty in the choice of data sources.

Published health economic evaluations of rotavirus vaccination up until July 2008 were reviewed. We assess whether differences in the results and conclusions of the various studies are due to differences in methodological and modelling choices, and/or the way parameter uncertainty was taken into account, or whether these are merely the result of genuine country/region-specific differences. No unambiguous single answer emerged as to whether universal rotavirus vaccination is or is not cost effective. The relevance and merits of each study need to be assessed within its context. This is illustrated by the fact that comparisons of different analyses for a single country show that one of the most important explanations for the variations in results and conclusions seems to be the use of different information sources for the estimation of input parameters. Future studies should gather reliable and relevant information focusing on the most influential input parameters, i.e. rotavirus mortality (and efficacy against rotavirus deaths) for low- and middle-income countries, and a range of variables for high-income countries, including the incidence and cost of rotavirus hospitalization. Moreover, if no information is available for an important input parameter, the impact of a wide range of values should be explored rather than excluding it from the analysis or specifying a single-point value. Furthermore, future analyses may have to consider ways of accounting for herd immunity (e.g. by using a dynamic model).