Cost-effectiveness of a web-based decision aid for parents deciding about MMR vaccination

Background: Levels of measles in England and Wales are at their highest for 18 years and strategies targeting the different groups of parents who don’t vaccinate their children continue to be needed. Decision aids for childhood immunisation decisions appear to be effective in achieving vaccine uptake, however their cost effectiveness is unknown. Aim: To assess the cost-effectiveness of a web-based decision aid to increase MMR vaccine uptake. Design and Setting: Economic evaluation conducted alongside a cluster randomised controlled trial. 50 GP practices in the North of England were randomised to one of three trial arms (decision aid, leaflet, nothing) alongside usual practice. 220 first-time parents (child aged 3 to 12 months) were recruited. Methods: Parents self-reported their contacts with the NHS and other previous/expected resource utilisation; associated costs were calculated. Vaccine uptake was collected from GP practices. Cost-effectiveness is expressed in terms of incremental cost per first vaccine uptake. Multiple imputations were used to account for missing data and findings were adjusted for baseline differences in parents’ levels of decisional conflict for the MMR decision. Results: MMR uptake was highest for those receiving the decision aid (42/42, 100% vs. usual practice 61/62, 98% and leaflet arm 69/75, 92%) and was associated with lower cost. The decision aid has a high chance of being cost-effective regardless of the value placed on obtaining additional vaccinations. Conclusions: The decision aid appears to offer an efficient means of decision support for parents.