The rationale for the selection of the comparators was clear and appropriate in that all possible prevention and treatment strategies were considered.
The authors did not describe the approach used to identify the primary studies, nor did they give any information about the sources of these data. Thus, it is not possible to judge the validity of the clinical estimates. It seems that most of the clinical evidence was based on assumptions and expert opinion. Given the uncertainty surrounding the estimates used in the model, these inputs were extensively investigated in the sensitivity analysis. Similarly, the derivation of the benefit measures was unclear and the authors performed a Monte Carlo simulation on the expected DALYs in order to address uncertainty around these parameters.
The analysis of the costs appears to have been consistent with the authors' stated perspective. However, the costs were presented as macro-categories and a detailed breakdown of the cost items was not given. Furthermore, the authors did not describe accurately the sources used, especially when the costs were obtained from published economic evaluations. This reduces the transparency of the study. Other details such as the price year and the use of discounting were reported.
Analysis and results:
The synthesis of the costs and benefits was clear in its performance and presentation. The sensitivity analysis addressed the key aspects of uncertainty, which were investigated using both deterministic and probabilistic techniques. The results of the analysis were presented clearly. The authors stated that, in general, their findings were in agreement with previous reports. Some limitations to the generalisability of the study findings were pointed out. First, the target population was not specified sufficiently for the implementation in real-world programmes. Second, the simulation model might not reflect actual vaccination programmes. Third, the impact of the programmes on people outside of the cohort or target population was not considered.
The study was, in general, characterised by assumptions with respect to the clinical estimates used to populate the decision model. Thus, caution will be required when interpreting the authors’ conclusions.