Interventions:
The rationale for the selection of the comparators was clear as the intervention was the recommended screening strategy, but it had not been fully implemented in Australia at the time of the study. Other options, such as sigmoidoscopy, colonoscopy, and guaiac-based FOBT, were not considered, but might have been valid comparators.
Effectiveness/benefits:
The key methods of the literature review were provided, but the designs of the selected studies were not given. Some data on the accuracy of the FOBT were from randomised controlled trials, which should have had good internal validity, but no further details were given and the quality of the evidence is not clear. The authors did not report the comparability of their sources and whether it was appropriate to combine the data. Other inputs were appropriately from the implementation of the screening programme in Australia. Life-years were an appropriate benefit measure as survival is a relevant outcome for a cancer screening programme.
Costs:
The perspective was not explicitly stated, but the cost categories reflected the perspective of the health care payer. The costs were from published economic evaluations in Australia and some data from the actual implementation of the screening programme. These appear to have been valid sources and relevant to the authors’ context. The unit costs and resource quantities were generally not presented separately, reducing the ability to reproduce the analysis. The authors provided a clear justification for the exclusion of patient-related costs, as well as lost productivity costs, due to the controversial methods used to assess them. No sensitivity analysis was conducted on the cost inputs.
Analysis and results:
The incremental results of the screening programme over no screening were reported. The uncertainty was not investigated and no sensitivity analyses were performed. The authors stated that discounting was not applied to the costs and benefits as the analysis focused on the immediate impact of the screening programme. The limitations of previous modelling studies were clearly stated and justified the additional modelling undertaken by the authors. They pointed out that the projected cost-effectiveness estimates were likely to be conservative because of several assumptions in their model. The analysis should be considered to be specific to Australia and will not be easy to transfer to other settings.
Concluding remarks:
The methods were valid and the data were from both a literature review and the implementation of the programme, but assumptions were required and the uncertainty was not investigated, which limits the reliability of the authors’ conclusions.