Interventions:
The comparators were appropriately selected as surgery was compared with radiation and both were effective treatments for this patient population.
Effectiveness/benefits:
A valid approach was used to identify the relevant sources of evidence. The author reported the key methods and conduct of the literature review in an appendix. A critical evaluation of the available evidence was undertaken. The author discussed the potential limitations of the published literature, which was affected by selection bias, the use of pathologic rather than clinical staging, the inclusion of patients treated for recurrent disease, and the use of non-standard therapy, such as chemotherapy. Most studies were case series with no comparison group. The author selected appropriate single arm studies that were pooled as a composite group using a random-effects model to account for heterogeneity. There was a lack of published data for the utility values and these were derived from a sample of patients, included in a pilot study, using a validated instrument. QALYs were an appropriate benefit measure, especially for this patient population, given the impact of the disease on quality of life.
Costs:
The author provided extensive information on the derivation of the costs of the two treatments. The two main cost categories were broken down into individual items and their unit costs and quantities of resources were reported in the appendix. The author reported the methods used to estimate the capital costs and these appear to have been valid. The data appear to have come from the author’s institution. The price year was not explicitly reported. Appropriate discounting was applied. Some costs were varied in the sensitivity analysis. In general, the economic analysis was well carried out.
Analysis and results:
The results were clearly presented. The costs and benefits were appropriately synthesised, using an incremental approach. The uncertainty was partly investigated, using a deterministic approach that focused on individual inputs to the model. A justification for the three-year time horizon was given. The author reported the results of several other economic evaluations, highlighting the limitations of each study. This analysis referred to the Canadian context, but the detailed presentation of cost data should allow adaptation to other settings.
Concluding remarks:
The methods were robust, which ensures the validity of the author’s conclusion.