Interventions:
A formal justification for the selection of the two procedures was not given, but they are likely to represent the available options for the patient population under examination.
Effectiveness/benefits:
The use of a prospective study to derive the clinical estimates was appropriate, although a randomised trial would have been more appropriate. The authors stated that study groups were well matched with respect to demographic and clinical characteristics. Several clinical end points were considered over different time points. These aspects of the analysis tend to enhance the internal validity of the comparison. Nevertheless, it is important to note that the most relevant limitation of the analysis was the failure to perform power calculations to demonstrate the appropriateness of the sample size, in order to show the statistical significance of the comparison. Thus, it is unclear whether the equal effectiveness of the two treatments was due to chance arising from an inadequate sample size, or whether it represented a true similarity. Moreover, the authors noted that the retrospective assessment of before-treatment health might not have been appropriate. It was also noted that a longer follow-up period would have been interesting. Finally, since the assessment of the treatment outcomes was not blinded, assessment bias cannot be totally ruled out.
Costs:
The cost analysis was presented clearly and the types of cost items included in the study were reported. The approach used to derive these costs (micro-costing) was appropriate and represents a strength of the analysis. The authors carried out statistical analyses of the costs, which enhance the robustness of the cost comparison. It was also pointed out that true costs rather than charges were used. The price year was reported. The unit costs were not presented separately from the quantities of resources used, but the costs were given as macro-categories. The authors noted that the inclusion of the costs of productivity losses would have been interesting.
Analysis and results:
A synthesis of the costs and benefits was not relevant to the scope of the analysis and was not performed. The results of the clinical and economic analyses were presented clearly. The issue of uncertainty was not addressed. The authors compared their results with those of other studies and highlighted differences in the settings and methods.
Concluding remarks:
The quality of the study methodology was generally good and the study was presented clearly and discussed. However, the authors’ conclusions should be considered with a degree of caution given the limitations described.