Interventions:
The rationale for the selection of the comparators was clear, in that the authors considered a wide range of possible recommended regimens for the treatment of PID. The dosages were reported.
Effectiveness/benefits:
The clinical evidence came from mixed sources, which were not described in detail. No information was provided on the study design, patient population, type of treatment administered, length of follow-up, and other issues regarding the combination of data from different studies. The key assumption made to derive the comparative efficacy of treatments was not supported by any published evidence, but the scope of the study was to assess the cost-effectiveness by varying this assumption. In fact, to overcome these potential limitations, the authors undertook an extensive sensitivity analysis on the clinical inputs. The use of QALYs was appropriate as they detect the impact of disease on the patients’ health and allow cross-disease comparisons to be made.
Costs:
The authors stated that a societal perspective was adopted, but only the direct medical costs appear to have been included. The costs and their sources were not clearly described. The unit costs and resource quantities were not reported separately, with most of the costs being presented as macro-categories. Other details such as the price year and the use of discounting were reported.
Analysis and results:
The costs and benefits were appropriately reported and were synthesised using an incremental approach, the results of which were presented. Conventional discounting was applied to both the costs and benefits. Extensive details of the decision model were provided. The issue of uncertainty was appropriately and fully investigated, and the results were clearly reported and discussed. The authors acknowledged that it was unclear whether any real differences in the efficacy of the treatment regimens existed, and the analysis was based on assumptions, as previously stated.
Concluding remarks:
The study was based on valid methodology, especially for the analysis of uncertainty, but it was also based on assumptions on the clinical effectiveness of the treatments compared, and the authors’ conclusions should be viewed considering this issue.