Interventions:
The interventions were reported clearly and in detail. The comparator was appropriately usual practice (no specialised assessment clinic).
Effectiveness/benefits:
Clinical effectiveness came from a before-and-after cohort study. For both phases of the study, the authors reported that outcome information was recorded prospectively, which limited any potential bias common in studies with historical controls for which patients and data were collected retrospectively. However, as the authors acknowledged, before-and-after studies may be confounded by external factors; for example, in this study, the authors noted that the number of patients who underwent surgery gradually increased, which might have led to an increase in expertise, which may have affected the data.
Costs:
The authors did not report the perspective adopted for the analysis. A simple costing study was performed, in which only the costs of stays in post-anaesthesia care, high dependency and intensive care unit were included, but the sources for the unit costs were not reported. No costs associated with the pre-assessment anaesthetic clinic appeared to have been included. There was no assessment of whether the cost differences between the two groups were statistically significant. The price year was not reported.
Analysis and results:
Cost and outcome information came from a single before-and-after cohort study. The authors performed t-test analyses on all clinical outcomes, regardless of whether the data was continuous or categorical. The study had substantial limitations, including the fact that external factors, such as the gradual rise in surgical rates observed, could have biased the results.
Concluding remarks:
Given that the results of this study were based on a before-and-after cohort study and the costs of the pre-assessment clinics did not appear to be included in the analysis, it is not clear whether the authors’ conclusions are appropriate.