Hypothesis
The aim of the study was to assess the cost-effectiveness of prophylactic ondansetron and dexamethasone compared with placebo in the prevention of postoperative nausea and vomiting (PONV) in children undergoing strabismus repair. The strategy of using placebo was explicitly regarded as the comparator. The perspective adopted in the analysis was not explicitly specified.
Bibliographic details
Subramaniam B, Madan R, Sadhasivam S, Sennaraj B, Tamilselvan P, Rajeshwari S, Jagan D, Shende D. Dexamethasone is a cost-effective alternative to ondansetron in preventing PONV after paediatric strabismus repair. British Journal of Anaesthesia, 2001; 86(1): 84-89
Status
This record was compiled by CRD commissioned reviewers according to a set of guidelines developed in collaboration with a group of leading health economists.
CRD commentary
Selection of comparators:
The strategy of using placebo allowed the active value of the drug strategies to be evaluated. The authors justified this choice.
Validity of estimate of measure of effectiveness:
The internal validity of the effectiveness results is likely to be high due to the randomised nature of the study design, power analysis being used to calculate the number of patients required in each group, and the comparability of the study groups in terms of the baseline characteristics. In this trial, the groups were comparable with respect to patient characteristics, surgical procedure, anaesthetics administered and i.v. fluids used in the perioperative period. Therefore, the difference in the incidence and severity of PONV and true and therapeutic outcome measures among the groups in this trial may reasonably be attributed to the study antiemetics that were administered. However, it was acknowledged that the study sample size was inadequate to identify an adverse effect with an incidence of less than 2.2% (100/45). The study sample appears to have been representative of the study population. No dates were given for the effectiveness data collection, which may adversely affect the generalisability of the effectiveness analysis.
Validity of estimate of measure of benefit:
The estimate of the benefit measure was directly obtained from the effectiveness analysis. The choice of the benefit measure appears to be justified, although no explanation was given as to why no utility measure was adopted in the light of satisfaction being one of the outcome measures included in the study. Future studies in this area should consider this method.
Validity of estimate of costs:
The cost analysis was rather brief and future studies should undertake more robust cost-analyses. The perspective adopted in the cost analysis was not stated and nor was the price year. Statistical analysis was not performed on the cost outcomes, although it was conducted on some of the resource use data. These features tend to limit the generalisability of the cost results.
Other issues:
Despite the strength of the effectiveness part of the study, the study results may need to be treated with some degree of caution with respect to the limitations surrounding the cost analysis. The issue of generalisability to other settings or countries was not addressed, but some comparisons were made with other studies. The question of whether the study sample was representative of the study population was not discussed in the authors' comments. A cost-utility approach may also have been useful in the context in question.
Author's conclusions
The cost to benefit a patient (i.e. NNTP times the cost of drug per patient) was 22 times higher in the ondansetron group than in the dexamethasone group. This reasserts the value of prophylactic dexamethasone as a cost-effective alternative to ondansetron.
