The cost effectiveness of amoxicillin/clavulanic acid as antibacterial prophylaxis in abdominal and gynaecological surgery.

The objective of this study was to compare the cost effectiveness of amoxicillin/clavulanic acid with other antibacterial regimens for prophylaxis of infection after elective abdominal or gynaecological surgery. Data from 21 previously published comparative clinical trials were used to calculate statistical confidence intervals for differences in postoperative wound infection rate. A simple model was used to produce a tabular sensitivity analysis of cost effectiveness over a wide range of costs of wound infection and potential differences in efficacy. For more expensive comparator regimens, including combination regimens utilising gentamicin and metronidazole, amoxicillin/clavulanic acid was either likely to be more cost effective or equally cost effective. For example, in trials of colonic surgery the comparators were on average 11.39 pounds more expensive than amoxicillin/clavulanic acid, which was > 95% likely to be more cost effective unless the cost of wound infection was estimated to be > 1519 pounds. Amoxicillin/clavulanic acid was more expensive than only 2 of the 21 comparators. Furthermore, in one of these 2 trials it was also significantly more effective than the comparator. In this trial, amoxicillin/clavulanic acid was > 95% likely to be more cost effective as prophylaxis in hysterectomy than rectal metronidazole, provided that the cost of wound infection was estimated to be > 179 pounds. In conclusion, this analysis shows that amoxicillin/clavulanic acid, given as monotherapy, is likely to be equally or more cost effective than a wide range of comparator regimens for prophylaxis of elective abdominal or gynaecological surgery.