Abstract

Evaluate the postoperative change in cost of anti-epileptic drugs in patients undergoing surgery for intractable epilepsy. A retrospective cohort study of 46 patients who underwent surgery for intractable epilepsy during the period January 2003-May 2008. Clinical notes were accessed via the electronic patient record. Age, sex, operation, laterality, date of operation and preoperative and postoperative anti-epileptic regimens were recorded. The recorded preoperative regimen was the last prescribed before undergoing surgery. The recorded postoperative regimen was the most current as of May 2008. The monthly cost of each drug was calculated using pricing in the British National Formulary 55 (March 2008 edition). The total cost of preoperative and postoperative drugs were calculated and compared, using Wilcoxon's signed ranks test. Correlations between date of operation, preoperative cost and postoperative saving were plotted and tested with the Pearson correlation coefficient. Median preoperative drug cost was £115.72 per month. Median postoperative cost was £47.55 per month. Median postoperative saving per patient was £28.55 per month (p=0.037). There was no correlation between operation date and postoperative saving (p=0.221). There was significant correlation between preoperative cost and postoperative saving (p=0.001). Surgery is associated with significant postoperative savings in anti-epileptic drugs cost. The saving is higher in patients with more expensive preoperative regimens.