COST-EFFECTIVENESS ANALYSIS OF ANTIEMETIC THERAPY FOR AMBULATORY SURGERY

Study Objective: To compare the relative cost-effectiveness ratios of (I) therapy with ondansetron, droperidol, and metoclopramide in the pr evention of postoperative nausea and vomiting (PONV), and (2) prophyla ctic versus rescue therapy of PONV with these agents. Design: Cost-eff ectiveness analysis based on the estimated costs of 12 mutually exclus ive outcomes identified by decision analysis. Setting: Computer model of outcome established using data extracted from published studies and a survey of current practice in two university-affiliated hospitals. Patients: Patients undergoing operations associated with a high risk o f PONV. Interventions: The cost-effectiveness of prophylactic antiemet ic therapy was compared among three drugs and also compared with limit ing treatment to established PONV. Measurements and Main Results: Dire ct costs included drug acquisition, drug delivery, equipment used in m anaging vomiting, and additional nursing time costs. Indirect costs in cluded drugs and materials used to treat persistent nausea and/or vomi ting and the side effects of prophylactic drugs, increased time spent in the postanesthesia care unit, unanticipated hospitalization, and lo st earnings due to hospitalization. Separate models were created for p atients with both nausea and vomiting and with isolated nausea. The to tal incremental costs associated with the prophylactic use of ondanset ron metoclopramide, and droperidol were $37.74, $28.43, and $18.17 per patient, respectively. The costs per emesis-free patient with the pro phylactic use of ondansetron, metoclopramide, and droperidol, were $55 .91, $71.08, and $30.15, respectively, and per nausea-free patient $68 .93, $82.74, and $33.52, respectively. Prophylactic antiemetic therapy was cost-effective for operations with a high frequency of emesis, wh ereas treatment of established symptoms was more cost-effective when t he frequency was lower For ondansetron, prophylactic use was cost-effe ctive only when the frequency of emesis exceeded 33%, whereas prophyla ctic droperidol was cost-effective even if the frequency was 10%. Conc lusions: When drug costs, efficacy, and adverse events were all consid ered, prophylactic droperidol was more cost-effective than ondansetron , and both drugs were more cost-effective than metoclopramide. However , the expected frequency of PONV, as well as local drug acquisition co sts, cart significantly influence whether a particular antiemetic is c ost-effective when given prophylactically or only as therapy for estab lished PONV.