Economic evaluation of intravenous immune globulin therapy for Kawasaki syndrome

OBJECTIVE: To determine the costs and clinical outcomes of three alternative treatments of the acute phase of Kawasaki syndrome: aspirin alone; low doses of intravenously administered immune globulin (IVIG-LD), 400 mg/kg per dose for 4 days; and high doses of intravenously administered immune globulin (IVIG-HD), 2.0 gm/kg for one dose. DESIGN: A model was developed that assumed the inclusion of 100 patients with acute Kawasaki syndrome in each treatment option. Costs were valued by using the Chedoke-McMaster Corporate Cost Model in 1992 Canadian dollars. Clinical outcome, based on the published literature, was measured by the prevalence of coronary artery dilation at 7 weeks from the diagnosis of Kawasaki syndrome. RESULTS: For every 100 patients with Kawasaki syndrome, the cost was reduced by $323,400 when aspirin therapy alone was changed to IVIG-HD therapy and 14 cases of coronary artery dilation were thereby prevented. When IVIG-HD therapy was compared with IVIG-LD therapy, the cost was reduced by $118,200 because two cases of coronary artery aneurysm were prevented. This latter result was sensitive to the duration of hospitalization, with IVIG-HD costing $8500 more for every 100 patients than IVIG-LD when it was assumed that both groups were hospitalized for 5 days, an unlikely occurrence. CONCLUSIONS: Treatment with IVIG-HD for Kawasaki syndrome is preferred because it results in both lower costs and lower rates of coronary artery dilation.