Cost-effectiveness of ampicillin/sulbactam versus imipenem/cilastatin in the treatment of limb-threatening foot infections in diabetic patients

A cost-effectiveness analysis was performed following a double-blind, randomized study of ampicillin/sulbactam (A/S) versus imipenem/cilastatin (I/C) for the treatment of limb-threatening foot infections in 90 diabetic patients. There were no significant differences between the treatments in terms of clinical success rate, adverse-event frequency, duration of study antibiotic treatment, or length of hospitalization. Costs of the study antibiotics, treatment of failures and adverse events, and hospitalization were calculated. Mean per-patient treatment cost in the A/S group was $14,084, compared with $17,008 in the I/C group (P = .05), primarily because of lower drug and hospitalization costs and less-severe adverse events in the A/S group. Sensitivity analyses varying drug prices or hospital costs demonstrated that A/S was consistently more cost-effective than I/C. Varying the clinical success rate for each drug revealed that I/C would have to be 30% more effective than A/S to change the economic decisions.