Hospital management of complicated intra-abdominal infections: pharmacoeconomic evaluation

Complicated intra-abdominal infections (cIAIs) represent a heavy burden for the italian National Health System (NHS) and the italian society, with estimated annual costs of 1.5 and 3 billion euros, respectively. Both monotherapy and antibiotic combinations induce significantly different acquisition and administration costs but substantially equivalent therapeutic results, with average clinical effectiveness rates of 70-80%. this apparent equivalence presumably depends on the widespread trend to individualize the therapeutic strategy according to the clinical severity and the community or nosocomial origin of cIAIs, as well as to the degree of non-appropriateness when empirically choosing a first-line antibiotic.The average cost of nosocomial management of cIAI patients depends on several factors: posology, antibiotic drug acquisition, administration costs, duration of therapy, mix of antibiotic schedules, rates of the therapeutic failures, prolonged hospitalization. The introduction of a new antibiotic like tigecycline to the therapeutic arsenal leads to a small increase in average antibiotic acquisition and treatment costs per patient: this increase is proportional to the percentage of patients treated with the new antibiotic. According to a decisional model, implemented on international outcome data and italian costs, the mean cost for first-line antibiotic acquisition and the mean cost for first- and second-line antibiotic treatment represent respectively only 2% and 8% of the mean overall hospitalization cost. the mean hospitalization cost estimated by the model is noticeably higher than the mean value of Diagnosis Related Group (DRG) tariffs presumably reimbursed by the italian NHS to hospitals for ciAi-related hospitalizations. Greater overall efficiency levels in the nosocomial management of cIAI patients are achievable mainly through the reduction of non-appropriateness rates in first-line antibiotic choices and better treatment individualization, possible if the physician is offered the choice of as many valid therapeutic options as possible, in order to guarantee the best possibility of cure for each patient.