Cost of care and antibiotic prescribing attitudes for community-acquired complicated intra-abdominal infections in Italy: a retrospective study

INTRODUCTION: Complicated intra-abdominal infections (cIAIs) are a common cause of morbidity worldwide, and in spite of improvements in patient care, therapeutic failure still occurs, impacting in-hospital resource consumption. This study aimed to assess the costs associated with the treatment of community-acquired cIAIs, from the Italian National Health Service perspective. METHODS: This retrospective study analyzed the charts of patients who were discharged from four Italian university hospitals between January 1 and December 31, 2009 with a primary diagnosis of community-acquired cIAIs. Patient characteristics, diagnosis, surgical procedure, antibiotic therapy, and length of hospital stay were all recorded and the cost of total hospital care was estimated. Costs were calculated in Euros at 2009 values. RESULTS: The records of 260 patients (mean age 48.9 years; 57% males) were analyzed. The average cost of care for a patient hospitalized due to cIAI was €4385 (95% CI 3650–5120), with an average daily cost of €419 (95% CI 378–440). Antibiotic therapy represented just under half (44.3%) of hospitalization costs. The strongest predictor of the increase in hospital costs was clinical failure: patients who clinically failed received an average of 8.2 additional days of antibiotic therapy and spent 11 more days in hospital compared with patients who responded to first-line therapy (both p < 0.05 vs. patients who were successfully treated). Furthermore, they incurred €5592 in additional hospitalization costs (2.88 times the cost associated with clinical success) with 53% (€2973) of the additional costs attributable to antibiotic therapy. Overall, antibiotic appropriateness rate was 78.8% (n = 205), and was significantly higher in patients receiving combination therapy compared with those treated with monotherapy (97.3% vs. 64.6%). CONCLUSION: The results of this study suggest that hospitals need to be aware of the clinical and economic consequences of antibiotic therapy of cIAIs and to reduce overall resource use and costs by improving the rate of success with appropriate initial empiric therapy.