[Impact of misuse of antimicrobial therapies on inpatient costs].

Objective: To evaluate the impact of inappropriate antibiotic use on inpatients' cost during hospitalization.

Methods: 1 000 cases with antibiotic treatment were extracted from 10 hospitals of 5 provinces in China in 2005. We created multivariate linear regression model for hospital cost and Logistic regression model for evaluation of rationality in antibiotic use.

Results: We collected 946 valid cases. Rate of inappropriate antibiotic use was 58.4%. Costs of inpatients with inappropriate antibiotic use was 1.55 times of the ones with appropriate use (P<0.001). Risk factors included antibiotic prophylaxis (OR=2.929), medication for surgery (OR=2.44), long hospital stay (OR=1.021 for every prolonged day) and regional factors. Protection factor was in tertiary hospital (OR=0.510).

Conclusion: Inappropriate antibiotic use could add 55% unnecessary cost on inpatients. Efforts to control misuse of antibiotics such as regulating antibiotic prophylaxis and medication for surgery, and decreasing length of stay should be pursued.