Category: Professional Posters

Purpose: To determine if the implementation of an indication-based default antimicrobial stop-date initiative decreased the duration of antimicrobial therapy for the treatment of intra-abdominal infections.


Methods: This was an IRB approved retrospective cohort study evaluating the duration of treatment for intra-abdominal infections due to perforation before and after the implementation of an indication-based 7-day default stop-date initiative at four not-for-profit community hospitals. All patients 18 years and older admitted for complicated intra-abdominal infection who underwent a procedure to achieve source control with one of the corresponding MS-DRG codes between March 2016 and September 2016 for the pre-intervention group and March 2018 to September 2018 for the post-intervention group were included in this study. Patients were excluded based on the following: age under 18 years old, active cancer, life expectancy under 30 days, non-specified MS-DRG codes, did not undergo a source control procedure, advanced age (> 80 years old), pregnant women, or had a concurrent infection requiring antimicrobial treatment. The primary outcome was the duration of inpatient antimicrobial therapy. Secondary outcomes included: duration of outpatient antimicrobial therapy, total duration of antimicrobial therapy, and re-admission, re-intervention, mortality or development of C. difficile within 30 days of discharge. A sample size of 42 patients per study group were required to meet a 90% power and all p-values < 0.05 were considered statistically significant. Categorical data was compared using the Chi-square test. Continuous data was compared using the Student’s t-and non-normally distributed continuous data had the medians analyzed utilizing the Mann-Whitney test.


Results: Of the 414 patients screened for the study, 314 failed to meet inclusion criteria with the primary reasons being lack of adequate source control and no reported perforation. Both the pre-intervention group and the post-intervention group had 50 patients that were included and analyzed in the study. There were no statistically significant differences in baseline characteristics between the groups. In regards to the primary outcome, there was a slight decrease in the duration of inpatient antimicrobial duration from 8 days in the pre-intervention group to 7.5 days in the post-intervention group, however, these findings were not statistically significant (p-value = 0.56). The outpatient days of therapy decreased from an average duration of 7 days in the pre-intervention group to 3.5 days in the post-intervention group (p-value = 0.02). The total days of antimicrobial therapy decreased from an average of 14.5 days to 8 days (p-value = 0.035). There were no statistically or clinically significant differences in the length of stay or readmissions due to intra-abdominal infections, number of patients with C. difficile, or mortality within 30 days of discharge. However, the number of patients requiring re-intervention was lower in the post intervention group (16% vs 2%; p-value = 0.03).


Conclusion: There was no difference in the duration of inpatient antimicrobial therapy for the treatment of intra-abdominal infections after the implementation of an indication-based 7-day default stop-date initiative. However, there was a significant decrease in both outpatient and total duration of antimicrobial therapy.