Can a collaborative subspecialty antimicrobial stewardship intervention have lasting effects?

We previously demonstrated the benefit of direct, daily collaboration between infectious disease (ID) and critical care practitioners (CCP) on guideline adherence and antibiotic use in the medical intensive care unit (MICU). In this post-intervention review, we sought to establish whether the effect on antibiotic use and guideline adherence was sustainable.

A retrospective review of 87 patients, admitted to the 24-bed MICU, was done 3 (n = 45) and 6 months (n = 42) after the intervention.

Data included demographics, severity indicators, admitting pathology, infectious diagnosis, clinical outcomes [mechanical ventilation days (MVD) and MICU length of stay (LOS), antibiotic days of therapy (DOT), in-hospital mortality], and antibiotic appropriateness based on current guidelines.

In the 3-month (3-PI) and 6-month post-intervention (6-PI), there were no significant differences in the APACHE II score, MVD, LOS, DOT, or total antibiotic use at 3 (p = 0.59) and 6-PI (p = 0.87). There was no change in the mean use of extended-spectrum penicillins, cephalosporin, and carbapenems. While there were significant differences in vancomycin usage at 3-PI [3.1 DOT vs. 4.3 DOT (p = 0.007)], this finding was not seen after 6 months [3.1 DOT vs. 3.4 DOT (p = 0.08)]. When compared to the intervention period, the inappropriateness of antibiotic use at 3 (p = 1.00) and 6-PI (p = 0.30) did not change significantly.

There were no significant differences in either total antibiotic use or inappropriate antibiotic use at the 6-PI time period. Continuous, daily, direct collaboration between ID and CCP, once implemented, can have lasting effects even at 6 months after the interaction has been discontinued.