Lack of improvement in antimicrobial prescribing after a diagnosis of Clostridium difficile and impact on recurrence.

BACKGROUND

Antimicrobial use is one of the largest modifiable risk factors for development of Clostridium difficile infection (CDI). We sought to determine if a recent diagnosis of CDI affected the appropriateness of subsequent antimicrobial prescribing.

METHODS

This study is a retrospective electronic chart review of the Greater Los Angeles Veterans Administration. Medication administration records were reviewed for all patients with new CDI from 2015-2016 to determine the appropriateness (drug choice, duration, and dosage) of all non-CDI antimicrobials prescribed within 90 days pre- and post-initial CDI (iCDI) positive testing.

RESULTS

Of the 210 patients diagnosed with new-onset iCDI, 140 met inclusion criteria. Of antimicrobial courses prescribed, 40.6% of pre-iCDI were inappropriate compared with 43.1% of post-iCDI, demonstrating no difference in prescribing habits (P = .717). Thirty-three patients developed recurrent CDI (rCDI). After adjustment for other known risk factors, inappropriate antimicrobial use was associated with a significant increased risk of recurrence compared with appropriate use alone (odds ratio [OR], 6.19; 95% confidence interval [CI], 1.45-26.42). Antimicrobial use in general was associated with increased recurrence compared with no antimicrobial use post-iCDI (OR, 2.6; 95% CI, 1.16-5.84); however, after adjustment, it was no longer significant (OR, 2.13; 95% CI, 0.90-5.04).

CONCLUSIONS

The appropriateness of antimicrobial prescribing was not affected by the diagnosis of recent CDI. Inappropriate antimicrobial use after iCDI was associated with higher risk of rCDI.