Updated CDI Treatment Guidelines Change Prescribing Therapy

The 2017 IDSA guideline update was associated with a substantial increase in vancomycin (VAN) use and decrease in metronidazole (MTZ) use. In addition, Fidaxomicin (FDX) use rates remained low (< 2%), according to the results from a study presented virtually at the 2021IDWeek.

Back in 2017, IDSA changed its guidelines for the treatment of CDI and recommended the antibiotic use of either VAN or FDX for first-line use and phased out MTZ.

Investigators examined changes in CDI antibiotic use and clinical outcomes among Medicare beneficiaries with CDI pre- vs. post- the guideline update. This patient population is older and more likely to be hospitalized and or be prescribed antibiotics that could lead to CDI.

This was a retrospective analysis using national Medicare claims data from 2016-2018. “The two study samples included continuously eligible fee-for-service Medicare beneficiaries aged ³66 years with a new CDI diagnosis followed by an antibiotic fill in the pre-period (04/01/2017-09/30/2017) and post-period (04/01/2018-09/30/2018), respectively,” the investigators wrote. “Outcomes included type of CDI antibiotic received; sustained response and CDI recurrence. Multivariable regressions compared pre- vs. post-period outcomes while controlling for sociodemographic and clinical factors.”

Even with the updated guidelines, investigators did not see an improvement.

“Surprisingly, clinical outcomes did not improve between the pre- and post-period,” the investigators wrote. “Even after adjustment, overall sustained response rates decreased (Odds Ratio [OR]: 0.93, p=0.0197) and overall CDI recurrence rates increased (OR: 1.13, p=0.0018) slightly in the post- vs. pre-period.”

The study’s authors said it remains to be seen if the increase in prescribing vancomycin is better for clinical outcomes than fidaxomicin.

“Overall CDI outcomes did not improve post guideline update despite the shift to guideline-indicated VAN,” the investigators concluded. “This may be because VAN was not associated with meaningfully improved outcomes relative to MTZ. However, improved outcomes seen with FDX relative to VAN and MTZ suggest potential benefits from its greater use in Medicare patients.”

The study, “Real-World Changes in Clostridioides difficile infection (CDI) Treatment Utilization and Clinical Outcomes Associated with Updated 2017 IDSA Guidelines among Medicare Beneficiaries in the US,” was presented virtually at IDWeek 2021, held September 29-October 3, 2021.