Mandatory approval process for C. diff testing linked to lower hospital-onset infection rates

An intervention that required mandatory approval from an infectious diseases physician before testing for Clostridioides difficile was associated with a greater than 50% decrease in hospital-onset C. difficile infection rates at one hospital.

A mandatory Clostridioides difficile testing approval process halved the rate of hospital-onset C. difficile infection (CDI) at one U.S. hospital, a recent study found.

Researchers performed the retrospective study from March 2012 through December 2019 at a large academic hospital, which in December 2017 instituted a policy that all C. difficile testing on hospital day 4 or later required approval by an infectious diseases attending. They compared three consecutive time periods: 37 months in which there was no decision support for testing, 32 months in which there was computer decision support, and the 25-month intervention period. During the intervention period, infectious diseases physicians used a local guideline for appropriateness of C. difficile testing and could also use clinical judgment in approving testing outside of guidelines (e.g., testing despite recent laxative use if clinical history was concerning for true infection). The primary outcome was the facility-wide hospital-onset CDI rate, as defined by the CDC's National Healthcare Safety Network. Results were published May 9 by Clinical Infectious Diseases.

The study evaluated hospital-onset CDIs across 331,180 admissions and 1,172,015 patient-days. During the intervention period, there was a median of one hospital-onset CDI test approval request per day (range, 0 to 6 alerts/day). Ordering clinician adherence to obtaining approval was 85%. The hospital-onset CDI rate was 10.2, 10.4, and 4.3 events per 10,000 patient-days for each consecutive time period, respectively. In adjusted analyses, the hospital-onset CDI rate did not differ significantly between the two baseline periods (P=0.14) but significantly differed between the computer decision support period and the intervention period (P<0.001). Reasons for inappropriate test ordering did not significantly differ among the periods, with less than three documented stools being the most common criterion in inappropriate orders.

Limitations of the study include the fact that the intervention targeted the hospital-onset C. difficile testing period and not the community-onset testing period (first three hospital days), the authors noted. They added that the intervention was implemented at a single academic medical center and occurred in the context of other ongoing infection control efforts.

“A decrease in hospital-onset CDI rate had not been seen earlier in the baseline period, when computer decision support was in place,” the authors noted. “Our experience suggests that infectious diseases specialists can provide an active and impactful role in diagnostic stewardship of C. difficile testing in the healthcare setting.”