# A mixed-methods study assessing the performance of a clinical decision support tool for Clostridioides difficile testing for patients receiving laxatives

## TL;DR

This study examined how clinicians respond to a tool that warns against unnecessary C. difficile testing in patients using laxatives.

## Contribution

The study introduces a clinical decision support tool and evaluates its real-time impact on clinician behavior.

## Key findings

- 74.5% of clinicians bypassed the decision support alert for CDI testing.
- Residents and APPs bypassed alerts more frequently than attendings.
- Common reasons for overriding alerts included increased stool frequency and antibiotic use.

## Abstract

To better understand clinicians’ rationale for ordering testing for C. difficile infection (CDI) for patients receiving laxatives and the impact of the implementation of a clinical decision support (CDS) intervention.

A mixed-methods, case series was performed from March 2, 2017 to December 31, 2018.

Yale New Haven Hospital, a 1,541 bed tertiary academic medical center.

Hospitalized patients ≥ 18 years old, and clinicians who were alerted by the CDS.

CDS was triggered in real-time when a clinician sought to order testing for CDI for a patient who received one or more doses of laxatives within the preceding 24 hours.

A total of 3,376 CDS alerts were triggered during the 21-month study period from 2,567 unique clinician interactions. Clinicians bypassed the CDS alert 74.5% of the time, more frequent among residents (48.3% bypass vs. 39.9% accept) and advanced practice providers (APPs) (34.9% bypass vs. 30.6% accept) than attendings (11.3% bypass vs. 22.5% accept). Ordering clinicians noted increased stool frequency/output (48%), current antibiotic exposure (34%), and instructions by an attending physician to test (28%) were among the most common reasons for overriding the alert and proceeding with testing for CDI.

Testing for CDI despite patient laxative use was associated with an increased clinician concern for CDI, patient risk for CDI, and attending physician instruction for testing. Attendings frequently accepted CDS guidance while residents and APPs often reinstated CDI test orders, suggesting a need for greater empowerment and discretion when ordering tests.