Incorporating preauthorization into antimicrobial stewardship pharmacist workflow reduces Clostridioides difficile...

Area of Science:

• Infectious Diseases
• Antimicrobial Stewardship
• Diagnostic Stewardship

Background:

• Clostridioides difficile infection (CDI) diagnosis relies on specific testing, but inappropriate utilization can occur.
• Alternative etiologies for diarrhea are common, leading to potential overuse of CDI diagnostic tests.
• Antimicrobial stewardship programs (ASPs) aim to optimize antimicrobial use and diagnostic test appropriateness.

Purpose of the Study:

• To assess the impact of mandatory prior authorization for Clostridioides difficile testing on diagnostic test utilization.
• To evaluate the effectiveness of integrating prior authorization into an antimicrobial stewardship pharmacist workflow.
• To determine if this intervention reduces testing in patients with non-CDI diarrhea causes.

Main Methods:

• A quasi-experimental, before-and-after study design was employed at a single tertiary-care academic medical center.
• A best-practice alert was implemented, requiring antimicrobial stewardship program (ASP) pharmacist approval for C. difficile enzyme immunoassay (EIA) and gastrointestinal pathogen panel (GIPAN) testing.
• Approval necessitated direct communication between the ordering provider and the ASP pharmacist to discuss testing rationale.

Main Results:

• The weekly rate of EIA orders per 1,000 patient days decreased significantly from 6.05 to 4.87 (IRR 0.72, P = .010).
• The weekly rate of GIPAN orders per 1,000 patient days also decreased significantly from 1.72 to 0.89 (IRR 0.53, P = .001).
• An average of 2.5 requests per day were managed by the ASP during the 3-month intervention period.

Conclusions:

• Mandatory prior authorization integrated into ASP workflow is an efficient and effective model for diagnostic stewardship.
• This intervention successfully reduced the utilization of C. difficile and GIPAN testing.
• The study highlights a practical approach to improve appropriate diagnostic test ordering in healthcare settings.