Assessing the Impact of 2-Step Clostridioides difficile Testing at the Healthcare Facility Level

Area of Science:

• Infectious Diseases
• Clinical Diagnostics
• Healthcare Epidemiology

Background:

• Two-step testing for Clostridioides difficile infection (CDI) aims to enhance diagnostic specificity.
• Concerns exist regarding potential underdiagnosis and adverse outcomes with two-step testing.
• The impact on reported epidemiology and treatment patterns requires thorough investigation.

Purpose of the Study:

• To evaluate the effect of two-step testing on the reported incidence of hospital-onset CDI (HO-CDI).
• To assess the impact of two-step testing on C. difficile-specific antibiotic use.
• To examine changes in colectomy rates as indicators of harm from underdiagnosis or delayed treatment.

Main Methods:

• A longitudinal cohort study analyzed 2,657,324 patient-days across 8 hospitals from July 2017 to March 2022.
• Time series analysis with generalized estimating equation regression models was employed.
• The study assessed changes in HO-CDI incidence, C. difficile-specific antibiotic use, and colectomy rates.

Main Results:

• Two-step testing correlated with a significant decrease in HO-CDI incidence (IRR, 0.53; P < .001).
• Utilization rates for oral vancomycin and fidaxomicin also decreased significantly (URR, 0.63; P < .001).
• No significant changes in emergent colectomy rates were observed (level rate ratio, 1.16; P = .18; trend rate ratio, 0.85; P = .51).

Conclusions:

• Two-step testing is linked to reduced reported HO-CDI incidence, likely due to improved diagnostic specificity.
• The concurrent decrease in specific antibiotic use suggests that clinically significant CDI cases are still being identified and treated.
• The stable colectomy rates provide reassurance against increased rates of severe or fulminant CDI requiring surgical intervention.