Association between postdischarge antibiotic use and C. difficile testing as a surrogate for clinically significant...

Area of Science:

• Infectious Diseases
• Health Services Research
• Pharmacology

Background:

• Postdischarge antibiotic use is common but often sub-optimal or unnecessary.
• Clinically significant diarrhea, often caused by Clostridioides difficile (C. diff), is a potential adverse event associated with antibiotic therapy.

Purpose of the Study:

• To quantify the risk of C. diff testing, a surrogate for clinically significant diarrhea, in recently hospitalized patients treated with postdischarge antibiotics.
• To identify factors influencing the risk of C. diff testing after hospital discharge.

Main Methods:

• Retrospective cohort study of over 1.6 million hospital admissions within the Veterans Health Administration (VHA) from 2018-2021.
• Exposure was defined as receiving postdischarge antibiotics.
• Primary outcome was time to C. diff testing within 30 days of discharge, analyzed using a Cox proportional hazards model.

Main Results:

• Nearly 20% of admissions received postdischarge antibiotics.
• Patients on postdischarge antibiotics had a 40-56% increased hazard of C. diff testing compared to those not on these medications.
• The median time to testing was shorter for patients on antibiotics (6.7 days) versus those not (14.1 days).

Conclusions:

• Postdischarge antibiotic prescribing is associated with a significantly increased risk of C. diff testing.
• Optimizing antibiotic prescribing at hospital discharge, including reducing duration and avoiding high-risk agents, is crucial for mitigating patient risk.
• These findings support efforts to de-escalate antibiotic therapy upon hospital discharge.