An IP, infectious disease physician, and pharmacy and laboratory staff collaborating to improve C. difficile testing exemplifies which concept?

• A. Antimicrobial stewardship
• B. Quality improvement
• C. Diagnostic stewardship
• D. Environmental infection control

Answer: (C)

Diagnostic stewardship is about using diagnostic tests in a thoughtful, coordinated way to maximize accuracy and clinical usefulness while minimizing harm and waste. In this scenario, bringing together infection prevention, an infectious disease physician, pharmacy, and laboratory staff to improve C. difficile testing shows this approach in action. The team would work to ensure testing is appropriate for the patient’s symptoms (for example, testing mainly when there is clinically significant diarrhea rather than testing colonized but asymptomatic individuals), choose or sequence tests wisely (such as using an algorithm that combines GDH screening with toxin detection or a confirmatory molecular test, and applying reflex testing rules), and decide when not to test or when to repeat testing. They would also align how results are interpreted and communicated back to clinicians, and may restrict reflex or repeat testing to prevent false positives or unnecessary treatment. All of these steps aim to improve diagnostic accuracy, reduce misdiagnosis, and guide better patient management, including avoiding unnecessary isolation or antibiotic use. This focus on the testing process itself distinguishes diagnostic stewardship from broader quality improvement or environmental infection control concepts, which address different aspects of healthcare delivery.