Studybox Research 510(k) Clinical Studies
Clostridioides difficile Point-of-Care Test
Clinical and analytical performance to support substantial equivalence.
Studybox
510(k) Clinical Studies
C. difficile testing carries a long-running debate about what to measure: toxin, which indicates disease, or toxigenic organism, which indicates colonization or disease. The clinical study reflects this directly, with cytotoxicity neutralization as the reference for toxin claims and toxigenic culture for organism and molecular claims, and the labeling describes what a positive means in those terms. A point-of-care version does not change the references, only where the test is run.
Specimens must be unformed stool from patients with clinically significant diarrhea, and this acceptance criterion is applied at the site before testing. Enrollment is largely inpatient and emergency department, where C. difficile infection is concentrated, and the slow, specialized reference methods must be arranged with a laboratory experienced in anaerobic culture and cell culture. Leftover stool from clinical testing is often used for a retrospective arm.
- Analyte
- C. difficile toxins A and B, glutamate dehydrogenase (GDH) antigen, or toxin gene nucleic acid, depending on the device
- Therapeutic area
- Gastrointestinal Health
- Specimens
- Stool
- Intended-use settings
- hospital POC, emergency department, urgent care
- Operators
- Hospital and emergency department point-of-care staff; laboratory staff for moderate-complexity versions.
- Comparator
- Typically a cell cytotoxicity neutralization assay for toxin detection claims and toxigenic culture (anaerobic culture with toxin confirmation) for organism and nucleic acid claims; the protocol states which reference applies to each analyte.
510(k) Studies specifics
What Changes for This Assay on This Pathway.
- Each analyte is compared to its appropriate reference; toxin tests compared only to toxigenic culture will appear insensitive, and molecular tests compared only to cytotoxicity will appear falsely positive, so the reference choice must match the claim.
- Specimen acceptance criteria (unformed stool, no repeat testing within a defined window, no recent laxative use) are eligibility criteria and labeling limitations that should align.
- Fresh prospective specimens and leftover frozen specimens are typically both used and reported separately, with freeze-thaw history documented.
- Two-step algorithm devices (GDH screen with toxin confirmation) need the combined interpretation evaluated as well as each component.
Endpoints the study must support
- Sensitivity and specificity against the analyte-appropriate reference (cytotoxicity assay for toxin, toxigenic culture for GDH or nucleic acid), with 95% confidence intervals
- Performance on unformed stool meeting the specimen acceptance criteria, by inpatient versus outpatient setting
- Invalid rate and, for algorithm devices (GDH plus toxin), agreement of the combined interpretation
Enrollment realities
Driven by reference-positive diarrheal specimens, concentrated in hospitalized patients; outpatient and urgent care enrollment yields fewer positives. Access to a laboratory performing cytotoxicity assay and toxigenic culture constrains site selection more than patient volume does.
How Studybox runs it
Pre-Qualified Sites, Embedded Coordinators.
Our 100+ pre-qualified U.S. sites are matched to the intended-use population and setting, with Studybox coordinators embedded on site for recruitment, consent, specimen handling, and data capture. Typical activation is about four weeks. How we run 510(k) clinical studies →
Relevant FDA guidance
- Guidance on Informed Consent for In Vitro Diagnostic Device Studies Using Leftover Human Specimens that are Not Individually Identifiable
- Statistical Guidance on Reporting Results from Studies Evaluating Diagnostic Tests
- Requests for Feedback and Meetings for Medical Device Submissions: The Q-Submission Program
FAQ
Clostridioides difficile Point-of-Care Test Study Questions.
01 Who operates the clostridioides difficile point-of-care test in a 510(k) studies study?
Hospital and emergency department point-of-care staff; laboratory staff for moderate-complexity versions.
02 What is the comparator for a clostridioides difficile point-of-care test study?
Typically a cell cytotoxicity neutralization assay for toxin detection claims and toxigenic culture (anaerobic culture with toxin confirmation) for organism and nucleic acid claims; the protocol states which reference applies to each analyte.
03 What drives enrollment for a clostridioides difficile point-of-care test study?
Driven by reference-positive diarrheal specimens, concentrated in hospitalized patients; outpatient and urgent care enrollment yields fewer positives. Access to a laboratory performing cytotoxicity assay and toxigenic culture constrains site selection more than patient volume does.
Let's talk IVD research
Planning a clostridioides difficile point-of-care test study?
Tell us the intended use and setting. We'll come back with a site plan, operator strategy, and a realistic activation timeline for the 510(k) studies pathway.