Studybox Research Resources
Notes From Running IVD Studies.
Practical writing on the parts of diagnostic research that decide timelines: pathway choices, site readiness, and where programs actually lose months.
Field notes
Resources
The guides
10 field notes, newest first
- A prospective flu, RSV or COVID-19 test study has to be enrolling before the virus arrives, so the season sets the schedule, not the sponsor.
Guide
Planning IVD Clinical Studies Around Respiratory Season
- PPA and NPA are calculated exactly like sensitivity and specificity. The difference is the comparator: against a reference standard you report sensitivity and specificity, and against anything less, FDA expects positive and negative percent agreement.
Guide
PPA and NPA vs Sensitivity and Specificity: Which One FDA Expects
- An OTC lay user study has to show that untrained people, using only the box and its instructions, can collect an adequate sample, run the test, read the result correctly and understand what to do next, and that the test still performs to its claim when they do.
Guide
Lay User Studies for OTC IVDs: Designing a Home-Use Diagnostic Study
- An intended-use operator is the person who will actually run the test once it is marketed. For a CLIA-waived test that means untrained site staff; for a moderate complexity test, qualified laboratory personnel; for an OTC test, the lay user.
Guide
Who Is an Intended-Use Operator in an IVD Study? Waived, Moderate Complexity and Lay Users
- FDA recommends a CLIA waiver study at a minimum of three sites representative of CLIA-waived settings, with 1–3 untrained operators per site and at least nine untrained operators across all sites.
Guide
How Many Sites for a CLIA Waiver Study? Three Minimum, Nine Untrained Operators
- For a qualitative CLIA waiver study, the binding constraint is usually the number of comparator-positive specimens needed for the lower bound of the two-sided 95% confidence interval to clear the acceptance criterion. Prevalence and the evaluable rate then turn that number of positives into a total enrollment target.
Guide
CLIA Waiver Study Sample Size: Working Back From the Wilson Score Lower Bound
- A flex study deliberately stresses a test system, through wrong volumes, early and late reads, temperature and humidity extremes and the like, to show that results stay correct, or that the device catches the error, under the conditions a waived setting will create.
Guide
Flex Studies for CLIA Waiver: What FDA Expects and How to Design Them
- Most CRO selection advice is written for drug trials. Diagnostics run on different endpoints, different sites, and a different definition of done.
Guide
How to Choose a CRO for an IVD Study
- Sponsors budget for enrollment and get surprised by activation. Startup is where diagnostic programs quietly lose a quarter.
Operations
Why IVD Study Startup Slips (and What Actually Fixes It)
- Every CRO claims a site network. The word 'pre-qualified' can mean a signed contract and a stocked freezer, or it can mean a spreadsheet.
Site network
What 'Pre-Qualified' Should Mean for an IVD Clinical Site
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