Protocol, consent, records: the three failures behind most clinical citations

For all the complexity of a clinical trial, the FDA's warning letters to sites keep coming back to three fundamentals. Follow the protocol. Get consent properly. Keep the records straight. Most clinical citations are a failure of one of those three, and understanding how sites actually lose them is the best inoculation against being the next letter.

Failure one: the protocol

Following the protocol is the most-cited failure, and it is more varied than it sounds. It covers enrolling subjects who do not meet the inclusion and exclusion criteria, dosing errors, giving prohibited medications, and blinding or randomization mistakes. Two recent letters show the range: one investigator was cited for enrolling subjects whose BMI fell outside the study's criteria, and another, at a site in India, was cited for giving all enrolled subjects a prohibited drug that interfered with the study medication. Neither is exotic. Both are the kind of drift that happens when a site is moving fast and nobody is checking eligibility and dosing against the protocol closely enough.

Failure two: consent

Informed consent failures are the second recurring theme, and they carry the heaviest ethical weight because they go to whether subjects were properly protected. The failures range from consent not obtained or obtained improperly, to consent forms missing required elements. A 2025 pediatric case cited an investigator for consent problems including failure to verify legal guardianship. Consent is also where IRBs get cited: one university IRB was cited for approving consent forms that omitted required disclosures about alternative treatments, injury compensation, and the possibility of FDA inspection.

Failure three: records

The third is failure to keep adequate and accurate case histories. In clinical research the record is the evidence, and if it is missing, incomplete, or contradictory, the work effectively did not happen as far as the regulator is concerned. Records findings often travel with the others: a protocol deviation that was not documented, a consent whose timing cannot be proven, an adverse event whose reporting trail is broken. The standard FDA warning about data validity and integrity usually starts here.

Why the basics are the ones that break

These three fail not because they are intellectually hard but because they are relentless. Eligibility has to be checked on every subject, consent documented perfectly every time, records kept contemporaneously through every visit. That relentlessness is exactly what erodes under pressure: too many subjects, too few staff, monitoring visits too far apart to catch the drift early. The three failures are what happens when the fundamentals meet an under-resourced site.

What the letters cannot tell you

The citations name the failure. They do not name the conditions: the site that was short-staffed, the coordinator running too many studies, the monitoring that was cut before the records slipped. Those conditions are the real story behind most warning letters, and they live only with the people who worked the site. If you have seen how a site actually loses one of these three, that is knowledge the next site needs. Share what you can, and add your datapoint.