Criteria are written for people
A protocol’s eligibility section is written to be read by investigators and coordinators. It mixes precise thresholds (“eGFR between 30 and 59 mL/min/1.73 m²”) with clauses that depend on clinical judgement (“in the opinion of the investigator”) and practical requirements (“able to attend weekly visits”).
Operationalising criteria means deciding, for each one, whether it can be checked against structured data, partly checked, or only assessed by a person.
Three kinds of criteria
Data-checkable criteria have a clear value, unit, operator and time window. Partly checkable criteria have a checkable core but an ambiguous term — “stable dose” without a duration is a common example. Screener-assessed criteria need judgement or information that usually isn’t in a dataset.
Treating the third kind as if it were the first produces false confidence. Keeping them visible as screener tasks keeps the checklist honest.
Where the details hide
Look for time windows (“within 90 days before screening”), which value counts (most recent, any, all), units, and differences between the synopsis and the main eligibility section — especially after an amendment.
A working checklist
For each criterion, record: the source passage, the type, the rule, the window, what happens when data is missing, and who assesses it. That record is what TrialBridge’s criteria builder is designed to hold.