A good checker is not clever software, it is well-written criteria: one test per line, a stated source and a clear answer. This page shows how to convert inclusion and exclusion text into a checklist or eCRF, with rewrites, a demo checker and the sign-off steps. The investigator makes the eligibility decision.
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Criteria checked
8 of 8
Not met / present
1
What makes a checker work
Why bother
Enrolling someone who does not meet the criteria is among the most commonly reported protocol deviations, and a participant may have to be withdrawn, with their data handled under the analysis plan. The cause is rarely carelessness. It is usually a criterion that was long, ambiguous or buried in a protocol paragraph, checked from memory at the end of a long screening visit. A checker moves that check onto a page where each test is visible, answered, dated and signed.
You can build one on paper, in a spreadsheet or in an eCRF. The paper and spreadsheet versions are fine for pilots and for the pre-screening conversation. They lose their value when several people check, when criteria change after an amendment, or when an auditor asks who answered what and when. The eCRF version records the answer, the person, the time and any later change.
Two checks happen at different moments. Pre-screening is a lighter check against what can be known without consent, such as a medical record review or a short questionnaire, and its purpose is to avoid bringing in people who will clearly fail. Screening is the full check after consent, including tests, with every criterion confirmed. Read clinical trial pre-screening tools and online patient screening for the first, and patient eligibility screening software for the software category. This page is about turning the criteria themselves into something checkable.
How to build one
Break every sentence with "and" or "or" into separate lines. "Aged 18 to 75 with BMI 27 to 40" is two criteria and needs two answers.
Label items I1, I2, E1, E2 exactly as in the protocol, so that a failure maps to the clause an inspector will read.
Met or not met, present or not present, a number, or a date. Use a number or a date wherever the criterion has a threshold, so that a rule can test it.
For each, record where the answer comes from (consent date, screening lab, medical record) and the time window, for example "within 28 days before randomisation".
Calculate age, BMI or eGFR from entered values, and add a check that raises a query when a threshold is breached or an exclusion is present.
Require an investigator confirmation, and a structured reason if the participant is not eligible. Test the whole form with invented participants before use.
Criteria wording
The rewrites below keep the intent and make the test explicit. They are illustrations, not clinical advice; your protocol and medical monitor decide the actual wording.
| Typical wording | Why it fails as a check | Checkable version |
|---|---|---|
| Adults in good general health | Nobody can answer "good" the same way twice | Age 18 years or older at consent. Investigator judges no clinically significant finding at screening exam (yes / no), with finding documented. |
| Recent laboratory values within normal limits | "Recent" and "normal" are undefined | Screening eGFR 45 mL/min/1.73 m2 or higher, measured within 28 days before randomisation (value and date). |
| No significant cardiac disease | Significant is a judgement with no threshold | No history of myocardial infarction or heart failure (present / not present), plus QTcF at screening below the protocol threshold (value). |
| Not taking interfering medications | Which, and since when? | No use of any drug on the protocol prohibited list (appendix number) in the 14 days before randomisation (present / not present, with the drug name if present). |
| Women of childbearing potential must use contraception | Mixes who is affected with what is required | Is the participant of childbearing potential (yes / no)? If yes: highly effective contraception confirmed (yes / no). Pregnancy test negative at screening (result and date). |
| Willing and able to comply | Cannot be tested at the form level | Investigator confirms participant has understood the visit schedule and diary (yes / no). Consent signed on date, before any study procedure. |
If a criterion cannot be rewritten into a value, a date or a yes or no from a named source, raise it with the protocol author before the study starts.
Wording tips
Good criteria share some habits. Write each as one statement with one subject. Prefer thresholds to adjectives, and give the unit. State the time window and what it is measured from, because "within 4 weeks" is ambiguous until you say before what. Say which source counts, so that a participant's memory is not accepted where a laboratory result is required. Avoid double negatives such as "no history of not being able to". Keep inclusion statements positive (met) and exclusion statements about the thing to avoid (present), so that "yes" does not mean good in one section and bad in the next. Finally, put the clause number on every item.
These habits matter most at amendment time. When a protocol amendment changes a threshold, a one-statement criterion changes in one place, the form version is updated for every site, and the change is recorded. A criterion buried in a long paragraph tends to be updated in the protocol but not in the checklist that sites actually use. For the form side of this, see the eligibility screening eCRF template, and for the log that records the outcome of each screening, the screening and enrollment log template.
Calculated values
Date of birth
BRTHDTCAge at consent
AGECalculated, read-only
52 years CalculatedeGFR (CKD-EPI 2021)
EGFRCalculated, read-only
41 mL/min/1.73 m2 CalculatedExclusion criteria
E3. eGFR below 45 mL/min/1.73 m2
EXCL03Exclusion present: not eligible unless the investigator documents otherwise
Paste your criteria, have the AI draft the form for your review, add the rules and test with invented participants. Free sandbox, every feature, no credit card.
Choosing a format
| Format | Works well when | Watch out for |
|---|---|---|
| Paper checklist | Pre-screening calls at a single site; very small pilots | No record of changes, easy to lose, no calculation of age or eGFR, no link to the study record |
| Spreadsheet | Internal feasibility counts before the study; a first draft of the criteria list | Anyone can overwrite an answer; no reason for change; hard to separate names from study data |
| Eligibility eCRF | Any study with more than one site or checker, or with an inspection or sponsor in view | Needs the criteria to be well worded first; amendments still need an ethics-approved protocol change |
The eCRF is not a better medical judgement, it is a better record of one.
In Capture
Capture's eligibility screening eCRF template has one question per inclusion and exclusion criterion and an investigator confirmation with a re-authenticated electronic signature. Edit checks raise a query when an inclusion is not met or an exclusion is present, calculated fields such as age from date of birth and eGFR are shown read-only during entry, and a screen failure gets a structured reason. If you start from a protocol, the AI study builder can draft the form from the document; nothing is saved without your review, and only draft forms can be changed. The decision on eligibility stays with the investigator.
Consent signed
Before any trial procedure
Criteria answered
8 of 8, calculated fields read-only
Query on E3
Exclusion present
Investigator confirms
Re-authenticated e-signature
Test before go-live
Run each case with invented participants and keep the results with your test documentation.
The form reaches investigator confirmation without a query.
A query is raised that names the criterion, and confirmation is blocked or flagged according to your procedure.
A query is raised that names the criterion, and a screen-failure reason is required.
A value of 45 against "below 45" behaves as the protocol intends.
Consent after the first study procedure is caught.
Age, BMI and eGFR agree with a hand calculation for at least two participants.
A changed threshold appears in the new form version, and old records keep the version they were entered on.
A list or form that turns each inclusion and exclusion criterion into a separate, answerable test, so that eligibility is recorded criterion by criterion and confirmed by the investigator. It can be paper, a spreadsheet or an eCRF.
No. The form records the answers, calculates values such as age and eGFR, and raises a query when an inclusion is not met or an exclusion is present. The investigator confirms eligibility. No automatic AI matching of participants to trials is claimed.
One statement per line, a threshold and unit instead of an adjective, a named source, a time window measured from a stated event, and the protocol clause number. If it cannot be answered with a value, a date or a yes or no, rewrite it.
Yes. Separate questions let the form flag the exact criterion that failed, and make the screen-failure reasons countable.
Change the criterion in the form as a new version and approve it, so every site uses the same version. Make sure the amendment itself has the ethics and regulatory approvals your jurisdiction requires before the new form is used.
You can use the same wording for a lighter pre-screening list, limited to what can be known without consent. Full eligibility is confirmed after consent, with tests. Capture also has a pre-screening eConsent template.
The AI study builder reads a protocol and drafts visits and forms for your review. Nothing is saved without human review, and you still check every criterion against the protocol.
Failures with a coded reason give the screen-fail rate and show which criterion causes most of them. Use the screen failure rate calculator to turn that into the number to screen.
Keep exploring
Eligibility screening eCRF template
Inclusion and exclusion criteria with investigator confirmation.
Screen failure rate calculator
Turn failures into a number to screen.
Patient eligibility screening software
The software category explained.
Clinical trial pre-screening tools
Check before consent.
Pre-screening consent template
Consent wording for pre-screening.
Screening and enrollment log template
Record every screening outcome.
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