See exactly who a clinical trial enrolled, and who it left out
Inclusion criteria define who could take part in a trial; exclusion criteria define who could not. Together they decide which people the results describe. Ask Search+ "What were the inclusion and exclusion criteria, and how were participants recruited?" and open the citation to read the eligibility text, which is often a long numbered list in the methods or the protocol.
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Last updated October 2026
How to read eligibility criteria with Search+
- Upload the report and the protocol
Journal articles often shorten the eligibility list; the protocol or appendix usually gives it in full. Put both in the workspace so you can see the complete criteria.
- Ask for inclusion and exclusion separately
Ask for the inclusion criteria first, then the exclusion criteria. A separate answer for each keeps the two lists distinct and each tied to its own citation.
- Compare the criteria with who actually enrolled
Ask for the baseline characteristics of the people randomized. Eligibility says who could join; the baseline table shows who did.
Questions to ask about eligibility
What age range could enroll, and were there any limits by sex?
How did participants have to be diagnosed, and with what severity or stage?
Were people who had already received certain treatments excluded?
Which other health conditions excluded people from the trial?
Where and how were participants recruited, and over what period?
How many people were screened, and how many were found ineligible?
What to look for in inclusion criteria
Inclusion criteria set the target group; exclusion criteria remove people within it, often for safety reasons or to reduce other influences on the outcome. Read both lists.
Strict criteria can produce a population that is younger or healthier than the people who later receive the treatment. This is a question of applicability, which readers judge from the eligibility text.
Articles commonly summarize eligibility and point to a protocol or registry entry for the complete list. Ask whether the report refers you elsewhere.
The participant flow usually reports how many were screened and excluded and why. Ask for it to see how much the criteria narrowed the group.
Each answer cites the eligibility passage it relied on, with a page or section reference when available.
Ask across both documents at once, or narrow the question to the protocol alone.
Eligibility wording and what it signals
| Wording you may see | What it usually signals | A follow-up question |
|---|---|---|
| "aged 18 years or older" | An adult-only trial | Was there an upper age limit as well? |
| "confirmed diagnosis of" | A diagnostic requirement for entry | How was the diagnosis confirmed? |
| "treatment-naive" | No prior treatment for the condition | Were people with any earlier treatment excluded? |
| "adequate organ function" | Laboratory thresholds for entry | Which laboratory values had to be met? |
| "pregnant or breastfeeding" | A common exclusion | Which other groups were excluded for safety? |
| "at the investigator's discretion" | Room for judgment in enrollment | Does the report say how that discretion was used? |
What are inclusion criteria in a clinical trial?
Inclusion criteria are the conditions a person must meet to enter a clinical trial, such as age, diagnosis, disease stage or prior treatment. Exclusion criteria list the conditions that keep an otherwise eligible person out.
Inclusion criteria questions
Can Search+ pull out the full eligibility list?
Can it tell me whether I would qualify for this trial?
Can it show how many people were screened out?
Can I compare eligibility between two trials?
What if the protocol is a scanned document?
Could the answer leave out a criterion?
Know who the results are about
Start a workspace, upload the report and protocol, and ask who could and could not enroll.
Start a workspace