Inclusion / Exclusion Criteria
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A definition is SPEQ’s plain-language decode of how a term is used in practice, cited to the documents that define it. It is a practitioner reference, not legal or regulatory advice, it does not replace the definition in the source, and where a regulator’s wording differs the regulator’s wording governs.
The pre-specified characteristics that qualify a subject for trial enrollment (inclusion) or disqualify them (exclusion), defining the study population to which the trial’s results can be generalized. Criteria balance scientific need — ensuring a population able to show the treatment effect safely — against feasibility of recruitment and generalizability of findings.
Criteria that are too narrow slow recruitment and produce results that generalize poorly to the real-world population that will eventually receive the treatment; criteria that are too broad introduce heterogeneity that can dilute the trial’s ability to detect a genuine treatment effect.
Screening logs and eligibility checklists document that each enrolled subject was actually assessed against every criterion, providing the audit trail an inspector uses to confirm eligibility decisions were made correctly and on time.
Enrolling a subject who does not, in fact, meet the eligibility criteria is one of the most common categories of protocol deviation, and repeated occurrences at a site are a frequent trigger for enhanced monitoring or a for-cause audit.
- —Define the trial population and directly bound the generalizability of the results to real-world patients.
- —Enrolling a subject who does not meet eligibility criteria is one of the most common protocol deviation types.
- —Overly restrictive criteria can slow recruitment and limit how representative the trial population is.
- —Screening logs and eligibility checklists provide the audit trail evidencing criteria were assessed and met before enrollment.
ICH E6(R3) GCP; ICH E8(R1) General Considerations for Clinical Studies
Frequently asked questions
What is Inclusion / Exclusion Criteria?
The pre-specified characteristics that qualify a subject for trial enrollment (inclusion) or disqualify them (exclusion), defining the study population to which the trial’s results can be generalized. Criteria balance scientific need — ensuring a population able to show the treatment effect safely — against feasibility of recruitment and generalizability of findings.
Which regulations cover Inclusion / Exclusion Criteria?
ICH E6(R3) GCP; ICH E8(R1) General Considerations for Clinical Studies