Inclusion & Exclusion Criteria
How to write clear, reproducible eligibility criteria that determine which studies enter your systematic review.
Why Eligibility Criteria Matter
Inclusion and exclusion criteria are the rules that decide which studies are in and which are out of your review. They are derived directly from your PICO question and must be defined before you start screening.
✅ Inclusion Criteria
Characteristics a study must have to be included. These are the minimum requirements for relevance.
❌ Exclusion Criteria
Characteristics that disqualify a study, even if it otherwise meets inclusion criteria. Used for practical or methodological reasons.
Key Categories of Criteria
Structure your criteria using these standard categories (based on PICO):
Population
- • Adults aged 18+ with diagnosed type 2 diabetes
- • Both sexes, any ethnicity
- • Type 1 diabetes or gestational diabetes
- • Pediatric populations (<18 years)
Intervention
- • Metformin as monotherapy or adjunct
- • Any dosage or duration
- • Studies where metformin is combined with insulin from the start
- • Non-pharmacological interventions only
Study Design
- • Randomized controlled trials (RCTs)
- • Quasi-experimental studies
- • Case reports, editorials, commentaries
- • Narrative reviews, conference abstracts only
Other Practical Criteria
- • Published in English
- • Published between 2010–present
- • Full text available
- • Non-English language (unless translator available)
- • Grey literature, unpublished data
- • Animal-only studies
Common Mistakes
Don't include "RCTs only" in inclusion AND "non-RCTs" in exclusion — that's redundant. State it once.
Overly narrow criteria may miss important evidence. Start broader, refine in full-text screening.
"High quality studies" is subjective. Use objective criteria like "RoB score ≤ 3" or "sample size ≥ 50".
Applying Criteria Faster with AI
Once you've defined your criteria, enter them into Lumina. The AI reads each abstract and ranks papers by how well they match your inclusion criteria — so you screen the most relevant papers first.
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