Table 2Evidence statements

DescriptionQualityQuantity
Strong evidenceGood qualityLarge amount of data/meta analysis
Good evidenceGood quality
Moderate evidenceReasonable amount
Fair evidenceAcceptable quality
Limited evidenceNot much evidence: trial < 50 people
Weak evidencePoor quality
Insufficient evidenceNot enough evidence to judge: trial size < 20 people or wide confidence interval

From: 5, Methods used to develop the guideline

Cover of Irritable Bowel Syndrome in Adults
Irritable Bowel Syndrome in Adults: Diagnosis and Management of Irritable Bowel Syndrome in Primary Care [Internet].
NICE Clinical Guidelines, No. 61.
National Collaborating Centre for Nursing and Supportive Care (UK).
Copyright © 2008, Royal College of Nursing.

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