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Table 1. Quality of Evidence and Strength of
Recommendations
Quality of
Evidence Interpretation
High-quality
evidence
Studies that provide high confidence in the effect estimate. New
data from future studies are thought unlikely to change the effect.
Moderate-quality
evidence
Studies that provide confidence that the true effect is likely to be
close to the estimate but could be substantially different.
Low-quality
evidence
Studies that provide limited confidence about the effect. e true
effect may be substantially different from the estimate.
Very low-quality
evidence
Studies that provide very little certainty about the effect. e true
effect may be quite different from the estimate.
Strength of
Recommendation Interpretation
Strong
recommendation
Supported by moderate- to high-quality evidence (e.g., multiple
randomized controlled trials). Recommended course of action
would apply to all or almost all patients. Only a small proportion of
clinicians/patients would not want to follow the recommendation.
In rare instances, a strong recommendation may be based on very
low- to low-certainty evidence. For example, an intervention may
be strongly recommended if it is considered benign, low-cost,
without harms, and the consequence of not performing the
intervention may be catastrophic. An intervention may be strongly
recommended against if there is high certainty of more harm than
the comparison with very low or low certainty about its benefit.
Conditional
recommendation
Supported by lower-quality evidence or a close balance
between desirable and undesirable outcomes. Recommended
course of action would apply to the majority of the patients,
but the alternative is a reasonable consideration. Conditional
recommendations always warrant a shared decision-making
approach.
Ungraded Position
Statement
Evidence for a PICO question did not support a graded
recommendation or did not favor one intervention over the
other. Guidance for this question provided by the voting panel.