Table 4: Reporting organizations, evidence grading tools and interpretation of each evidence grade

Organization	Evidence grading tool	Grade	Interpretation
Agency for Healthcare Research and Quality	Evidence-based Practice Centers program¹³	High	High confidence that the evidence reflects the true effect. Further research is very unlikely to change our confidence in the estimate of the effect.
		Moderate	Moderate confidence that the evidence reflects the true effect. Further research may change our confidence in the estimate of the effect and may change the estimate.
		Low	Low confidence that the evidence reflects the true effect. Further research is likely to change our confidence in the estimate of the effect and is likely to change the estimate.
		Insufficient	Evidence is either unavailable or does not permit a conclusion
Institute for Healthcare Improvement¹⁴	Level 1	Evidence obtained from at least 1 properly designed randomized controlled trial
National Quality Measures Clearinghouse¹⁵	Evidence synthesis	-	Clinical practice guideline or other peer-reviewed synthesis of the clinical research evidence
Category 1A	Strongly recommended for implementation and strongly supported by well-designed experimental, clinical or epidemiologic studies
Category 1B	Strongly recommended for implementation and supported by some experimental, clinical or epidemiologic studies and a strong theoretical rationale; or an accepted practice (e.g., aseptic technique) supported by limited evidence
Society of Critical Care Medicine, European Society of Intensive Care Medicine¹⁶	Grading of Recommendations, Assessment, Development and Evaluation (GRADE)¹¹	1A	Strong recommendation, high quality of evidence
		1B	Strong recommendation, moderate quality of evidence
		1C	Strong recommendation, low quality of evidence
		2C	Weak recommendation, low quality of evidence

Grading of Recommendations, Assessment, Development and Evaluation (GRADE)¹¹

Canadian Patient Safety Institute

Centers for Disease Control and Prevention framework¹²