Systematic review guide

Grading of Recommendations Assessment, Development, and Evaluation (GRADE) provides a clear and organised method for presenting evidence summaries, including their quality assessment. It helps to move from evaluating evidence quality (methods) to evidence certainty (findings) allowing for the possibility of recommendations. Both NICE and the Cochrane Collaboration use GRADE for reviews and guidelines. While your review may not be suitable for making clinical practice recommendations, use of GRADE will make it more useful for decision makers who do.

It was designed to rate the quality of evidence and determine the strength of recommendations for clinical practice guidelines and is suitable for reviews of effectiveness of interventions, guidelines and health technology assessments. GRADE provides a transparent framework to provide a recommendation for each outcome, not just for each included study as a whole, as quality of evidence may differ from one outcome to another in a single study.

In GRADE Randomised controlled trials (RCTs) are considered as high-quality evidence, while observational studies are seen as weaker when determining the effectiveness of interventions. There are five factors leading to rating down the quality of evidence and three that can lead to rating up. 
At the end of the GRADE process you will have an evidence profile (EP) and summary of findings table (SoF). 

The links below will help you understand when and how to use GRADE, including the GRADE-CERQual approach for confidence in findings of qualitiative evidence synthesis.