• What are the review’s objectives?
• What sources were searched to identify primary studies? Were there any restrictions?
• What were the inclusion/exclusion criteria and how were they applied?
• What criteria were used to assess the quality of primary studies and how were they applied?
• How were the data extracted from the primary studies?
• How were the data synthesised? How were differences between studies investigated? How were the data combined? Was it reasonable to combine the studies? Do the conclusions flow from the evidence?