8. Data extraction

Data extraction implies the process of extracting the information from the selected studies that will be ultimately reported. In order to allow an efficient data extraction, the process should be detailed in the protocol before the literature search is started. Key components of the data extraction include:

• information about study reference(s) and author(s);
• verification of study eligibility;
• study characteristics:
  • study methods
  • participants
  • interventions
  • outcomes measures and results