Once you complete screening and have your final set of included studies, you may begin Data Extraction.
The Cochrane Handbook recommends:
After you have completed the full-text screening and resolved all conflicts, you are ready to move onto Data Extraction.
We strongly encourage you to review the tutorials and help guides created by Covidence prior to developing a data extraction template. The data elements that need to be extracted from each study are based on interventions and outcomes established during the development of your research question, inclusion/exclusion criteria, and research protocol.
Before you begin data extraction, go to your Covidence project's settings, and change the extraction tool to Extraction 2. The Extraction 2 tool is more flexible and customizable than the Extraction 1 tool.
Next, go to the Review Summary page => Extraction => Continue.
Select Data Extraction Template.
Review the Covidence tutorials and help guides for instructions on how to create a customized data extraction form.
Complete a Data Extraction form for each article.
Note: The first study you begin data extraction for in each systematic review will become the 'Review Template'. The tables set up here will be carried over to subsequently started extractions, where they can be individually edited if needed. Only the first reviewer can edit the template; the first reviewer can be changed at any time by clicking Manage Reviewers on the study pane's Extraction page.