This article covers the key differences between Data extraction 1.0 and Data extraction 2.0, Covidence's most up-to-date tool. 

Data extraction 1.0

Data extraction 1.0 is designed specifically for intervention reviews. We recommend it for Cochrane reviews because it has an export pathway to Review Manager (RevMan). 

Data extraction 2.0

For all other projects, including scoping reviews and qualitative reviews, we recommend Data extraction 2.0. This tool was developed through extensive consultation with our user community and is designed to be flexible and fully customisable to the needs of your project. 

Updating the template

In Data extraction 1.0 changes to the template are not retroactive. If you edit the template, the changes are applied to the template itself and to any studies that have not yet started extraction. But editing the template does not update the forms that are already in use: changes to these need to be made individually.

In Extraction 2.0 changes to the template apply to every form. 

Extraction and consensus

In Data extraction 1.0, the process has two stages: 

  1. the extraction itself, which must be performed by two reviewers working independently of each other to produce their own set of data, and 
  2. the consensus stage: one person reviews the two sets of extracted data and decides on the final dataset. This is the consensus data that will be included in the review.

Data extraction 2.0 has a similar two-stage process consisting of extraction and consensus but, unlike Data extraction 1.0, it can be done either by two reviewers, as described above, or by one single reviewer. In single-reviewer data extraction the second stage is a simple check, rather than a comparison, of the data. This check can be done by any member of the team.

Re-assigning reviewers

If a reviewer has started data extraction or consensus you can re-assign the study to someone else on your reviewing team with using the 'manage reviewers' option. This feature is available in Data extraction 1.0 and Data extraction 2.0.

View history

In Data extraction 1.0, it is possible to view the previous actions taken on a study by selecting the 'View history' button. This is not yet available in Data extraction 2.0.

Un-merge studies

In Data extraction 2.0 is is possible to un-merge studies but this is not possible in Data extraction 1.0.

Switching between the tools

You can switch between the two version of extraction in Settings. This can be useful as a workaround if the tool you are working in does not allow you to un-merge studies or to view history. When you switch to the other tool, all the data in the current tool will be saved. It is not possible, however, to transfer data from one tool to the other.n

Demo review

When you are logged in to Covidence you can try out both versions of extraction in our demo review and decide which one best suits your needs. Just hover over your name in the top right of screen and 'switch to demo'. The demo review is reset regularly.

Summary comparison

The features of Data extraction 1.0 and Extraction 2.0 are compared in the following table: