Constructing a comparison table

Cochrane Intervention reviews are based on the comparison of two interventions, and the comparison table reflects this. Studies will be analysed as two-way comparisons (e.g. X versus control, or X versus Y).

The comparison table has a maximum of three levels:

You create the comparison table by adding your comparisons, and then adding the relevant outcomes and subgroups. When you have created your outcomes, you can add studies to these for use in the analysis, see Adding studies to an analysis. When the comparison table has been created and studies have been added, you will be able to enter the data for the review - see Entering data.

Other types of review have other ways of handling the analyses, see Data and analyses in diagnostic reviews.

Comparisons

To add a comparison

  1. Right-click the Data and Analyses heading in the outline and choose Add Comparison.
    The New Comparison Wizard opens.

  2. Enter a Name for the comparison.
    You can type in the name, or base the name on that of an existing comparison. To do so:

    1. Click the down arrow at the end of the Name box to open a pull-down list of all comparisons.

    2. Choose the comparison you wish to base the name on.

    3. Edit the name.  

  3. Click Finish.

Other ways of adding a comparison:

Outcomes

To add an outcome

  1. Right-click the relevant comparison in the outline and choose Add Outcome.
    The New Outcome Wizard opens.

  2. Choose the data type for the outcome, and click Next.

  3. Enter a Name for the outcome.
    You can type in the name, or use the name of an existing outcome. To use an existing name:

    1. Click the down arrow at the end of the Name box to open a pull-down list of all outcomes.

    2. Choose the outcome name you wish to use. You can edit the name, if necessary.  

  4. Edit the Group Labels, and click Next.

  5. Specify the analysis method, and click Next.

  6. Specify the analysis details, and click Next.

  7. Specify the graphs details, and click Next.

  8. Choose the next action, and click Finish.

Once you have created an outcome, you can change the details of the analysis by modifying the properties of the outcome. See Outcome properties.

Subgroups

To add a subgroup

  1. Right-click the relevant outcome in the outline and choose Add Subgroup.
    The New Subgroup Wizard opens.

  2. Enter a Name for the Subgroup.
    You can type in the name, or use the name of an existing subgroup. To do so:

    1. Click the down arrow at the end of the Name box to open a pull-down list of all subgroups.

    2. Choose the subgroup name you wish to use. You can edit the name, if necessary.  

  3. Click Finish.

Outcomes can contain either studies or subgroups (which contain studies). If studies have been added to an outcome, you cannot also add subgroups. If you do need to use subgroups for that outcome, you can use the Introduce Subgroup option to create a subgroup and move all the studies to this.