How to do a subgroup analysis

1. Create the first subgroup

In the 'Analysis' section, create and name the outcome for which you want to do a subgroup analysis (see How to set up an analysis for more details). Click on the 'Add Subgroup' button, name the subgroup, then add the studies and the data to the table (see How to set up an analysis for more details).

2. Create additional subgroup(s)

When you've entered the study data for the first subgroup, you can create one or more additional subgroups – just click on the 'Add Subgroup' button and fill out the table as for the first subgroup. You can click on the 'Graphs' tab to see and adjust the forest plot with the subgroup analysis (see How to set up an analysis for more details).

3. Combine subgroups

You can combine the existing subgroups by clicking on the 'Combine subgroups' button. The subgroup titles will disappear and all the included studies and data will be listed together. Note that the combining cannot be undone – if you want to revert to the subgroups, you will need to recreate them – see the next point (below).

4. Creating subgroups from the existing outcome

If studies and data have already been added to an outcome and you want to use subgroups for that outcome, click on the ‘Add subgroup’ button. All the studies for this outcome will be included in the first subgroup. You can then create additional subgroup(s) and move the studies from one subgroup to another by using ‘Action’ button (click on ‘Move to’ and select the destination subgroup).