I have four individual groups with two controls and two interventions. The second control group is specifically related to the first the intervention group, making the comparison to the second intervention group unnecessary.
Differences between the groups are being analysed by the Kruskal-Wallis test followed by Dunn's test for multiple comparisons (dunntest command in Stata). It's been suggested that I remove the pairwise comparison between the second control group and the second intervention and then correct for 5 multiple comparisons rather than the 6 run by the test. Is this an appropriate thing to do?