Table 2.

Multiple comparisons of groups

Study groups	Multiple comparisons (Mann–Whitney test)
I and II	(p = 0.008*) S
I and III	(p = 0.008*) S
I and IV	(p = 0.009*) S
II and III	(p = 0.008*) S
II and IV	(p = 0.151) NS
III and IV	(p = 0.009*) S

^*p < 0.05; S, significant

p > 0.05; NS, not significant